CN110967806B

CN110967806B - Optical lens

Info

Publication number: CN110967806B
Application number: CN201811156979.6A
Authority: CN
Inventors: 李响; 王东方; 姚波
Original assignee: Ningbo Sunny Automotive Optech Co Ltd
Current assignee: Ningbo Sunny Automotive Optech Co Ltd
Priority date: 2018-09-30
Filing date: 2018-09-30
Publication date: 2021-07-30
Anticipated expiration: 2038-09-30
Also published as: CN110967806A

Abstract

The present application discloses an optical lens, which sequentially comprises, from an object side to an image side along an optical axis: the lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth 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 both the object side surface and the image side surface of the third lens are convex surfaces; the fourth lens can have positive focal power, and both the object side surface and the image side surface of the fourth lens are convex surfaces; the fifth lens element may have a negative focal power, and both the object-side surface and the image-side surface thereof may be concave; and the sixth lens element may have a positive optical power, and both the object-side surface and the image-side surface thereof are convex. According to the optical lens of the present application, at least one of advantageous effects of miniaturization, high resolution, a large field angle, low cost, a small front end aperture, low sensitivity, a large aperture, a small CRA, and the like can be achieved.

Description

Optical lens

Technical Field

The present application relates to an optical lens, and more particularly, to an optical lens including six lenses.

Background

Owing to the rapid development of automobile driving-assisting systems in recent years, lenses are increasingly widely applied to automobiles. With the rapid popularization of rearview mirrors, panoramic lenses and the like, the requirements of wide-angle lenses are continuously increased, and a wider field of view and clearer resolving power are required.

In general, an optical lens can improve resolution by increasing the number of lenses, and an aspherical surface is used to correct aberration. In order to improve the resolution, the overall length of the system is often sacrificed, which is contrary to the miniaturization trend of the existing vehicle-mounted lens, and meanwhile, the cost is greatly increased. In addition, the optical lens requires a larger aperture to achieve use in low light environments; smaller CRAs are also required so that no color cast occurs when the chips are matched.

Disclosure of Invention

The present application provides an optical lens that is adaptable for on-board installation and that overcomes, at least in part, at least one of the above-identified deficiencies in the prior art.

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

In one embodiment, any two lenses of the first to sixth lenses may be separated from each other.

In one embodiment, the optical lens may have at least four aspheric lenses.

In one embodiment, each of the second lens, the fourth lens, and the sixth lens may be an aspheric lens.

In one embodiment, the optical back focus BFL of the optical lens and the total optical length TTL of the optical lens may satisfy: BFL/TTL is less than or equal to 0.3.

In one embodiment, the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, and the image height H corresponding to the maximum field angle of the optical lens may satisfy: D/H/FOV is less than or equal to 0.06.

In one embodiment, the sago 22 of the image side surface of the second lens and the half aperture d22 of the image side surface of the second lens satisfy: arctan (SAG22/d22) ≧ 55.

In one embodiment, a radius of curvature R12 of the object-side surface of the sixth lens and a radius of curvature R13 of the image-side surface of the sixth lens may satisfy: the ratio of (R12+ R13)/(R12-R13) is not more than 0.4 and not more than-0.05.

In one 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 0.045.

In one embodiment, the focal length value F6 of the sixth lens and the focal length value F of the whole group of the optical lens satisfy: F6/F is less than or equal to 4.2.

In one embodiment, the maximum field angle FOV of the optical lens may be greater than or equal to 180 °.

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

Another aspect of the present application provides an optical lens that may include, in order from an object side to an image side along an optical axis: the lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The first lens, the second lens and the fifth lens can all have negative focal power; the third lens, the fourth lens and the sixth lens may each have positive optical power; and the optical back focus BFL of the optical lens and the optical total length TTL of the optical lens can meet the following requirements: BFL/TTL is less than or equal to 0.3.

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

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

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

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

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

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

In one embodiment, the optical lens may have at least four aspheric lenses.

The optical lens adopts six lenses, and at least one of the beneficial effects of high resolution, large field angle, miniaturization, small front end caliber, low sensitivity, high production yield, low cost, large aperture, small CRA and the like of the optical lens is realized by optimally setting the shapes of the lenses and reasonably distributing the focal power of each lens.

