CN110488470B

CN110488470B - Optical lens

Info

Publication number: CN110488470B
Application number: CN201810454010.0A
Authority: CN
Inventors: 王东方; 李响; 姚波
Original assignee: Ningbo Sunny Automotive Optech Co Ltd
Current assignee: Ningbo Sunny Automotive Optech Co Ltd
Priority date: 2018-05-14
Filing date: 2018-05-14
Publication date: 2021-10-26
Anticipated expiration: 2038-05-14
Also published as: CN110488470A

Abstract

The present application discloses an optical lens, sequentially from an object side to an image side along an optical axis, comprising: the lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens, wherein the first lens is a meniscus lens with negative focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has negative focal power, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a concave surface; the third lens has positive focal power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface; the fourth lens has positive focal power, and the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has negative focal power, the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a concave surface; the sixth lens has positive focal power, and the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface; the seventh lens element is a meniscus lens element with a convex object-side surface and a concave image-side surface. The optical lens according to the present application has the characteristics of high resolution, for example, up to 12M and above, miniaturization, large aperture, low cost, and small CRA.

Description

Optical lens

Technical Field

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

Background

With the popularization of unmanned technologies, the pixel requirements of vehicle-mounted lenses as automobile eyes are higher and higher. Currently, million-pixel vehicle-mounted lenses have become increasingly popular, and are moving towards the trend of tens of millions of high-definition pixels.

In order to achieve high resolution of the lens, it is generally possible to achieve by increasing the number of lenses, but this affects miniaturization of the lens. Moreover, to be used in low light environments, tens of millions of pixel lenses require a larger aperture; to not produce color cast when matching tens of millions of pixel chips, a smaller CRA is required.

Therefore, it is necessary to design a lens that has high resolution and high imaging quality at the level of ten million pixels, and that is compact and low-cost, and that can be used in low-light environments.

Disclosure of Invention

The present application provides an optical lens applicable for vehicle-mounted installation that at least overcomes or partially overcomes at least one of the above-mentioned deficiencies in the prior art.

An aspect of the present application provides an optical lens, in order from an object side to an image side along an optical axis, comprising: the lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens, wherein the first lens is a meniscus lens with negative focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has negative focal power, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a concave surface; the third lens has positive focal power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface; the fourth lens has positive focal power, and the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has negative focal power, the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a concave surface; the sixth lens has positive focal power, and the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface; the seventh lens element is a meniscus lens element with a convex object-side surface and a concave image-side surface.

In one embodiment, the seventh lens has a positive optical power.

In one embodiment, the seventh lens has a negative optical power.

In one embodiment, the second lens and the third lens are cemented to each other.

In one embodiment, the fifth lens and the sixth lens are cemented to each other.

In one embodiment, the fourth lens, the fifth lens and the sixth lens are cemented to each other.

In one embodiment, at least one of the first lens, the sixth lens, and the seventh lens is an aspherical mirror.

In one embodiment, an effective radius R2 of an image side surface of a first lens of the optical lens and an effective radius R3 of an object side surface of a second lens of the optical lens satisfy-3 ≦ (R2-R3)/(R2+ R3) ≦ -0.5.

In one embodiment, TTL/F is less than or equal to 4.5 between the optical length TTL of the optical lens and the focal length value F of the whole group of the optical lens.

In one embodiment, the focal length value F23 of the second and third cemented combination lenses of the optical lens and the focal length value F of the whole optical lens set satisfy 1.5 ≦ F23/F ≦ 4.

In one embodiment, the central curvature radius R12 of the image side surface of the seventh lens of the optical lens and the central curvature radius R11 of the object side surface of the seventh lens of the optical lens satisfy R12/R11 ≦ 2.

An aspect of the present application provides an optical lens, in order from an object side to an image side along an optical axis, comprising: the lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens, wherein the first lens is a meniscus lens with negative focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has negative focal power; the third lens has positive focal power; the fourth lens has positive focal power; the fifth lens has negative focal power; the sixth lens has positive focal power; the seventh lens is a meniscus lens, the object side of which is convex, and the image side of which is concave; the effective radius R2 of the image side surface of the first lens of the optical lens and the effective radius R3 of the object side surface of the second lens of the optical lens meet the requirement that (R2-R3)/(R2+ R3) is less than or equal to-3 and less than or equal to-0.5.

