CN110412727B

CN110412727B - Optical lens

Info

Publication number: CN110412727B
Application number: CN201810403955.XA
Authority: CN
Inventors: 王东方; 陈雨曦; 姚波
Original assignee: Ningbo Sunny Automotive Optech Co Ltd
Current assignee: Ningbo Sunny Automotive Optech Co Ltd
Priority date: 2018-04-28
Filing date: 2018-04-28
Publication date: 2021-11-12
Anticipated expiration: 2038-04-28
Also published as: CN110412727A

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 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 negative focal power, and both the object side surface and the image side surface of the third lens are concave; the fourth lens can have positive focal power, and the object side surface of the fourth lens is a convex surface; and the seventh lens can have positive focal power, and both the object-side surface and the image-side surface of the seventh lens are convex surfaces, wherein the fifth lens and the sixth lens can be cemented to form a cemented lens. According to the optical lens, at least one beneficial effect of miniaturization, high resolution, low cost, good temperature performance, small front-end caliber 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

The current requirements of the vehicle-mounted industry for vehicle-mounted lenses relate to miniaturization, low cost and high resolution. Meanwhile, because the driving environment of the automobile is more variable, the lens loaded outside the automobile must have the capability of still keeping high resolution in various severe environments.

However, with the gradual use of large-size and high-pixel chips, the original pixels of the vehicle-mounted lens cannot be matched with the chips, and a new lens with higher pixels is urgently needed to be developed to replace the existing low-pixel lens in the market. The objective of achieving higher pixels of the lens is to increase the number of lenses or to use aspheric lenses, which is limited by the requirements of low cost and miniaturization.

In order not to increase the cost substantially, the above objective is generally achieved by adding plastic lenses. However, due to the limitation of the plastic material, the use of a large number of plastic lenses can prevent the vehicular lens from maintaining high resolution in high and low temperature environments.

The four requirements of low cost, higher resolution requirement, miniaturization and no large deviation of the resolution under high and low temperature can not all reach the best, so that the design which can balance the four requirements and meet the market form is very urgent.

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 negative focal power, and both the object side surface and the image side surface of the third lens are concave; the fourth lens can have positive focal power, and the object side surface of the fourth lens is a convex surface; and the seventh lens can have positive focal power, and both the object-side surface and the image-side surface of the seventh lens are convex surfaces, wherein the fifth lens and the sixth lens can be cemented to form a cemented lens.

In one embodiment, the image-side surface of the fourth lens element may be convex.

In another embodiment, the image-side surface of the fourth lens element can be concave.

In one embodiment, the fifth lens can have a positive optical power, and both the object-side surface and the image-side surface can be convex.

In one embodiment, the sixth lens element can have a negative optical power and can have a concave object-side surface and a concave image-side surface.

In one embodiment, the refractive index of the material of the first lens may be 1.65 or more.

In one embodiment, at least three lenses in the optical lens may be aspheric lenses.

In one embodiment, the seventh lens may be an aspherical mirror.

In one embodiment, at least one of the optical lenses may be a glass lens.

In one embodiment, the conditional formula may be satisfied: D/h/FOV is less than or equal to 0.025, wherein the FOV 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.

In one embodiment, the conditional formula may be satisfied: TTL/h/FOV is less than or equal to 0.025, wherein TTL is the distance between the center of the object side surface of the first lens and the imaging surface of the optical lens on the optical axis; h is the image height corresponding to the maximum field angle of the optical lens; and FOV is the maximum field angle of the optical lens.

In one embodiment, the conditional formula may be satisfied: BFL/TTL is more than or equal to 0.1, wherein BFL is the distance from the center of the image side surface of the seventh lens to the imaging surface of the optical lens on the optical axis; and TTL is the distance from the center of the object side surface of the first lens to the imaging surface of the optical lens on the optical axis.

In one embodiment, the radius of curvature r31 of the object-side surface of the third lens, the radius of curvature r32 of the image-side surface of the third lens, and the center thickness d3 of the third lens may satisfy: (| r31| + d3)/| r32|, is less than or equal to 12.

