CN111323889A

CN111323889A - Optical lens and imaging apparatus

Info

Publication number: CN111323889A
Application number: CN201811527450.0A
Authority: CN
Inventors: 金嘉俊; 王东方; 姚波
Original assignee: Ningbo Sunny Automotive Optech Co Ltd
Current assignee: Ningbo Sunny Automotive Optech Co Ltd
Priority date: 2018-12-13
Filing date: 2018-12-13
Publication date: 2020-06-23
Anticipated expiration: 2038-12-13
Also published as: CN111323889B

Abstract

An optical lens and an imaging apparatus including the same are disclosed. The optical lens 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 and a fifth lens. The first lens can have negative focal power, and the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens can have negative focal power, and the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the third lens can have positive focal power, and the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; and the fourth lens and the fifth lens may have positive power or negative power, respectively. According to the optical lens, at least one of the advantages of special field angle, small f-theta distortion, small front end caliber, high resolution, capability of controlling resolution at different positions, low cost and the like can be realized.

Description

Optical lens and imaging apparatus

Technical Field

The present application relates to an optical lens and an imaging apparatus, and more particularly, to an optical lens including five lenses and an imaging apparatus including the optical lens.

Background

With the development of scientific technology, more and more fields need to use lenses to serve as "eyes", such as vehicle-mounted, monitoring, projection, industry, and the like. The demand and the technology development are increased, and the demand of the lens performance is more and more diversified. For example, in a rear-view and a panoramic optical lens in a vehicle-mounted field, since an aspect ratio (a view field ratio) of an object plane and an aspect ratio (i.e., a chip aspect ratio, for example, 16: 9) of an image plane are greatly different, a utilization rate of a chip size is low.

Therefore, the optical lens needs to image an object on a fixed-size camera chip at different field of view angles (FOV) in different directions (e.g., x, y directions, see fig. 1) to make full use of the chip and minimize the image cropping. In order to meet the requirement of the special field angle, the lens is required to have different focal length values in the x and y directions, that is, the magnification of the lens in the x direction is different from that in the y direction, and the even aspheric lens and the spherical lens commonly used at present are difficult to meet the requirement.

In addition, in some specific application scenarios, the optical lens needs to have the capability of controlling the resolution of different positions of the imaging surface (for example, the resolution requirement of the upper half area of the imaging surface of the vehicle-mounted rearview mirror is higher than that of the lower half area), and this requirement is also difficult to be met by the commonly used optical lens.

Therefore, there is a need in the market for an optical lens with a special field of view, which is small in size and distortion and can control the different positions of the image to be resolved, so as to meet the application requirements of, for example, driving an automobile.

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 and a fifth lens. The first lens can have negative focal power, and the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens can have negative focal power, and the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the third lens can have positive focal power, and the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; and the fourth lens and the fifth lens may have positive power or negative power, respectively.

The fourth lens element has a negative focal power, and has a convex object-side surface and a concave image-side surface. Alternatively, the fourth lens may have positive optical power, and both the object-side surface and the image-side surface thereof may be convex.

The fifth lens can have positive focal power, and both the object side surface and the image side surface of the fifth lens can be convex surfaces. Alternatively, the fifth lens element may have a negative power, with a concave object-side surface and a convex image-side surface.

Wherein, the refractive index n3 of the lens of the third lens can satisfy: n3 is more than or equal to 1.5 and less than or equal to 1.55. Additionally or further, the lens abbe number Vd3 of the third lens may satisfy: vd3 is more than or equal to 55 and less than or equal to 58.

Wherein the fourth lens and the fifth lens can be cemented with each other to form a cemented lens.

Wherein the second lens element may be a biconic free-form surface optic.

The optical lens can have at least three aspheric lenses.

The third lens, the fourth lens and the fifth lens can be aspheric lenses.

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 is less than or equal to 0.04.

Wherein, the x-direction focal length value F2x of the second lens and the y-direction focal length value F2y of the second lens satisfy: the absolute value of F2y/F2x is more than or equal to 1 and less than or equal to 5.

Wherein, can satisfy between the whole group of x direction focal length value Fx of optical lens and the whole group of y direction focal length value Fy of optical lens: the absolute value Fy/Fx is more than or equal to 1 and less than or equal to 5.

