CN111239964B - Optical lens and imaging apparatus - Google Patents

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, 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 object side surface of the second lens can be a concave surface, and the image side surface can be a convex surface; the third lens can have positive focal power, and the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; 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 can have positive focal power, and both the object side surface and the image side surface of the fifth lens are convex surfaces; and the sixth lens element can have a negative power, and the object-side surface of the sixth lens element is concave and the image-side surface of the sixth lens element is convex. According to the optical lens, at least one of the beneficial effects of high resolution, miniaturization, small front-end caliber, small distortion, low cost, good temperature performance 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 including the same, and more particularly, to an optical lens and an imaging apparatus including six lenses.

Background

Owing to the rapid development of automobile driving-assisting systems in recent years, lenses are increasingly widely applied to automobiles, and the pixel requirements of vehicle-mounted application optical lenses are increasingly higher. At the same time more and more companies are beginning to study autonomous optical lenses.

For safety reasons, the performance requirements of optical lenses for vehicle-mounted applications are usually very high, while those for automatic driving are more stringent. First, the optical lens for automatic driving requires extremely high pixel requirements, and based on the original optical lens for vehicle-mounted applications, the optical lens for automatic driving usually adopts 6, 7 or even more lens structures to improve the resolution, but this will seriously affect the miniaturization of the lens. Especially, the working environment of the optical lens is changeable, and the optical lens needs to have good optical performance in severe weather, so that the requirement on the temperature stability is higher, the variation of the image height is smaller when the temperature changes, and the back focus offset is strictly controlled, so that the imaging quality of the lens is prevented from being reduced due to the fact that the lens has different temperatures. On the other hand, such optical lenses require less distortion to reduce distortion of the image.

Therefore, there is a need in the market for an optical lens with high resolution and small size, good temperature performance, small distortion, low cost, etc. to meet the requirements of, for example, automotive applications.

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 object side surface of the second lens can be a concave surface, and the image side surface can be a convex surface; the third lens can have positive focal power, and the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; 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 can have positive focal power, and both the object side surface and the image side surface of the fifth lens are convex surfaces; and the sixth lens element can have a negative power, and the object-side surface of the sixth lens element is concave and the image-side surface of the sixth lens element is convex.

In one embodiment, the fifth lens and the sixth lens may be cemented with each other to form a cemented lens.

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

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 0.035.

In one embodiment, the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface of the first lens corresponding to the maximum field angle of the optical lens, and the image height H corresponding to the maximum field angle of the optical lens may satisfy: D/H/FOV is less than or equal to 0.03.

In one embodiment, the focal length value F5 of the fifth lens and the focal length value F6 of the sixth lens satisfy: the ratio of F5 to F6 is less than or equal to 4.

In one embodiment, a center thickness dn (n ═ 3, 5, 8, 10, 11) of any of the second to sixth lenses and a center thickness dm (m ═ 3, 5, 8, 10, 11) of any of the second to sixth lenses may satisfy: max { dn/dm }. is less than or equal to 2.5.

In one embodiment, the center radius of curvature R3 of the object-side surface of the second lens, the center radius of curvature R4 of the image-side surface of the second lens, and the center thickness d3 of the second lens may satisfy: the ratio of (R4+ d3)/R3 is less than or equal to 1.5.

In one embodiment, the center radius of curvature R5 of the object-side surface of the third lens, the center radius of curvature R6 of the image-side surface of the third lens, and the center thickness d5 of the third lens may satisfy: the ratio of (R6+ d5)/R5 is less than or equal to 2.5.

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. Wherein the first lens and the sixth lens can both have negative focal power; the third lens, the fourth lens and the fifth lens can all have positive focal power; the fifth lens and the sixth lens can be mutually glued to form a cemented 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 can satisfy the following conditions: TTL/H/FOV is less than or equal to 0.035.

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 second lens element can have a positive or negative power, and the object side surface can be concave and the image side surface can be convex.

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

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

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

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

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

In one embodiment, the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface of the first lens corresponding to the maximum field angle of the optical lens, and the image height H corresponding to the maximum field angle of the optical lens may satisfy: D/H/FOV is less than or equal to 0.03.

In one embodiment, the focal length value F5 of the fifth lens and the focal length value F6 of the sixth lens satisfy: the ratio of F5 to F6 is less than or equal to 4.

