CN109425958B

CN109425958B - Optical lens

Info

Publication number: CN109425958B
Application number: CN201710750843.7A
Authority: CN
Inventors: 姚波; 王东方; 谢前森
Original assignee: Ningbo Sunny Automotive Optech Co Ltd
Current assignee: Ningbo Sunny Automotive Optech Co Ltd
Priority date: 2017-08-28
Filing date: 2017-08-28
Publication date: 2021-10-15
Anticipated expiration: 2037-08-28
Also published as: CN109425958A

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. Wherein the first lens, the third lens and the sixth lens may all have negative optical power; the second lens, the fourth lens, the fifth lens and the seventh lens may all have positive optical power; the object side surfaces of the first lens and the third lens can be concave surfaces, and the image side surfaces of the first lens and the third lens can be convex surfaces; the object side surface and the image side surface of the second lens and the fifth lens can be convex surfaces; the object side surface and the image side surface of the sixth lens can be concave; and the object side surface of the seventh lens element can be convex, and the image side surface can be concave.

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 the requirements for the resolution of imaging devices (e.g., cameras) are gradually increased, the corresponding chip size is also increased, resulting in an increase in the overall size of the lens. Meanwhile, in some special applications, such as night use of a vehicle-mounted lens, in order to improve the effect of night use of the lens, the clear aperture of the lens generally needs to be increased, which also results in an increase in the aperture of the lens.

In general, the resolution of the lens can be improved by increasing the number of lenses, but the size and weight of the lens are increased, which is disadvantageous to the miniaturization of the lens and causes an increase in manufacturing cost. Conventionally, in order to satisfy miniaturization, in the case of compressing the total optical length of the lens, the lens resolving power is greatly affected.

Moreover, for some applications with limited mounting locations, small size lenses are required to meet the mounting requirements. For example, an on-vehicle lens needs to be mounted inside a windshield, and since there is a risk of interference with the windshield and the mounting position is limited, a special lens design needs to be used to meet the requirements of a small aperture, a small size, and a high resolution.

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. Wherein the first lens, the third lens and the sixth lens may all have negative optical power; the second lens, the fourth lens, the fifth lens and the seventh lens may all have positive optical power; the object side surfaces of the first lens and the third lens can be concave surfaces, and the image side surfaces of the first lens and the third lens can be convex surfaces; the object side surface and the image side surface of the second lens and the fifth lens can be convex surfaces; the object side surface and the image side surface of the sixth lens can be concave; and the object side surface of the seventh lens element can be convex, and the image side surface can be concave.

In one 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 fourth lens may be convex.

In one embodiment, the optical lens may further include a stop disposed between the object side of the optical lens and the first lens.

In one embodiment, the optical lens may further include a stop disposed between the first lens and the second lens.

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

In one embodiment, the second lens and the third lens may be cemented to form a first cemented lens.

In one embodiment, the fifth lens and the sixth lens may be cemented to constitute a second cemented lens.

In one embodiment, a distance TTL between a center of an object side surface of the first lens element and an imaging surface of the optical lens on an optical axis and a full-group focal length value f of the optical lens may satisfy: TTL/f is less than or equal to 3.5.

In one embodiment, D/h/FOV ≦ 0.08 may be satisfied, where 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.

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. Wherein the first lens, the third lens and the sixth lens may all have negative optical power; the second lens, the fourth lens and the fifth lens can all have positive focal power; the object side surfaces of the first lens and the third lens can be concave surfaces, and the image side surfaces of the first lens and the third lens can be convex surfaces; the object side surface and the image side surface of the second lens and the fifth lens can be convex surfaces; the object side surface and the image side surface of the sixth lens can be concave; the second lens and the third lens are cemented to form a first cemented lens; and the fifth lens and the sixth lens are cemented to form a second cemented lens.

In one embodiment, the at least one subsequent lens comprises a seventh lens having a positive optical power, and the object-side surface of the seventh lens may be convex and the image-side surface may be concave.