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, the third lens and the sixth lens all have negative focal power; the fourth lens, the fifth lens and the seventh lens may each have positive optical power; and the fifth lens and the sixth lens can be glued to form a cemented lens, wherein the distance TTL from the center of the object side surface of the first lens to the imaging surface of the optical lens on the optical axis, the image height h corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens can satisfy the conditional expression: TTL/h/FOV is less than or equal to 0.025.

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

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

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

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

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

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

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

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

In one embodiment, the seventh lens may be an aspherical mirror.

In one embodiment, at least one of the optical lenses may be a glass lens.

The optical lens adopts seven lenses, the shape of the lenses is set optimally, the focal power of each lens is distributed reasonably, and at least one of the beneficial effects of high resolution, miniaturization, low cost, good temperature performance, small front port diameter 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, the vehicle-mounted lens outdoor installation and use environment is considered, the vehicle-mounted lens outdoor installation and use environment can be in severe weather such as rain, snow and the like, and the design of the meniscus shape protruding towards the object side is more suitable for the environments such as rain, snow and the like, is beneficial to the falling of water drops, is not easy to accumulate water and dust, and therefore the influence of the external environment on imaging is reduced.

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 can compress the light collected by the first lens, so that the trend of the light is stably transited to the rear optical system. The image side surface of the second lens is a concave surface, so that the distance between the first lens and the second lens can be reduced, the physical total length of the lens can be shortened more easily, and the miniaturization characteristic is realized.

The third lens element can have a negative optical power, and can have a concave object-side surface and a concave image-side surface. The third lens can disperse light, so that the light is transited to a rear optical system, the aberration caused by the front lens and the rear lens is balanced, the overall length of the lens can be reduced due to the biconcave shape design of the third lens, and meanwhile, the negative focal length lens adopted by the third lens can be beneficial to compensating the back focal offset of the overall lens at high and low temperatures, so that the lens has good resolving power at high and low temperatures.

The fourth lens element may have a positive optical power and the object-side surface may be convex. The fourth lens can converge light rays, so that the light rays are smoothly transited to the rear optical system.

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 sixth lens element can have a negative optical power, and can have a concave 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. The seventh lens is a converging lens which can properly converge light.

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 fifth lens and the sixth lens may be combined into a cemented lens by cementing the image-side surface of the fifth lens with the object-side surface of the sixth lens. By introducing the cemented lens consisting of the fifth lens and the sixth lens, the chromatic aberration influence can be eliminated, the field curvature is reduced, and the coma is corrected; meanwhile, the cemented lens may also retain a part of chromatic aberration to balance the entire chromatic aberration of the optical system. The air space between the two lenses is omitted by gluing the lenses, so that the optical system is compact as a whole, and the requirement of system miniaturization is met. Furthermore, the gluing of the lenses reduces tolerance sensitivity problems of the lens units due to tilt/decentration during assembly.

In the cemented lens, the fifth lens close to the object side has positive focal power, and the sixth lens close to the image side has negative focal power, so that the arrangement is favorable for further converging light rays passing through the fourth lens and then transferring the light rays to a rear optical system, the caliber/size of the rear end of the lens is favorably reduced, the total length of the system is reduced, and the short TTL is realized. In addition, the light rays are slightly diverged after passing through the sixth lens, which is favorable for the lens to match with a chip with a larger size.

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 four lenses and the fifth lens, the front light and the rear light can be effectively converged, the total length of the optical system is shortened, and the calibers of the front lens group and the rear lens group are reduced.

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 less than or equal to 0.025, and more desirably D, h and FOV further satisfy D/h/FOV is less than or equal to 0.02. The conditional expression D/h/FOV is less than or equal to 0.025, and the small caliber of the front end of the lens can be ensured.

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 that BFL/TTL is greater than or equal to 0.1, and further, the BFL and TTL may further satisfy that BFL/TTL is greater than or equal to 0.13. The integral framework of the optical lens is combined, the back focus setting with BFL/TTL more than or equal to 0.1 is met, and the assembly of the optical lens can be facilitated.