In one embodiment, the seventh lens has a positive or negative optical power.

In one embodiment, the second lens element has a concave object-side surface and a concave image-side surface.

In one embodiment, the object-side surface of the third lens element is convex and the image-side surface of the third lens element is convex.

In one embodiment, the fourth lens element has a convex object-side surface and a convex image-side surface.

In one embodiment, the fifth lens element has a concave object-side surface and a concave image-side surface.

In one embodiment, the object-side surface of the sixth lens element is convex, and the image-side surface of the sixth lens element is convex.

The lens of this application can realize tens of millions of pixel resolution through the setting of reasonable lens shape and the setting of focal power, compromises the low-cost requirement that the camera lens is miniaturized, the sensitivity is low, the production yield is high simultaneously. The lens CRA is small, can be well matched with a vehicle-mounted cmos chip with RA at 0 ℃, and does not generate color cast and dark corner phenomena; in addition, the lens has a large aperture, the imaging effect is good, the image quality reaches ten million high-definition levels, and the imaging definition can be ensured even in a low-light environment or at night. The lens of the application has the characteristics of high resolution, for example, 12M or more, miniaturization, large aperture, low cost and small CRA.

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, seven lenses having optical power, i.e., a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. The seven 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).

In an exemplary embodiment, the first lens is a meniscus lens with negative power, with the object side surface being convex and the image side surface being concave. Specifically, the first lens is in a meniscus shape facing the object, so that light rays with a large field of view can be collected as far as possible, the collected light rays enter a rear optical system, and the light flux is increased. In practical application, considering outdoor installation and use environment of the vehicle-mounted lens, namely the vehicle-mounted lens can be in severe weather such as rain, snow and the like, the first lens is in a meniscus shape, so that water drops can slide off, and the influence of the water drops on the lens on lens imaging is reduced. Preferably, the first lens is an aspheric lens, which can further improve the resolution quality.

In an exemplary embodiment, the second lens has a negative power, and the object side surface is concave and the image side surface is concave.

In an exemplary embodiment, the third lens has positive optical power, and the object side surface is convex and the image side surface is convex.

In an exemplary embodiment, the second lens and the third lens are cemented to each other. In other words, the second lens having negative power and the third lens having positive power are combined into an assembly. Wherein the positive lens (i.e., the second lens) has a higher refractive index and the negative lens (i.e., the third lens) has a lower refractive index with respect to the positive lens. One of the two lenses is negative and the other is positive, the low refractive index and the high refractive index materials are matched, and the rapid transition of the front light is facilitated, so that the aperture of the diaphragm is increased, and the night vision requirement is met. Moreover, the system chromatic aberration can be effectively reduced by adopting the gluing piece, the whole structure of the optical system is more compact so as to meet the miniaturization requirement, and meanwhile, the tolerance sensitivity problems of inclination/core deviation and the like generated in the assembling process of the lens unit can be reduced. In particular, if discrete lenses are located at the light ray transitions, sensitivity is easily caused by processing/assembly errors, and the cemented lens assembly according to the exemplary embodiment effectively reduces such sensitivity. The lens with negative focal power is arranged in front of the lens, the lens with positive focal power is arranged behind the lens, the front light can be quickly converged after being diverged, and then the transition is carried out to the rear, so that the reduction of the optical path of the rear light is facilitated, and the short TTL is realized, wherein the TTL refers to the optical length of the optical lens.

In an exemplary embodiment, the diaphragm is arranged between the third lens and the fourth lens, and can effectively collect light rays entering the optical system and reduce the aperture of the lens of the optical system. In other embodiments, the aperture may be located in other positions as desired.

In an exemplary embodiment, the fourth lens has positive optical power, and the object-side surface is convex and the image-side surface is convex. The fourth lens with positive focal power is arranged behind the aperture stop, so that aberration generated by the front lens group can be further corrected, and meanwhile, light beams are converged again, namely, the aperture of the lens can be increased, the total length of the lens can be shortened, and the optical system is more compact and has relatively shorter total length of the lens.

In an exemplary embodiment, the fifth lens has a negative power, and the object side surface is concave and the image side surface is concave.

