CN110927923A

CN110927923A - Optical lens

Info

Publication number: CN110927923A
Application number: CN201811093825.7A
Authority: CN
Inventors: 周宝; 王东方; 姚波
Original assignee: Ningbo Sunny Automotive Optech Co Ltd
Current assignee: Ningbo Sunny Automotive Optech Co Ltd
Priority date: 2018-09-19
Filing date: 2018-09-19
Publication date: 2020-03-27
Anticipated expiration: 2038-09-19
Also published as: CN110927923B

Abstract

The present application discloses an optical lens, sequentially from an object side to an image side along an optical axis, comprising: 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 positive focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has negative focal power, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface; the third lens has positive focal power, and both the object side surface and the image side surface of the third lens are convex surfaces; the fourth lens has 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 negative focal power, and both the object side surface and the image side surface of the fifth lens are concave; the sixth lens has positive focal power, and both the object side surface and the image side surface of the sixth lens are convex surfaces; and the seventh lens element has a negative power, and both the object-side surface and the image-side surface thereof are concave.

Description

Optical lens

Technical Field

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

Background

With the development of science, more and more fields need to serve as "eyes" with lenses, such as fields of vehicle-mounted, monitoring, projection, industry, and the like. Particularly, with the development and popularization of emerging technologies such as active driving or assisted driving, the demand of the market for vehicle-mounted cameras is increasing, and the imaging requirements, particularly the resolution requirements, of the cameras are also increasing.

As the requirement for camera pixels becomes higher and higher, the size of the chip increases, which results in the increase of the size of the whole lens and the cost.

In view of the need for the vehicle-mounted lens to be used in a harsh outdoor environment, it is important to maintain stable imaging performance at different temperatures, so as to prevent the lens from imaging blur and endanger the safety of drivers. Meanwhile, due to the limitations of installation space and overall layout in the vehicle, for example, a front view lens installed inside a front windshield has a large size, which may cause interference to the vehicle, and thus there is a corresponding demand for miniaturization of the lens.

In addition, in some special applications, for example, in night applications of vehicle-mounted lenses, it is necessary to increase the aperture of the lens to improve the night imaging effect, but this also increases the aperture of the lens.

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.

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

In one embodiment, the sixth lens and the seventh lens may be cemented to form a cemented lens.

In one embodiment, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens may each be a spherical lens.

In one embodiment, the optical lens may further include a diaphragm disposed at an object side of the first lens.

In one embodiment, the radius of curvature R3 of the object-side surface of the second lens, the center thickness d3 of the second lens on the optical axis, and the radius of curvature R4 of the image-side surface of the second lens can satisfy 0.6 ≦ (R3-d3)/R4 ≦ 1.7.

In one embodiment, the focal length value f7 of the seventh lens and the focal length value f of the whole group of the optical lens can satisfy f7/f ≦ -0.3.

In one embodiment, the focal length value f6 of the sixth lens and the focal length value f7 of the seventh lens may satisfy | f6/f7| ≦ 4.

In one embodiment, the air space d4 between the second lens and the third lens on the optical axis and the total optical length TTL of the optical lens can satisfy d4/TTL ≦ 0.008.

In one embodiment, the air space d6 between the third lens and the fourth lens on the optical axis and the total optical length TTL of the optical lens can satisfy d6/TTL ≦ 0.008.

In one embodiment, the air space d8 between the fourth lens and the fifth lens on the optical axis and the total optical length TTL of the optical lens can satisfy d8/TTL ≦ 0.1.

In one embodiment, the air space d10 between the fifth lens and the sixth lens on the optical axis and the total optical length TTL of the optical lens can satisfy d10/TTL ≦ 0.1.

In one embodiment, the total optical length TTL of the optical lens and the total focal length f of the optical lens can satisfy TTL/f ≦ 3.5.

In one embodiment, the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface of the first lens corresponding to the maximum field angle of the optical lens, and the image height h corresponding to the maximum field angle of the optical lens may satisfy D/h/FOV ≦ 0.08.