In an exemplary embodiment, TTL/h/FOV ≦ 0.025 may be satisfied between the total optical length TTL of the optical lens, the maximum field angle FOV of the optical lens, and the image height h corresponding to the maximum field angle of the optical lens, and more desirably, TTL, FOV, and h may further satisfy TTL/h/FOV ≦ 0.02. The TTL/h/FOV is less than or equal to 0.025, compared with other lenses, the TTL is shorter under the same imaging plane with the same field angle, and the miniaturization characteristic of the lens can be realized.

In an exemplary embodiment, the radius of curvature of the object-side surface r31, the radius of curvature of the image-side surface r32, and the center thickness d3 of the third lens may satisfy: (| r31| + d3)/| r32| ≦ 12, more ideally, can further satisfy (| r31| + d3)/| r32| ≦ 8. The shape design of the third lens is beneficial to improving the imaging quality and shortening the optical total length of the system.

In an exemplary embodiment, the first lens may use a high refractive index material, and specifically, for example, the refractive index of the first lens material may be 1.65 or more, and more desirably, the refractive index of the first lens material may be 1.7 or more. The arrangement is beneficial to reducing the front end caliber of the lens and improving the imaging quality.

In an exemplary embodiment, at least three of the optical lenses according to the present application are 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, which may be beneficial for improving the resolution quality. The seventh lens can adopt an aspheric lens to reduce the optical path of peripheral rays reaching an imaging surface, correct the off-axis point aberration of the system, and optimize the performances of distortion, CRA and the like. In addition, the seventh lens adopts an aspheric surface, so that light can be effectively and stably converged at last, and the overall weight and cost of the system are reduced.

In an exemplary embodiment, the lens used in the optical lens may be a plastic lens, or may be a glass lens. Because the thermal expansion coefficient of the lens made of plastic is large, when the ambient temperature change of the lens is large, the lens made of plastic has a large influence on the overall performance of the lens. And the glass lens can reduce the influence of temperature on the performance of the lens. At least one lens in the optical lens according to the application is a glass lens so as to reduce the influence of the environment on the whole system and improve the overall performance of the optical lens. For example, the first lens may be a glass lens. More desirably, the first lens can adopt a glass aspheric lens to further improve the imaging quality and reduce the front end aperture.

According to the optical lens of the above embodiment of the present application, the shape of the lens is optimally set, the focal power is reasonably distributed, the aperture of the front end can be reduced, the TTL is shortened, and the resolution is improved while the miniaturization of the lens is ensured. Meanwhile, under the condition of improving the same resolving power, compared with an optical lens which must adopt a glass aspheric surface, the optical lens according to the application can meet the same requirement without adopting the glass aspheric surface, and the cost is reduced. This application uses 7 lenses can keep high resolution under high low temperature ability stable, the fine user demand who is suitable for on-vehicle environment.

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 biconcave lens with negative optical power, and both the object-side surface S5 and the image-side surface S6 are concave. The third lens element L3 is an aspherical lens, and both the object-side surface S5 and the image-side surface S6 are aspherical.

The fourth lens L4 is a biconvex lens with positive optical power, and has both the object-side surface S7 and the image-side surface S8 convex.

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 fifth lens element L5 is an aspherical lens, and both the object-side surface S10 and the image-side surface S11 are aspherical. The sixth lens L6 is a biconcave lens with negative optical power, and has concave object-side surface S11 and concave image-side surface S12. The sixth lens element L6 is an aspherical lens, and both the object-side surface S11 and the image-side surface S12 are aspherical. Wherein the fifth lens L5 and the sixth lens L6 are cemented with each other to constitute a cemented lens.

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. The seventh lens element L7 is an aspherical lens, and both the object-side surface S13 and the image-side surface S14 are aspherical.