In one embodiment, a center thickness dn (n ═ 3, 5, 8, 10, 11) of any of the second to sixth lenses and a center thickness dm (m ═ 3, 5, 8, 10, 11) of any of the second to sixth lenses may satisfy: max { dn/dm }. is less than or equal to 2.5.

In one embodiment, the center radius of curvature R3 of the object-side surface of the second lens, the center radius of curvature R4 of the image-side surface of the second lens, and the center thickness d3 of the second lens may satisfy: the ratio of (R4+ d3)/R3 is less than or equal to 1.5.

In one embodiment, the center radius of curvature R5 of the object-side surface of the third lens, the center radius of curvature R6 of the image-side surface of the third lens, and the center thickness d5 of the third lens may satisfy: the ratio of (R6+ d5)/R5 is less than or equal to 2.5.

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 six lenses, the focal power of each lens is reasonably distributed and the cemented lens is formed by optimally setting the shape of the lens, so that at least one of the beneficial effects of high resolution, miniaturization, small front-end caliber, small distortion, low cost, good temperature performance and the like of the optical lens is realized.

Drawings

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

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

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

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

Detailed Description

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

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

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

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

It will be further understood that the terms "comprises," "comprising," "has," "having," "includes" and/or "including," when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Moreover, when a statement such as "at least one of" appears after a list of listed features, the entirety of the listed features is modified rather than modifying individual elements in the list. Furthermore, when describing embodiments of the present application, the use of "may" mean "one or more embodiments of the present application. Also, the term "exemplary" is intended to refer to an example or illustration.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

The features, principles, and other aspects of the present application are described in detail below.

An optical lens according to an exemplary embodiment of the present application includes, for example, 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 set to be in a meniscus shape with the convex surface facing the object side, so that light rays with a large field of view can be collected as far as possible, the light rays enter a rear optical system, and the light flux is increased. In practical application, the vehicle-mounted application-type lens is considered to be installed outside a room and used in severe weather such as rain, snow and the like, so that the meniscus shape with the convex surface facing the object side is beneficial to the sliding of water drops and reduces the influence on imaging.

The second lens element can have a positive or negative power, and can have a concave object-side surface and a convex image-side surface. The second lens is designed into a meniscus shape with the convex surface facing the image side, so that light rays can correctly and stably enter a rear light ray system, the distortion is favorably reduced, and the resolution is improved.

The third lens element can have a positive power, and can have a convex object-side surface and a concave image-side surface. The third lens is a meniscus lens with positive focal power and is arranged in front of the aperture diaphragm, so that light rays can be converged, the caliber and the lens length of the optical lens are reduced, and the miniaturization is facilitated.

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 has positive focal power, and the fourth lens with positive focal power is used after the aperture stop is arranged, so that aberration generated by the front lens group can be further corrected, and meanwhile, light beams are converged again, so that the aperture of the lens can be enlarged, the total length of the lens can be shortened, the optical system is more compact, and the optical system has relatively shorter total length of the lens.

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

The sixth lens element can have a negative power, and can have a 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, the aperture of the lens of the optical system is reduced, and the aperture of the lens is enlarged. 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.

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

In an exemplary embodiment, the fifth lens and the sixth lens may be combined into a cemented lens by cementing the image-side surface of the fifth lens with the object-side surface of the sixth lens. In the cemented lens, the fifth lens can be an aspheric lens and has positive focal power, and the sixth lens can be an aspheric lens and has negative focal power, so that the light rays passing through the fifth lens can be smoothly transited to an imaging surface, and the total length is reduced. In addition, various aberrations of the optical system can be fully corrected, and on the premise of compact structure, the resolution can be improved, and optical performances such as distortion, CRA and the like can be optimized. The double-cemented lens group can effectively reduce the air space between the two lenses and reduce the total length of the system; the assembling parts between the two lenses can be reduced, the assembling procedures can be reduced, and the cost can be reduced; the tolerance sensitivity problems of inclination/core deviation and the like generated in the assembling process of the lens unit can be reduced; the light quantity loss caused by reflection between the lenses can be reduced, and the illumination intensity is improved; in addition, the cemented lens itself can be achromatic, which can further reduce curvature of field and correct the off-axis point aberration of the system. The use of the cemented lens shares the whole chromatic aberration correction of the system, can effectively correct the aberration so as to improve the resolution, and ensures that the optical system is integrally compact and meets the miniaturization requirement.