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

The optical lens adopts seven lenses, and the beneficial effects of small caliber, miniaturization and high resolution of the optical lens are realized by optimally setting the shapes of the lenses, reasonably distributing the focal power of each lens, adopting an aspheric lens, forming a cemented lens and the like.

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;

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

fig. 4 is a schematic view showing a structure of an optical lens according to embodiment 4 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.

The optical lens according to the 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 concave object-side surface and a convex image-side surface. The first lens is arranged to be a meniscus lens with the concave surface facing the object side, so that light rays with a large field of view can be collected as far as possible, the collected light rays can enter a rear optical system, and the reduction of the caliber of the optical system is facilitated.

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

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

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

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 power, and can have a convex object-side surface and a concave image-side surface.

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 second lens and the third lens may be combined into the first cemented lens by cementing the image-side surface of the second lens with the object-side surface of the third lens. By introducing the first cemented lens consisting of the second lens and the third lens, which can help to eliminate the chromatic aberration effect and reduce the tolerance sensitivity of the system, partial chromatic aberration can be remained by the cemented second lens and the third lens to balance the overall chromatic aberration of the optical system. In the first cemented lens, the second lens near the object side has positive power, and the third lens near the image side has negative power, which is favorable for further gently transiting the light rays passing through the first lens to the fourth lens, and is favorable for shortening the total length of the optical system, thereby realizing short TTL and miniaturization characteristic.

In addition, the fifth lens and the sixth lens can also be combined into a second cemented lens by cementing the image-side surface of the fifth lens with the object-side surface of the sixth lens. By introducing a second cemented lens consisting of a fifth lens and a sixth lens, chromatic aberration effects can be helped to be eliminated, and tolerance sensitivity of the system is reduced; the cemented fifth lens and sixth lens may also retain some chromatic aberration to balance the overall chromatic aberration of the optical system. In the second 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 and smoothly transiting the light rays passing through the fourth lens to the seventh lens, and the total length of the optical system is favorably shortened at the rear, so that short TTL is realized, and simultaneously, the rear end size of the optical lens is favorably reduced, and the miniaturization characteristic is realized.

Further, the configuration of the cemented lens can omit the air space between each lens in the cemented lens, so that the optical system is compact as a whole and meets the requirement of system miniaturization. Furthermore, the gluing of the lenses reduces tolerance sensitivity problems of the lens units due to tilt/decentration during assembly.

In an exemplary embodiment, a stop for limiting the light beam may be disposed between the object side and the first lens or between the first lens and the second lens, for example, to further improve the imaging quality of the lens. When the diaphragm is disposed between the object side and the first lens element (i.e., the diaphragm is disposed in front) or between the first lens element and the second lens element, incident light can be shrunk, which is beneficial to reducing the aperture of the front and rear lens elements of the lens, shortening the total length of the optical system, and realizing miniaturization.

The fourth lens assembles the light that the third lens collected, makes light transition to the fifth lens gently, is favorable to reducing the bore of lens, still plays the effect of adjustment light simultaneously.

The seventh lens further converges the light collected by the sixth lens, and the light trend is adjusted, so that the light is stably transited to an imaging surface of a light system, and the reduction of the rear end aperture of the optical lens is facilitated.

An overall optical length TTL (i.e., a distance on an optical axis from a center of an object side surface of the first lens element to an imaging surface of the optical lens) of the optical lens and a whole group focal length value f of the optical lens may satisfy TTL/f ≦ 3.5, and more specifically, TTL and f may further satisfy TTL/f ≦ 2.82. The condition formula TTL/f is less than or equal to 3.5, and the miniaturization characteristic of the lens can be embodied.

The maximum field angle FOV of the optical lens, the maximum light-passing 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 can satisfy the following conditions: D/h/FOV ≦ 0.08, more specifically D, h and FOV may further satisfy D/h/FOV ≦ 0.05. The conditional expression D/h/FOV is less than or equal to 0.08, and the small caliber of the front end of the lens can be ensured.

In an exemplary embodiment, the seventh lens may be arranged as an aspherical mirror. 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.