Optionally, the optical lens may further include a filter L8 having an object-side surface S15 and an image-side surface S16, and a protective lens L9 having an object-side surface S17 and an image-side surface S18. Filter L8 can be used to correct for color deviations. The protective lens L9 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 S18 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 (i.e., between the fourth lens L4 and the cemented lens) 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	10.2000	1.0000	1.77	49.61
2	3.8000	2.9200
					3	19.3000	0.5000	1.77	49.61
4	2.4000	1.3000
					5	-25.9000	0.8500	1.54	56.00
6	4.5000	0.4000
					7	4.7000	2.4000	1.92	20.88
8	-23.4000	0.2440
					STO	All-round	0.1740
10	4.4000	2.1000	1.54	56.00
					11	-1.8000	0.5800	1.64	23.53
12	10.0000	0.5580
					13	3.3000	2.5000	1.59	61.16
14	-4.7000	0.1000
					15	All-round	0.5500	1.52	64.21
16	All-round	0.5000
					17	All-round	0.4000	1.52	64.21
18	All-round	2.2000
					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 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, low cost, small front-end caliber, good temperature performance 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 S5, S6, S10 to S14 usable in example 1.

TABLE 2

Flour mark

K

A

B

C

D

E

5

0.0000

-7.7679E-03

5.7406E-04

1.0166E-04

4.9333E-06

-3.3705E-07

6

-5.2609

-2.2839E-04

-2.3626E-03

1.7896E-03

-4.3271E-04

8.7120E-05

10

0.0000

1.7843E-03

-3.6582E-03

4.7222E-03

-1.9787E-03

1.5540E-04

11

0.0000

-6.9696E-02

2.7876E-02

-1.5212E-02

5.4528E-03

-1.7209E-03

12

0.0000

-3.0812E-02

1.0730E-02

-2.7698E-03

5.1930E-04

-2.0319E-05

13

-6.8067

-4.4136E-03

7.7472E-04

-3.8967E-04

7.9255E-05

-8.9638E-06

14

0.0000

2.0513E-03

-1.7451E-04

-3.3349E-05

2.0447E-06

3.5016E-07

Table 3 below gives the entire group focal length value F of the optical lens of example 1, the refractive index Nd1 of the material of the first lens L1, the radius of curvature r31 of the object-side surface S5 of the third lens L3, the radius of curvature r32 of the image-side surface S6 of the third lens L3, the center thickness D3 of the third lens L3, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum angle of view of the optical lens, the image height h corresponding to the maximum angle of view of the optical lens, the maximum angle of view FOV of the optical lens, 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 seventh lens L7 to the imaging surface S19), and the optical total 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 S19).

TABLE 3

In the present embodiment, the radius of curvature r31 of the object-side surface S5 of the third lens L3, the radius of curvature r32 of the image-side surface S6 of the third lens L3, and the center thickness d3 of the third lens L3 satisfy (| r31| + d3)/| r32| -5.944; D/h/FOV is 0.014 between 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; the BFL/TTL between the optical back focus BFL of the optical lens and the optical total length TTL of the optical lens is 0.195; and the total optical length TTL of the optical lens, the image height h corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens meet the condition that TTL/h/FOV is 0.019.

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.

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.

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 S5, S6, S10-S14 in example 2. Table 6 below gives the entire group focal length value F of the optical lens of example 2, the refractive index Nd1 of the material of the first lens L1, the radius of curvature r31 of the object-side surface S5 of the third lens L3, the radius of curvature r32 of the image-side surface S6 of the third lens L3, the center thickness D3 of the third lens L3, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum angle of view of the optical lens, the image height h corresponding to the maximum angle of view of the optical lens, the maximum angle of view FOV of the optical lens, 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 seventh lens L7 to the imaging surface S19), and the optical total 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 S19).

TABLE 4

TABLE 5

Flour mark

K

A

B

C

D

E

5

0

-5.5352E-03

6.2754E-04

1.7277E-04

-6.0125E-06

-2.8063E-06

6

-31.188548

-1.4680E-03

-1.9551E-03

1.7968E-03

-4.2798E-04

8.7120E-05

10

0

-5.1674E-03

-3.0060E-03

4.5413E-03

-1.9708E-03

1.5540E-04

11

0

-6.7613E-02

2.0916E-02

-1.1965E-02

4.6629E-03

-4.3022E-04

12

0

-3.0587E-02

1.0840E-02

-2.7738E-03

5.0917E-04

-8.1275E-05

13

-7.161578

-4.5768E-03

8.3462E-04

-3.8943E-04

7.8644E-05

-8.9361E-06

14

0

1.7889E-03

-9.1603E-05

-3.9052E-05

1.7705E-06

4.2037E-07

TABLE 6

F(mm)	1.493	h(mm)	5.030
				Nd1	1.8	FOV(°)	196
\|r31\|(mm)	5.300	BFL(mm)	3.350
				\|r32\|(mm)	9.500	TTL(mm)	17.940
d3(mm)	0.840
				D(mm)	12.478

