CN111061033A

CN111061033A - Optical lens

Info

Publication number: CN111061033A
Application number: CN201811207480.3A
Authority: CN
Inventors: 栾晓宇; 王东方; 姚波
Original assignee: Ningbo Sunny Automotive Optech Co Ltd
Current assignee: Ningbo Sunny Automotive Optech Co Ltd
Priority date: 2018-10-17
Filing date: 2018-10-17
Publication date: 2020-04-24
Anticipated expiration: 2038-10-17
Also published as: CN111061033B

Abstract

The present application discloses an optical lens, which sequentially comprises, from an object side to an image side along an optical axis: the lens includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens. The first lens can have negative focal power, the object side surface of the first lens is a concave surface, and the image side surface of the first lens is a convex surface; the second lens can have positive focal power, and both the object side surface and the image side surface of the second lens are convex surfaces; the third lens can have positive focal power, and both the object side surface and the image side surface of the third lens are convex surfaces; the fourth lens element may have a negative focal power, and both the object-side surface and the image-side surface thereof may be concave; and the fifth lens element can have positive focal power, and the object-side surface of the fifth lens element is convex and the image-side surface of the fifth lens element is concave. According to the optical lens of the application, at least one of the beneficial effects of miniaturization, high resolution, large chip, large aperture, low cost, low sensitivity and the like can be realized.

Description

Optical lens

Technical Field

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

Background

In recent years, the market of Advanced Driver Assistance Systems (ADAS) has been growing rapidly, and various performance requirements of the in-vehicle lens as an important component thereof have been more stringent.

Because of the need to be mounted on the inside of the windshield, conventional size vehicular lenses pose a risk of interference with the windshield, and therefore require special lens designs to achieve the small size requirements.

In addition, the autopilot lens requires extremely high pixel requirements, so that the size of a chip is increased, and on the basis of the original vehicle-mounted optical lens, 6, 7 or more lens structures can be selected for improving the resolution capability, but the miniaturization of the lens is seriously influenced.

Under the use of special environments, such as the requirement of using effect of vehicle-mounted lens at night, the effect at night is generally required to be improved by increasing the light-transmitting aperture of the lens.

Therefore, an optical lens with high resolution and small size and low cost, which can be used in low light environment, is needed to meet the requirements of automatic driving application.

Disclosure of Invention

The present application provides an optical lens that is adaptable for on-board installation and that overcomes, at least in part, at least one of the above-identified deficiencies in the prior art.

An aspect of the present application provides an optical lens that may include, in order from an object side to an image side along an optical axis: the lens includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens. The first lens can have negative focal power, the object side surface of the first lens is a concave surface, and the image side surface of the first lens is a convex surface; the second lens can have positive focal power, and both the object side surface and the image side surface of the second lens are convex surfaces; the third lens can have positive focal power, and both the object side surface and the image side surface of the third lens are convex surfaces; the fourth lens element may have a negative focal power, and both the object-side surface and the image-side surface thereof may be concave; and the fifth lens element can have positive focal power, and the object-side surface of the fifth lens element is convex and the image-side surface of the fifth lens element is concave.

In one embodiment, the third lens, the fourth lens, and the fifth lens may be cemented to form a cemented lens.

In one embodiment, the first lens, the second lens, and the fifth lens may each be an aspheric lens.

In one embodiment, the total optical length TTL of the optical lens and the entire focal length F of the optical lens may satisfy: TTL/F is less than or equal to 5.

In one embodiment, the focal length value F2 of the second lens and the focal length value F of the whole group of the optical lens satisfy: F2/F is more than or equal to 0.8 and less than or equal to 2.5.

In one embodiment, the air space d2 between the first lens and the second lens and the total optical length TTL of the optical lens may satisfy: d2/TTL is more than or equal to 0.1.

In one embodiment, the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface of the first lens corresponding to the maximum field angle of the optical lens, and the image height H corresponding to the maximum field angle of the optical lens may satisfy: D/H/FOV is less than or equal to 0.1.

In one embodiment, the center radius of curvature R1 of the object-side surface of the first lens, the center radius of curvature R2 of the image-side surface of the first lens, and the center thickness d1 of the first lens may satisfy: the ratio of | (R1 | + d1)/| R2| -is not less than 0.5 and not more than 1.5.