Drawings

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

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

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

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

fig. 4 schematically shows the half aperture d of the maximum clear aperture of the object-side surface of the lens and its corresponding sago value SAG.

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, six lenses having optical power, i.e., a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The six lenses are arranged in order from the object side to the image side along the optical axis.

The optical lens according to the exemplary embodiment of the present application may further include a photosensitive element disposed on the image plane. Alternatively, the photosensitive element provided to the imaging surface may be a photosensitive coupling element (CCD) or a complementary metal oxide semiconductor element (CMOS).

The first lens element can have a negative power, and can have a convex object-side surface and a concave image-side surface. The first lens is arranged in a meniscus shape which is convex towards the object side, so that light with a large view field can be collected as far as possible, the light enters a rear optical system, and the light flux is increased. In practical application, considering that the outdoor installation and use environment of the vehicle-mounted lens can be in severe weather such as rain, snow and the like, the design of the meniscus shape protruding towards the object side is beneficial to the sliding of water drops, is beneficial to the barrier-free use of the lens in severe environments such as rain, snow and the like, and reduces the influence on imaging. Optionally, the first lens can be made of a high-refractive-index material, for example, the refractive index Nd1 of the material of the first lens can satisfy Nd1 ≥ 1.65, and further, Nd1 ≥ 1.7, so as to facilitate further reducing the front-end aperture and improving the imaging quality of the lens.

The second lens element can have a negative power, and can have a convex object-side surface and a concave image-side surface. The second lens can give off light, makes the light trend gently transition to rear optical system, can collect wide-angle light as far as possible simultaneously, promotes the illuminance, and such setting more is favorable to reducing rear light optical path, helps realizing short TTL.

The third lens element can have a positive optical power, and both the object-side surface and the image-side surface can be convex. The third lens can converge the light, so that the diffused light can smoothly enter the rear optical system. In addition, the third lens is arranged to have positive focal power and can compensate the spherical aberration introduced by the first two groups of lenses.

The fourth lens element can have a positive optical power, and can have a convex object-side surface and a convex image-side surface. The fourth lens with positive focal power can further correct the aberration generated by the front lens group and make the light beam converge again, so that the arrangement can not only increase the aperture of the lens, but also shorten the total length of the lens, so that the optical system is more compact, and the whole lens has relatively short total length.

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 is used, and the lenses with positive focal lengths are matched in front and back, so that the field curvature can be further reduced, and the off-axis point aberration of the system can be corrected.

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 sixth lens can converge the light passing through the regional lens, so that the light is more smoothly transited to an imaging surface, and the total length of the system is favorably reduced; meanwhile, various aberrations of the optical system can be fully corrected, the resolution can be improved, and the optical performances such as distortion, CRA and the like can be optimized on the premise of compact structure.

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, the light rays entering the system can be effectively converged, and the aperture of the lens of the optical system can be 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 sixth lens and the imaging surface to filter light rays having different wavelengths, as necessary; and may further include a protective glass disposed between the optical filter and the imaging surface to prevent internal elements (e.g., chips) of the optical lens from being damaged.

In an exemplary embodiment, the optical back focus BFL of the optical lens and the total optical length TTL of the optical lens may satisfy: the BFL/TTL is less than or equal to 0.3, and more ideally, the BFL/TTL is more than or equal to 0.02 and less than or equal to 0.2. By such arrangement, and in combination with the overall structure, the optical back focus can be controlled within a reasonable range, so as to prevent the back focus from being too short to facilitate the assembly of the lens group, and prevent the total length of the lens group from being too long due to the too long back focus.

In an exemplary embodiment, the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface of the first lens corresponding to the maximum field angle of the optical lens, and the image height H corresponding to the maximum field angle of the optical lens may satisfy: D/H/FOV is less than or equal to 0.06, and more desirably, D/H/FOV is less than or equal to 0.045. The conditional expression D/H/FOV is less than or equal to 0.06, and the small caliber at the front end of the lens can be realized.