In the present embodiment, the radius of curvature r31 of the object-side surface S5 of the third lens L3, the radius of curvature r32 of the image-side surface S6 of the third lens L3, and the center thickness d3 of the third lens L3 satisfy (| r31| + d3)/| r32| -0.646; D/h/FOV is 0.013 between 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; the BFL/TTL between the optical back focus BFL of the optical lens and the optical total length TTL of the optical lens is 0.187; and the total optical length TTL of the optical lens, the image height h corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens meet the condition that TTL/h/FOV is 0.018.

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 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 second lens element L2 is an aspherical lens element, and both the object-side surface S3 and the image-side surface S4 are aspherical

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 S14 in example 3. Table 9 below gives the entire group focal length value F of the optical lens of example 3, the refractive index Nd1 of the material of the first lens L1, the radius of curvature r31 of the object-side surface S5 of the third lens L3, the radius of curvature r32 of the image-side surface S6 of the third lens L3, the center thickness D3 of the third lens L3, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum angle of view of the optical lens, the image height h corresponding to the maximum angle of view of the optical lens, the maximum angle of view FOV of the optical lens, 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 seventh lens L7 to the imaging surface S19), and the optical total 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 S19).

TABLE 7

TABLE 8

Flour mark

K

A

B

C

D

E

3

0.0000

2.4718E-03

-2.2737E-05

-9.0605E-06

-5.2396E-07

9.0088E-08

4

0.0000

1.2019E-03

-3.7074E-04

8.3937E-04

-1.1458E-04

-3.8856E-15

5

0.0000

1.4846E-03

1.6877E-03

-7.0954E-05

-6.8738E-05

9.3558E-06

6

-778.4501

2.1543E-03

-1.3294E-03

1.2485E-03

-3.3753E-04

4.3560E-05

10

0.0000

-1.2827E-02

-1.4919E-04

3.0007E-03

-3.1310E-03

3.1080E-04

11

0.0000

-5.2983E-02

3.9616E-03

-1.9028E-03

2.9815E-03

-4.3022E-04

12

0.0000

-2.9858E-02

1.0882E-02

-2.7895E-03

5.3184E-04

-9.0565E-05

13

-7.368392

-3.6104E-03

8.2765E-04

-3.9850E-04

3.8968E-05

-4.3137E-06

14

0.0000

3.7122E-03

-4.1116E-05

-5.3617E-05

6.7947E-07

2.1656E-06

TABLE 9

F(mm)	1.510	h(mm)	5.318
				Nd1	1.77	FOV(°)	196
\|r31\|(mm)	3.400	BFL(mm)	2.350
				\|r32\|(mm)	26.000	TTL(mm)	16.090
d3(mm)	0.840
				D(mm)	12.658

In the present embodiment, the radius of curvature r31 of the object-side surface S5 of the third lens L3, the radius of curvature r32 of the image-side surface S6 of the third lens L3, and the center thickness d3 of the third lens L3 satisfy (| r31| + d3)/| r32| -0.163; D/h/FOV is 0.012 as the maximum view 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 view field angle of the optical lens and the image height h corresponding to the maximum view field angle of the optical lens; the BFL/TTL is 0.146 between the optical back focus BFL of the optical lens and the optical total length TTL of the optical lens; and the total optical length TTL of the optical lens, the image height h corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens meet the condition that TTL/h/FOV is 0.015.

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

Watch 10

Conditions/examples	1	2	3
				(\|r31\|+d3)/\|r32\|	5.944	0.646	0.163
D/h/FOV	0.014	0.013	0.012
				BFL/TTL	0.195	0.187	0.146
TTL/h/FOV	0.019	0.018	0.015

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

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

wherein the fifth lens and the sixth lens are cemented to form a cemented lens;

the fifth lens has positive focal power;

the sixth lens has a negative optical power;

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

the optical lens satisfies the conditional expression: (TTL is multiplied by 180 degrees) and/(hxFOV) is less than or equal to 4.5,

wherein, TTL is a distance on the optical axis from a center of an object-side surface of the first lens element to an imaging surface of the optical lens;

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

the FOV is the maximum field angle of the optical lens.