Wherein, the cemented surface opening angle of optical lens can satisfy: arctan (SAG (S9)/d (S9)) > 35, wherein d (S9) is a half aperture of the maximum clear aperture of the cemented surface S9 of the fourth lens and the fifth lens corresponding to the maximum field angle of the optical lens, and SAG (S9) is a SAGs value corresponding to the cemented surface S9.

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 may satisfy: TTL/h/FOV is less than or equal to 0.05.

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 and a fifth lens. Wherein the first lens and the second lens can both have negative focal power; the third lens may have a positive optical power; the fourth lens and the fifth lens can be mutually glued to form a cemented lens; and the whole group of the x-direction focal length values Fx of the optical lens and the whole group of the y-direction focal length values Fy of the optical lens can satisfy the following conditions: the absolute value Fy/Fx is more than or equal to 1 and less than or equal to 5.

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

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

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

The fourth lens element has a negative focal power, and has a convex object-side surface and a 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.

Alternatively, the fourth lens may have positive optical power, and both the object-side surface and the image-side surface thereof may be convex. The fifth lens element can have a negative power, and can have a concave object-side surface and a convex image-side surface.

Wherein the second lens element may be a biconic free-form surface optic.

The optical lens can have at least three aspheric lenses.

The third lens, the fourth lens and the fifth lens can be aspheric lenses.

Still another aspect of the present application provides an imaging apparatus that may include the optical lens according to the above-described embodiment and an imaging element for converting an optical image formed by the optical lens into an electrical signal.

The optical lens adopts five lenses, for example, the shapes of the lenses are optimally set, the focal power of each lens is reasonably distributed, the cemented lens is formed, and the like, so that at least one of the beneficial effects of small f-theta distortion, small front end caliber, high resolution, capability of controlling the resolution at different positions, low cost 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 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, five lenses having optical power, i.e., a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. The five 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 with the convex surface facing the object side, so that light with a large field of view can be collected as far as possible, the light enters a rear optical system, and the light flux is increased. In practical application, the outdoor installation and use environment of the vehicle-mounted lens is considered, the vehicle-mounted lens can be in severe weather such as rain and snow, the meniscus shape design with the convex surface facing the object side is more suitable for the environments such as rain and snow, water drops can slide off easily, water and dust are not accumulated easily, 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 lens shape of the second lens can be a biconical free-form surface, the shape of the x section of the second lens is different from that of the y section of the second lens, so that the focal lengths of the lens in the x direction are different from that in the y direction, the magnification ratios in the x direction and the y direction are different, and the functions of adjusting the magnification ratios in the x direction and the y direction and ensuring the magnification ratios in the x direction and the y direction of the compressed image surface are achieved; the curvature of different positions of the lens can be controlled, so that the positions of the light rays with different angles for focusing the image height can be controlled, and the distortion can be effectively reduced; in addition, the second lens shape is symmetrical to the rear third lens shape, so that coma aberration can be effectively reduced.

The third lens element can have a positive power, and can have a concave object-side surface and a convex image-side surface. The third lens can adjust the light emergent angle, and the shape of the third lens is symmetrical to that of the second lens in front, so that coma can be effectively reduced.

The fourth lens element can have a positive or negative power, and can be a biconvex lens element or a meniscus lens element, and further can have a convex object-side surface and a convex or concave image-side surface.

The fifth lens element can have a positive or negative power, and can be a biconvex lens element or a meniscus lens element, and further can have a convex or concave object-side surface and a convex image-side surface.

In an exemplary embodiment, a diaphragm for limiting the light beam may be disposed between, for example, the third lens and the fourth lens to further improve the imaging quality of the lens. When the diaphragm is arranged between the third lens and the fourth lens, light rays entering the optical system can be effectively converged, and the aperture of the lens of the optical system is reduced. It should be noted, however, that the positions of the diaphragms disclosed herein are merely examples and not limitations; in alternative embodiments, the diaphragm may be disposed at other positions according to actual needs.

In an exemplary embodiment, the optical lens according to the present application may further include a filter disposed between the fifth lens and the image plane to filter light rays having different wavelengths, as needed; and may further include a protective glass disposed between the optical filter and the imaging surface to prevent internal elements (e.g., chips) of the optical lens from being damaged.