In an exemplary embodiment, the sago 22 and the half aperture d22 of the image side surface of the second lens can satisfy: the arctan (SAG22/d22) is more than or equal to 55, and more ideally, the arctan (SAG22/d22) can be further satisfied to be more than or equal to 60. The condition that arctan (SAG22/d22) is equal to or more than 55 is met, so that the illumination can be favorably improved; on the other hand, a fast transition of the light can be facilitated.

In an exemplary embodiment, a radius of curvature R12 of the object-side surface and a radius of curvature R13 of the image-side surface of the sixth lens may satisfy: (R12+ R13)/(R12-R13) is not more than-0.4 but not more than-0.05, more preferably not more than-0.35 (R12+ R13)/(R12-R13) is not more than-0.1. The sixth lens is the lens most sensitive to the yield among all the lenses, and the conditional expressions are satisfied, so that the forming processability of the sixth lens is facilitated, and the manufacturing yield is improved. In addition, through the arrangement, tolerance sensitivity problems such as inclination/decentration generated in the assembling process of the lens unit can be reduced.

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 0.045, and ideally, TTL/H/FOV is less than or equal to 0.035. The condition TTL/H/FOV is less than or equal to 0.045, and the miniaturization characteristic of the lens can be ensured.

In an exemplary embodiment, a focal length value F6 of the sixth lens and a focal length value F of the entire group of the optical lens may satisfy: F6/F is not more than 4.2, and more preferably, F6/F is not more than 3.5. By controlling the sixth lens to have a short focal length, it is possible to control the light-receiving performance of the sixth lens and ensure the amount of transmitted light.

In an exemplary embodiment, the maximum field angle FOV of the optical lens may be greater than or equal to 180 °. With this configuration, a wide-angle function of the lens can be realized.

In an exemplary embodiment, an optical lens according to the present application may have at least four aspherical lenses. Further, the second lens, the fourth lens and the sixth lens can be aspheric 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. It is understood that the optical lens according to the present application may increase the number of aspherical lenses in order to improve the imaging quality.

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

According to the optical lens of the embodiment of the application, the shape of the lens is optimally set, the focal power is reasonably distributed, the lens material is reasonably selected, and a six-separation framework is adopted, so that the lens has more degrees of freedom, and high resolution of a wide-angle lens can be realized; meanwhile, the requirements of miniaturization, low sensitivity and high production yield of the lens and low cost can be met; the lens CRA is small, stray light generated when the rear end of light rays is emitted to the lens cone is avoided, the lens CRA can be well matched with a vehicle-mounted chip, and color cast and dark corner phenomena cannot be generated; the large-aperture optical lens has the advantages of large aperture and large field angle, good imaging effect, high image quality reaching high definition level, and capability of ensuring the definition of images even in a low-light environment or at night. Therefore, the optical lens according to the above-described embodiment of the present application can better meet the requirements of the in-vehicle lens.

However, it will be appreciated by those skilled in the art that the number of lenses constituting the lens barrel may be varied to achieve the various results and advantages described in the present specification without departing from the claimed subject matter. For example, although six lenses are exemplified in the embodiment, the optical lens is not limited to including six lenses. The optical lens may also include other numbers of lenses, if desired.

Specific examples of an optical lens applicable to the above-described embodiments are further described below with reference to the drawings.

Example 1

An optical lens according to embodiment 1 of the present application is described below with reference to fig. 1. Fig. 1 shows a schematic structural diagram of an optical lens according to embodiment 1 of the present application.

As shown in fig. 1, the optical lens includes, in order from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6.

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 biconvex lens with positive optical power, and has both the object-side surface S5 and the image-side surface S6 being convex.

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 biconcave lens with negative optical power, and both the object-side surface S10 and the image-side surface S11 are concave.

The sixth lens L6 is a biconvex lens with positive optical power, and has both the object-side surface S12 and the image-side surface S13 convex.

In this embodiment, the second lens L2, the fourth lens L4, and the sixth lens L6 are each an aspherical lens, and each of the object-side surface and the image-side surface thereof is aspherical.