The optical lens according to the above-described embodiment of the present application may employ a plurality of lenses, for example, seven lenses as described above. The optical focal power and the surface type of each lens of the optical lens are optimized, the shape of the first lens is controlled, the total optical length of the lens is shortened by reasonably using a cemented lens and the like, and the miniaturization characteristic is realized; still further shorten the bore of optical system anterior segment through the diaphragm is leading, realize the promotion of the resolution performance of camera lens, improve the resolution definition, make the camera lens have better image quality, the image is clear to reduce the risk that software misjudges, thereby make this camera lens can accord with the requirement of on-vehicle camera lens better.

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 concave and the image side S2 being convex.

The second lens L2 is a biconvex lens with positive power, and has a convex object-side surface S4 and a convex image-side surface S5. The third lens L3 is a meniscus lens with negative power, with the object side S5 being concave and the image side S6 being convex. Wherein, the second lens L2 and the third lens L3 are cemented to form a first cemented lens.

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 element L5 is a biconvex lens with positive power, and has a convex object-side surface S9 and a convex image-side surface S10. The sixth lens L6 is a biconcave lens with negative power, and has a concave object-side surface S10 and a concave image-side surface S11. Wherein, the fifth lens L5 and the sixth lens L6 are cemented to form a second cemented lens.

The seventh lens L7 is a meniscus lens with positive power, with the object side S12 being convex and the image side S13 being concave. The seventh lens L7 is an aspherical lens.

Optionally, the optical lens may further include a filter L8 and/or a protective lens L8' having an object side S14 and an image side S15. Color filters may be used to correct for color deviations. The protective lens may be used to protect the image sensing chip located at the imaging surface S16. The light from the object sequentially passes through the respective surfaces S1 to S15 and is finally imaged on the imaging surface S16.

In the optical lens of the present embodiment, a stop STO may be provided between the first lens L1 and the second lens L2 (i.e., between the first lens L1 and the first 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	-10.2422	2.3219	1.73	54.67
2	-24.0431	0.0705
					STO	All-round	-0.0034
4	15.9589	6.7656	1.52	64.21
					5	-9.6517	2.0135	1.72	38.02
6	-20.6669	0.0671
					7	11.6923	2.8293	1.88	40.81
8	74.1607	0.2685
					9	12.0805	3.1699	1.62	60.37
10	-15.2671	0.8725	1.76	27.55
					11	6.8365	0.8390
12	7.2124	4.6981	1.81	41.02
					13	7.2662	0.6712
14	All-round	0.9500	1.52	64.21
					15	All-round	1.2400
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 realize the effects of reducing the total optical length and reducing the lens aperture while ensuring a large imaging size and high pixels. Each aspherical surface type Z is defined by the following formula:

wherein Z is the distance rise from the vertex of the aspheric surface when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c being 1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1 above); k is the conic coefficient conc; A. b, C, D, E are all high order term coefficients. Table 2 below shows the conic coefficients k and the high-order term coefficients A, B, C, D and E that can be used for the aspherical lens surfaces S12 and S13 in example 1.

TABLE 2

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 example 1, the image height h corresponding to the maximum field angle of the optical lens, the maximum field angle FOV of the optical lens, 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 image plane S16), and the entire group focal length value f of the optical lens.

TABLE 3

Parameter(s)	TTL(mm)	f(mm)	D(mm)	h(mm)	FOV(°)
						Numerical value	26.774	10.126	6.999	5.822	31.400

In the present embodiment, TTL/f is 2.644 between the total optical length TTL of the optical lens and the whole focal length f of the optical lens; and D/h/FOV is 0.038 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.

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 element L4 is a biconvex lens with positive power, and has a convex object-side surface S7 and a convex image-side surface S8.

Table 4 below shows a radius of curvature R, a thickness T, a refractive index Nd, and an abbe number Vd of each lens of the optical lens of example 2, where the radius of curvature R and the thickness T are both in units of millimeters (mm). Table 5 below shows the conic coefficients k and the high-order term coefficients A, B, C, D and E that can be used for the aspherical lens surfaces S12 and S13 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 maximum field angle FOV of the optical lens, 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 image plane S16), and the entire group focal length value f of the optical lens. Wherein each aspherical surface type can be defined by the formula (1) given in the above-described embodiment 1.

