CN110865450B

CN110865450B - Optical lens

Info

Publication number: CN110865450B
Application number: CN201810989905.4A
Authority: CN
Inventors: 王东方; 施亚飞; 姚波
Original assignee: Ningbo Sunny Automotive Optech Co Ltd
Current assignee: Ningbo Sunny Automotive Optech Co Ltd
Priority date: 2018-08-28
Filing date: 2018-08-28
Publication date: 2022-01-18
Anticipated expiration: 2038-08-28
Also published as: CN110865450A

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, a fifth lens, a sixth lens, and a seventh lens. The first lens has 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 convex 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 concave surface, and the image side surface of the third lens is a convex surface; the fourth lens has positive focal power, the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a concave surface; the fifth lens has positive focal power, and both the object side surface and the image side surface of the fifth lens are convex surfaces; the sixth lens has negative 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 concave surface; and the seventh lens has positive focal power, and both the object-side surface and the image-side surface of the seventh lens are convex. According to the optical lens disclosed by the application, at least one of the beneficial effects of small caliber, high pixel, long back focus, large field angle, high peripheral illumination 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 seven lenses.

Background

As science develops, more and more fields need to use lenses to act as "eyes", such as vehicle-mounted, monitoring, projection, industrial fields, and the like. Particularly, with the increasing concern of the society on traffic safety, emerging technologies such as active driving/auxiliary driving and the like are more and more popularized, the demand of the market on the vehicle-mounted optical lens is stronger and the performance requirement, particularly the resolution requirement, on the lens is higher and higher.

The lens is limited by the installation position when being installed on the automobile, the problem of miniaturization has to be considered, and the problem of practical use of the optical lens can occur due to the overlarge size of the lens, for example, a front-view lens arranged behind a front windshield can cause interference to driving; meanwhile, the overall layout of the automobile is also challenged by the fact that the size of the lens is too large. In addition, the vehicle-mounted optical lens needs to be used in a severe outdoor environment, so that the stable imaging performance can be kept at different temperatures, and the situation that the driver is endangered due to imaging blur of the lens is avoided.

Nowadays, high resolution can be generally obtained by increasing the number of lenses, but with further improvement of resolution requirements, increasing the number of lenses tends to conflict with miniaturization and low cost. The imaging performance can be improved by adopting the aspheric surface, and if the plastic aspheric surface is adopted, the problem of defocusing image surface blurring caused by temperature change exists due to the fact that the plastic lens is too much determined by the characteristics of the plastic. If the glass aspheric surface is adopted, the cost is too high, the price cannot be accepted by the market, and the processing limit of the glass aspheric surface is large.

Meanwhile, the field angle requirement of the vehicle-mounted optical lens is higher and higher, and the problems that the requirements for high resolution and small distortion are met as much as possible, the small caliber is met, and the peripheral illumination is improved are also considered.

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, a fifth lens, a sixth lens, and a seventh lens. The first lens can have negative focal power, and 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 can have negative focal power, and the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the third lens can have positive focal power, and the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; the fourth lens can have 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 concave surface; the fifth lens can have positive focal power, and both the object side surface and the image side surface of the fifth lens are convex surfaces; the sixth lens element has negative focal power, and has a convex object-side surface and a concave image-side surface; and the seventh lens element may have a positive optical power, and both the object-side surface and the image-side surface thereof are convex.

Alternatively, the sixth lens and the seventh lens may be cemented with each other to form a cemented lens.

Alternatively, the first lens to the seventh lens may be glass lenses.

Alternatively, the optical lens may have at least three aspherical lenses.

Optionally, at least three of the second lens to the seventh lens are aspheric lenses.

Alternatively, the conditional expression may be satisfied: D/H/FOvm is less than or equal to 0.03, wherein FOvm is the maximum field angle of the optical lens; d is the maximum light-passing aperture of the object side surface of the first lens corresponding to the maximum field angle of the optical lens; and H is the image height corresponding to the maximum field angle of the optical lens.