In an exemplary embodiment, the sixth lens element has positive optical power, and has a convex object-side surface and a convex image-side surface. The sixth lens is preferably an aspherical lens to further improve the resolution quality.

In an exemplary embodiment, the fifth lens and the sixth lens are cemented to each other. In other words, the fifth lens with negative focal power and the sixth lens with positive focal power are combined into a composite member, and the composite member can perform self achromatization, reduce tolerance sensitivity and also can remain partial chromatic aberration so as to balance chromatic aberration of a system. Further, the glue can reduce field curvature, correct off-axis point aberration of the system, and optimize optical performance such as distortion, CRA, etc. The fifth lens and the sixth lens are mutually glued, so that the total length of the system can be reduced, and the single-lens sensitivity is reduced.

In an exemplary embodiment, the fourth lens, the fifth lens and the sixth lens may be cemented with each other. The three lenses are respectively glued with each other, so that the following advantages are achieved: the air interval of the three lenses is reduced, and the total length of the system is reduced; the assembling parts among the fourth lens, the fifth lens and the sixth lens are reduced, the working procedures are reduced, and the cost is reduced; the tolerance sensitivity problems of inclination/core deviation and the like generated in the assembling process of the lens unit are reduced; and reduce the light loss caused by reflection between the lenses, promote the illumination intensity; the total length of the system is reduced, and the sensitivity of a single lens is reduced.

In an exemplary embodiment, the seventh lens element is a meniscus lens element with a convex object-side surface and a concave image-side surface. The seventh lens can adopt an aspheric lens, and the light rays passing through the sixth lens are diffused, so that the light rays are smoothly transited to an imaging surface, and the total length of the optical system is reduced. With the above arrangement, various aberrations of the optical system are sufficiently corrected, and a compact structure can be realized while providing a high resolution.

The optical lens adopts the gluing piece, so that the whole chromatic aberration of the system can be shared, the aberration can be effectively corrected, the image resolution can be improved, the whole optical system is compact, and the miniaturization requirement can be met. In the exemplary embodiment, it is preferable that each of the first to seventh lenses may be aspheric to improve the resolution quality.

In an exemplary embodiment, an effective radius R2 of an image side surface of the first lens of the optical lens and an effective radius R3 of an object side surface of the second lens of the optical lens satisfy-3 ≦ (R2-R3)/(R2+ R3) ≦ -0.5. More specifically, it satisfies-2.3 ≦ (R2-R3)/(R2+ R3) ≦ -1. By satisfying-3 ≦ (R2-R3)/(R2+ R3) ≦ -0.5, aberration of the optical system can be corrected, and it is ensured that when the light outgoing from the first lens is incident to the first face of the second lens, the incident angle is not too large, thereby reducing tolerance sensitivity of the optical system.

In an exemplary embodiment, TTL/F ≦ 4.5 is satisfied between the optical length TTL of the optical lens and the entire group focal length value F of the optical lens. More specifically, TTL/F ≦ 4 is satisfied. The optical lens with TTL/F less than or equal to 4.5 has shorter back focal length, and is beneficial to realizing the miniaturization of the lens.

In the exemplary embodiment, the focal length value F23 of the second and third cemented combination lenses of the optical lens and the focal length value F of the whole optical lens group satisfy 1.5 ≦ F23/F ≦ 4. More specifically, 1.8. ltoreq. F23/F. ltoreq.3.5 is satisfied.

In an exemplary embodiment, R12/R11 ≦ 2 is satisfied between the central radius of curvature R12 of the image side surface of the seventh lens of the optical lens and the central radius of curvature R11 of the object side surface of the seventh lens of the optical lens. More specifically, R12/R11. ltoreq.1.5 is satisfied.

However, it will be appreciated by those skilled in the art that the number of lenses constituting the lens barrel may be varied to achieve the various results and advantages described in the present specification without departing from the claimed subject matter. For example, although seven lenses are exemplified in the embodiment, the optical lens is not limited to include seven 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 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, a fifth lens L5, a sixth lens L6, and a seventh lens L7.

The first lens element L1 is a negative meniscus lens element with a convex object-side surface and a concave image-side surface. The first lens L1 is an aspherical lens. The object-side surface and the image-side surface of the first lens are both aspheric surfaces.

