CN111999863B

CN111999863B - Optical lens and imaging apparatus

Info

Publication number: CN111999863B
Application number: CN201910444869.8A
Authority: CN
Inventors: 赵哲; 王东方
Original assignee: Ningbo Sunny Automotive Optech Co Ltd
Current assignee: Ningbo Sunny Automotive Optech Co Ltd
Priority date: 2019-05-27
Filing date: 2019-05-27
Publication date: 2022-01-14
Anticipated expiration: 2039-05-27
Also published as: CN111999863A

Abstract

An optical lens and an imaging apparatus including the same are disclosed. The optical lens 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 concave surface; the third lens can have positive focal power, and the image side surface of the third lens is a convex 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 the image side surface of the fifth lens is a convex surface; and the sixth lens element may have a negative power, and the object-side surface thereof may be concave. The optical lens can realize at least one of the advantages of high resolution, small CRA (cray), miniaturization, low sensitivity, low cost, long back focal length and the like.

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

An IHS (all-round-the-globe perspective automobile department) of a globally-known economic consulting organization in 12 and 31 months in 2013 predicts that nearly 5400 thousands of automatically-driven automobiles are available in the world as of 2035; the total global sales of autonomous vehicles is expected to rise from 23 to 1180 thousands in 2025 by the year 2035, while unmanned, fully automated vehicles are expected to emerge around 2030.

Optical lenses are indispensable eye windows in autonomous cars and are extremely demanding in terms of performance due to the unmanned requirements.

The demand and technology development are increased, and the performance requirement of the optical lens is higher and higher, especially the pixel requirement of the optical lens is very high, and the size of the chip is increased, so that the size of the whole lens is increased, and the cost is increased. Meanwhile, under some special application conditions, for example, the requirement of night use effect of the vehicle-mounted lens, the night effect needs to be improved by increasing the light-transmitting aperture of the lens, which also leads to the aperture increase of the lens.

Therefore, there is a need in the market for an optical lens that can achieve both high resolution and small size, small aperture, low cost, and the like.

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

The image side surface of the second lens can be convex or concave.

The object side surface of the third lens can be a convex surface or a concave surface.

The object side surface of the fifth lens can be a convex surface or a concave surface.

The image-side surface of the sixth lens element can be convex or concave.

The second lens and the third lens can be mutually glued to form a first cemented lens.

The fifth lens and the sixth lens can be mutually glued to form a second cemented lens.

The first lens and the fourth lens can be aspheric lenses.

Wherein, the total optical length TTL of the optical lens and the whole group of focal length values F of the optical lens can satisfy the following conditions: TTL/F is less than or equal to 4.

Wherein, can satisfy between optical lens's the whole focal length value F of group of lens length TL and optical lens: TL/F is less than or equal to 2.5.

Wherein, the maximum field angle FOV of the optical lens, the maximum light-passing aperture D of the object side surface of the first lens corresponding to the maximum field angle of the optical lens and the image height H corresponding to the maximum field angle of the optical lens can satisfy: D/H/FOV is less than or equal to 0.025.

Wherein, can satisfy between focus BFL behind optical lens's optics and optical lens's the battery of lens length TL: BFL/TL is more than or equal to 0.2.

Wherein, the focal length value F2 of the second lens and the focal length value F3 of the third lens can satisfy the following conditions: the ratio of F2 to F3 is less than or equal to 1.5.

The focal length value F5 of the fifth lens and the focal length value F of the whole group of the optical lens can satisfy: F5/F is less than or equal to 2.5.

The combined focal length value F23 of the second lens and the third lens and the whole focal length value F of the optical lens can satisfy the following conditions: and | F23/F | ≧ 3.

The focal length value F4 of the fourth lens and the focal length value F of the whole group of the optical lens can satisfy: the ratio of F4/F is less than or equal to 1.7.

The focal length value F6 of the sixth lens element and the focal length value F of the whole group of the optical lens can satisfy: i F6/F | ≧ 1.0.

The central curvature radius R32 of the image side surface of the third lens and the central curvature radius R41 of the object side surface of the fourth lens can satisfy the following conditions: and | (| R32| - | R41|)/(| R32| + | R41|) | is less than or equal to 0.6.