Optionally, the radius of curvature R5 of the object-side surface of the third lens, the radius of curvature R6 of the image-side surface of the third lens, and the center thickness d5 of the third lens may satisfy: i R6I/(IR 5I + d5) is less than or equal to 1.5.

Optionally, a radius of curvature R7 of the object-side surface of the fourth lens and a radius of curvature R8 of the image-side surface of the fourth lens may satisfy: R7/R8 is less than or equal to 2.

Optionally, an optical back focus BFL of the optical lens and an optical total length TTL of the optical lens may satisfy: BFL/TTL is more than or equal to 0.1.

Optionally, the maximum field angle FOVm of the optical lens, the image height H corresponding to the maximum field angle of the optical lens, and the entire group of focal length values F of the optical lens may satisfy: (FOVm F)/H is less than or equal to 80.

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, a fifth lens, a sixth lens, and a seventh lens. The first lens, the second lens and the sixth lens can all have negative focal power; the third lens, the fourth lens, the fifth lens and the seventh lens may each have positive optical power; the sixth lens and the seventh lens may be cemented with each other to form a cemented lens; and the maximum field angle FOvm of the optical lens, the image height H corresponding to the maximum field angle of the optical lens and the whole group of focal length values F of the optical lens can satisfy the following conditions: (FOVm F)/H is less than or equal to 80.

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

Alternatively, the object-side surface of the second lens element can be convex and the image-side surface can be concave.

Alternatively, the object-side surface of the third lens element can be concave and the image-side surface can be convex.

Alternatively, the object-side surface of the fourth lens element can be convex and the image-side surface can be concave.

Optionally, both the object-side surface and the image-side surface of the fifth lens can be convex.

Alternatively, the object-side surface of the sixth lens element can be convex and the image-side surface can be concave.

Optionally, both the object-side surface and the image-side surface of the seventh lens element may be convex.

Alternatively, the first lens to the seventh lens may be glass lenses.

Alternatively, the optical lens may have at least three aspherical lenses.

The optical lens adopts seven lenses, for example, the shapes of the lenses are optimally set, the focal power of each lens is reasonably distributed, the cemented lens is formed, and the like, so that at least one of the beneficial effects of small caliber, high pixel, long back focus, large field angle, high peripheral illumination 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, and the first cemented lens may also be referred to as the second cemented 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).

The first lens element can have a negative power, and can have a convex object-side surface and a concave image-side surface. The first lens is arranged in a meniscus shape which is convex towards the object side, so that light rays with a large field of view can be collected as far as possible and enter a rear optical system. In practical application, considering that the outdoor installation and use environment of the vehicle-mounted lens can be in severe weather such as rain, snow and the like, the design of the meniscus shape protruding towards the object side is beneficial to the sliding of water drops, is beneficial to the barrier-free use of the lens in severe environments such as rain, snow and the like, and reduces the influence on imaging. Optionally, the first lens can be made of a high-refractive-index material, for example, the refractive index Nd1 of the material of the first lens can satisfy Nd1 ≧ 1.7, so that the front-end aperture can be reduced, and the imaging quality of the lens can be improved.

The second lens element can have a negative power, and can have a convex object-side surface and a concave image-side surface. The second lens is in a meniscus shape convex to the object side, and can properly disperse light rays, so that the light rays are in stable transition, and meanwhile, the light rays with large angles can enter the rear optical system as far as possible.

The third lens element can have a positive power, and can have a concave object-side surface and a convex image-side surface. The third lens can converge light rays, so that the diffused light rays can smoothly enter the rear optical system; meanwhile, the focal power is positive, so that chromatic aberration introduced by the first two negative-power lenses (the first lens and the second lens) can be compensated.

The fourth lens element can have a positive power, and can have a convex object-side surface and a concave image-side surface. The fourth lens can share the focal power of the third lens and further converge light rays, so that peripheral light rays can enter the rear lens more smoothly, and the peripheral illumination is improved; in addition, the fourth lens and the third lens are matched, so that the aberration of the first two negative-power lenses (the first lens and the second lens) can be balanced, light rays can be in stable transition, and the illumination intensity is improved.