The second lens element L2 has negative power, and has a concave object-side surface and a concave image-side surface.

The third lens element L3 has positive power, and has a convex object-side surface and a convex image-side surface.

The fourth lens element L4 has positive power, and has a convex object-side surface and a convex image-side surface.

The fifth lens element L5 has a negative power, and has a concave object-side surface and a concave image-side surface.

The sixth lens element L6 has positive power, and has a convex object-side surface and a convex image-side surface.

The seventh lens element L7 is a meniscus lens element with negative power, and has a convex object-side surface and a concave image-side surface. The seventh lens L7 is an aspherical lens. The object side surface and the image side surface of the seventh lens are both aspheric surfaces.

Optionally, the optical lens may further include a filter L8 having an object-side surface S13 and an image-side surface S14, and a protective glass L9 having an object-side surface S15 and an image-side surface S16. Filters may be used to correct for color deviations. The protective glass can be used for protecting the image sensing chip positioned on the imaging plane IMA. The light from the object sequentially passes through the respective surfaces S1 to S16 and is finally imaged on the imaging surface S17.

In the optical lens of the present embodiment, a stop STO may be provided between the third lens L3 and the fourth lens L4 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

Number of noodle S	Radius of curvature R	Thickness T	Refractive index Nd	Abbe number Vd
					1	5.1489	1.8607	1.81	41.00
2	3.2532	5.1166
					3	-15.4288	3.9341	1.49	70.42
4	12.4460	4.0884	1.74	44.90
					5	-12.0570	0.4960
STO	Infinity	-0.3352
					7	8.4830	3.0662	1.62	60.37
8	-11.8615	0.6000	1.76	27.55
					9	10.1872	2.6034	1.50	81.59
10	-18.2380	1.1556
					11	18.5632	2.4023	1.74	49.34
12	13.2118	2.6814
					13	Infinity	0.5000	1.52	64.21
14	Infinity	1.8102
					15	Infinity	0.4000	1.52	64.21
16	Infinity	0.1250
					IMA	Infinity

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 the conic coefficients k and the high-order term coefficients A, B, C, D and E that can be used for the aspherical lens surfaces S1, S2, S11, and S12 in example 1.

TABLE 2

Number of noodle S

K

A

B

C

D

E

1

-0.6319

-7.5484E-04

-1.5702E-05

-9.4022E-07

3.2245E-08

-3.2256E-10

2

-1.0118

1.3807E-04

-2.5630E-05

-4.0241E-06

2.3875E-07

-3.9803E-09

11

12.3895

-8.1593E-04

-2.4172E-05

5.5202E-07

-6.4357E-08

1.6439E-09

12

1.4952

-2.8454E-04

-2.0094E-05

1.0528E-06

-7.2278E-08

2.3074E-09

Table 3 below shows the focal length value F23 of the second and third cemented group lenses, the focal length value F of the entire group of the optical lens, the optical length TTL of the optical lens (i.e., the distance from the center of the object side of the first lens of the optical lens to the imaging focal plane of the optical lens), the effective radius R2 of the image side surface of the first lens of the optical lens, the effective radius R3 of the object side surface of the second lens of the optical lens, the central radius R11 of the object side surface of the seventh lens of the optical lens, and the central radius R12 of the image side surface of the seventh lens of the optical lens in example 1.

TABLE 3

F23	F	TTL	R2	R3	R11	R12
							16.8509	8.2559	30.5000	3.2532	-15.4288	18.5632	13.2118

In the present embodiment, an effective radius R2 of the image side surface of the first lens of the optical lens and an effective radius R3 of the object side surface of the second lens of the optical lens satisfy (R2-R3)/(R2+ R3) — 1.5344; the 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 3.694; F23/F is 2.041 between the focal length value F23 of the second and third cemented combination lenses of the optical lens and the focal length value F of the whole optical lens group; and the central curvature radius R12 of the image side surface of the seventh optical lens and the central curvature radius R11 of the object side surface of the seventh optical lens meet the condition that R12/R11 is 0.712.

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, a fifth lens L5, a sixth lens L6, and a seventh lens L7.