The center distance d12 between the image side surface of the first lens and the object side surface of the second lens and the total optical length TTL of the optical lens can satisfy the following conditions: d12/TTL is more than or equal to 0.05.

Wherein, the central distance d34 between the image side surface of the third lens and the object side surface of the fourth lens and the central thickness T4 of the fourth lens can satisfy: d34/T4 is less than or equal to 0.3.

Wherein, the central distance d45 between the image side surface of the fourth lens and the object side surface of the fifth lens and the central thickness T4 of the fourth lens can satisfy: d45/T4 is less than or equal to 0.2.

The central curvature radius R42 of the image side surface of the fourth lens element and the lens group length TL of the optical lens can satisfy: and the | R42/TL | is more than or equal to 0.2.

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 sixth lens can all have negative focal power; the third lens, the fourth lens and the fifth lens can all have positive focal power; the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; both the object-side surface and the image-side surface of the fourth lens can be convex surfaces; and the total optical length TTL of the optical lens and the whole group of focal length values F of the optical lens can meet the following requirements: TTL/F is less than or equal to 4.

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

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

The object-side surface and the image-side surface of the fifth lens element can both be convex surfaces. Alternatively, the object-side surface of the fifth lens element can be concave and the image-side surface can be convex.

The object-side surface of the sixth lens element can be concave, and the image-side surface can be convex. Alternatively, both the object-side surface and the image-side surface of the sixth lens may be concave.

The first lens and the fourth lens can be aspheric lenses.

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

The optical lens adopts 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, and at least one of the beneficial effects of high resolution, small principal ray angle CRA, miniaturization, low sensitivity, low cost, back focal length 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;

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

fig. 4 is a schematic structural view showing an optical lens according to embodiment 4 of the present application; and

fig. 5 is a schematic view showing a structure of an optical lens according to embodiment 5 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 in a meniscus shape with the convex surface facing the object side, can collect large-field light as far as possible to enter the rear optical system, increases the light flux and improves the illumination. In practical application, considering the outdoor installation and use environment of the vehicle-mounted application lens, the lens can be in severe weather such as rain, snow and the like, the first lens is arranged in the meniscus shape with the convex surface facing the object side, so that water drops and the like can slide off favorably, the influence on the imaging quality of the lens is reduced, and the service life of the lens is prolonged.

The second lens element can have a negative power and can have a concave object-side surface and optionally a convex or concave image-side surface.

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

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 is arranged to be convex towards the object side, more light rays can be focused to enter the image surface, strong image surface illumination is obtained, the image side surface has large curvature, the total length can be favorably reduced, the aberration of the optical system can be further corrected, and high resolution can be provided on the premise of promoting the compact structure.

The fifth lens element can have a positive optical power, and can optionally have a convex or concave 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 optionally a convex or concave 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 and is close to the fourth lens, light rays entering the optical system can be favorably effectively converged, the aperture of the fourth lens is reduced, and the cost is reduced. It should be noted, however, that the positions of the diaphragms disclosed herein are merely examples and not limitations; in alternative embodiments, the diaphragm may be disposed at other positions according to actual needs.

In an exemplary embodiment, the optical lens according to the present application may further include a filter disposed between the 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 second lens and the third lens may be combined into the first cemented lens by cementing the image-side surface of the second lens with the object-side surface of the third lens. In the first cemented lens, the second lens has negative focal power, the third lens has positive focal power and a negative-positive combination, the refractive index of the negative lens is lower, and the refractive index of the positive lens is higher, so that the matching is favorable for the rapid transition of light rays, the aperture of the diaphragm can be increased, and the light transmission quantity can be improved; in this first cemented lens, negative lens arranges in the front, and positive lens arranges in the back, can diverge the place ahead light and converge the back fast and transition to the rear again, more is favorable to the reduction of rear light optical path to realize short TTL. When the second lens and the third lens are mutually glued, the structure is compact, the system is miniaturized, and the risk of tolerance sensitivity such as inclination/decentration and the like of a single lens in assembly is reduced.