Another aspect of the present application provides an optical lens that may include, in order from an object side to an image side along an optical axis: the lens includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens. Wherein the first lens and the fourth lens can both have negative focal power; the second lens, the third lens and the fifth lens may each have a positive focal power; the third lens, the fourth lens and the fifth lens can be cemented to form a cemented lens; and the total optical length TTL of the optical lens and the whole group of focal length values F of the optical lens can meet the following requirements: TTL/F is less than or equal to 5.

In one embodiment, the object-side surface of the first lens element can be concave and the image-side surface can be convex.

In one embodiment, both the object-side surface and the image-side surface of the second lens can be convex.

In one embodiment, both the object-side surface and the image-side surface of the third lens can be convex.

In one embodiment, both the object-side surface and the image-side surface of the fourth lens may be concave.

In one embodiment, the object-side surface of the fifth lens element can be convex and the image-side surface can be concave.

The optical lens adopts five lenses, for example, the focal power of each lens is reasonably distributed and the cemented lens is formed by optimally setting the shape of the lens, so that at least one of the beneficial effects of miniaturization, high resolution, large chip, large aperture, low cost, low sensitivity and the like of the optical lens is realized.

Drawings

Other features, objects, and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments when taken in conjunction with the accompanying drawings. In the drawings:

fig. 1 is a schematic view showing a structure of an optical lens according to embodiment 1 of the present application;

fig. 2 is a schematic structural view showing an optical lens according to embodiment 2 of the present application; and

fig. 3 is a schematic view showing a structure of an optical lens according to embodiment 3 of the present application.

Detailed Description

For a better understanding of the present application, various aspects of the present 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 present application and does not limit the scope of the present 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 this specification, the expressions first, second, third, etc. are used only to distinguish one feature from another, and do not represent any limitation on the features. Thus, the first lens discussed below may also be referred to as the second lens or the third lens without departing from the teachings of the present application.

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

Herein, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the 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.

It will be further understood that the terms "comprises," "comprising," "has," "having," "includes" 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. Moreover, when a statement such as "at least one of" appears after a list of listed features, the entirety of the listed features is modified rather than modifying individual elements in the list. Furthermore, when describing embodiments of the present application, the use of "may" mean "one or more embodiments of the present 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 the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

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

An optical lens according to an exemplary embodiment of the present application includes, for example, five lenses having optical power, i.e., a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. The five lenses are arranged in order from the object side to the image side along the optical axis.

The optical lens according to the exemplary embodiment of the present application may further include a photosensitive element disposed on the image plane. Alternatively, the photosensitive element provided to the imaging surface may be a photosensitive coupling element (CCD) or a complementary metal oxide semiconductor element (CMOS).

The first lens element can have a negative power, and can have a concave object-side surface and a convex image-side surface. The first lens is in a meniscus shape with the concave surface facing the object side, so that light with a large view field can be collected as far as possible, the light enters a rear optical system, and the reduction of the front end caliber is facilitated.

The second lens can have positive optical power, and both the object side surface and the image side surface of the second lens can be convex. The second lens is a biconvex lens with a positive focal length, which is favorable for converging light rays, so that the light rays enter a rear optical system, and the total length of the system is favorably shortened.

The third lens element can have a positive optical power, and both the object-side surface and the image-side surface can be convex.

The fourth lens element can have a negative optical power, and can have a concave object-side surface and a concave image-side surface.

The fifth lens element can have a positive power, and can have a convex object-side surface and a concave image-side surface. The overall shape of the fifth lens is a meniscus lens with the convex surface facing the object side, so that peripheral light rays can be diffused, matching of a large-size chip is facilitated, and relative brightness of a peripheral field of view is improved.

In an exemplary embodiment, a diaphragm for limiting the light beam may be disposed between, for example, the first lens and the second lens to further improve the imaging quality of the lens. When the diaphragm is arranged between the first lens and the second lens, light rays entering the optical system can be effectively converged, and the aperture of the lens of the optical system is reduced. It should be noted, however, that the positions of the diaphragms disclosed herein are merely examples and not limitations; in alternative embodiments, the diaphragm may be disposed at other positions according to actual needs.