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 the conic coefficients k and the high-order term coefficients A, B, C, D and E that can be used for the aspherical lens surfaces S1, S2, S11, and S12 in example 2. Table 6 below shows the focal length value F23 of the second and third cemented group lenses, the focal length value F of the entire group of the optical lens, the optical length TTL of the optical lens (i.e., the distance from the center of the object side of the first lens of the optical lens to the imaging focal plane of the optical lens), the effective radius R2 of the image side surface of the first lens of the optical lens, the effective radius R3 of the object side surface of the second lens of the optical lens, the central radius R11 of the object side surface of the seventh lens of the optical lens, and the central radius R12 of the image side surface of the seventh lens of the optical lens in example 2.

TABLE 4

TABLE 5

Number of noodle S

K

A

B

C

D

E

1

-0.7028

-7.2147E-04

-1.6094E-05

-8.8483E-07

3.2182E-08

-3.5891E-10

2

-1.0455

1.6930E-04

-1.4551E-05

-4.0471E-06

2.4416E-07

-4.7766E-09

11

11.1133

-7.0727E-04

-2.7514E-05

7.1134E-07

-8.9653E-08

3.0759E-09

12

3.1002

-1.7940E-04

-3.2130E-05

1.7808E-06

-1.5286E-07

5.2121E-09

TABLE 6

F23	F	TTL	R2	R3	R11	R12
							20.3779	8.1082	29.8799	3.3010	-11.5409	20.1925	14.7193

In the present embodiment, an effective radius R2 of the image side surface of the first lens of the optical lens and an effective radius R3 of the object side surface of the second lens of the optical lens satisfy (R2-R3)/(R2+ R3) — 1.8012; the 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 3.685; the focal length value F23 of the second and third cemented combination lenses of the optical lens and the focal length value F of the whole optical lens set satisfy F23/F-2.513; and the central curvature radius R12 of the image side surface of the seventh optical lens and the central curvature radius R11 of the object side surface of the seventh optical lens meet the condition that R12/R11 is 0.729.

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, a fifth lens L5, a sixth lens L6, and a seventh lens L7.

The sixth lens element L6 has positive power, and has a convex object-side surface and a convex image-side surface. The image side surface of the sixth lens is an aspheric surface.

The seventh lens L7 is a meniscus lens with positive power, and has a convex object-side surface and a concave image-side surface. The seventh lens L7 is an aspherical lens. The object side surface and the image side surface of the seventh lens are both aspheric surfaces.

Optionally, the optical lens may further include a filter L8 having an object-side surface S14 and an image-side surface S15, and a protective glass L9 having an object-side surface S16 and an image-side surface S17. Filters may be used to correct for color deviations. The protective glass can be used for protecting the image sensing chip positioned on the imaging plane IMA. The light from the object sequentially passes through the respective surfaces S1 to S17 and is finally imaged on the imaging surface S18.

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, S2, S11, S12, and S13 in example 3. Table 9 below shows the focal length value F23 of the second and third cemented group lenses, the focal length value F of the entire group of the optical lens, the optical length TTL of the optical lens (i.e., the distance from the center of the object side of the first lens of the optical lens to the imaging focal plane of the optical lens), the effective radius R2 of the image side surface of the first lens of the optical lens, the effective radius R3 of the object side surface of the second lens of the optical lens, the central radius R11 of the object side surface of the seventh lens of the optical lens, and the central radius R12 of the image side surface of the seventh lens of the optical lens in example 3.

TABLE 7

TABLE 8

Number of noodle S

K

A

B

C

D

E

1

-0.3356

-8.0987E-04

-2.9596E-05

4.2230E-07

1.4977E-09

-7.8020E-11

2

-0.9817

-1.0939E-04

-8.4798E-05

3.7400E-06

-3.3888E-08

-1.8587E-10

11

0.6521

-2.3857E-04

5.6024E-05

-2.2067E-06

6.6989E-08

-2.3851E-10

12

0.1218

-1.7907E-03

4.8160E-05

-1.2600E-06

2.0823E-08

2.0650E-11

13

0.0679

-1.9210E-03

4.0377E-05

-1.1512E-07

-3.0896E-08

9.4451E-10

TABLE 9

F23	F	TTL	R2	R3	R11	R12
							27.1177	8.4826	29.7420	3.3483	-12.6027	7.6851	8.9121

In the present embodiment, an effective radius R2 of the image side surface of the first lens of the optical lens and an effective radius R3 of the object side surface of the second lens of the optical lens satisfy (R2-R3)/(R2+ R3) — 1.7236; the 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 3.506; the focal length value F23 of the second and third cemented combination lenses of the optical lens and the focal length value F of the whole optical lens set satisfy F23/F-3.197; and the central curvature radius R12 of the image side surface of the seventh optical lens and the central curvature radius R11 of the object side surface of the seventh optical lens meet the condition that R12/R11 is 1.160.