The fifth lens element can have a positive optical power, and can have a convex object-side surface and a convex image-side surface. The fifth lens is in a biconvex shape, can converge light rays and further balances spherical aberration introduced by the negative-power lens.

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

The seventh lens element can have a positive optical power, and can have a convex object-side surface and a convex image-side surface.

In an exemplary embodiment, a stop for limiting the light beam may be disposed between, for example, the fourth lens and the fifth lens to further improve the imaging quality of the lens. When the diaphragm is arranged between the fourth lens and the fifth lens, the front and the rear light rays can be collected, the total length of the optical system is shortened, and the aperture of the front and the rear lens groups 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 seventh lens and the imaging surface to filter light rays having different wavelengths, as necessary; 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 sixth lens and the seventh lens may be combined into a cemented lens by cementing the image-side surface of the sixth lens with the object-side surface of the seventh lens. The adoption of the cemented lens can reduce the air space between the lenses, so that the whole optical system is compact and meets the miniaturization requirement; tolerance sensitivity of the lens unit caused by inclination/core deviation and the like in the assembling process can be reduced, and sensitivity is easily caused by processing/assembling errors if discrete lenses are positioned at the light ray turning positions, so that the sensitivity is effectively reduced by the arrangement of the cemented lens group; the assembly parts and the assembly process can be reduced, and the cost is reduced; the light loss caused by reflection between the lenses can be reduced, and the illumination intensity is improved.

In the cemented lens, the sixth lens close to the object side has negative power, and the seventh lens close to the image side has positive power, so that the lens arrangement can diverge and converge the light rays emitted by the fifth lens, and then smoothly transit to the imaging surface, which is beneficial to properly increasing the back focal length.

In an exemplary embodiment, the maximum field angle FOVm 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/FOVm is less than or equal to 0.03, and more preferably, D/H/FOVm is less than or equal to 0.02. The conditional expression D/H/FOVm is less than or equal to 0.03, and the small caliber at the front end of the lens can be realized.

In an exemplary embodiment, the radius of curvature R5 of the object-side surface, the radius of curvature R6 of the image-side surface, and the center thickness d5 of the third lens may satisfy: i R6I/(| R5| + d5) is less than or equal to 1.5, and more ideally, can further satisfy | R6|/(| R5| + d5) is less than or equal to 1. The special shape of the third lens is beneficial to compensating the aberration of the first two negative-power lenses (the first lens and the second lens), and the imaging quality is improved.

In an exemplary embodiment, a radius of curvature R7 of the object-side surface of the fourth lens and a radius of curvature R8 of the image-side surface may satisfy: R7/R8. ltoreq.2, more preferably R7/R8. ltoreq.1.5. Through the special shape setting like this of fourth lens, use with the third lens cooperation, can make the smooth transition of light, help improving the illuminance.

In an exemplary embodiment, the optical back focus BFL of the optical lens and the total optical length TTL of the optical lens may satisfy: the BFL/TTL is more than or equal to 0.1, and more ideally, the BFL/TTL can be further more than or equal to 0.15. The long back focus setting which meets the condition that BFL/TTL is more than or equal to 0.1 is combined with the whole framework of the optical lens, so that the assembly of an optical system can be facilitated.

In an exemplary embodiment, the maximum field angle FOVm of the optical lens, the image height H corresponding to the maximum field angle of the optical lens, and the entire set of focal length values F of the optical lens may satisfy: (FOVm F)/H.ltoreq.80, and more preferably (FOVm F)/H.ltoreq.72. Satisfies the conditional expression (FOVm F)/H ≦ 80, and can realize a small distortion characteristic.