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 0.035, and more preferably, TTL/H/FOV is less than or equal to 0.03. Satisfies the conditional expression TTL/H/FOV less than or equal to 0.03, and can ensure the miniaturization characteristic.

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 0.03 or less, and more preferably, D/H/FOV is 0.025 or less. The requirement of the conditional expression D/H/FOV is less than or equal to 0.03, the small caliber at the front end can be ensured, and the miniaturization characteristic is realized.

In an exemplary embodiment, a focal length value F5 of the fifth lens and a focal length value F6 of the sixth lens may satisfy: the | F5/F6| is less than or equal to 4, and more ideally, the | F5/F6| is less than or equal to 3.5. The focal length values of the fifth lens and the sixth lens are close to each other through arrangement, so that smooth transition of light rays can be facilitated, and chromatic aberration can be corrected.

In an exemplary embodiment, a center thickness dn (n ═ 3, 5, 8, 10, 11) of any of the second to sixth lenses and a center thickness dm (m ═ 3, 5, 8, 10, 11) of any of the second to sixth lenses may satisfy: max { dn/dm }. ltoreq.2.5, and more desirably, max { dn/dm }. ltoreq.2 can be further satisfied. The central thicknesses of the lenses in the second lens to the sixth lens are close to each other through arrangement, so that the light deflection change of the integral optical lens at high and low temperatures is small, and the temperature performance is good.

In an exemplary embodiment, the center radius of curvature R3 of the object-side surface of the second lens, the center radius of curvature R4 of the image-side surface of the second lens, and the center thickness d3 of the second lens may satisfy: i (R4+ d 3)/R3I is not more than 1.5, more preferably, it further satisfies I (R4+ d 3)/R3I not more than 1. Through the special shape setting of second lens, can reduce the distortion, promote the formation of image quality.

In an exemplary embodiment, the center radius of curvature R5 of the object-side surface of the third lens, the center radius of curvature R6 of the image-side surface of the third lens, and the center thickness d5 of the third lens may satisfy: i (R6+ d 5)/R5I is not more than 2.5, more preferably, it further satisfies I (R6+ d 5)/R5I not more than 2. Through the special shape setting of third lens, can reduce the distortion, promote the formation of image quality.

In an exemplary embodiment, the second lens, the fifth lens, and the sixth lens in the optical lens according to the present application may employ 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. It is to be understood that the optical lens according to the present application may also increase the number of aspherical lenses in order to improve the imaging quality. For example, the first lens may optionally employ an aspheric lens to further improve the resolution quality. In the case of focusing on the resolution quality of the lens, the first lens element to the sixth lens element may be aspheric lens elements.

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 above embodiment of the present application, through reasonable lens shape setting and focal power setting, high resolution can be achieved by using a 6-piece structure, and the low-cost requirements of small lens volume, low sensitivity and high production yield can be met. The optical lens CRA is small, stray light generated when the rear end of light rays is emitted to a lens barrel can be avoided, the optical lens CRA can be well matched with a vehicle-mounted chip, and color cast and dark corner phenomena cannot be generated. The optical lens has good temperature performance, small imaging effect change at high and low temperatures, stable image quality, small distortion and good imaging effect. Therefore, the optical lens according to the above-mentioned embodiment of the present application can have at least one of the advantages of high resolution, miniaturization, small aperture at the front end, small distortion, low cost, good temperature performance, etc., and can better meet the application requirements of, for example, an in-vehicle 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 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 concave and the image side S4 being convex.

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

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 biconvex lens with positive optical power, and has both the object-side surface S10 and the image-side surface S11 convex. The sixth lens L6 is a meniscus lens with negative power, and has a concave object-side surface S11 and a convex image-side surface S12. Wherein the fifth lens L5 and the sixth lens L6 are cemented with each other to form a cemented lens.

The second lens L2, the fifth lens L5, and the sixth lens L6 are aspheric lenses, and both object-side surfaces and image-side surfaces of the aspheric lenses are aspheric.