In an exemplary embodiment, the fifth lens and the sixth lens may also be combined into a second cemented lens by cementing the image-side surface of the fifth lens with the object-side surface of the sixth lens. The second cemented lens is composed of a positive lens (namely, a fifth lens) and a negative lens (namely, a sixth lens), the fifth lens is made of a low-refractive-index high-Abbe-number material, and the sixth lens is made of a high-refractive-index low-Abbe-number material, so that the rapid transition of light rays can be facilitated, the chromatic aberration of the system is effectively reduced, and the structure is compact. The double cemented lens may have at least one of the following advantages: the air interval is reduced, and the total length of the system is reduced; the working procedures are reduced, and the cost is reduced; the tolerance sensitivity problems of inclination/core deviation and the like generated in the assembling process of the lens unit are reduced; the light quantity loss caused by reflection between the lenses is reduced, and the illumination is improved; the lens can be achromatic, further can reduce the curvature of field, and can correct the off-axis point aberration of the system.

The use of the first cemented lens and the second cemented lens shares the whole chromatic aberration correction of the system, can improve the chromatic aberration of the system, effectively corrects the chromatic aberration, is beneficial to improving the resolution, reduces the air space and is beneficial to the miniaturization of the system.

In an exemplary embodiment, an optical total length TTL of the optical lens and a whole set of focal length values F of the optical lens may satisfy: TTL/F is less than or equal to 4, and more ideally, TTL/F is less than or equal to 3.7. The condition TTL/F is less than or equal to 3.5, and the miniaturization characteristic of the system can be ensured.

In an exemplary embodiment, a lens group length TL of the optical lens and a whole group focal length value F of the optical lens may satisfy: TL/F is less than or equal to 2.5, and more ideally, TL/F is less than or equal to 2. The condition TL/F is less than or equal to 2.5, the length of the lens group is smaller, and the system miniaturization can be realized.

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 0.025 or less, and more preferably, D/H/FOV is 0.02 or less. Satisfies the conditional expression D/H/FOV less than or equal to 0.025, can ensure the small caliber at the front end and realize miniaturization.

In an exemplary embodiment, the optical back focus BFL of the optical lens and the lens group length TL of the optical lens may satisfy: the BFL/TL ratio is more than or equal to 0.2, and more ideally, the BFL/TL ratio is more than or equal to 0.4. By satisfying the condition that BFL/TL is more than or equal to 0.2, the optical lens has the characteristic of back focal length on the basis of realizing miniaturization and is beneficial to the assembly of the optical lens; in addition, the lens group has short length TL and compact structure, can reduce the sensitivity of the lens to modulation transfer function MTF, improve the production yield and reduce the production cost.

In an exemplary embodiment, a focal length value F2 of the second lens and a focal length value F3 of the third lens may satisfy: the | F2/F3| is less than or equal to 1.5, and more ideally, the | F2/F3| is less than or equal to 1.2. The arrangement makes the focal lengths of the two adjacent lenses close, which can help the light to smoothly transit.

In an exemplary embodiment, a focal length value F5 of the fifth lens and a focal length value F of the entire group of the optical lens may satisfy: F5/F is not more than 2.5, and more preferably, F5/F is not more than 2.2. The conditional expression F5/F is less than or equal to 2.5, so that more light rays can enter the sixth lens, and the light flux is ensured.

In an exemplary embodiment, a combined focal length value F23 of the second and third lenses and a full set focal length value F of the optical lens may satisfy: and | F23/F | ≧ 3, more preferably, | F23/F | ≧ 5 can be further satisfied. The conditional expression of | F23/F | ≧ 3 is satisfied, the light trend can be controlled, aberration caused by entering large-angle light is reduced, and meanwhile, the structure of the lens is compact, and miniaturization is facilitated.

In an exemplary embodiment, a focal length value F4 of the fourth lens and a focal length value F of the entire group of the optical lens may satisfy: the ratio of F4/F is less than or equal to 1.7, and more preferably, the ratio of F4/F is less than or equal to 1.5. The fourth lens has a short focal length, and can help to collect light and ensure the light transmission amount.

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: and | F6/F | ≧ 1.0, more preferably, | F6/F | ≧ 1.2 can be further satisfied. The condition F6/F | ≧ 1.0 is satisfied, which is helpful for realizing long focal length.