TABLE 4

TABLE 5

Flour mark

K

A

B

C

D

E

12

0.2500

-3.8526E-04

2.2286E-05

-2.6064E-06

8.4503E-08

-3.7272E-10

13

4.9000

-1.9060E-04

-1.2186E-04

1.7777E-05

-2.5223E-06

-2.2654E-08

TABLE 6

Parameter(s)	TTL(mm)	f(mm)	D(mm)	h(mm)	FOV(°)
						Numerical value	26.651	9.698	5.440	5.512	31.400

In the present embodiment, TTL/f is 2.748 between the total optical length TTL of the optical lens and the total focal length f of the optical lens; and D/h/FOV is 0.031 satisfied among the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, the image height h corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens.

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). Table 8 below shows the conic coefficients k and the high-order term coefficients A, B, C, D and E that can be used for the aspherical lens surfaces S12 and S13 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 maximum field angle FOV of the optical lens, 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 image plane S16), and the entire group focal length value f of the optical lens. Wherein each aspherical surface type can be defined by the formula (1) given in the above-described embodiment 1.

TABLE 7

Flour mark	Radius of curvature R	Thickness T	Refractive index Nd	Abbe number Vd
					1	-10.3650	2.4497	1.73	54.67
2	-20.7397	0.0705
					STO	All-round	-0.0034
4	20.5443	6.0809	1.52	64.21
					5	-8.2884	2.0135	1.72	38.02
6	-21.1088	0.0671
					7	13.9966	4.6537	1.88	40.81
8	-80.0000	0.2685
					9	9.9447	2.6659	1.62	60.37
10	-17.7170	0.8725	1.76	27.55
					11	6.8365	0.8390
12	7.0944	4.6981	1.59	61.16
					13	6.4577	0.6712
14	All-round	0.9500	1.52	64.21
					15	All-round	0.5185
IMA	All-round

TABLE 8

Flour mark

K

A

B

C

D

E

12

-0.0310

-5.4692E-04

3.9216E-05

-4.9282E-06

1.6139E-07

-1.2285E-09

13

4.5000

7.4856E-04

-2.7522E-04

5.1371E-05

-2.7060E-06

-3.2772E-07

TABLE 9

Parameter(s)	TTL(mm)	f(mm)	D(mm)	h(mm)	FOV(°)
						Numerical value	26.816	9.559	8.611	5.516	31.400

In the present embodiment, TTL/f is 2.805 between the total optical length TTL of the optical lens and the total focal length f of the optical lens; and D/h/FOV of 0.050 is satisfied among 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, the image height h corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens.

Example 4

An optical lens according to embodiment 4 of the present application is described below with reference to fig. 4. 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. 4 shows a schematic structural diagram of an optical lens according to embodiment 4 of the present application.

As shown in fig. 4, 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.

In the optical lens of the present embodiment, a stop STO (i.e., stop-leading) may be provided between the object side and the first lens L1 to improve the imaging quality.

Table 10 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 4, where the radius of curvature R and the thickness T are both in units of millimeters (mm). Table 11 below shows the conic coefficients k and the high-order term coefficients A, B, C, D and E that can be used for the aspherical lens surfaces S12 and S13 in example 4. Table 12 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 4, the image height h corresponding to the maximum field angle of the optical lens, the maximum field angle FOV of the optical lens, 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 image plane S16), and the entire group focal length value f of the optical lens. Wherein each aspherical surface type can be defined by the formula (1) given in the above-described embodiment 1.