Optionally, the optical lens may further include a filter L7 and/or a protective lens L7' having an object side S13 and an image side S14. Filter L7 can be used to correct for color deviations. The protective lens L7' 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 S14 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

Flour mark	Radius of curvature R	Thickness T	Refractive index Nd	Abbe number Vd
					1	149.4997	1.2164	1.79	44.21
2	4.6102	3.7178
					3	-5.1452	3.0070	1.52	58.66
4	-6.1884	1.8658
					5	7.4882	5.0261	1.69	31.08
6	6.7642	0.5746
					STO	All-round	0.1175
8	5.6633	3.8260	1.59	67.33
					9	-12.8261	0.0917
10	20.2224	2.9119	1.54	56.11
					11	-3.3506	2.4839	1.64	23.28
12	-15.2224	0.1545
					13	All-round	0.9543	1.52	64.21
14	All-round	3.7871
					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, miniaturization, small front-end caliber, small distortion, low cost, good temperature performance and the like. Each aspherical surface type Z is defined by the following formula:

wherein Z is the distance rise from the vertex of the aspheric surface when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c being 1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1 above); k is the conic coefficient conc; A. b, C, D, E are all high order term coefficients. Table 2 below shows cone coefficients k and high-order term coefficients A, B, C, D and E of aspherical lens surfaces S3 to S4 and S10 to S12 that can be used in example 1.

TABLE 2

Flour mark

K

A

B

C

D

E

3

0.0288

-3.9853E-05

8.3761E-05

-2.9533E-06

1.4630E-07

-1.1908E-09

4

0.0229

2.5249E-04

2.8227E-05

-9.9691E-07

4.8163E-08

-3.6749E-10

10

-6.2683

-1.4612E-03

-3.2673E-05

-1.2722E-05

5.9100E-07

-1.8068E-08

11

-0.0939

-2.0205E-03

8.5990E-04

4.5872E-05

-3.1273E-06

7.2405E-08

12

2.3522

-1.2735E-03

9.9346E-05

-1.9982E-06

1.4659E-08

3.0997E-09

Table 3 below gives an optical total length TTL of the optical lens of embodiment 1 (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 full group focal length value F of the optical lens, a maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to a maximum field angle of the optical lens, an image height H corresponding to a maximum field angle of the optical lens, a maximum field angle FOV of the optical lens, central curvature radii R3-R4 of the object-side surface S3 and the image-side surface S4 of the second lens L2, central curvature radii R5-R6 of the object-side surface S5 and the image-side surface S6 of the third lens L3, focal length values F5-F6 of the fifth lens L5 to the sixth lens L6, and central thicknesses D3, D5, D867, D87458, D11D and 11D of the second lens L2 to the sixth lens L6.

TABLE 3

In the embodiment, TTL/H/FOV is 0.0208 between the total optical length TTL of the optical lens, the maximum field angle FOV of the optical lens, and the image height H corresponding to the maximum field angle of the optical lens; 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 satisfy a D/H/FOV of 0.0090; a focal length value F5 of the fifth lens L5 and a focal length value F6 of the sixth lens L6 satisfy | F5/F6| ═ 0.7690; a maximum { dn/dm } 2.0234 is satisfied between a center thickness dn (n is 3, 5, 8, 10, 11) of any one of the second lens L2 to the sixth lens L6 and a center thickness dm (m is 3, 5, 8, 10, 11) of any one of the second lens L2 to the sixth lens L6; a central curvature radius R3 of the object-side surface S3 of the second lens L2, a central curvature radius R4 of the image-side surface S4, and a central thickness d3 of the second lens L2 satisfy | (R4+ d3)/R3| ═ 0.6183; and 1.5745 is satisfied between a central curvature radius R5 of the object-side surface S5 of the third lens L3, a central curvature radius R6 of the image-side surface S6, and a central thickness d5 of the third lens L3 (R6+ d5)/R5 |.

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.

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 positive power, with the object side S3 being concave and the image side S4 being convex.

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

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 biconvex lens with positive optical power, and has both the object-side surface S10 and the image-side surface S11 convex. The sixth lens L6 is a meniscus lens with negative power, and has a concave object-side surface S11 and a convex image-side surface S12. Wherein the fifth lens L5 and the sixth lens L6 are cemented with each other to form a cemented lens.

The second lens L2, the fifth lens L5, and the sixth lens L6 are aspheric lenses, and both object-side surfaces and image-side surfaces of the aspheric lenses are aspheric.