In an exemplary embodiment, a center radius of curvature R32 of the image-side surface of the third lens and a center radius of curvature R41 of the object-side surface of the fourth lens may satisfy: the absolute value (| R32| - | R41|)/(| R32| + | R41|) | is less than or equal to 0.6, and more desirably, the absolute value (| R32| - | R41|)/(| R32| + | R41|) is less than or equal to 0.4. Satisfying the conditional expression | (| R32| - | R41|)/(| R32| + | R41|) | ≦ 0.6, can correct aberration of the optical system, and ensure that the incident angle is not too large when the light emitted from the third lens is incident on the object side of the fourth lens, thereby reducing tolerance sensitivity of the optical system.

In an exemplary embodiment, a center distance d12 between the image side surface of the first lens and the object side surface of the second lens and an optical total length TTL of the optical lens may satisfy: d12/TTL is not less than 0.05, more preferably, d12/TTL is not less than 0.08. The distance between the first lens and the second lens is large, and smooth transition of light rays can be facilitated.

In an exemplary embodiment, a center distance d34 between an image-side surface of the third lens and an object-side surface of the fourth lens and a center thickness T4 of the fourth lens may satisfy: d34/T4 is not more than 0.3, and more preferably, d34/T4 is not more than 0.2. The distance between the third lens and the fourth lens is small, so that more light rays can enter the fourth lens, and the light flux of the system is ensured.

In an exemplary embodiment, a center distance d45 between an image-side surface of the fourth lens and an object-side surface of the fifth lens and a center thickness T4 of the fourth lens may satisfy: d45/T4 is not more than 0.2, and more preferably, d45/T4 is not more than 0.1. The distance between the fourth lens and the fifth lens is small, so that the compact structure can be facilitated, and the system miniaturization can be realized.

In an exemplary embodiment, a center curvature radius R42 of the image side surface of the fourth lens and a lens group length TL of the optical lens may satisfy: the | R42/TL | is more than or equal to 0.2, and more ideally, the | R42/TL | is more than or equal to 0.4. The central curvature radius of the image side surface of the fourth lens is larger, so that the total length of the system can be favorably reduced.

In an exemplary embodiment, the first lens and the fourth lens may each employ an aspherical mirror. The aspheric lens has the characteristics that: the curvature varies continuously from the center of the lens to the periphery. Unlike a spherical lens having a constant curvature from the center to the periphery of the lens, an aspherical lens has better curvature radius characteristics, and has the advantages of improving distortion aberration and improving astigmatic aberration. After the aspheric lens is adopted, the aberration generated in imaging can be eliminated as much as possible, so that the imaging quality of the lens is improved. For example, the first lens adopts an aspheric lens, which can correct the aberration of the optical system, improve the resolving power of the optical system and make the whole structure relatively simple. 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, an optical lens according to the present application may employ a plastic lens or a glass lens. Generally, the thermal expansion coefficient of a lens made of plastic is large, and when the ambient temperature change of the lens is large, the lens made of plastic causes the optical back focus change of the lens to be large. 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 application, the shape of the lens is optimally set, the focal power is reasonably distributed, the lens material is reasonably selected, and the advantages of low sensitivity, small volume and the like can be achieved while high resolution is achieved. The optical lens only has 6 lenses, has compact structure and long back focal length, is easy to assemble and can realize low cost. Therefore, the optical lens according to the above-described embodiment of the present application can better meet the requirements of, for example, an in-vehicle application.

It will be understood by those skilled in the art that the total optical length TTL of the optical lens used above refers to the on-axis distance from the center of the object-side surface of the first lens to the center of the imaging surface; the optical back focus BFL of the optical lens refers to the axial distance from the center of the image side surface of the sixth lens of the last lens to the center of the imaging surface; and the lens group length TL of the optical lens means an on-axis distance from the center of the object side surface of the first lens to the center of the image side surface of the sixth lens of the last 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 biconcave lens with negative optical power, and both the object-side surface S3 and the image-side surface S4 are concave. The third lens L3 is a biconvex lens with positive optical power, and has both the object-side surface S4 and the image-side surface S5 being convex. Wherein the second lens L2 and the third lens L3 are cemented with each other to form a first cemented lens.

The fourth lens L4 is a biconvex lens with positive optical power, and has both the object-side surface S7 and the image-side surface S8 convex.

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

The first lens element L1 and the fourth lens element L4 are both aspheric lenses, and both object-side surfaces and image-side surfaces thereof are aspheric.