Optionally, the optical lens may further include a filter L7 having an object-side surface S14 and an image-side surface S15 and/or a protective lens L8 having an object-side surface S16 and an image-side surface S17. Filter L7 can be used to correct for color deviations. The protective lens L8 may be used to protect the image sensing chip on the imaging plane IMA. Light from the object passes through each of the surfaces S1 to S17 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 near the object side S8 near the fourth lens L4 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

Flour mark	Radius of curvature R	Thickness T	Refractive index Nd	Abbe number Vd
					1	23.3373	1.2500	1.73	54.67
2	6.1622	3.7901
					3	3.2727	1.2056	1.53	56.07
4	1.0444	3.5685
					5	7.5027	3.2447	1.62	36.26
6	-6.3006	2.4533
					STO	All-round	-0.1402
8	2.4845	0.9361	1.53	56.07
					9	-3.8659	0.2111
10	-2.7575	0.3144	1.64	23.53
					11	2.4941	0.0516
12	2.0426	1.9480	1.53	56.07
					13	-3.0761	0.1000
14	All-round	0.5500	1.52	64.21
					15	All-round	0.9901
16	All-round	0.4000	1.52	64.21
					17	All-round	0.1250
IMA	All-round

The present embodiment adopts six 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 high resolution, large field angle, miniaturization, small front end aperture, low sensitivity, high production yield, low cost, large aperture, small CRA and the like. Each aspherical surface type Z is defined by the following formula:

wherein Z is the distance rise from the vertex of the aspheric surface when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c being 1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1 above); k is the conic coefficient conc; A. b, C, D are all high order term coefficients. Table 2 below shows cone coefficients k and high-order term coefficients A, B, C and D of aspherical lens surfaces S3 to S4, S8 to S13 usable in example 1.

TABLE 2

Flour mark	K	A	B	C	D
						3	-1.5618	-7.9113E-03	3.4396E-04	-8.9224E-06	1.0101E-07
4	-0.8984	-1.1399E-02	-3.1103E-03	4.6841E-04	-3.6028E-05
						8	-0.5128	8.4470E-03	3.0250E-05	-8.5687E-04	-2.6595E-03
9	-0.7649	-2.5173E-03	-7.9444E-03	-4.3630E-03	-3.6365E-03
						10	0.0744	-2.7409E-03	-4.6057E-03	-4.1041E-03	-3.2750E-04
11	-4.9203	-2.2207E-02	2.8944E-02	-8.9993E-03	1.6281E-03
						12	-7.0449	4.0183E-03	6.5296E-03	-1.4433E-03	1.0719E-04
13	0.6617	2.3548E-02	7.0045E-04	4.8236E-04	1.6289E-05

Table 3 below gives an optical back focus BFL of the optical lens of embodiment 1 (i.e., an on-axis distance from the center of the image-side surface S13 of the last lens sixth lens L6 to the imaging surface IMA), an optical total length TTL of the optical lens (i.e., an on-axis distance from the center of the object-side surface S1 of the first lens L1 to the imaging surface IMA), a maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to a maximum angle of view of the optical lens, an image height H corresponding to a maximum angle of view of the optical lens, a maximum angle of view FOV of the optical lens, a refractive index Nd1 of a material of the first lens L1, a full-group focal length value F of the optical lens, curvature radii R12 and R13 of the object-side surface S12 and the image-side surface S13 of the sixth lens L6, and a focal length value F6 of the sixth lens L6.

TABLE 3

BFL(mm)	2.1651	F(mm)	1.1412
				TTL(mm)	20.9983	R12(mm)	2.0426
D(mm)	21.0157	R13(mm)	-3.0761
				H(mm)	4.8460	F6(mm)	2.6369
FOV(°)	189
				Nd1	1.73

In the present embodiment, D/H/FOV is 0.023 between the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, and the image height H corresponding to the maximum field angle of the optical lens; the BFL/TTL is 0.103 between the optical back focus BFL of the optical lens and the optical total length TTL of the optical lens; the arrow height SAG22 and the half-aperture d22 (as shown in fig. 4) of the image side surface S4 of the second lens L2 satisfy 66.092 (SAG22/d 22); the radii of curvature R12 and R13 of the object-side surface S12 and the image-side surface S13 of the sixth lens L6 satisfy (R12+ R13)/(R12-R13) — 0.202; F6/F is 2.311 between the focal length value F6 of the sixth lens L6 and the focal length value F of the entire group of the optical lens; and 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 meet that TTL/H/FOV is 0.023.