Optionally, the optical lens may further include a filter L7 and/or a protective lens L7' having an object side S13 and an image side S14. Filter L7 can be used to correct for color deviations. The protective lens L7' 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 S14 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 4 below shows a radius of curvature R, a thickness T, a refractive index Nd, and an abbe number Vd of each lens of the optical lens of example 2, where the radius of curvature R and the thickness T are both in units of millimeters (mm). The following table 5 shows the conic coefficients k and the high-order term coefficients A, B, C, D and E that can be used for the aspherical lens surfaces S3 to S4 and S10 to S12 in example 2. Table 6 below gives the total optical length TTL of the optical lens of example 2, the entire group focal length value F of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum angle of view of the optical lens, the image height H corresponding to the maximum angle of view of the optical lens, the maximum angle of view FOV of the optical lens, the central radii of curvature R3-R4 of the object-side surface S3 and the image-side surface S4 of the second lens L2, the central radii of curvature R5-R6 of the object-side surface S5 and the image-side surface S6 of the third lens L3, the focal length values F5-F6 of the fifth lens L5 to the sixth lens L6, and the central thicknesses D3, D5, D8, D10 and D11 of the second lens L2 to the sixth lens L6.

TABLE 4

Flour mark	Radius of curvature R	Thickness T	Refractive index Nd	Abbe number Vd
					1	265.8148	1.1880	1.77	49.61
2	4.6658	4.0431
					3	-6.1174	3.0868	1.54	56.11
4	-6.2321	2.2705
					5	7.9617	4.9979	1.65	33.65
6	6.5855	0.5448
					STO	All-round	0.1401
8	5.7946	3.3046	1.59	61.25
					9	-9.8539	0.1021
10	35.0000	2.3938	1.53	60.47
					11	-3.8771	2.4914	1.64	23.28
12	-25.9192	0.2107
					13	All-round	0.9500	1.52	64.21
14	All-round	4.3981
					IMA	All-round

TABLE 5

Flour mark

K

A

B

C

D

E

3

0.2945

-7.1537E-04

4.5359E-05

-3.1996E-06

1.3107E-07

-1.4970E-10

4

0.1535

-6.4008E-05

3.4015E-05

-1.6228E-06

6.8787E-08

-4.5818E-10

10

7.1402

-1.4251E-03

-4.0006E-05

-7.4478E-06

9.4014E-07

-7.8667E-08

11

-0.3728

-4.1052E-03

3.0352E-06

9.0978E-05

-1.4132E-05

7.5168E-07

12

-0.6450

-1.5542E-03

7.1311E-05

-2.8696E-06

-4.9293E-09

7.0685E-09

TABLE 6

TTL(mm)	30.1218	F5(mm)	6.6998
				F(mm)	3.9608	F6(mm)	-7.3842
D(mm)	12.9355	d3(mm)	3.0868
				H(mm)	8.0400	d5(mm)	4.9979
FOV(°)	176	d8(mm)	3.3046
				R3(mm)	-6.1174	d10(mm)	2.3938
R4(mm)	-6.2321	d11(mm)	2.4914
				R5(mm)	7.9617
R6(mm)	6.5855

In the embodiment, TTL/H/FOV is 0.0213 between the total optical length TTL of the optical lens, the maximum field angle FOV of the optical lens, and the image height H corresponding to the maximum field angle of the optical lens; 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 satisfy a D/H/FOV of 0.0091; a focal length value F5 of the fifth lens L5 and a focal length value F6 of the sixth lens L6 satisfy | F5/F6| ═ 0.9073; a maximum { dn/dm } 2.0878 is satisfied between a center thickness dn (n is 3, 5, 8, 10, 11) of any one of the second lens L2 to the sixth lens L6 and a center thickness dm (m is 3, 5, 8, 10, 11) of any one of the second lens L2 to the sixth lens L6; a central curvature radius R3 of the object-side surface S3 of the second lens L2, a central curvature radius R4 of the image-side surface S4, and a central thickness d3 of the second lens L2 satisfy | (R4+ d3)/R3| ═ 0.5142; and 1.4549 is satisfied between a central curvature radius R5 of the object-side surface S5 of the third lens L3, a central curvature radius R6 of the image-side surface S6, and a central thickness d5 of the third lens L3 (R6+ d5)/R5 |.

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.

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 positive power, with the object side S3 being concave and the image side S4 being convex.

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

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 biconvex lens with positive optical power, and has both the object-side surface S10 and the image-side surface S11 convex. The sixth lens L6 is a meniscus lens with negative power, and has a concave object-side surface S11 and a convex image-side surface S12. Wherein the fifth lens L5 and the sixth lens L6 are cemented with each other to form a cemented lens.