As known to those skilled in the art, cemented lenses may be used to minimize or eliminate chromatic aberration. The use of the cemented lens in the optical lens can improve the image quality and reduce the reflection loss of light energy, thereby improving the imaging definition of the lens. In addition, the use of the cemented lens can also simplify the assembly process in the lens manufacturing process.

In an exemplary embodiment, the fourth lens and the fifth lens may be combined into a cemented lens by cementing the image-side surface of the fourth lens with the object-side surface of the fifth lens. The cemented lens consists of a positive lens and a negative lens, and the matching of the positive lens and the negative lens with high refractive index and low refractive index can effectively reduce the chromatic aberration of the system and simultaneously reduce the tolerance sensitivity problems of inclination/core deviation and the like generated in the assembling process of the lens units. If the discrete lens is located at the turning point of the light, the sensitivity is easily caused by processing/assembling errors, and the sensitivity of the cemented lens is effectively reduced. The use of the cemented lens shares the whole chromatic aberration correction of the system, and the cemented lens uses the aspheric lens to effectively correct the aberration such as astigmatism, curvature of field and the like generated by the front lens group.

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 not more than 0.04, and more preferably, D/h/FOV is not more than 0.039. The characteristic of small caliber and miniaturization of the front end can be realized by satisfying the conditional expression D/h/FOV less than or equal to 0.04.

In an exemplary embodiment, the x-direction focal length value F2x and the y-direction focal length value F2y of the second lens may satisfy: the absolute value of F2y/F2x is more than or equal to 1 and less than or equal to 5, and more ideally, the absolute value of F2y/F2x is more than or equal to 1 and less than or equal to 3. By adjusting the magnification ratio of the second lens in the x direction and the y direction, the focal lengths of the lens in the x direction and the y direction are different, so that the magnification ratio of the lens in the x direction and the y direction is different, and the requirement of a special field angle is met.

In an exemplary embodiment, the total set of x-direction focal length values Fx and the total set of y-direction focal length values Fy of the optical lens may satisfy: the | Fy/Fx | is more than or equal to 1 and less than or equal to 5, and more ideally, the | Fy/Fx | is more than or equal to 1 and less than or equal to 3. By ensuring the magnification ratio of the compressed image surface in the x direction and the y direction and the different focal lengths of the lens in the x direction and the y direction, the magnification ratio of the lens in the x direction and the y direction can be different, so that the requirement of a special field angle is met.

In an exemplary embodiment, the cemented opening angle of the optical lens may satisfy: and the arctan (SAG (S9)/d (S9)) > 35, more preferably, the arctan (SAG (S9)/d (S9)) > 39 can be further satisfied, wherein d (S9) is the half aperture of the maximum clear aperture of the cemented surface S9 of the fourth lens and the fifth lens corresponding to the maximum field angle of the optical lens, and SAG (S9) is the sagged value corresponding to the sagged value. The lens has a larger opening angle of the bonding surface, which is beneficial to the quick focusing of peripheral light rays and can improve the imaging quality.

In an exemplary embodiment, 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 may satisfy: TTL/h/FOV is less than or equal to 0.05, and more ideally, TTL/h/FOV is less than or equal to 0.04. By satisfying the conditional expression TTL/h/FOV less than or equal to 0.05, the miniaturization characteristic can be ensured.

In an exemplary embodiment, the refractive index n3 and abbe number Vd3 of the optic of the third lens may satisfy: n3 is more than or equal to 1.5 and less than or equal to 1.55, Vd3 is more than or equal to 55 and less than or equal to 58, and the imaging quality is improved by reasonably configuring the refractive index and Abbe number of the lens.

In an exemplary embodiment, the abbe number Vd4 of the fourth lens and the abbe number Vd5 of the fifth lens may satisfy: vd4 is less than or equal to 40, Vd5 is more than or equal to 50, and the chromatic aberration and spherical aberration are adjusted by reasonably distributing Abbe numbers. Alternatively, in another exemplary embodiment, the abbe number Vd4 of the fourth lens and the abbe number Vd5 of the fifth lens may satisfy: vd5 is less than or equal to 40, Vd4 is more than or equal to 50, and the chromatic aberration and spherical aberration are adjusted by reasonably distributing Abbe numbers.