Example 2

An optical lens according to embodiment 2 of the present application is described below with reference to fig. 2. In this embodiment and the following embodiments, descriptions of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 2 shows a schematic structural diagram of an optical lens according to embodiment 2 of the present application.

As shown in fig. 2, the optical lens includes, in order from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6.

Table 4 below shows a radius of curvature R, a thickness T, a refractive index Nd, and an abbe number Vd of each lens of the optical lens of example 2, where the radius of curvature R and the thickness T are both in units of millimeters (mm). The following table 5 shows the conic coefficients k and the high-order term coefficients A, B, C and D which can be used for the aspherical lens surfaces S3 to S4, S8 to S13 in example 2. Table 6 below gives the optical back focus BFL of the optical lens of example 2, the optical total 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 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 refractive index Nd1 of the material of the first lens L1, the entire group focal length value F of the optical lens, the curvature radii R12 and R13 of the object-side surface S12 and the image-side surface S13 of the sixth lens L6, and the focal length value F6 of the sixth lens L6.

TABLE 4

TABLE 5

Flour mark	K	A	B	C	D
						3	-1.5815	-7.9268E-03	3.4342E-04	-8.9323E-06	1.0117E-07
4	-0.8980	-1.1309E-02	-3.1359E-03	4.6493E-04	-3.6061E-05
						8	-0.3409	9.4396E-03	-2.4175E-04	1.5800E-04	-6.4808E-03
9	-1.3724	-6.1670E-04	-1.2415E-02	-5.4181E-03	-8.6947E-03
						10	0.5099	-6.5627E-03	-6.4298E-03	-8.6204E-03	-1.0002E-03
11	-4.7081	-2.1993E-02	2.9079E-02	-8.5032E-03	1.3985E-03
						12	-6.7790	6.6596E-03	7.3369E-03	-1.6466E-03	8.7825E-05
13	0.5425	2.4247E-02	1.3407E-03	6.5465E-04	7.9095E-06

TABLE 6

BFL(mm)	2.1245	F(mm)	1.1441
				TTL(mm)	20.4501	R12(mm)	2.0426
D(mm)	19.7985	R13(mm)	-3.2094
				H(mm)	4.8360	F6(mm)	2.6529
FOV(°)	189
				Nd1	1.73

In the present embodiment, D/H/FOV is 0.022 between the maximum field angle 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 image height H corresponding to the maximum field angle of the optical lens; the BFL/TTL is 0.104 between the optical back focus BFL of the optical lens and the optical total length TTL of the optical lens; the arrow height SAG22 and the half-bore d22 of the image side surface S4 of the second lens L2 satisfy 65.244 (SAG22/d 22); the radii of curvature R12 and R13 of the object-side surface S12 and the image-side surface S13 of the sixth lens L6 satisfy (R12+ R13)/(R12-R13) — 0.222; F6/F2.319 is satisfied between the focal length value F6 of the sixth lens L6 and the focal length value F of the entire group of optical lenses; and 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 meet that TTL/H/FOV is 0.022.

Example 3

An optical lens according to embodiment 3 of the present application is described below with reference to fig. 3. In this embodiment and the following embodiments, descriptions of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 3 shows a schematic structural diagram of an optical lens according to embodiment 3 of the present application.

As shown in fig. 3, the optical lens includes, in order from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6.

Table 7 below shows a radius of curvature R, a thickness T, a refractive index Nd, and an abbe number Vd of each lens of the optical lens of example 3, where the radius of curvature R and the thickness T are both in units of millimeters (mm). The following table 8 shows the conic coefficients k and the high-order term coefficients A, B, C and D which can be used for the aspherical lens surfaces S3 to S4, S8 to S13 in example 3. Table 9 below gives the optical back focus BFL of the optical lens of example 3, the optical total 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 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 refractive index Nd1 of the material of the first lens L1, the entire group focal length value F of the optical lens, the radius of curvature R12 and R13 of the object-side surface S12 and the image-side surface S13 of the sixth lens L6, and the focal length value F6 of the sixth lens L6.