The second lens L2, the fifth lens L5, and the sixth lens L6 are aspheric lenses, and both object-side surfaces and image-side surfaces of the aspheric lenses are aspheric.

Optionally, the optical lens may further include a filter L7 and/or a protective lens L7' having an object side S13 and an image side S14. Filter L7 can be used to correct for color deviations. The protective lens L7' 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 S14 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 7 below shows a radius of curvature R, a thickness T, a refractive index Nd, and an abbe number Vd of each lens of the optical lens of example 3, where the radius of curvature R and the thickness T are both in units of millimeters (mm). The following table 8 shows the conic coefficients k and the high-order term coefficients A, B, C, D and E that can be used for the aspherical lens surfaces S3 to S4 and S10 to S12 in example 3. Table 9 below gives the total optical length TTL of the optical lens of example 3, the entire group focal length value F of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum angle of view of the optical lens, the image height H corresponding to the maximum angle of view of the optical lens, the maximum angle of view FOV of the optical lens, the central radii of curvature R3-R4 of the object-side surface S3 and the image-side surface S4 of the second lens L2, the central radii of curvature R5-R6 of the object-side surface S5 and the image-side surface S6 of the third lens L3, the focal length values F5-F6 of the fifth lens L5 to the sixth lens L6, and the central thicknesses D3, D5, D8, D10 and D11 of the second lens L2 to the sixth lens L6. .

TABLE 7

TABLE 8

Flour mark

K

A

B

C

D

E

3

0.2895

-7.1874E-04

4.5554E-05

-3.1696E-06

1.3543E-07

1.0541E-10

4

0.1451

-4.2403E-05

3.4369E-05

-1.6053E-06

6.7573E-08

-3.8122E-10

10

-6.3860

-1.4851E-03

-4.6301E-05

-7.9626E-06

9.1638E-07

-7.5715E-08

11

-0.4384

-2.8517E-03

1.5935E-05

8.1207E-05

-1.4158E-05

7.5285E-07

12

3.3880

-1.5849E-03

5.0093E-05

-2.8539E-06

1.0303E-09

7.7602E-09

TABLE 9

TTL(mm)	29.4855	F5(mm)	6.5898
				F(mm)	3.7546	F6(mm)	-7.4232
D(mm)	12.0853	d3(mm)	3.1002
				H(mm)	7.2160	d5(mm)	5.1281
FOV(°)	154	d8(mm)	3.1548
				R3(mm)	-6.1138	d10(mm)	2.5119
R4(mm)	-6.2170	d11(mm)	2.3932
				R5(mm)	7.7964
R6(mm)	6.5680

In the embodiment, TTL/H/FOV is 0.0265 between the total optical length TTL of the optical lens, the maximum field angle FOV of the optical lens, and the image height H corresponding to the maximum field angle of the optical lens; 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 satisfy D/H/FOV of 0.0109; a focal length value F5 of the fifth lens L5 and a focal length value F6 of the sixth lens L6 satisfy | F5/F6| ═ 0.8877; a maximum { dn/dm } of 2.1428 is satisfied between a center thickness dn (n is 3, 5, 8, 10, 11) of any one of the second lens L2 to the sixth lens L6 and a center thickness dm (m is 3, 5, 8, 10, 11) of any one of the second lens L2 to the sixth lens L6; a central curvature radius R3 of the object-side surface S3 of the second lens L2, a central curvature radius R4 of the image-side surface S4, and a central thickness d3 of the second lens L2 satisfy | (R4+ d3)/R3| ═ 0.5098; and 1.5002 is satisfied between a central curvature radius R5 of the object-side surface S5 of the third lens L3, a central curvature radius R6 of the image-side surface S6, and a central thickness d5 of the third lens L3 (R6+ d5)/R5 |.

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

Watch 10

Conditions/examples	1	2	3
				TTL/H/FOV	0.0208	0.0213	0.0265
D/H/FOV	0.0090	0.0091	0.0109
				|F5/F6|	0.7690	0.9073	0.8877
max{dn/dm}	2.0234	2.0878	2.1428
				|(R4+d3)/R3|	0.6183	0.5142	0.5098
|(R6+d5)/R5|	1.5745	1.4549	1.5002

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 (21)

1. The optical lens sequentially comprises from an object side to an image side along an optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth 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 object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface;

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

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

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

the number of lenses having focal power in the optical lens is six; and

a center thickness dn (n is 3, 5, 8, 10, 11) of any one of the second to sixth lenses and a center thickness dm (m is 3, 5, 8, 10, 11) of any one of the second to sixth lenses satisfy: max { dn/dm }. is less than or equal to 2.5.