In an exemplary embodiment, an optical lens according to the present application has at least three 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 third lens element may be an aspheric lens element to correct astigmatism caused by the front lens element. The fourth lens and/or the fifth lens may be aspheric lenses to improve the resolution. Desirably, the third lens, the fourth lens and the fifth lens may each be an aspherical mirror.

In an exemplary embodiment, the lens used in the optical lens may be a plastic lens, or may be a glass lens. The lens made of plastic has a large thermal expansion coefficient, and when the ambient temperature change of the lens is large, the lens made of plastic causes a large amount of change of the optical back focus of the lens. The glass lens can reduce the influence of temperature on the optical back focus of the lens, but has higher cost.

According to the optical lens of the embodiment of the application, only 5 pieces of frameworks are used through reasonable lens shape setting and optical power setting, so that the cost is effectively reduced; the second lens adopts a free-form surface lens, so that focal distances in the x direction and the y direction of the lens are different, the magnification ratio in the x direction and the y direction can be effectively adjusted, the requirement of a special field angle is met, and the utilization rate of the chip size is effectively improved; the third lens, the fourth lens and the fifth lens are aspheric lenses, so that the lens has excellent resolving power, and the diaphragm is arranged at the rear end of the system, so that the light flux can be ensured to be as large as possible; by controlling the shape of the second lens of the free-form surface lens at different positions, the resolving power of the designated area can be further improved, and the area can achieve higher resolving effect. The wide-angle lens has generally large f-theta distortion, the optical lens controls the positions of light rays with different angles for focusing image height by controlling the curvatures of the second lens of the free-form surface lens at different positions so as to achieve the effect of reducing the f-theta distortion of the lens, and the f-theta distortion of the optical lens can be less than or equal to 8%; and the front port diameter of the optical lens is smaller, so that the miniaturization requirement is met, and the optical lens can be conveniently installed. Therefore, the optical lens according to the above-mentioned embodiment of the present application can have at least one of the advantages of a special field angle, a small f- θ distortion, a small front end aperture, high resolution, capability of controlling resolution at different positions, low cost, and the like, and can better meet the application requirements of, for example, a vehicle-mounted lens.

It will be understood by those skilled in the art that the number of lenses making up the lens barrel may be varied to achieve the various results and advantages described in this specification without departing from the claimed subject matter. For example, although five lenses are exemplified in the embodiment, the optical lens is not limited to include five 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 L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5.

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

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

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

The fourth lens L4 is a meniscus lens with negative power, with the object side S8 being convex and the image side S9 being concave. The fifth lens L5 is a biconvex lens with positive optical power, and has both the object-side surface S9 and the image-side surface S10 convex. Wherein the fourth lens L4 and the fifth lens L5 are cemented with each other to form a cemented lens.

The third lens element L3, the fourth lens element L4, and the fifth lens element 5 are aspheric lenses each having an aspheric object-side surface and image-side surface, and the second lens element L2 is a biconic free-form surface lens element.

Optionally, the optical lens may further include a filter L6 and/or a protective lens L6' having an object side S11 and an image side S12. Filter L6 can be used to correct for color deviations. The protective lens L6' 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 S12 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 third lens L3 and the fourth lens L4 to improve the imaging quality.

Table 1 shows a radius of curvature R, a thickness T, a refractive index Nd, and an abbe number Vd of each lens of the optical lens of example 1, where the radius of curvature R and the thickness T are both in units of millimeters (mm).

TABLE 1

The present embodiment adopts five 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 a special field angle, small f-theta distortion, small front end aperture, high resolution, capability of controlling the resolution at different positions, low cost and the like. Each aspherical surface type Z is defined by the following formula (1):

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. The biconic free-form surface type Z of the second lens L2 is defined by the following equation (2):

when the free-form surface is at the position of the space coordinates x and y along the optical axis direction, Z is the rise of the distance from the top point of the free-form surface; c. C_x、c_yC is 1/R (i.e., paraxial curvature c is the inverse of radius of curvature R, c is the paraxial curvature of the free-form surface)_x＝1/R_x，c_y＝1/R_y)；k_x、k_yConic coefficients, conic, α, in the x and y directions_i、β_iThe value of i is 4, 6, 8, 10 and 12 for high-order coefficient. Table 2 below shows cone coefficients k and high-order term coefficients A, B, C, D and E of aspherical lens surfaces S5 to S6 and S8 to S10 that can be used in example 1. Table 3 below shows the paraxial curvature c of biconic freeform lens surfaces S3-S4 that may be used in example 1_x、c_yCoefficient of conicity k_x、k_yAnd high order coefficient α_i、β_i。