Another aspect of the present disclosure provides an optical lens, in order from an object side to an image side along an optical axis, comprising: 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 positive focal power, the object side surface of the first lens can be a convex surface, and the image side surface of the first lens can be a concave surface; the second lens may have a negative optical power; the third lens can have positive focal power, and both the object side surface and the image side surface of the third lens can be convex surfaces; the fourth lens can have positive focal power, and the object side surface of the fourth lens can be a convex surface, and the image side surface of the fourth lens can be a concave surface; the fifth lens can have negative focal power, and both the object side surface and the image side surface of the fifth lens can be concave; the sixth lens may have a positive optical power; the seventh lens may have a negative optical power; and the focal length value f6 of the sixth lens and the focal length value f7 of the seventh lens can satisfy | f6/f7| ≦ 4.

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

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

The optical lens adopts seven spherical glass lenses, and has at least one of the advantages of small caliber, high resolution, miniaturization, low cost and the like by optimally setting the shape and focal power of each lens and reasonably distributing the air space between the adjacent lenses.

Drawings

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

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

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

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

Detailed Description

For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that the detailed description is merely illustrative of exemplary embodiments of the present application and does not limit the scope of the present application in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.

It should be noted that in this specification, the expressions first, second, third, etc. are used only to distinguish one feature from another, and do not represent any limitation on the features. Thus, the first lens discussed below may also be referred to as the second lens or the third lens without departing from the teachings of the present application.

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

Herein, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the convex position is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is called the object side surface of the lens, and the surface of each lens closest to the image side is called the image side surface of the lens.

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 along the optical axis in sequence from the object side to the image side.

The first lens element can have a positive power, and can have a convex object-side surface and a concave image-side surface. The first lens is arranged to be a meniscus lens convex towards the object side, so that the collection of light rays with a large field of view as far as possible into a rear optical system is facilitated, and the reduction of the caliber of the front end of the system is facilitated. In practical application, considering that the environment for outdoor installation and use of the vehicle-mounted lens is possibly severe, the object side surface of the first lens is configured into a convex surface, so that water drops on the object side surface can slide off, and the influence of severe weather such as rain and snow on the imaging quality of the lens is reduced.

Optionally, a stop may be disposed near the surface of the first lens to facilitate the contraction of the incident light, thereby facilitating the reduction of the front aperture of the system. In an exemplary embodiment, the stop may be arranged at the object side of the first lens at a position close to the edge of the first lens optic.

The second lens element can have a negative power, and has a concave object-side surface and a convex image-side surface. The second lens is arranged to be the negative lens with the meniscus shape, so that light emitted by the first lens can be properly dispersed, the light transmission caliber of the system is increased, and the relative illumination is improved. The shape design of the convex side of the second lens is favorable for reasonable focal power and space distribution at the front end of the system, and the imaging quality of the system is ensured.

The third lens can have a positive optical power, and can be convex on both the object side and the image side. The third lens is arranged into the biconvex positive lens, so that light emitted by the second lens is favorably converged appropriately, the aperture of the rear-end lens is reduced, and meanwhile, the third lens can play a role in adjusting the light, so that the optical trend is smoothly transited to the fourth lens.

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 is arranged as a meniscus lens with the convex surface facing the object side, so that the light rays emitted by the third lens can be further converged, and the rear port diameter of the system is reduced.

The fifth lens element can have a negative optical power, and can have a concave object-side surface and a concave image-side surface. The fifth lens with negative focal power can properly diverge the light rays emitted by the fourth lens, so that the enlargement of an imaging surface is facilitated, and the resolution quality is improved.

The sixth 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 element can have a negative optical power, and can have a concave object-side surface and a concave image-side surface. The sixth lens is arranged to be a double-convex lens with positive focal power, and the seventh lens is arranged to be a double-concave lens with negative focal power, so that light rays emitted by the fifth lens can be smoothly transited to an imaging surface, and meanwhile, the rear port diameter of the system can be reduced.

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. By introducing the cemented lens composed of the sixth lens and the seventh lens, not only is self-chromatic aberration eliminated, but also partial chromatic aberration can be remained to balance chromatic aberration of the system. And the air space between the two lenses is omitted by gluing the lenses, so that the whole optical system is compact, the total optical length TTL of the system can be shortened, and the miniaturization requirement can be met. In addition, the gluing of the lens can reduce tolerance sensitivity problems of inclination/decentration and the like of the lens unit in the assembling process, and can improve the mass production of the optical system. Compared with a single lens structure, the lens adopting the gluing structure has the advantage that the resolution quality can be effectively improved due to the fact that one more lens is added. Meanwhile, the sixth lens and the seventh lens are glued, so that the total optical length TTL of the lens can be shortened while the imaging quality is improved.