Optionally, the optical lens may further include a filter L7 and/or a protective lens L7' having an object side S12 and an image side S13. 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 S13 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 the radius of curvature R and the thickness T (it is understood that T is₁Is the center thickness, T, of the first lens L1₂An air space between the first lens L1 and the second lens L2, and so on), a refractive index Nd, and an abbe number Vd, wherein the radius of curvature R and the thickness T are both in millimeters (mm).

TABLE 1

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, small CRA, miniaturization, low sensitivity, low cost, long back focus 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 the conic coefficients k and the high-order term coefficients A, B, C, D and E of the aspherical lens surfaces S1 to S2, S7 to S8 usable in example 1.

TABLE 2

Flour mark

K

A

B

C

D

E

1

-0.8742

-1.0497E-03

-1.2754E-04

-1.7671E-06

2.8442E-07

-5.4971E-09

2

-1.0367

1.3732E-03

-2.8398E-04

-5.4210E-06

1.6467E-06

-5.2301E-08

7

7.1870

2.4017E-04

1.5173E-05

5.4996E-07

3.0272E-08

1.0419E-09

8

-2.2174

9.3274E-05

1.6003E-05

1.2575E-06

-3.6944E-08

5.3708E-09

Table 3 below gives the total optical length TTL of the optical lens of example 1 (i.e., the on-axis distance from the center of the object-side surface S1 of the first lens L1 to the imaging surface IMA), the entire group focal length value F of the optical lens, the maximum field angle FOV of the optical lens, the image height H corresponding to the maximum field angle of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, the optical back focus BFL of the optical lens (i.e., the on-axis distance from the center of the image-side surface S11 of the last lens sixth lens L6 to the imaging surface IMA), the lens group length TL of the optical lens (i.e., the on-axis distance from the center of the object-side surface S1 of the first lens L1 to the center of the image-side surface S11 of the last lens sixth lens L6), the center thickness T4 of the fourth lens L4, the on-axis distance D3985D between the image-side surface S9638 of the first lens L9636 and the center of the image-side surface S2 of the first lens L1, the fourth lens L9636, the fourth lens L8285, A center distance d34 between an image side surface S5 of the third lens L3 and an object side surface S7 of the fourth lens L4, a center distance d45 between an image side surface S8 of the fourth lens L4 and an object side surface S9 of the fifth lens L5, focal length values F2-F6 of the second lens L2 to the sixth lens L6, a combined focal length value F23 of the second lens L2 and the third lens L3, a center radius of curvature R32 of the image side surface S5 of the third lens L3, and center radii of curvature R41-R42 of the object side surface S7 and the image side surface S8 of the fourth lens L4.

TABLE 3

TTL(mm)	27.8500	F2(mm)	-8.1498
				F(mm)	9.6760	F3(mm)	8.7702
D(mm)	8.4720	F4(mm)	12.5320
				H(mm)	8.5200	F5(mm)	12.3751
FOV(°)	54.2000	F6(mm)	-17.0367
				BFL(mm)	11.2334	F23(mm)	108.1795
TL(mm)	16.6166	R32(mm)	-14.0002
				T4(mm)	2.3234	R41(mm)	20.0850
d12(mm)	3.2214	R42(mm)	-11.1460
				d34(mm)	0.3367
d45(mm)	0.1170