In an exemplary embodiment, an optical lens according to the present application may have at least 3 aspherical lenses. Further, at least three of the second lens to the seventh lens may be 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. Optionally, the first lens may be an aspheric lens to improve resolution and other performance. 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. According to the optical lens's of this application first lens can adopt the glass lens to reduce the environment and to the holistic influence of system, promote optical lens's wholeness ability. Ideally, the first lens can adopt a glass aspheric lens to further improve the imaging quality and reduce the front end aperture. Ideally, the first lens to the seventh lens can be made of glass lens to further improve the imaging quality.

According to the optical lens of the above embodiment of the present application, the lens shape is optimally set, the focal power is reasonably distributed, and the lens material is reasonably selected, so that the characteristics of high resolution, small distortion and small aperture can be integrally realized. The light converging effect is shared by the fourth lens, and peripheral light as much as possible is collected and enters the fifth lens, so that the peripheral illumination is improved. The optical lens according to the above-described embodiment of the present application can better meet the requirements of an in-vehicle lens.

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

The second lens L2 is a meniscus lens with negative power, with the object side S3 being convex and the image side S4 being concave.

The third lens L3 is a meniscus lens with positive power, with the object side S5 being concave and the image side S6 being convex.

The fourth lens L4 is a meniscus lens with positive power, with the object side S7 being convex and the image side S8 being concave.

The fifth lens L5 is a biconvex lens with positive optical power, and has both the object-side surface S10 and the image-side surface S11 convex.

The sixth lens element L6 is a meniscus lens element with negative power, and has a convex object-side surface S12 and a concave image-side surface S13. The seventh lens L7 is a biconvex lens with positive optical power, and has both the object-side surface S13 and the image-side surface S14 convex. Wherein the sixth lens L6 and the seventh lens L7 are cemented with each other to form a cemented lens.

In this embodiment, the second lens L2, the third lens L3, and the fifth lens L5 are each an aspherical lens, and each of the object-side surface and the image-side surface thereof is aspherical.

Optionally, the optical lens may further include a filter L8 and/or a protective lens L8' having an object side S15 and an image side S16. Filter L8 can be used to correct for color deviations. The protective lens L8' may be used to protect the image sensing chip on the imaging plane IMA. Light from the object passes through each of the surfaces S1 to S16 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 fourth lens L4 and the fifth lens L5 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	82.4280	1.2645	1.79	44.2
2	5.5270	2.9567
					3	47.0241	3.8000	1.69	31.2
4	17.9127	2.5251
					5	-10.3338	2.8318	1.81	41.0
6	-7.4781	0.1000
					7	11.9283	4.0000	1.76	27.5
8	10.8951	1.0923
					STO	All-round	0.1000
10	10.8119	3.1976	1.61	44.1
					11	-13.1697	1.1688
12	50.9790	0.6000	1.85	23.8
					13	6.0755	3.0000	1.62	63.4
14	-18.2858	0.1937
					15	All-round	0.9500	1.52	64.2
16	All-round	7.4047
					IMA	All-round

The present embodiment adopts seven lenses as an example, and by reasonably distributing the focal power and the surface type of each lens, the central thickness of each lens and the air space between each lens, the lens can have at least one of the advantages of small aperture, high pixel, long back focus, large field angle, high peripheral illumination 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 the conic coefficients k and the high-order term coefficients A, B, C, D and E of the aspherical lens surfaces S3 to S6, S10 to S11 usable in example 1.