The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens can all be lenses made of all-glass materials. In an exemplary embodiment, the six lenses may each be a spherical glass lens. Spherical glass lenses are mostly adopted in optical lenses, which is beneficial to meeting the requirements of low cost, stable temperature performance and the like.

In an exemplary embodiment, the optical lens of the present application may satisfy the conditional expression of 0.6 ≦ (R3-d3)/R4 ≦ 1.7, where R3 is a radius of curvature of an object-side surface of the second lens, d3 is a center thickness of the second lens on an optical axis, and R4 is a radius of curvature of an image-side surface of the second lens. More specifically, R3, d3 and R4 may further satisfy 0.8. ltoreq. R3-d 3)/R4. ltoreq.1.5, for example, 1.09. ltoreq. R3-d 3)/R4. ltoreq.1.20. The shape of the second lens is reasonably set, so that reasonable focal power and space distribution at the front end of the system are facilitated, and the imaging quality of the lens is ensured.

In an exemplary embodiment, the optical lens of the present application may satisfy the conditional expression | f6/f7| ≦ 4, where f6 is a focal length value of the sixth lens and f7 is a focal length value of the seventh lens. More specifically, f6 and f7 can further satisfy | f6/f7| ≦ 3.2, for example, 0.92 ≦ f6/f7| ≦ 1.25. The focal lengths of the sixth lens and the seventh lens are reasonably controlled, so that the focal length values of the two adjacent lenses are close, light can be stably transited, the rear-end caliber of the system is favorably reduced, and the resolution quality is improved.

In an exemplary embodiment, the optical lens of the present application may satisfy the conditional expression f7/f ≦ -0.3, where f7 is a focal length value of the seventh lens, and f is a focal length value of the entire group of the optical lens. More specifically, f7 and f can further satisfy f 7/f.ltoreq.0.42, e.g., -0.61. ltoreq. f 7/f.ltoreq.0.54. Satisfies the conditional expression f7/f is less than or equal to-0.3, and is beneficial to matching large-size chips.

In an exemplary embodiment, an air space between any two adjacent lenses of the second lens to the sixth lens may be optimized to make the optical system compact, increase a space utilization rate of the system, and further contribute to miniaturization of the lens barrel.

The air space d4 between the second lens and the third lens on the optical axis (i.e., the distance between the center of the image-side surface of the second lens and the center of the object-side surface of the third lens on the optical axis) and the total optical length TTL of the optical lens (i.e., 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) can satisfy d4/TTL ≦ 0.008, more specifically, d4 and TTL can further satisfy d4/TTL ≦ 0.006, for example, 0.001 ≦ d4/TTL ≦ 0.005.

The air interval d6 between the third lens and the fourth lens on the optical axis (i.e., the distance between the center of the image-side surface of the third lens and the center of the object-side surface of the fourth lens on the optical axis) and the total optical length TTL of the optical lens can satisfy d6/TTL ≦ 0.008, more specifically, d6 and TTL can further satisfy d6/TTL ≦ 0.006, for example, 0.001 ≦ d6/TTL ≦ 0.003.

The air space d8 between the fourth lens and the fifth lens on the optical axis (i.e., the distance between the center of the image side surface of the fourth lens and the center of the object side surface of the fifth lens on the optical axis) and the total optical length TTL of the optical lens can satisfy d8/TTL ≦ 0.1, more specifically, d8 and TTL can further satisfy d8/TTL ≦ 0.08, for example, 0.016 ≦ d8/TTL ≦ 0.025.

The air space d10 between the fifth lens and the sixth lens on the optical axis (i.e., the distance between the center of the image side surface of the fifth lens and the center of the object side surface of the sixth lens on the optical axis) and the total optical length TTL of the optical lens can satisfy d10/TTL ≦ 0.1, more specifically, d10 and TTL can further satisfy d10/TTL ≦ 0.08, for example, 0.036 ≦ d10/TTL ≦ 0.041.