In the present embodiment, TTL/F is 2.8783 between the total optical length TTL of the optical lens and the whole focal length F of the optical lens; the length TL of the lens group of the optical lens and the whole group focal length value F of the optical lens meet the condition that TL/F is 1.7173; 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 0.0183; the distance between the optical back focus BFL of the optical lens and the lens group length TL of the optical lens is 0.6760; a focal length value F2 of the second lens L2 and a focal length value F3 of the third lens L3 satisfy | F2/F3| ═ 0.9293; F5/F1.2789 is satisfied between the focal length value F5 of the fifth lens L5 and the focal length value F of the entire group of optical lenses; a combined focal length value F23 of the second lens L2 and the third lens L3 and a whole group focal length value F of the optical lens satisfy | F23/F | ═ 11.1802; a focal length value F4 of the fourth lens L4 and a focal length value F of the entire group of the optical lens satisfy | F4/F | > -1.2952; a focal length value F6 of the sixth lens L6 and a focal length value F of the entire group of the optical lens satisfy | F6/F | > -1.7607; a center distance d12 between an image side surface S2 of the first lens L1 and an object side surface S3 of the second lens L2 and an optical total length TTL of the optical lens satisfy d12/TTL 0.1157; the central distance d34 between the image-side surface S5 of the third lens L3 and the object-side surface S7 of the fourth lens L4 and the central thickness T4 of the fourth lens L4 satisfy d 34/T4-0.1449; a center distance d45 between an image side surface S8 of the fourth lens L4 and an object side surface S9 of the fifth lens L5 and a center thickness T4 of the fourth lens L4 satisfies d12/T4 being 0.0504; a center curvature radius R42 of the image side surface S8 of the fourth lens L4 and a lens group length TL of the optical lens satisfy | R42/TL | ═ 0.6708; and the central radius of curvature R32 of the image-side surface S5 of the third lens L3 and the central radius of curvature R41 of the object-side surface S7 of the fourth lens L4 satisfy | (| R32| - | R41|)/(| R32| + | R41|) | > |, 0.2526.

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, D and E that can be used for the aspherical lens surfaces S1 to S2, S7 to S8 in example 2. Table 6 below gives the total optical length TTL of the optical lens, the entire group focal length value F of the optical lens, the maximum field angle FOV of the optical lens, the image height H corresponding to the maximum field angle of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, the optical back focus BFL of the optical lens, the lens group length TL of the optical lens, the center thickness T4 of the fourth lens L4, the center distance D12 between the image-side surface S2 of the first lens L1 and the object-side surface S3 of the second lens L2, the center distance D589 between the image-side surface S5 of the third lens L3 and the object-side surface S7 of the fourth lens L4, the center distance D45 between the image-side surface S8 of the fourth lens L4 and the object-side surface S9 of the fifth lens L5, the center distances D45 between the image-side surfaces S8258 of the second lens L2 and the third lens L2F 2, The center radius of curvature R32 of the image-side surface S5 of the third lens L3, and the center radii of curvature R41 to R42 of the object-side surface S7 and the image-side surface S8 of the fourth lens L4.

TABLE 4

Flour mark	Radius of curvature R	Thickness T	Refractive index Nd	Abbe number Vd
					1	3.6623	1.3550	1.59	61.10
2	2.3384	3.2173
					3	-9.5199	1.6476	1.52	64.20
4	7.7612	2.9783	1.62	63.40
					5	-13.4132	0.3909
STO	All-round	-0.1955
					7	21.3016	2.3151	1.59	61.10
8	-10.6567	0.1170
					9	31.6069	3.1676	1.50	81.60
10	-7.4590	0.7052	1.85	23.80
					11	-15.9209	0.3117
12	All-round	0.9500	1.52	64.20
					13	All-round	11.4095
IMA	All-round

TABLE 5

Flour mark

K

A

B

C

D

E

1

-0.8721

-1.0431E-03

-1.3339E-04

-2.2846E-06

2.8172E-07

-4.6482E-09

2

-1.0278

1.4348E-03

-2.9211E-04

-6.6149E-06

1.5682E-06

-4.1777E-08

7

8.1119

2.6176E-04

1.4658E-05

5.4773E-07

3.3223E-08

1.4347E-09

8

-2.0471

8.1338E-05

1.4823E-05

3.0269E-06

-4.5574E-08

6.7440E-09

TABLE 6

TTL(mm)	28.3697	F2(mm)	-7.9826
				F(mm)	9.6783	F3(mm)	8.3767
D(mm)	8.2780	F4(mm)	12.4092
				H(mm)	9.3720	F5(mm)	12.4427
FOV(°)	54.2000	F6(mm)	-17.0686
				BFL(mm)	12.6712	F23(mm)	84.6614
TL(mm)	15.6985	R32(mm)	-13.4132
				T4(mm)	2.3151	R41(mm)	21.3016
d12(mm)	3.2173	R42(mm)	-10.6567
				d34(mm)	0.1954
d45(mm)	0.1170