TABLE 2

Flour mark

K

A

B

C

D

E

5

0.9490

-1.0586E-02

1.6704E-02

-9.6148E-04

-7.5384E-04

-5.3515E-06

6

-1.3382

-1.6398E-03

3.5368E-02

-4.8892E-02

1.9095E-02

3.8263E-04

8

-1.8436

-2.5338E-03

3.7619E-02

-1.0823E-01

1.1471E-01

-2.6540E-04

9

-1.3918

-8.1067E-02

6.4724E-02

-4.2118E-02

1.1623E-02

2.5162E-05

10

-3.2695

-6.7116E-02

4.7587E-02

-1.4518E-02

2.4092E-03

8.8580E-06

TABLE 3

Flour mark	cy	ky	cx	kx
						3	0.4032	-1.2303	0.2956	1.1784
4	0.8229	-0.7876	0.6912	-1.4324
						Flour mark	α4	α6	α8	α10	α12
3	3.4273E-02	-6.8534E-03	7.6143E-05	1.9771E-04	-3.2740E-05
						4	7.5613E-02	-5.3537E-03	-7.8986E-04	-2.8419E-03	1.0726E-03
Flour mark	β4	β6	β8	β10	β12
						3	1.4811E-02	-2.6610E-03	8.5077E-05	2.0401E-05	-2.6423E-07
4	-9.9739E-03	-3.7950E-03	-4.6107E-03	1.3437E-03	1.1439E-05

Table 4 below gives the x-direction focal length value F2x and the y-direction focal length value F2y of the second lens L2 of example 1, the entire group of x-direction focal length value Fx and the entire group of y-direction focal length value Fy 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 imaging surface IMA), 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 x-direction image height x _ h and the y-direction image height y _ h corresponding to the maximum field angle of the optical lens, the maximum x-direction field angle x _ FOV and the maximum y-direction field angle y _ FOV of the optical lens.

TABLE 4

In the present embodiment, | Fy/Fx |, which is 1.0256, is satisfied between the entire set of x-direction focal length values Fx and the entire set of y-direction focal length values Fy of the optical lens; the second lens L2 satisfies | F2y/F2x | -1.0399 between the x-direction focal length value F2x and the y-direction focal length value F2 y; the cemented surface angle arctan (SAG (S9)/d (S9)) -40.9124 of the optical lens, where d (S9) is the half aperture of the maximum clear aperture of the cemented surface S9 of the fourth lens L4 and the fifth lens L5 corresponding to the maximum field angle of the optical lens, and SAG (S9) is the SAG value corresponding thereto; d/x _ h/x _ FOV is 0.0167 which is satisfied between the maximum x-direction field angle x _ FOV of the optical lens, the maximum light-passing aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, and the x-direction image height x _ h corresponding to the maximum field angle of the optical lens; the total optical length TTL of the optical lens, the maximum x-direction field angle x _ FOV of the optical lens and the x-direction image height x _ h corresponding to the maximum field angle of the optical lens meet the condition that TTL/x _ h/x _ FOV is 0.0196; d/y _ h/y _ FOV is 0.0297 between the maximum y-direction angle of view y _ 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 angle of view of the optical lens, and the y-direction image height y _ h corresponding to the maximum angle of view of the optical lens; the total optical length TTL of the optical lens, the maximum y-direction field angle y _ FOV of the optical lens and the y-direction image height y _ h corresponding to the maximum y-direction field angle of the optical lens meet the condition that TTL/y _ h/y _ FOV is 0.0349.

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, and a fifth lens L5.