In an exemplary embodiment, the optical lens of the present application may satisfy a conditional expression TTL/f ≦ 3.5, where TTL is an optical total length of the optical lens, and f is a whole group focal length value of the optical lens. More specifically, TTL and f further can satisfy TTL/f ≦ 3, e.g., 1.86 ≦ TTL/f ≦ 2.14. The condition formula TTL/f is less than or equal to 3.5, and the miniaturization of the lens is favorably realized.

In an exemplary embodiment, the optical lens of the present application may satisfy a conditional expression D/h/FOV ≦ 0.08, where FOV is a maximum angle of view of the optical lens, D is a maximum clear aperture of an object-side surface of the first lens corresponding to the maximum angle of view of the optical lens, and h is an image height corresponding to the maximum angle of view of the optical lens. More specifically, D, h and the FOV further can satisfy D/h/FOV ≦ 0.06, e.g., 0.04 ≦ D/h/FOV ≦ 0.05. The condition that D/h/FOV is less than or equal to 0.08 is met, and the small aperture at the front end of the lens can be reflected.

In an exemplary embodiment, the lens used in the optical lens may be a plastic lens, or may be a glass lens. However, since the thermal expansion coefficient of the plastic lens is large, when the ambient temperature used by the lens changes greatly, the plastic lens causes a large amount of change in the optical back focus of the lens, and further causes problems such as a blurred out-of-focus image plane. The glass lens has a slightly higher cost, but the influence of temperature on the optical back focus of the lens can be obviously reduced.

In an exemplary embodiment, the optical lens in the present application mostly uses a spherical lens made of glass, and compared with a lens using an aspheric lens made of glass, the optical lens in the present application can achieve the same resolution on the basis of using a full glass spherical surface, and at the same time, the cost and the manufacturing difficulty of the lens can be reduced.

However, the optical lens in the present application may fully or partially adopt a glass aspheric lens to further improve the resolution of the lens without considering the cost and the manufacturing difficulty. In addition, in the case of not considering temperature stability or requiring low temperature stability, the optical lens of the present application may also fully or partially adopt a plastic aspheric lens, so as to further reduce the manufacturing cost of the lens.

Optionally, the optical lens may further include a filter for correcting color deviation and/or a protective glass for protecting a photosensitive element located on an image plane.

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 optical lens according to the above-described embodiment of the present application achieves a requirement for a small aperture at the tip by controlling the shape of the first lens, and further reduces the aperture at the tip by placing the aperture stop on the surface of the first lens. The optical lens of this application all adopts the spherical lens of glass material, and for the camera lens of the aspherical lens who adopts glass material, optical lens in this application can reach same resolution on the basis that adopts full glass sphere, but the manufacturing degree of difficulty of cost and camera lens simultaneously. In addition, according to the optical lens of the above embodiment, the focal length ratio of the sixth lens and the seventh lens is reasonably controlled, so that the rear port diameter of the lens is favorably reduced, the miniaturization is realized, and the improvement of the resolution quality of the lens is favorably realized.

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 an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, and a seventh lens element L7.

The first lens L1 is a meniscus lens with positive 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 concave and the object side S4 being convex. The third lens L3 is a biconvex lens with positive power, and has a convex object-side surface S5 and a convex image-side surface S6. 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 biconcave lens with negative power, and has a concave object-side surface S9 and a concave image-side surface S10. The sixth lens element L6 is a biconvex lens with positive refractive power, and has a convex object-side surface S11 and a convex image-side surface S12. The seventh lens L7 is a biconcave lens with negative power, and has a concave object-side surface S12 and a concave image-side surface S13. The sixth lens L6 and the seventh lens L7 may be cemented to constitute a cemented lens.

In the present embodiment, the object-side surface and the image-side surface of any one of the first lens L1 through the seventh lens L7 are spherical surfaces.

The optical lens may further include a filter and/or a cover glass L8 having an object side S14 and an image side S15. 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 at the object side surface S1 of the first lens L1 to improve the imaging quality.

Table 1 shows the radius of curvature R, thickness T, refractive index Nd, and abbe number Vd of each lens of the optical lens of example 1.