TABLE 2

Surf

K

A

B

C

D

E

3

0.0000

2.7746E-04

2.6700E-06

-6.6872E-08

1.0966E-09

-1.3111E-10

4

0.0000

1.1556E-03

-2.1712E-05

1.0471E-06

-3.4165E-08

-1.2973E-09

5

-7.6982

-7.9588E-05

-3.2617E-05

-5.4236E-07

4.1847E-08

-8.7324E-10

6

-0.8239

7.2133E-05

-3.7929E-06

-1.7009E-07

4.0199E-09

-2.8103E-10

10

-0.2169

7.6661E-04

3.1300E-05

1.1396E-06

2.0112E-08

-7.3081E-09

11

-0.0126

7.4354E-04

4.9910E-05

2.4118E-06

9.7998E-09

-9.9964E-09

Table 3 below gives 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 of embodiment 1, the image height H corresponding to the maximum field angle of the optical lens, the radii of curvature R5 and R6 of the object-side surface S5 and the image-side surface S6 of the third lens L3, the center thickness D5 of the third lens L3, the radii of curvature R7 and R8 of the object-side surface S7 and the image-side surface S8 of the fourth lens L4, the total optical length TTL of the optical lens (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 optical back focus BFL of the optical lens (i.e., the on-axis distance from the center of the image-side surface S14 of the last lens L7 to the imaging surface), the maximum field angle vm of the optical lens, and the entire group focal length value F of the optical lens.

TABLE 3

In the present embodiment, a radius of curvature R5 of the object-side surface S5 of the third lens L3, a radius of curvature R6 of the image-side surface S6, and a center thickness d5 of the third lens L3 satisfy | R6|/(| R5| + d5) ═ 0.568; R7/R8 of the fourth lens L4 satisfies 1.095 between the radius of curvature R7 of the object-side surface S7 and the radius of curvature R8 of the image-side surface S8; D/H/FOVm is 0.013 between the maximum field angle FOVm of the optical lens, the maximum light-passing 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; the BFL/TTL is 0.243 between the optical back focus BFL of the optical lens and the optical total length TTL of the optical lens; and the maximum angle of view FOvm of the optical lens, the image height H corresponding to the maximum angle of view of the optical lens and the whole group of focal length values F of the optical lens satisfy (FOvm × F)/H as 60.459.

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). The following table 5 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 S3 to S6, S10 to S11 in example 2. Table 6 below gives 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 of example 2, the image height H corresponding to the maximum field angle of the optical lens, the radii of curvature R5 and R6 of the object-side surface S5 and the image-side surface S6 of the third lens L3, the center thickness D5 of the third lens L3, the radii of curvature R7 and R8 of the object-side surface S7 and the image-side surface S8 of the fourth lens L4, the total optical length TTL of the optical lens, the optical back focus BFL of the optical lens, the maximum field angle FOVm of the optical lens, and the entire group focal length value F of the optical lens.

TABLE 4

TABLE 5

Flour mark

K

A

B

C

D

E

3

0.0000

4.2806E-04

7.7148E-06

-1.6248E-06

8.1624E-08

-1.7763E-09

4

0.0000

9.3444E-04

1.2045E-04

-1.8517E-05

1.2422E-06

-3.7445E-08

5

-6.5906

-1.7224E-03

4.1709E-04

-5.8436E-05

3.7971E-06

-1.0147E-07

6

-1.0361

-5.7538E-04

1.1559E-04

-1.2631E-05

5.6544E-07

-1.0448E-08

10

-0.2069

8.0385E-04

-9.3672E-06

3.7533E-07

2.7314E-08

-1.8024E-10

11

0.0126

7.4609E-04

1.1437E-05

6.2676E-07

-3.0263E-08

3.0960E-09

TABLE 6

D(mm)	13.0957	TTL(mm)	33.0030
				H(mm)	9.306	BFL(mm)	8.2012
R5(mm)	-9.0705	FOVm(°)	120
				R6(mm)	-7.0044	F(mm)	4.7368
d5(mm)	2.6707
				R7(mm)	10.5164
R8(mm)	9.5074

In the present embodiment, a radius of curvature R5 of the object-side surface S5 of the third lens L3, a radius of curvature R6 of the image-side surface S6, and a center thickness d5 of the third lens L3 satisfy | R6|/(| R5| + d5) ═ 0.597; the radius of curvature R7 of the object-side surface S7 of the fourth lens L4 and the radius of curvature R8 of the image-side surface S8 satisfy R7/R8 of 1.106; the maximum field angle FOVm of the optical lens, the maximum light-passing 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/FOVm of 0.012; the BFL/TTL between the optical back focus BFL of the optical lens and the optical total length TTL of the optical lens is 0.248; and the maximum angle of view FOvm of the optical lens, the image height H corresponding to the maximum angle of view of the optical lens and the whole group of focal length values F of the optical lens satisfy (FOvm × F)/H as 61.080.