In an exemplary embodiment, the optical lens according to the present application may further include a filter disposed between the fifth lens and the image plane to filter light rays having different wavelengths, as needed; and may further include a protective glass disposed between the optical filter and the imaging surface to prevent internal elements (e.g., chips) of the optical lens from being damaged.

As known to those skilled in the art, cemented lenses may be used to minimize or eliminate chromatic aberration. The use of the cemented lens in the optical lens can improve the image quality and reduce the reflection loss of light energy, thereby improving the imaging definition of the lens. In addition, the use of the cemented lens can also simplify the assembly process in the lens manufacturing process.

In an exemplary embodiment, the third lens, the fourth lens and the fifth lens can be combined into a cemented lens by cementing the image side surface of the third lens with the object side surface of the fourth lens and cementing the image side surface of the fourth lens with the object side surface of the fifth lens, the cemented lens is a triple cemented lens, and the adoption of the triple cemented lens can have the advantages that ① reduces the air space between the three lenses and the total length of the system, ② reduces the assembly components between the three lenses, reduces the working procedures and the cost, ③ reduces the tolerance sensitivity problems of inclination/decentration and the like of the lens units generated in the assembly process, ④ reduces the light quantity loss caused by reflection between the lenses and improves the illumination, ⑤ can further reduce the field curvature and can correct the off-axis point aberration of the system.

In an exemplary embodiment, an optical total length TTL of the optical lens and a whole set of focal length values F of the optical lens may satisfy: TTL/F is less than or equal to 5, and more ideally, TTL/F is less than or equal to 4.5. The condition formula TTL/F is less than or equal to 5, and the miniaturization characteristic of the system can be ensured.

In an exemplary embodiment, a focal length value F2 of the second lens and a focal length value F of the entire group of the optical lens may satisfy: F2/F is 0.8-2.5, preferably 1.2-2F 2/F-2.0. By controlling the direction of the light rays between the first lens and the third lens, the aberration caused by the large-angle light rays entering through the first lens can be reduced, and meanwhile, the lens has a compact structure and is beneficial to miniaturization.

In an exemplary embodiment, an air interval d2 between the first lens and the second lens and an optical total length TTL of the optical lens may satisfy: d2/TTL is not less than 0.1, and more preferably d2/TTL is not less than 0.15. By properly controlling the air space between the first lens and the second lens, reasonable light trend can be ensured, and the system has better imaging quality.

In an exemplary embodiment, the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface of the first lens corresponding to the maximum field angle of the optical lens, and the image height H corresponding to the maximum field angle of the optical lens may satisfy: D/H/FOV is 0.1 or less, and more preferably, D/H/FOV is 0.08 or less. The D/H/FOV satisfying the conditional expression is less than or equal to 0.1, and the small-caliber characteristic at the front end of the lens can be realized.

In an exemplary embodiment, the center radius of curvature R1 of the object side surface and the center radius of curvature R2 of the image side surface of the first lens and the center thickness d1 of the first lens may satisfy: more desirably, the ratio of | R1| + d1 |/| R2| -1.5 is not more than 0.5, and more desirably, 0.8 | (| R1| + d1)/| R2| -1.2 is not more than 0.8. The special shape of the first lens is arranged, so that light can be collected favorably, and the imaging quality of the system is improved.

In an exemplary embodiment, an optical lens according to the present application may have at least 3 aspherical lenses. The aspheric lens has the characteristics that: the curvature varies continuously from the center of the lens to the periphery. Unlike a spherical lens having a constant curvature from the center to the periphery of the lens, an aspherical lens has better curvature radius characteristics, and has the advantages of improving distortion aberration and improving astigmatic aberration. After the aspheric lens is adopted, the aberration generated in imaging can be eliminated as much as possible, so that the imaging quality of the lens is improved. For example, the first lens may be an aspheric lens to reduce aberration, which helps to further improve the resolution quality. The second lens can be an aspheric lens to further improve the imaging quality. The fifth lens element can be an aspheric lens element to further improve the resolution and correct the aberration of the peripheral light. Ideally, the first lens, the second lens and the fifth lens are all aspheric lenses so as to further improve the imaging quality of the lens. It is understood that the optical lens according to the present application may increase the number of aspherical lenses in order to improve the imaging quality.