TABLE 1

Table 2 below gives the total optical length TTL of the optical lens of example 1 (i.e., the on-axis distance from the center of the object-side surface S1 of the first lens L1 to the imaging surface S16), the entire group focal length value f of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, the image height h corresponding to the maximum field angle of the optical lens, the maximum field angle FOV of the optical lens, the focal length value f6 of the sixth lens L6, and the focal length value f7 of the seventh lens L7.

TTL(mm)	32.6813	FOV(°)	33
				f(mm)	15.2962	f6(mm)	7.8086
D(mm)	12.5381	f7(mm)	-8.4004
				h(mm)	9.2080

TABLE 2

The optical lens in embodiment 1 satisfies:

2.137, where TTL is the total optical length of the optical lens, and f is the entire focal length of the optical lens;

D/h/FOV is 0.041, where D is the maximum clear aperture of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, 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;

i f6/f7| -0.930, where f6 is the focal length of the sixth lens L6, and f7 is the focal length of the seventh lens L7;

(R3-d3)/R4 is 1.112, where R3 is a radius of curvature of the object-side surface S3 of the second lens L2, d3 is a central thickness of the second lens L2 on the optical axis, and R4 is a radius of curvature of the image-side surface S4 of the second lens L2;

f7/f is-0.549, wherein f7 is the focal length value of the seventh lens L7, and f is the focal length value of the whole group of the optical lens;

d4/TTL is 0.004, where d4 is an air space between the second lens L2 and the third lens L3 on the optical axis, and TTL is the total optical length of the optical lens system;

d6/TTL is 0.002, where d6 is an air space on the optical axis between the third lens L3 and the fourth lens L4, and TTL is the total optical length of the optical lens system;

d8/TTL is 0.017, where d8 is an air interval between the fourth lens L4 and the fifth lens L5 on the optical axis, and TTL is the total optical length of the optical lens system;

d10/TTL is 0.037, where d10 is an air space between the fifth lens element L5 and the sixth lens element L6 on the optical axis, and TTL is the total optical length of the optical lens system.

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 an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, and a seventh lens element L7.

Table 3 shows the radius of curvature R, thickness T, refractive index Nd, and abbe number Vd of each lens of the optical lens of example 2.

TABLE 3

Table 4 below gives the total optical length TTL of the optical lens of example 2 (i.e., the on-axis distance from the center of the object-side surface S1 of the first lens L1 to the imaging surface S16), the entire group focal length value f of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, the image height h corresponding to the maximum field angle of the optical lens, the maximum field angle FOV of the optical lens, the focal length value f6 of the sixth lens L6, and the focal length value f7 of the seventh lens L7.

TTL(mm)	30.0838	FOV(°)	33
				f(mm)	16.1041	f6(mm)	11.5833
D(mm)	13.4205	f7(mm)	-9.2813
				h(mm)	9.4920

TABLE 4

The optical lens in embodiment 2 satisfies:

TTL/f is 1.868, where TTL is the total optical length of the optical lens, and f is the entire focal length of the optical lens;

D/h/FOV is 0.043, where D is the maximum clear aperture of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, 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;

1.248, | f6/f7|, where f6 is the focal length of the sixth lens L6, and f7 is the focal length of the seventh lens L7;

(R3-d3)/R4 is 1.197, where R3 is a radius of curvature of the object-side surface S3 of the second lens L2, d3 is a central thickness of the second lens L2 on the optical axis, and R4 is a radius of curvature of the image-side surface S4 of the second lens L2;

f7/f is-0.576, where f7 is the focal length value of the seventh lens L7, and f is the focal length value of the whole group of the optical lens;

d4/TTL is 0.002, where d4 is an air space on the optical axis between the second lens L2 and the third lens L3, and TTL is the total optical length of the optical lens system;

d8/TTL is 0.022, where d8 is an air space between the fourth lens L4 and the fifth lens L5 on the optical axis, and TTL is the total optical length of the optical lens system;

and d10/TTL is 0.040, where d10 is an air space on the optical axis between the fifth lens L5 and the sixth lens L6, and TTL is the total optical length 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. 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 an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, and a seventh lens element L7.

TABLE 5

Table 6 below gives the total optical length TTL of the optical lens of example 3 (i.e., the on-axis distance from the center of the object-side surface S1 of the first lens L1 to the imaging surface S16), the entire group focal length value f of the optical lens, 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 focal length value f6 of the sixth lens L6, and the focal length value f7 of the seventh lens L7.