In the present embodiment, TTL/F is 2.9313 between the total optical length TTL of the optical lens and the whole focal length F of the optical lens; the length TL of the lens group of the optical lens and the whole group focal length value F of the optical lens meet the condition that TL/F is 1.6220; 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 0.0163; the distance between the optical back focus BFL of the optical lens and the lens group length TL of the optical lens is 0.8072; a focal length value F2 of the second lens L2 and a focal length value F3 of the third lens L3 satisfy | F2/F3| ═ 0.9530; F5/F1.2856 is satisfied between the focal length value F5 of the fifth lens L5 and the focal length value F of the entire group of optical lenses; a combined focal length value F23 of the second lens L2 and the third lens L3 and a whole group focal length value F of the optical lens satisfy | F23/F | ═ 8.7476; a focal length value F4 of the fourth lens L4 and a focal length value F of the entire group of the optical lens satisfy | F4/F | > -1.2822; a focal length value F6 of the sixth lens L6 and a focal length value F of the entire group of the optical lens satisfy | F6/F | > -1.7636; a central distance d12 between an image side surface S2 of the first lens L1 and an object side surface S3 of the second lens L2 and an optical total length TTL of the optical lens satisfy that d12/TTL is 0.1134; the center distance d34 between the image side surface S5 of the third lens L3 and the object side surface S7 of the fourth lens L4 and the center thickness T4 of the fourth lens L4 satisfy d34/T4 equal to 0.0844; a center distance d45 between an image side surface S8 of the fourth lens L4 and an object side surface S9 of the fifth lens L5 and a center thickness T4 of the fourth lens L4 satisfies d12/T4 being 0.0506; a center curvature radius R42 of the image side surface S8 of the fourth lens L4 and a lens group length TL of the optical lens satisfy | R42/TL | ═ 0.6788; and the central radius of curvature R32 of the image-side surface S5 of the third lens L3 and the central radius of curvature R41 of the object-side surface S7 of the fourth lens L4 satisfy | (| R32| - | R41|)/(| R32| + | R41|) | > |, 0.2277.

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, D and E which can be used for the aspherical lens surfaces S1 to S2, S7 to S8 in example 3. The following table 9 shows the total optical length TTL of the optical lens, the entire group focal length value F of the optical lens, the maximum field angle FOV of the optical lens, the image height H corresponding to the maximum field angle of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, the optical back focus BFL of the optical lens, the lens group length TL of the optical lens, the center thickness T4 of the fourth lens L4, the center distance D12 between the image-side surface S2 of the first lens L1 and the object-side surface S3 of the second lens L2, the center distance D589 between the image-side surface S5 of the third lens L3 and the object-side surface S7 of the fourth lens L4, the center distance D45 between the image-side surface S8 of the fourth lens L4 and the object-side surface S9 of the fifth lens L5, the center distances D45 between the image-side surfaces S8258 of the second lens L2 and the third lens L2F 2, The center radius of curvature R32 of the image-side surface S5 of the third lens L3, and the center radii of curvature R41 to R42 of the object-side surface S7 and the image-side surface S8 of the fourth lens L4.

TABLE 7

Flour mark	Radius of curvature R	Thickness T	Refractive index Nd	Abbe number Vd
					1	3.6637	1.3345	1.59	61.10
2	2.3559	3.3198
					3	-9.4504	1.7133	1.52	64.20
4	7.9348	3.1439	1.62	63.40
					5	-13.4959	0.4793
STO	All-round	-0.1955
					7	21.0831	2.3014	1.59	61.10
8	-11.3327	0.1170
					9	29.5179	3.3610	1.50	81.60
10	-7.4137	0.7728	1.85	23.80
					11	-15.8099	0.3117
12	All-round	0.9500	1.52	64.20
					13	All-round	10.8183
IMA	All-round