2. An optical lens barrel according to claim 1, wherein the image side surface of the fourth lens element is convex.

3. An optical lens barrel according to claim 1, wherein the image side surface of the fourth lens is concave.

4. An optical lens barrel according to claim 1, wherein the object-side surface and the image-side surface of the fifth lens element are convex.

5. An optical lens barrel according to claim 1, wherein the object-side surface and the image-side surface of the sixth lens element are both concave.

6. An optical lens according to claim 1, characterized in that the refractive index of the material of the first lens is 1.65 or more.

7. An optical lens according to any one of claims 1 to 6, characterized in that at least three lenses in the optical lens are aspherical lenses.

8. An optical lens according to claim 7, characterized in that the seventh lens is an aspherical mirror.

9. An optical lens according to any one of claims 1 to 6, characterized in that at least one of the optical lenses is a glass lens.

10. An optical lens according to any one of claims 1 to 6, characterized in that the conditional expression is satisfied: (D is multiplied by 180 degrees) and/(h is multiplied by FOV) is less than or equal to 4.5,

wherein the FOV 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.

11. An optical lens according to any one of claims 1 to 6, characterized in that the conditional expression is satisfied: the BFL/TTL is more than or equal to 0.1,

the BFL is the distance from the center of the image side surface of the seventh lens to the imaging surface of the optical lens on the optical axis; and

TTL is a distance on the optical axis from the center of the object-side surface of the first lens element to the imaging surface of the optical lens.

12. An optical lens according to any one of claims 1 to 6, characterized in that the radius of curvature of the object-side surface r31, the radius of curvature of the image-side surface r32 and the central thickness d3 of the third lens satisfy: (| r31| + d3)/| r32|, is less than or equal to 12.

13. 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, the third lens and the sixth lens each have a negative optical power;

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

the fifth lens and the sixth lens are cemented to form a cemented lens,

the distance TTL from the center of the object side surface of the first lens to the imaging surface of the optical lens on the optical axis, the image height h corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy the following conditional expression: (TTL is multiplied by 180 degrees) and/(h is multiplied by FOV) is less than or equal to 4.5;

the image side surface of the third lens is a concave surface;

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

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

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

16. An optical lens barrel according to claim 13, wherein the object side surface of the third lens is concave.

17. An optical lens barrel according to claim 13, wherein the object side surface and the image side surface of the fourth lens are convex.

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

19. An optical lens barrel according to claim 13, wherein the object-side surface and the image-side surface of the fifth lens element are convex.

20. An optical lens barrel according to claim 13, wherein the object side surface and the image side surface of the sixth lens are both concave.

21. An optical lens barrel according to claim 13, wherein the object side surface and the image side surface of the seventh lens element are convex.

22. An optical lens as claimed in any one of claims 13 to 21, characterized in that the refractive index of the material of the first lens is 1.65 or higher.

23. An optical lens according to any one of claims 13-21, characterized in that at least three lenses in the optical lens are aspherical lenses.

24. An optical lens according to claim 23, characterized in that the seventh lens is an aspherical mirror.

25. An optical lens according to any one of claims 13-21, characterized in that at least one of the optical lenses is a glass lens.

26. An optical lens according to any one of claims 13 to 21, characterized in that the conditional expression is satisfied: (D is multiplied by 180 degrees) and/(h is multiplied by FOV) is less than or equal to 4.5,

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

27. An optical lens according to any one of claims 13 to 21, characterized in that the conditional expression is satisfied: the BFL/TTL is more than or equal to 0.1,

28. An optical lens barrel according to any one of claims 13 to 21, wherein the radius of curvature r31 of the object side surface of the third lens, the radius of curvature r32 of the image side surface of the third lens and the central thickness d3 of the third lens satisfy: (| r31| + d3)/| r32|, is less than or equal to 12.