In an exemplary embodiment, the lens used in the optical lens may be a plastic lens, or may be a glass lens. The lens made of plastic has a large thermal expansion coefficient, and when the ambient temperature change of the lens is large, the lens made of plastic causes a large amount of change of the optical back focus of the lens. The glass lens can reduce the influence of temperature on the optical back focus of the lens, but has higher cost. In the case where the stability of the lens is important, the first to fifth lenses may optionally each be a glass lens.

According to the optical lens of the above embodiment of the present application, by setting the lens shape and the refractive power reasonably, high resolution can be achieved by using only a five-piece structure, and the requirements of miniaturization, low sensitivity and low cost of the lens can be met. In addition, the optical lens according to the above embodiment of the present application has a large aperture, an excellent imaging effect, and high image quality, and can ensure the definition of an image even in a low-light environment or at night. Therefore, the optical lens according to the above-described embodiment of the present application can have at least one of advantageous effects of miniaturization, high resolution, a large chip, a large aperture, low cost, low sensitivity, and the like, and can better meet the requirements of an in-vehicle lens.

It will be understood by those skilled in the art that the number of lenses making up the lens barrel may be varied to achieve the various results and advantages described in this specification without departing from the claimed subject matter. 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.

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

Example 1

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

As shown in fig. 1, the optical lens includes, in order from an object side to an image side along an optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5.

The first lens L1 is a meniscus lens with negative power, with the object side S1 being concave and the image side S2 being convex.

The second lens L2 is a biconvex lens with positive optical power, and has both the object-side surface S4 and the image-side surface S5 being convex.

The third lens L3 is a biconvex lens with positive optical power, and has both the object-side surface S6 and the image-side surface S7 being convex. The fourth lens L4 is a biconcave lens with negative optical power, and both the object-side surface S7 and the image-side surface S8 are concave. The fifth lens L5 has positive refractive power, and has a convex object-side surface S8 and a concave image-side surface S9. Wherein the third lens L3, the fourth lens L4, and the fifth lens L5 are cemented to form a cemented lens.

The first lens L1, the second lens L2, and the fifth lens L5 are all aspheric lenses, specifically, an object-side surface S1 and an image-side surface S2 of the first lens L1 and an object-side surface S4 and an image-side surface S5 of the second lens L2 are both aspheric, and an image-side surface S9 of the fifth lens L5 is aspheric.

Optionally, the optical lens may further include a filter L6 and/or a protective lens L6' having an object-side surface S10 and an image-side surface S11. Filter L6 can be used to correct for color deviations. The protection lens L6' can be used to protect the image sensing chip located on the imaging plane IMA. Light from the object passes through each of the surfaces S1 to S11 in sequence and is finally imaged on the imaging plane IMA.

In the optical lens of the present embodiment, a stop STO may be provided between the first lens L1 and the second lens L2 to improve the imaging quality.

Table 1 shows a radius of curvature R, a thickness T, a refractive index Nd, and an abbe number Vd of each lens of the optical lens of example 1, where the radius of curvature R and the thickness T are both in units of millimeters (mm).

TABLE 1

Flour mark	Radius of curvature R	Thickness T	Refractive index Nd	Abbe number Vd
					1	-11.5400	4.3600	1.82	41.00
2	-16.8600	6.1666
					STO	All-round	2.8334
4	29.0218	9.0000	1.62	63.41
					5	-30.7775	2.7408
6	19.3053	7.0700	1.62	60.36
					7	-30.1658	4.2900	1.76	27.55
8	9.0353	9.0400	1.81	41.00
					9	15.4293	1.0000
10	All-round	0.9500	1.52	64.21
					11	All-round	2.4936
IMA	All-round

The present embodiment adopts five lenses as an example, and by reasonably distributing the power and the surface type of each lens, the center thickness of each lens and the air space between each lens, the lens can have at least one of the advantages of miniaturization, high resolution, large chip, large aperture, low cost, low sensitivity and the like. Each aspherical surface type Z is defined by the following formula:

wherein Z is the distance rise from the vertex of the aspheric surface 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 conc; A. b, C, D, E are all high order term coefficients. Table 2 below shows conic coefficients k and high-order term coefficients A, B, C, D and E of the aspherical lens surfaces S1 to S2, S4 to S5, and S9 usable in example 1.