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

3. An optical lens according to claim 1, characterized in that the second lens, the fifth lens and the sixth lens are all aspherical lenses.

4. An optical lens according to any one of claims 1 to 3, wherein an overall optical length TTL of the optical lens, a maximum field angle FOV of the optical lens in degrees, and an image height H corresponding to the maximum field angle of the optical lens satisfy: (TTL is multiplied by 180 degrees) and/(H is multiplied by FOV) is less than or equal to 6.3.

5. An optical lens according to any one of claims 1 to 3, 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 in degrees: (D is multiplied by 180 degrees) and/(H is multiplied by FOV) is less than or equal to 5.4.

6. An optical lens according to any one of claims 1 to 3, characterized in that a focal length value F5 of the fifth lens and a focal length value F6 of the sixth lens satisfy: the ratio of F5 to F6 is less than or equal to 4.

7. An optical lens according to any one of claims 1 to 3, characterized in that the center radius of curvature R3 of the object side of the second lens, the center radius of curvature R4 of the image side of the second lens and the center thickness d3 of the second lens are such that: the ratio of (R4+ d3)/R3 is less than or equal to 1.5.

8. An optical lens according to any one of claims 1 to 3, characterized in that the central radius of curvature R5 of the object side of the third lens, the central radius of curvature R6 of the image side of the third lens and the central thickness d5 of the third lens are such that: the ratio of (R6+ d5)/R5 is less than or equal to 2.5.

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

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

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

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

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

the total optical length TTL of the optical lens, the maximum field angle FOV of the optical lens with the degree as a unit and the image height H corresponding to the maximum field angle of the optical lens satisfy the following conditions: (TTL is multiplied by 180 degrees) and/(H is multiplied by FOV) is less than or equal to 6.3;

the image side surface of the second lens is a convex surface;

the image side surface of the sixth lens is a convex surface;

the number of lenses having focal power in the optical lens is six; and

a center thickness dn (n is 3, 5, 8, 10, 11) of any one of the second to sixth lenses and a center thickness dm (m is 3, 5, 8, 10, 11) of any one of the second to sixth lenses satisfy: max { dn/dm }. is less than or equal to 2.5.

10. An optical lens barrel according to claim 9, wherein the object side surface of the first lens element is convex and the image side surface of the first lens element is concave.

11. An optical lens as claimed in claim 9, characterized in that the second lens has a positive or negative optical power and its object-side surface is concave.

12. An optical lens barrel according to claim 9, wherein the third lens element has a convex object-side surface and a concave image-side surface.

13. An optical lens barrel according to claim 9, wherein the object-side surface and the image-side surface of the fourth lens are convex.

14. An optical lens barrel according to claim 9, wherein the object-side surface and the image-side surface of the fifth lens element are convex.

15. An optical lens barrel according to claim 9, wherein the object side surface of the sixth lens element is concave.

16. An optical lens according to any one of claims 9 to 15, characterized in that the second lens, the fifth lens and the sixth lens are all aspherical lenses.

17. An optical lens according to any one of claims 9 to 15, 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 in degrees satisfy: (D is multiplied by 180 degrees) and/(H is multiplied by FOV) is less than or equal to 5.4.

18. An optical lens according to any one of claims 9-15, characterized in that between the focal length value F5 of the fifth lens and the focal length value F6 of the sixth lens, it is satisfied that: the ratio of F5 to F6 is less than or equal to 4.

19. An optical lens barrel according to any one of claims 9 to 15, wherein the center radius of curvature R3 of the object side surface of the second lens, the center radius of curvature R4 of the image side surface of the second lens and the center thickness d3 of the second lens satisfy: the ratio of (R4+ d3)/R3 is less than or equal to 1.5.

20. An optical lens barrel according to any one of claims 9 to 15, wherein the central radius of curvature R5 of the object side surface of the third lens, the central radius of curvature R6 of the image side surface of the third lens and the central thickness d5 of the third lens satisfy: the ratio of (R6+ d5)/R5 is less than or equal to 2.5.

21. An imaging apparatus comprising the optical lens of claim 1 or 9 and an imaging element for converting an optical image formed by the optical lens into an electric signal.

Images