TABLE 7

Flour mark	Radius of curvature R	Thickness T	Refractive index Nd	Abbe number Vd
					1	24.6450	1.2500	1.73	54.67
2	6.0935	2.4403
					3	3.3517	1.2065	1.53	56.07
4	1.0477	3.2774
					5	7.8929	3.6341	1.62	36.26
6	-5.9821	2.3863
					STO	All-round	-0.1410
8	2.3222	0.7566	1.53	56.07
					9	-4.2346	0.2220
10	-3.1081	0.4503	1.64	23.53
					11	2.5079	0.1075
12	2.0982	1.8083	1.53	56.07
					13	-3.4877	0.1000
14	All-round	0.5500	1.52	64.21
					15	All-round	0.9419
16	All-round	0.4000	1.52	64.21
					17	All-round	0.1250
IMA	All-round

TABLE 8

Flour mark	K	A	B	C	D
						3	-1.5899	-7.9341E-03	3.4330E-04	-8.9292E-06	1.0148E-07
4	-0.8978	-1.1511E-02	-3.1342E-03	4.6548E-04	-3.5920E-05
						8	-0.3279	9.7615E-03	-4.8562E-04	9.4299E-04	-1.1239E-02
9	-3.2698	2.0842E-03	-2.1019E-02	-7.9099E-03	-8.7576E-03
						10	0.9766	-9.1623E-03	-9.2293E-03	-1.1190E-02	1.7805E-03
11	-4.8089	-2.3351E-02	2.8818E-02	-7.3173E-03	1.1355E-03
						12	-6.2785	1.0065E-02	7.1227E-03	-2.0734E-03	2.1108E-04
13	0.3305	2.5288E-02	2.0996E-03	8.3829E-04	-6.0093E-05

TABLE 9

BFL(mm)	2.1169	F(mm)	1.1822
				TTL(mm)	19.5152	R12(mm)	2.0982
D(mm)	17.8466	R13(mm)	-3.4877
				H(mm)	4.8060	F6(mm)	2.7513
FOV(°)	189
				Nd1	1.73

In the present embodiment, D/H/FOV is 0.020 between the maximum field angle 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 image height H corresponding to the maximum field angle of the optical lens; the BFL/TTL between the optical back focus BFL of the optical lens and the optical total length TTL of the optical lens is 0.108; the arrow height SAG22 and the half-bore d22 of the image side surface S4 of the second lens L2 satisfy 65.083 (SAG22/d 22); the radii of curvature R12 and R13 of the object-side surface S12 and the image-side surface S13 of the sixth lens L6 satisfy (R12+ R13)/(R12-R13) — 0.249; F6/F is 2.327 between the focal length value F6 of the sixth lens L6 and the focal length value F of the entire group of the optical lens; and 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 meet the condition that TTL/H/FOV is 0.021.

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

Watch 10

Conditions/examples	1	2	3
				D/H/FOV	0.023	0.022	0.020
BFL/TTL	0.103	0.104	0.108
				arctan(SAG22/d22)	66.092	65.244	65.083
(R12+R13)/(R12-R13)	-0.202	-0.222	-0.249
				F6/F	2.311	2.319	2.327
TTL/H/FOV	0.023	0.022	0.021

The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by a person skilled in the art that the scope of the invention as referred to in the present application is not limited to the embodiments with a specific combination of the above-mentioned features, but also covers other embodiments with any combination of the above-mentioned features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.

Claims

1. An optical lens, wherein the number of lenses having refractive power is six, and the lenses are respectively a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, the first lens to the sixth lens are arranged in order from an object side to an image side along an optical axis,

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

the first lens 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, 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, and both the object side surface and the image side surface of the fourth lens are convex surfaces;

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

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;

wherein the focal length value F6 of the sixth lens and the focal length value F of the whole group of the optical lens satisfy: F6/F is less than or equal to 4.2; and

wherein the saggital height SAG22 of the image side surface of the second lens and the half aperture d22 of the image side surface of the second lens satisfy that: arctan (SAG22/d22) ≧ 55.