Table 5 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 6 below shows cone coefficients k and high-order term coefficients A, B, C, D and E of aspherical lens surfaces S5 to S6 and S8 to S10 that can be used in example 2. Table 7 below shows the paraxial curvature c of biconic freeform lens surfaces S3-S4 that may be used in example 2_x、c_yCoefficient of conicity k_x、k_yAnd high order coefficient α_i、β_i. Table 8 below shows the x-direction focal length value F2x and the y-direction focal length value F2y of the second lens L2 of example 2, the entire set of x-direction focal length value Fx and the entire set of y-direction focal length value Fy of the optical lens, the total optical length TTL 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 x-direction image height x _ h and the y-direction image height y _ h corresponding to the maximum field angle of the optical lens, the maximum x-direction field angle x _ FOV and the maximum y-direction field angle y _ FOV of the optical lens.

TABLE 5

TABLE 6

Flour mark

K

A

B

C

D

E

5

0.9470

-1.0585E-02

1.6717E-02

-9.5562E-04

-7.5422E-04

0.0000E+00

6

-1.3414

-1.4865E-03

3.5424E-02

-4.8883E-02

1.9595E-02

0.0000E+00

8

-1.9665

-2.9063E-03

3.6762E-02

-1.0808E-01

1.2883E-01

0.0000E+00

9

-1.3901

-8.1000E-02

6.4821E-02

-4.2018E-02

1.1730E-02

0.0000E+00

10

-3.2581

-6.7108E-02

4.7609E-02

-1.4511E-02

2.4134E-03

0.0000E+00

TABLE 7

Flour mark	cy	ky	cx	kx
						3	0.4098	-1.2047	0.2957	1.1801
4	0.8280	-0.7822	0.6840	-1.3748
						Flour mark	α4	α6	α8	α10	α12
3	3.4109E-02	-6.7245E-03	8.2931E-05	1.9841E-04	-3.2731E-05
						4	7.7635E-02	-5.2225E-03	-7.2746E-04	-2.8172E-03	1.0798E-03
Flour mark	β4	β6	β8	β10	β12
						3	1.5046E-02	-2.6459E-03	7.8530E-05	2.1611E-05	0.0000E+00
4	-9.7978E-03	-3.4335E-03	-4.5369E-03	1.3186E-03	0.0000E+00

TABLE 8

\|F2x\|(mm)	5.9160	x_h(mm)	3.6460
				\|F2y\|(mm)	6.1034	y_h(mm)	2.9700
\|Fx\|(mm)	1.1207	x_FOV(°)	180.0000
				\|Fy\|(mm)	1.1483	y_FOV(°)	124.0000
TTL(mm)	12.6387
				D(mm)	11.0321

In the present embodiment, | Fy/Fx |, which is 1.0246, is satisfied between the entire set of x-direction focal length values Fx and the entire set of y-direction focal length values Fy of the optical lens; the second lens L2 satisfies | F2y/F2x | -1.0317 between the x-direction focal length value F2x and the y-direction focal length value F2 y; the cemented surface angle arctan (SAG (S9)/d (S9)) -41.2757 of the optical lens, where d (S9) is the half aperture of the maximum clear aperture of the cemented surface S9 of the fourth lens L4 and the fifth lens L5 corresponding to the maximum field angle of the optical lens, and SAG (S9) is the SAG value corresponding thereto; d/x _ h/x _ FOV is 0.0168 between the maximum x-direction field angle x _ FOV of the optical lens, the maximum light-transmitting 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 x-direction image height x _ h corresponding to the maximum field angle of the optical lens; the total optical length TTL of the optical lens, the maximum x-direction field angle x _ FOV of the optical lens and the x-direction image height x _ h corresponding to the maximum field angle of the optical lens meet the condition that TTL/x _ h/x _ FOV is 0.0193; d/y _ h/y _ FOV is 0.0300 between the maximum y-direction angle of view y _ FOV of the optical lens, the maximum light-passing aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum angle of view of the optical lens, and the y-direction image height y _ h corresponding to the maximum angle of view of the optical lens; the total optical length TTL of the optical lens, the maximum y-direction field angle y _ FOV of the optical lens and the y-direction image height y _ h corresponding to the maximum y-direction field angle of the optical lens satisfy the condition that the TTL/y _ h/y _ FOV is 0.0343.

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, and a fifth lens L5.