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.

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). The following table 8 shows the conic coefficients k and the high-order term coefficients A, B, C, D and E which can be used for the aspherical lens surfaces S3 to S6, S10 to S11 in example 3. Table 9 below gives 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 of example 3, the image height H corresponding to the maximum field angle of the optical lens, the radii of curvature R5 and R6 of the object-side surface S5 and the image-side surface S6 of the third lens L3, the center thickness D5 of the third lens L3, the radii of curvature R7 and R8 of the object-side surface S7 and the image-side surface S8 of the fourth lens L4, the total optical length TTL of the optical lens, the optical back focus BFL of the optical lens, the maximum field angle FOVm of the optical lens, and the entire group focal length value F of the optical lens.

TABLE 7

Flour mark	Radius of curvature R	Thickness T	Refractive index Nd	Abbe number Vd
					1	79.4671	1.2645	1.79	44.2
2	5.7591	2.9567
					3	23.8254	3.8000	1.70	30.1
4	11.6367	2.6890
					5	-10.7622	2.9671	1.81	41.0
6	-7.4778	0.1000
					7	12.5295	3.5561	1.76	27.5
8	11.8570	1.1210
					STO	All-round	0.1000
10	11.4970	3.2580	1.61	44.1
					11	-12.1373	1.3168
12	55.8982	0.6000	1.85	23.8
					13	5.9855	3.0000	1.62	63.4
14	-20.2561	0.1937
					15	All-round	0.9500	1.52	64.2
16	All-round	6.6363
					IMA	All-round

TABLE 8

TABLE 9

D(mm)	12.5385	TTL(mm)	34.5093
				H(mm)	7.928	BFL(mm)	7.7801
R5(mm)	-10.7622	FOVm(°)	110
				R6(mm)	-7.4778	F(mm)	4.9128
d5(mm)	2.9671
				R7(mm)	12.5295
R8(mm)	11.8570

In the present embodiment, a radius of curvature R5 of the object-side surface S5 of the third lens L3, a radius of curvature R6 of the image-side surface S6, and a center thickness d5 of the third lens L3 satisfy | R6|/(| R5| + d5) ═ 0.545; R7/R8 of the fourth lens L4 satisfies 1.057 between the radius of curvature R7 of the object-side surface S7 and the radius of curvature R8 of the image-side surface S8; D/H/FOVm is 0.014 satisfied between the maximum field angle FOVm of the optical lens, the maximum light-passing 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; the BFL/TTL is 0.225 between the optical back focus BFL of the optical lens and the optical total length TTL of the optical lens; and the maximum angle of view FOvm of the optical lens, the image height H corresponding to the maximum angle of view of the optical lens and the whole group of focal length values F of the optical lens satisfy (FOvm × F)/H as 68.165.

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

Watch 10

Conditions/examples	1	2	3
				\|R6\|/(\|R5\|+d5)	0.568	0.597	0.545
R7/R8	1.095	1.106	1.057
				D/H/FOVm	0.013	0.012	0.014
BFL/TTL	0.243	0.248	0.225
				(FOVm×F)/H	60.459	61.080	68.165

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 has 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 convex 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 concave surface, and the image side surface of the third lens is a convex surface;

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

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

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

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

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

the conditional expression is satisfied:

(FOVm×F)/H≤80°，

wherein FOvm is the maximum field angle of the optical lens;

h is the image height corresponding to the maximum field angle of the optical lens; and

f is the whole group of focal length values of the optical lens.

2. An optical lens according to claim 1, wherein the sixth lens and the seventh lens are cemented to each other to form a cemented lens.