2. An optical lens according to claim 1, wherein any two of the first to sixth lenses are separated from each other.

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

4. An optical lens according to claim 3, wherein the second lens, the fourth lens to the sixth lens are all aspheric lenses.

5. An optical lens according to any one of claims 1-4, characterized in that between an optical back focus BFL of the optical lens and an optical total length TTL of the optical lens, it is satisfied that: BFL/TTL is less than or equal to 0.3.

6. An optical lens according to any one of claims 1 to 4, characterized in that the conditional expression is satisfied:

(D*180°)/(H*FOV)≤10.80，

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

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

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

7. An optical lens barrel according to any one of claims 1 to 4, wherein a radius of curvature R12 of an object side surface of the sixth lens and a radius of curvature R13 of an image side surface of the sixth lens satisfy: the ratio of (R12+ R13)/(R12-R13) is not more than 0.4 and not more than-0.05.

8. An optical lens according to any one of claims 1 to 4, characterized in that the conditional expression is satisfied:

(TTL*180°)/(H*FOV)≤8.100，

wherein, TTL is the total optical length of the optical lens;

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

9. An optical lens according to any of claims 1-4, characterized in that the maximum field angle FOV of the optical lens is equal to or larger than 180 °.

10. An optical lens as claimed in any one of claims 1 to 4, characterized in that the refractive index of the material of the first lens is 1.65 or higher.

11. An optical lens, wherein the number of lenses having refractive power is six, and the lenses are respectively a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, the first lens to the sixth lens are arranged in order from an object side to an image side along an optical axis,

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

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

the third lens, the fourth lens and the sixth lens each have positive optical 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; and

the optical back focus BFL of the optical lens and the optical total length TTL of the optical lens meet the following requirements: BFL/TTL is less than or equal to 0.3;

the focal length value F6 of the sixth lens and the focal length value F of the whole group of the optical lens satisfy that: F6/F is less than or equal to 4.2;

the saggital height SAG22 of the image side surface of the second lens and the half aperture d22 of the image side surface of the second lens satisfy that: arctan (SAG22/d22) ≧ 55.

12. An optical lens barrel according to claim 11, wherein the object side surface of the first lens element is convex and the image side surface of the first lens element is concave.

13. An optical lens barrel according to claim 11, wherein the object side surface and the image side surface of the third lens are convex.

14. An optical lens barrel according to claim 11, wherein the object-side surface and the image-side surface of the fourth lens are convex.

15. An optical lens barrel according to claim 11, wherein the fifth lens element has both object and image side surfaces that are concave.

16. An optical lens barrel according to claim 11, wherein the object-side surface and the image-side surface of the sixth lens element are convex.

17. An optical lens barrel according to any one of claims 11 to 16, wherein any two of the first to sixth lenses are separated from each other.

18. An optical lens according to any one of claims 11-16, characterized in that the optical lens has at least four aspherical lenses.

19. An optical lens according to claim 18, wherein the second lens, the fourth lens to the sixth lens are all aspheric lenses.

20. An optical lens according to any one of claims 11 to 16, characterized in that the conditional expression is satisfied:

(D*180°)/(H*FOV)≤10.80，

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

21. An optical lens barrel according to any one of claims 11 to 16, wherein a radius of curvature R12 of an object side surface of the sixth lens and a radius of curvature R13 of an image side surface of the sixth lens satisfy: the ratio of (R12+ R13)/(R12-R13) is not more than 0.4 and not more than-0.05.

22. An optical lens according to any one of claims 11 to 16, characterized in that the conditional expression is satisfied:

(TTL*180°)/(H*FOV)≤8.100，

wherein, TTL is the total optical length of the optical lens;

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

23. An optical lens as claimed in any one of claims 11 to 16, characterized in that the maximum field angle FOV of the optical lens is equal to or greater than 180 °.

24. An optical lens as claimed in any one of claims 11 to 16, characterized in that the refractive index of the material of the first lens is 1.65 or higher.