TABLE 2

Flour mark

K

A

B

C

D

E

1

-0.7657

6.1906E-05

3.2775E-07

-1.1031E-09

-7.1433E-12

2.6704E-14

2

-2.4575

1.6375E-05

2.7021E-07

-1.4563E-10

-3.9282E-12

1.2756E-14

4

-1.2000

3.4010E-06

-5.1646E-08

1.6635E-10

-4.8527E-13

-1.7374E-16

5

-0.3825

-1.4389E-07

1.9219E-08

-9.2231E-11

5.3890E-13

-2.2501E-15

9

4.6013

1.2747E-04

1.3453E-07

2.0104E-07

-8.1981E-09

1.0718E-10

Table 3 below gives the total optical length TTL of the optical lens of example 1 (i.e., the on-axis distance from the center of the object-side surface S1 of the first lens L1 to the imaging surface IMA), the focal length value F2 of the second lens L2, the entire group focal length value F of the optical lens, the image height H corresponding to the maximum field angle of the optical lens, the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, the central radius of curvature R1-R2 of the object-side surface S1 and the image-side surface S2 of the first lens L1, the central thickness D1 of the first lens L1, and the air interval D2 between the first lens L1 and the second lens L2.

TABLE 3

TTL(mm)	49.9444	\|R1\|(mm)	11.5400
				F2(mm)	25.4816	\|R2\|(mm)	16.8600
F(mm)	16.3749	d1(mm)	4.3600
				H(mm)	9.252	d2(mm)	9.0000
FOV(°)	32
				D(mm)	18.4091

In the present embodiment, F2/F is 1.556 between the focal length value F2 of the second lens L2 and the focal length value F of the entire group of optical lenses; the total optical length TTL of the optical lens and the whole group focal length value F of the optical lens meet the condition that TTL/F is 3.050; d2/TTL of 0.180 is satisfied between the air interval d2 between the first lens L1 and the second lens L2 and the total optical length TTL of the optical lens; the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens and the image height H corresponding to the maximum field angle of the optical lens satisfy that D/H/FOV is 0.062; and a central radius of curvature R1 of the object-side surface S1 of the first lens L1, a central radius of curvature R2 of the image-side surface S2, and a central thickness d1 of the first lens L1 satisfy (| R1| + d1)/| R2|, 0.943.

Example 2

An optical lens according to embodiment 2 of the present application is described below with reference to fig. 2. 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. 2 shows a schematic structural diagram of an optical lens according to embodiment 2 of the present application.

As shown in fig. 2, the optical lens includes, in order from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5.

Table 4 below shows a radius of curvature R, a thickness T, a refractive index Nd, and an abbe number Vd of each lens of the optical lens of example 2, where the radius of curvature R and the thickness T are both in units of millimeters (mm). Table 5 below shows cone coefficients k and high-order term coefficients A, B, C, D and E that can be used for the aspherical lens surfaces S1 to S2, S4 to S5, and S9 in example 2. Table 6 below gives the total optical length TTL of the optical lens of example 2, the focal length value F2 of the second lens L2, the entire group focal length value F of the optical lens, the image height H corresponding to the maximum field angle of the optical lens, the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, the central curvature radii R1-R2 of the object-side surface S1 and the image-side surface S2 of the first lens L1, the central thickness D1 of the first lens L1, and the air interval D2 between the first lens L1 and the second lens L2.