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

Watch 10

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, a fifth lens, a sixth lens, and a seventh lens,

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

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

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

the third lens has positive focal power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface;

the fourth lens has positive focal power, and the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface;

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

the sixth lens has positive focal power, and the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface;

the seventh lens is a meniscus lens, the object side of which is convex, and the image side of which is concave;

the second lens and the third lens are mutually glued;

the number of the optical lens with focal power is seven; and

the 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 less than or equal to 4.5.

2. An optical lens according to claim 1, characterized in that the seventh lens has a positive or negative optical power.

3. An optical lens according to claim 1, characterized in that the fifth lens and the sixth lens are cemented to each other.

4. An optical lens according to claim 1, wherein the fourth lens, the fifth lens and the sixth lens are cemented to each other.

5. An optical lens according to claim 1, characterized in that at least one of the first lens, the sixth lens and the seventh lens is an aspherical lens.

6. An optical lens as claimed in claim 1, characterized in that an effective radius R2 of the image side of the first lens element of the optical lens and an effective radius R3 of the object side of the second lens element of the optical lens satisfy-3 ≦ (R2-R3)/(R2+ R3) ≦ -0.5.

7. An optical lens according to any one of claims 1 to 5, wherein the focal length value F23 of the second and third cemented group lenses of the optical lens and the focal length value F of the whole group of the optical lens satisfy 1.5 ≦ F23/F ≦ 4.

8. An optical lens according to any one of claims 1 to 5, characterized in that R12/R11 ≦ 2 is satisfied between the central radius of curvature R12 of the image side surface of the seventh lens of the optical lens and the central radius of curvature R11 of the object side surface of the seventh lens of the optical lens.

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, a fifth lens, a sixth lens, and a seventh lens,

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

the second lens has negative focal power;

the third lens has positive focal power;

the fourth lens has positive focal power;

the fifth lens has negative focal power;

the sixth lens has positive focal power;

wherein the effective radius R2 of the image side surface of the first lens of the optical lens and the effective radius R3 of the object side surface of the second lens of the optical lens meet the requirement that (R2-R3)/(R2+ R3) is less than or equal to-3 and less than or equal to-0.5;

the second lens and the third lens are mutually glued;

the number of the optical lens with focal power is seven; and

10. An optical lens according to claim 9, characterized in that the seventh lens has a positive or negative optical power.

11. An optical lens barrel according to claim 9, wherein the second lens element has a concave object-side surface and a concave image-side surface.

12. An optical lens barrel according to claim 9, wherein the third lens element has a convex object-side surface and a convex image-side surface.

13. An optical lens barrel according to claim 9, wherein the fourth lens element has a convex object-side surface and a convex image-side surface.

14. An optical lens barrel according to claim 9, wherein the fifth lens element has a concave object-side surface and a concave image-side surface.

15. An optical lens barrel according to claim 9, wherein the sixth lens element has a convex object-side surface and a convex image-side surface.

16. An optical lens barrel according to claim 9, wherein the fifth lens and the sixth lens are cemented to each other.

17. An optical lens barrel according to claim 9, wherein the fourth lens, the fifth lens and the sixth lens are cemented to each other.

18. An optical lens according to claim 9, characterized in that at least one of the first lens, the sixth lens and the seventh lens is an aspherical lens.

19. An optical lens barrel according to any one of claims 9 to 18, wherein the focal length value F23 of the second and third cemented group lenses of the optical lens and the focal length value F of the whole group of the optical lens satisfy 1.5 ≦ F23/F ≦ 4.

20. An optical lens according to any one of claims 9 to 18, characterized in that R12/R11 ≦ 2 is satisfied between the central radius of curvature R12 of the image side surface of the seventh lens of the optical lens and the central radius of curvature R11 of the object side surface of the seventh lens of the optical lens.