The fourth lens L4 is a biconvex lens with positive optical power, and has both the object-side surface S8 and the image-side surface S9 convex. The fifth lens L5 is a meniscus lens with negative power, with the object side S9 being concave and the image side S10 being convex. Wherein the fourth lens L4 and the fifth lens L5 are cemented with each other to form a cemented lens.

Table 9 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 10 shows conic coefficients k and high-order term coefficients A, B, C, D and E that can be used for the aspherical lens surfaces S5 to S6 and S8 to S10 in example 3. Table 11 below shows the paraxial curvature c of biconic free-form surface lens surfaces S3-S4 that can be used in example 3_x、c_yCoefficient of conicity k_x、k_yAnd high order coefficient α_i、β_i. Table 12 below shows the x-direction focal length value F2x and the y-direction focal length value F2y of the second lens L2 of example 3, the entire set of x-direction focal length value Fx and the entire set of y-direction focal length value Fy of the optical lens, the total optical length TTL 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 x-direction image height x _ h and the y-direction image height y _ h corresponding to the maximum field angle of the optical lens, the maximum x-direction field angle x _ FOV and the maximum y-direction field angle y _ FOV of the optical lens.

TABLE 9

Watch 10

Flour mark

K

A

B

C

D

E

5

1.2342

-1.7671E-02

1.3655E-02

-1.0127E-03

-2.3279E-04

0.0000E+00

6

-0.7728

-9.1110E-03

2.8521E-02

-4.4507E-02

2.6476E-02

0.0000E+00

8

-1.5116

2.4434E-02

1.4500E-02

-1.1187E-02

1.0721E-02

0.0000E+00

9

-1.1327

-2.9933E-02

2.6428E-02

-3.0576E-02

-1.1005E-01

0.0000E+00

10

-11.8960

1.4227E-02

-2.0807E-03

-5.8751E-04

1.8274E-03

0.0000E+00

TABLE 11

	cy	ky	cx	kx
							0.4144	-1.1488	0.2939	0.8315
	0.7373	-0.4965	0.5664	0.2944
						Flour mark	α4	α6	α8	α10	α12
3	4.3544E-02	-8.0165E-03	1.3539E-04	2.1451E-04	-2.4918E-05
						4	4.9836E-02	9.6139E-03	-2.7196E-05	-3.8118E-03	1.2287E-03
Flour mark	β4	β6	β8	β10	β12
						3	9.6167E-03	-3.0127E-03	8.1824E-05	1.5661E-05	0.0000E+00
4	6.3958E-03	-7.0251E-03	-6.2003E-03	1.6730E-03	0.0000E+00

TABLE 12

\|F2x\|(mm)	9.3251	x_h(mm)	3.6060
				\|F2y\|(mm)	9.4514	y_h(mm)	2.8920
\|Fx\|(mm)	1.5434	x_FOV(°)	180.0000
				\|Fy\|(mm)	1.5995	y_FOV(°)	124.0000
TTL(mm)	12.1206
				D(mm)	13.9210

In the present embodiment, | Fy/Fx |, which is 1.0364, is satisfied between the entire set of x-direction focal length values Fx and the entire set of y-direction focal length values Fy of the optical lens; the second lens L2 satisfies | F2y/F2x | -1.0136 between the x-direction focal length value F2x and the y-direction focal length value F2 y; the cemented surface angle arctan (SAG (S9)/d (S9)) -70.9716 of the optical lens, where d (S9) is the half aperture of the maximum clear aperture of the cemented surface S9 of the fourth lens L4 and the fifth lens L5 corresponding to the maximum field angle of the optical lens, and SAG (S9) is the SAG value corresponding thereto; d/x _ h/x _ FOV is 0.0214 between the maximum x-direction field angle x _ FOV of the optical lens, the maximum light transmission 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 x-direction image height x _ h corresponding to the maximum field angle of the optical lens; the total optical length TTL of the optical lens, the maximum x-direction field angle x _ FOV of the optical lens and the x-direction image height x _ h corresponding to the maximum field angle of the optical lens meet the condition that TTL/x _ h/x _ FOV is 0.0187; d/y _ h/y _ FOV is 0.0388 between the maximum y-direction field angle y _ 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 y-direction image height y _ h corresponding to the maximum field angle of the optical lens; the total optical length TTL of the optical lens, the maximum y-direction field angle y _ FOV of the optical lens and the y-direction image height y _ h corresponding to the maximum y-direction field angle of the optical lens satisfy the condition that the TTL/y _ h/y _ FOV is 0.0338.