TABLE 4

Flour mark	Radius of curvature R	Thickness T	Refractive index Nd	Abbe number Vd
					1	-11.6220	4.6300	1.81	41.00
2	-17.2949	6.3500
					STO	All-round	2.6531
4	29.8660	9.0000	1.63	63.41
					5	-31.4299	3.0475
6	18.6896	7.0800	1.63	63.40
					7	-33.1526	4.1500	1.76	27.55
8	9.3200	9.0000	1.81	41.00
					9	15.5611	1.0000
10	All-round	0.9500	1.52	64.21
					11	All-round	2.1381
IMA	All-round

TABLE 5

Flour mark

K

A

B

C

D

E

1

-1.2500

6.0702E-05

3.1851E-07

-9.9350E-10

-6.9314E-12

3.5107E-14

2

-2.4500

1.5995E-05

2.5520E-07

-1.1590E-10

-3.4204E-12

9.1062E-16

4

0.0159

3.4236E-06

-4.7318E-08

1.4855E-10

-4.5592E-13

1.3546E-16

5

-0.3008

-5.6991E-07

1.8730E-08

-8.2938E-11

3.6664E-13

-1.7363E-15

9

6.2000

1.2818E-04

2.2017E-07

1.6284E-07

-6.1994E-09

1.5453E-10

TABLE 6

TTL(mm)	49.9986	\|R1\|(mm)	11.6220
				F2(mm)	25.8848	\|R2\|(mm)	17.2949
F(mm)	15.8438	d1(mm)	4.6300
				H(mm)	8.896	d2(mm)	9.0000
FOV(°)	32
				D(mm)	19.6543

In the present embodiment, F2/F is 1.634 is satisfied between the focal length value F2 of the second lens L2 and the focal length value F of the entire group of optical lenses; the total optical length TTL of the optical lens and the whole group focal length value F of the optical lens meet the condition that TTL/F is 3.156; d2/TTL of 0.180 is satisfied between the air interval d2 between the first lens L1 and the second lens L2 and the total optical length TTL of the optical lens; the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, and the image height H corresponding to the maximum field angle of the optical lens satisfy D/H/FOV of 0.069; and a central radius of curvature R1 of the object-side surface S1 and a central radius of curvature R2 of the image-side surface S2 of the first lens L1 and a central thickness d1 of the first lens L1 satisfy (| R1| + d1)/| R2|, 0.940.

Example 3

An optical lens according to embodiment 3 of the present application is described below with reference to fig. 3. 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 3 of the present application.

As shown in fig. 3, the optical lens includes, in order from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5.

Table 7 below shows a radius of curvature R, a thickness T, a refractive index Nd, and an abbe number Vd of each lens of the optical lens of example 3, where the radius of curvature R and the thickness T are both in units of millimeters (mm). Table 8 below shows cone coefficients k and high-order term coefficients A, B, C, D and E that can be used for the aspherical lens surfaces S1 to S2, S4 to S5, and S9 in example 3. Table 9 below gives the total optical length TTL of the optical lens of example 3, the focal length value F2 of the second lens L2, the entire group focal length value F of the optical lens, the image height H corresponding to the maximum field angle of the optical lens, the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, the central curvature radii R1-R2 of the object-side surface S1 and the image-side surface S2 of the first lens L1, the central thickness D1 of the first lens L1, and the air interval D2 between the first lens L1 and the second lens L2.

TABLE 7

Flour mark	Radius of curvature R	Thickness T	Refractive index Nd	Abbe number Vd
					1	-12.0110	5.3200	1.80	42.00
2	-18.0106	7.7791
					STO	All-round	1.2209
4	31.8921	9.0000	1.59	61.16
					5	-30.2229	2.5123
6	19.0838	7.3800	1.62	63.40
					7	-35.4278	5.1200	1.76	27.54
8	8.5940	9.0000	1.81	41.00
					9	16.1155	1.0000
10	All-round	0.9500	1.52	64.21
					11	All-round	2.2629
IMA	All-round

TABLE 8

Flour mark

K

A

B

C

D

E

1

-0.9250

5.6028E-05

2.7312E-07

-5.0214E-10

-8.2468E-12

3.5732E-14

2

-2.6600

1.2674E-05

2.1512E-07

7.7738E-11

-3.4649E-12

1.0186E-14

4

-0.0430

8.8735E-06

-6.1925E-08

3.2192E-10

-1.4963E-12

4.3548E-15

5

-0.2500

1.0315E-06

1.4541E-08

6.1075E-11

-5.6401E-13

2.6973E-15

9

5.5000

9.9579E-05

2.1500E-08

9.8796E-08

-3.6423E-09

7.8408E-11

TABLE 9

TTL(mm)	51.5452	\|R1\|(mm)	12.0110
				F2(mm)	27.7018	\|R2\|(mm)	18.0106
F(mm)	16.5048	d1(mm)	5.3200
				H(mm)	9.02	d2(mm)	9.0000
FOV(°)	32
				D(mm)	19.7601