Watch 10

Flour mark	Radius of curvature R	Thickness T	Refractive index Nd	Abbe number Vd
					STO	All-round	1.3441
2	-12.1597	2.2866	1.52	64.21
					3	-33.8503	0.1344
4	23.0926	9.8013	1.52	64.21
					5	-10.5204	2.7063	1.72	38.02
6	-23.1120	0.0902
					7	24.5904	3.1847	1.88	40.81
8	-107.5277	0.3608
					9	13.0654	4.0323	1.62	60.37
10	-46.2676	1.1727	1.76	27.55
					11	9.1888	1.1276
12	8.2482	6.3147	1.59	61.16
					13	7.8908	0.9021
14	All-round	1.2769	1.52	64.21
					15	All-round	1.3441
IMA	All-round

TABLE 11

Flour mark

K

A

B

C

D

E

12

0.2600

-1.8156E-04

1.4354E-05

-1.1553E-06

4.0027E-08

-5.8891E-10

13

3.5000

3.8731E-04

-3.7022E-05

-1.7198E-06

7.2161E-07

-5.2472E-08

TABLE 12

Parameter(s)	TTL(mm)	f(mm)	D(mm)	h(mm)	FOV(°)
						Numerical value	36.079	13.000	8.234	7.472	31.400

In the present embodiment, a total optical length TTL of the optical lens and a total focal length f of the optical lens satisfy TTL/f 2.775; and D/h/FOV of 0.035 is satisfied among 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, and the maximum angle of view FOV of the optical lens.

In summary, examples 1 to 4 each satisfy the relationship shown in table 13 below.

Watch 13

Conditional expression (A) example	1	2	3	4
					TTL/f	2.644	2.748	2.805	2.775
D/h/FOV	0.038	0.031	0.050	0.035

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. An optical lens in which the number of lenses having optical power is seven, which are: the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element, the sixth lens element and the seventh lens element are sequentially arranged from an object side to an image side along an optical axis,

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

the first lens, the third lens and the sixth lens all have negative optical power;

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

wherein,

the object side surfaces of the first lens and the third lens are both concave surfaces, and the image side surfaces of the first lens and the third lens are both convex surfaces;

the object side surface and the image side surface of the second lens and the fifth lens are convex surfaces;

the object side surface and the image side surface of the sixth lens are both concave surfaces; and

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

wherein the optical lens satisfies (D is multiplied by 180 degrees/(h is multiplied by FOV) is less than or equal to 14.4,

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.

2. An optical lens barrel according to claim 1, wherein the fourth lens element has a convex object-side surface and a concave image-side surface.

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

4. An optical lens according to claim 1, further comprising a stop disposed between the optical lens object side and the first lens.

5. An optical lens according to claim 1, characterized in that the optical lens further comprises a diaphragm disposed between the first lens and the second lens.

6. An optical lens barrel according to any one of claims 1 to 5, wherein the seventh lens is an aspherical lens.

7. An optical lens according to any one of claims 1 to 5, characterized in that the second lens and the third lens are cemented to constitute a first cemented lens.

8. An optical lens barrel according to any one of claims 1 to 5, wherein the fifth lens and the sixth lens are cemented to constitute a second cemented lens.

9. An optical lens barrel according to any one of claims 1 to 5, wherein a distance TTL between a center of an object side surface of the first lens and an imaging surface of the optical lens on the optical axis and a full group focal length value f of the optical lens satisfy: TTL/f is less than or equal to 3.5.

10. An optical lens, wherein the number of lenses having optical power is seven, which are: the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element, the sixth lens element and the seventh lens element are sequentially arranged from an object side to an image side along an optical axis,

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

wherein,

the object side surface and the image side surface of the sixth lens are both concave surfaces;

the second lens and the third lens are cemented to form a first cemented lens; and

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

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

11. 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.

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

13. An optical lens according to claim 10, further comprising a stop disposed between the object side of the optical lens and the first lens.

14. An optical lens according to claim 10, characterized in that the optical lens further comprises a diaphragm disposed between the first lens and the second lens.

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

16. An optical lens according to claim 15, characterized in that the seventh lens is an aspherical mirror.

17. An optical lens barrel according to any one of claims 10 to 15, wherein a distance TTL between a center of an object side surface of the first lens and an imaging surface of the optical lens on the optical axis and a full group focal length value f of the optical lens satisfy: TTL/f is less than or equal to 3.5.