In summary, examples 1 to 3 each satisfy the relationship shown in table 13 below.

Watch 13

Conditions/examples	1	2	3
				\|Fy/Fx\|	1.0256	1.0246	1.0364
\|F2y/F2x\|	1.0399	1.0317	1.0136
				Arctan(SAG(S9)/d(S9))	40.9124	41.2757	70.9716
D/x_h/x_FOV	0.0167	0.0168	0.0214
				TTL/x_h/x_FOV	0.0196	0.0193	0.0187
D/y_h/y_FOV	0.0297	0.0300	0.0388
				TTL/y_h/y_FOV	0.0349	0.0343	0.0338

The present application also provides an imaging apparatus that may include the optical lens according to the above-described embodiment of the present application and an imaging element for converting an optical image formed by the optical lens into an electrical signal. The imaging 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 device such as a range finding camera or may be an imaging module integrated on a device such as a range finding device.

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, and a fifth lens,

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

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

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

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

the fourth lens and the fifth lens have positive power or negative power, respectively.

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

3. An optical lens as recited in claim 1, wherein the fourth lens element has a positive optical power, and wherein both the object-side surface and the image-side surface are convex.

4. An optical lens barrel according to claim 1, wherein the fifth lens element has a positive optical power, and both the object-side surface and the image-side surface thereof are convex.

5. An optical lens barrel according to claim 1, wherein the fifth lens element has a negative power, and has a concave object-side surface and a convex image-side surface.

6. An optical lens according to claim 1, characterized in that the third lens has an optic refractive index n3 satisfying: n3 is more than or equal to 1.5 and less than or equal to 1.55.

7. An optical lens according to claim 6, wherein the third lens has a lens Abbe number Vd3 satisfying: vd3 is more than or equal to 55 and less than or equal to 58.

8. An optical lens barrel according to any one of claims 1 to 7, wherein the fourth lens and the fifth lens are cemented to each other to form a cemented lens.

9. An optical lens according to any one of claims 1 to 7, characterized in that the second lens element is a biconic free-form surface lens.

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

11. An optical lens according to claim 10, characterized in that the third lens, the fourth lens and the fifth lens are all aspherical lenses.

12. An optical lens according to any one of claims 1 to 7, wherein 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 satisfy: D/h/FOV is less than or equal to 0.04.

13. An optical lens barrel according to any one of claims 1 to 7, wherein the x-direction focal length value F2x of the second lens and the y-direction focal length value F2y of the second lens satisfy: the absolute value of F2y/F2x is more than or equal to 1 and less than or equal to 5.

14. An optical lens according to any one of claims 1 to 7, characterized in that the total set of x-direction focal length values Fx of the optical lens and the total set of y-direction focal length values Fy of the optical lens satisfy: the absolute value Fy/Fx is more than or equal to 1 and less than or equal to 5.

15. An optical lens according to any one of claims 1 to 7, characterized in that the cemented opening angle of the optical lens satisfies:

arctan(SAG(S9)/d(S9))≥35，

wherein d (S9) is a half aperture of a maximum clear aperture of a cemented surface S9 of the fourth lens and the fifth lens corresponding to a maximum angle of view of the optical lens, and

SAG (S9) is the saggital height Sg value corresponding to the gluing surface S9.

16. An optical lens according to any one of claims 1 to 7, wherein an overall optical length TTL of the optical lens, a maximum field angle FOV of the optical lens, and an image height h corresponding to the maximum field angle of the optical lens satisfy: TTL/h/FOV is less than or equal to 0.05.

17. 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, and a fifth lens,

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

the first lens and the second lens each have a negative optical power;

the third lens has positive optical power;

the fourth lens and the fifth lens are mutually glued to form a cemented lens; and

the whole group of x-direction focal length values Fx of the optical lens and the whole group of y-direction focal length values Fy of the optical lens meet the following conditions: the absolute value Fy/Fx is more than or equal to 1 and less than or equal to 5.

18. An imaging apparatus comprising the optical lens of claim 1 or 17 and an imaging element for converting an optical image formed by the optical lens into an electric signal.