In the present embodiment, F2/F is 1.678 between the focal length value F2 of the second lens L2 and the focal length value F of the entire group of optical lenses; the total optical length TTL of the optical lens and the whole group focal length value F of the optical lens meet the condition that TTL/F is 3.123; d2/TTL of 0.175 is satisfied between the air interval d2 between the first lens L1 and the second lens L2 and the total optical length TTL of the optical lens; the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, and the image height H corresponding to the maximum field angle of the optical lens satisfy D/H/FOV of 0.069; and a central radius of curvature R1 of the object-side surface S1 and a central radius of curvature R2 of the image-side surface S2 of the first lens L1 and a central thickness d1 of the first lens L1 satisfy (| R1| + d1)/| R2| -0.962.

In summary, examples 1 to 3 each satisfy the relationship shown in table 10 below.

Watch 10

Conditions/examples	1	2	3
				F2/F	1.556	1.634	1.678
TTL/F	3.050	3.156	3.123
				d2/TTL	0.180	0.180	0.175
D/H/FOV	0.062	0.069	0.069
				(\|R1\|+d1)/\|R2\|	0.943	0.940	0.962

The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by a person skilled in the art that the scope of the invention as referred to in the present application is not limited to the embodiments with a specific combination of the above-mentioned features, but also covers other embodiments with any combination of the above-mentioned features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.

Claims

1. The optical lens sequentially comprises from an object side to an image side along an optical axis: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens,

it is characterized in that the preparation method is characterized in that,

the first lens has negative focal power, the object side surface of the first lens is a concave surface, and the image side surface of the first lens is a convex surface;

the second lens has positive focal power, and both the object side surface and the image side surface of the second lens are convex surfaces;

the third lens has positive focal power, and both the object side surface and the image side surface of the third lens are convex surfaces;

the fourth lens has negative focal power, and both the object side surface and the image side surface of the fourth lens are concave surfaces; and

the fifth lens has positive focal power, and the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a concave surface.

2. An optical lens according to claim 1, wherein the third lens, the fourth lens and the fifth lens are cemented to form a cemented lens.

3. An optical lens according to claim 1, characterized in that the first lens, the second lens and the fifth lens are all aspherical lenses.

4. An optical lens according to any one of claims 1 to 3, wherein an overall optical length TTL of the optical lens and a total group focal length value F of the optical lens satisfy: TTL/F is less than or equal to 5.

5. An optical lens according to any one of claims 1 to 3, characterized in that the focal length value F2 of the second lens and the entire set of focal length values F of the optical lens satisfy: F2/F is more than or equal to 0.8 and less than or equal to 2.5.

6. An optical lens according to any one of claims 1 to 3, characterized in that an air interval d2 between the first lens and the second lens and an optical total length TTL of the optical lens satisfy: d2/TTL is more than or equal to 0.1.

7. An optical lens according to any one of claims 1 to 3, wherein the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface of the first lens corresponding to the maximum field angle of the optical lens, and the image height H corresponding to the maximum field angle of the optical lens satisfy: D/H/FOV is less than or equal to 0.1.

8. An optical lens according to any one of claims 1 to 3, characterized in that the central radius of curvature R1 of the object side of the first lens, the central radius of curvature R2 of the image side of the first lens and the central thickness d1 of the first lens are such that: the ratio of | (R1 | + d1)/| R2| -is not less than 0.5 and not more than 1.5.

9. The optical lens sequentially comprises from an object side to an image side along an optical axis: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens,

it is characterized in that the preparation method is characterized in that,

the first lens and the fourth lens each have a negative optical power;

the second lens, the third lens and the fifth lens each have positive optical power;

the third lens, the fourth lens and the fifth lens are cemented to form a cemented lens; and

the total optical length TTL of the optical lens and the whole group of focal length values F of the optical lens meet the following conditions: TTL/F is less than or equal to 5.