TTL(mm)	30.5509	FOV(°)	33
				f(mm)	16.2675	f6(mm)	9.7774
D(mm)	13.5565	f7(mm)	-9.7731
				h(mm)	9.5360

TABLE 6

The optical lens in embodiment 3 satisfies:

TTL/f is 1.878, where TTL is the total optical length of the optical lens, and f is the entire focal length of the optical lens;

i f6/f7| ═ 1.000, where f6 is the focal length value of the sixth lens L6, and f7 is the focal length value of the seventh lens L7;

(R3-d3)/R4 is 1.096, where R3 is a radius of curvature of the object-side surface S3 of the second lens L2, d3 is a central thickness of the second lens L2 on the optical axis, and R4 is a radius of curvature of the image-side surface S4 of the second lens L2;

f7/f is-0.601, where f7 is the focal length of the seventh lens L7, and f is the focal length of the entire optical lens group;

d8/TTL is 0.024, where d8 is an air space on the optical axis between the fourth lens L4 and the fifth lens L5, and TTL is the total optical length of the optical lens system;

In summary, examples 1 to 3 each satisfy the relationship shown in table 7 below.

Conditional expression (A) example	E1	E2	E3
				TTL/f	2.137	1.868	1.878
D/h/FOV	0.041	0.043	0.043
				\|f6/f7\|	0.930	1.248	1.000
(R3-d3)/R4	1.112	1.197	1.096
				f7/f	-0.549	-0.576	-0.601
d4/TTL	0.004	0.002	0.002
				d6/TTL	0.002	0.002	0.002
d8/TTL	0.017	0.022	0.024
				d10/TTL	0.037	0.040	0.040

TABLE 7

The present application also provides an imaging device whose electron photosensitive element may be a photo-coupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The imaging device may be a stand-alone imaging apparatus such as a vehicle-mounted camera, or may be an imaging module integrated on a driving assistance system such as a car. The imaging device is equipped with the optical lens described above.

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

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

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

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

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

the seventh lens element has a negative focal power, and both the object-side surface and the image-side surface thereof are concave.

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

3. An optical lens according to claim 1, wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all spherical lenses.

4. An optical lens according to claim 1, characterized in that the optical lens further comprises a diaphragm disposed at an object side surface of the first lens.

5. An optical lens according to claim 1, characterized in that a radius of curvature R3 of an object-side surface of the second lens, a center thickness d3 of the second lens on the optical axis, and a radius of curvature R4 of an image-side surface of the second lens satisfy 0.6 ≦ (R3-d3)/R4 ≦ 1.7.

6. An optical lens according to claim 1, characterized in that the focal length value f7 of the seventh lens and the focal length value f of the entire group of the optical lens satisfy f7/f ≦ -0.3.

7. The optical lens of claim 1, wherein a focal length value f6 of the sixth lens and a focal length value f7 of the seventh lens satisfy | f6/f7| ≦ 4.

8. The optical lens of claim 1, wherein an air gap d4 between the second lens and the third lens on the optical axis and an optical total length TTL of the optical lens satisfy d4/TTL ≦ 0.008.

9. The optical lens of claim 8, wherein an air gap d6 between the third lens and the fourth lens on the optical axis and an optical total length TTL of the optical lens satisfy d6/TTL ≦ 0.008.

10. The optical lens of claim 9, wherein an air gap d8 between the fourth lens and the fifth lens on the optical axis and an optical total length TTL of the optical lens satisfy d8/TTL ≦ 0.1.

11. The optical lens of claim 10, wherein an air gap d10 between the fifth lens and the sixth lens on the optical axis and an optical total length TTL of the optical lens satisfy d10/TTL ≦ 0.1.

12. An optical lens element according to any one of claims 1 to 11, wherein an overall optical length TTL of the optical lens element and a total focal length f of the optical lens element satisfy TTL/f ≦ 3.5.

13. An optical lens according to any one of claims 1 to 11, characterized in that D/h/FOV ≦ 0.08,

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.

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

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

the second lens has a negative optical power;

the sixth lens has positive optical power;

the seventh lens has a negative optical power; and

the focal length value f6 of the sixth lens and the focal length value f7 of the seventh lens meet | f6/f7| ≦ 4.