3. An optical lens according to claim 1, wherein the first lens to the seventh lens are all glass lenses.

4. An optical lens according to claim 1, characterized in that the optical lens has at least three aspherical lenses.

5. An optical lens according to claim 4, characterized in that at least three of the second lens to the seventh lens are aspherical mirror plates.

6. An optical lens according to any one of claims 1 to 5, characterized in that the conditional expression is satisfied:

D/H/FOVm×180°≤5.4，

wherein FOvm is the maximum field angle of the optical lens;

d is the maximum light-passing aperture of the object side surface of the first lens corresponding to the maximum field angle of the optical lens; and

and H is the image height corresponding to the maximum field angle of the optical lens.

7. An optical lens according to any one of claims 1 to 5, characterized in that a radius of curvature R5 of the object side surface of the third lens, a radius of curvature R6 of the image side surface of the third lens and a center thickness d5 of the third lens satisfy: i R6I/(IR 5I + d5) is less than or equal to 1.5.

8. An optical lens barrel according to any one of claims 1 to 5, wherein a radius of curvature R7 of an object side surface of the fourth lens and a radius of curvature R8 of an image side surface of the fourth lens satisfy: R7/R8 is less than or equal to 2.

9. An optical lens according to any one of claims 1-5, characterized in that between an optical back focus BFL of the optical lens and an optical total length TTL of the optical lens, it is satisfied that: BFL/TTL is more than or equal to 0.1.

10. 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, the second lens and the sixth lens each have a negative optical power;

the third lens, the fourth lens, the fifth lens and the seventh lens each have a positive optical power;

the sixth lens and the seventh lens are cemented with each other to form a cemented lens;

the maximum field angle FOvm of the optical lens, the image height H corresponding to the maximum field angle of the optical lens and the whole group of focal length values F of the optical lens satisfy the following conditions: (FOVm multiplied by F)/H is less than or equal to 80 degrees; and

the number of lenses having a power in the optical lens is seven.

11. An optical lens barrel according to claim 10, wherein the first lens element has a convex object-side surface and a concave image-side surface.

12. An optical lens barrel according to claim 10, wherein the second lens element has a convex object-side surface and a concave image-side surface.

13. An optical lens barrel according to claim 10, wherein the third lens element has a concave object-side surface and a convex image-side surface.

14. An optical lens barrel according to claim 10, wherein the fourth lens element has a convex object-side surface and a concave image-side surface.

15. An optical lens barrel according to claim 10, wherein the object-side surface and the image-side surface of the fifth lens element are convex.

16. An optical lens barrel according to claim 10, wherein the sixth lens element has a convex object-side surface and a concave image-side surface.

17. An optical lens barrel according to claim 10, wherein the object side surface and the image side surface of the seventh lens element are convex.

18. An optical lens according to any one of claims 10 to 17, characterized in that the first to seventh lenses are all glass lenses.

19. An optical lens according to any one of claims 10-17, characterized in that the optical lens has at least three aspherical lenses.

20. An optical lens according to claim 19, characterized in that at least three of the second to seventh lenses are aspherical lenses.

21. An optical lens according to any one of claims 10 to 17, characterized in that the conditional expression is satisfied:

D/H/FOVm×180°≤5.4，

wherein FOvm is the maximum field angle of the optical lens;

22. An optical lens barrel according to any one of claims 10 to 17, wherein the radius of curvature R5 of the object side surface of the third lens, the radius of curvature R6 of the image side surface of the third lens and the center thickness d5 of the third lens satisfy: i R6I/(IR 5I + d5) is less than or equal to 1.5.

23. An optical lens barrel according to any one of claims 10 to 17, wherein a radius of curvature R7 of an object side surface of the fourth lens and a radius of curvature R8 of an image side surface of the fourth lens satisfy: R7/R8 is less than or equal to 2.

24. An optical lens according to any one of claims 10-17, characterized in that between an optical back focus BFL of the optical lens and an optical total length TTL of the optical lens is satisfied: BFL/TTL is more than or equal to 0.1.