TABLE 8

Flour mark

K

A

B

C

D

E

1

-0.8624

-1.0647E-03

-1.2954E-04

-2.0759E-06

2.8554E-07

-5.2428E-09

2

-1.0327

1.3620E-03

-2.8315E-04

-5.9514E-06

2.0564E-06

-4.7765E-08

7

6.9331

2.3501E-04

1.3875E-05

4.3312E-07

2.3239E-08

1.2413E-09

8

-2.0630

8.3105E-05

1.3306E-05

9.9728E-07

1.1844E-10

5.4130E-09

TABLE 9

In the present embodiment, TTL/F is 2.9391 between the total optical length TTL of the optical lens and the whole focal length F of the optical lens; the length TL of the lens group of the optical lens and the whole group focal length value F of the optical lens meet the condition that TL/F is 1.6902; 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 0.0168; the distance between the optical back focus BFL of the optical lens and the lens group length TL of the optical lens is 0.7389; a focal length value F2 of the second lens L2 and a focal length value F3 of the third lens L3 satisfy | F2/F3| ═ 0.9426; F5/F1.2674 is satisfied between the focal length value F5 of the fifth lens L5 and the focal length value F of the entire group of optical lenses; a combined focal length value F23 of the second lens L2 and the third lens L3 and a whole group focal length value F of the optical lens satisfy | F23/F | ═ 9.2295; a focal length value F4 of the fourth lens L4 and a focal length value F of the entire group of the optical lens satisfy | F4/F | > -1.3306; a focal length value F6 of the sixth lens L6 and a focal length value F of the entire group of the optical lens satisfy | F6/F | > -1.7628; a center distance d12 between an image side surface S2 of the first lens L1 and an object side surface S3 of the second lens L2 and an optical total length TTL of the optical lens satisfy d12/TTL 0.1168; the center distance d34 between the image side surface S5 of the third lens L3 and the object side surface S7 of the fourth lens L4 and the center thickness T4 of the fourth lens L4 satisfy d34/T4 ═ 0.1233; the center distance d45 between the image side surface S8 of the fourth lens L4 and the object side surface S9 of the fifth lens L5 and the center thickness T4 of the fourth lens L4 satisfy d12/T4 ═ 0.0509; a center curvature radius R42 of the image side surface S8 of the fourth lens L4 and a lens group length TL of the optical lens satisfy | R42/TL | ═ 0.6932; and the central radius of curvature R32 of the image-side surface S5 of the third lens L3 and the central radius of curvature R41 of the object-side surface S7 of the fourth lens L4 satisfy | (| R32| - | R41|)/(| R32| + | R41|) | > |, 0.2192.

Example 4

An optical lens according to embodiment 4 of the present application is described below with reference to fig. 4. In this embodiment and the following embodiments, descriptions of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 4 shows a schematic structural diagram of an optical lens according to embodiment 4 of the present application.

As shown in fig. 4, the optical lens includes, in order from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6.

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 S4 being concave and the image side S5 being convex. Wherein the second lens L2 and the third lens L3 are cemented with each other to form a first cemented lens.

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

Table 10 below shows a radius of curvature R, a thickness T, a refractive index Nd, and an abbe number Vd of each lens of the optical lens of example 4, where the radius of curvature R and the thickness T are both in units of millimeters (mm). The following table 11 shows the conic coefficients k and the high-order term coefficients A, B, C, D and E which can be used for the aspherical lens surfaces S1 to S2, S7 to S8 in example 4. Table 12 below gives the total optical length TTL of the optical lens, the entire group focal length value F of the optical lens, the maximum field angle FOV of the optical lens, the image height H corresponding to the maximum field angle of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, the optical back focus BFL of the optical lens, the lens group length TL of the optical lens, the center thickness T4 of the fourth lens L4, the center distance D12 between the image-side surface S2 of the first lens L1 and the object-side surface S3 of the second lens L2, the center distance D589 between the image-side surface S5 of the third lens L3 and the object-side surface S7 of the fourth lens L4, the center distance D45 between the image-side surface S8 of the fourth lens L4 and the object-side surface S9 of the fifth lens L5, the center distances D45 between the image-side surfaces S8258 of the second lens L2 and the third lens L2F 2, The center radius of curvature R32 of the image-side surface S5 of the third lens L3, and the center radii of curvature R41 to R42 of the object-side surface S7 and the image-side surface S8 of the fourth lens L4.

Watch 10

Flour mark	Radius of curvature R	Thickness T	Refractive index Nd	Abbe number Vd
					1	4.1570	1.0563	1.59	61.12
2	2.7243	2.5866
					3	-7.4834	1.4872	1.52	64.21
4	-17.6495	2.0687	1.62	63.41
					5	-9.3647	0.4679
STO	All-round	0.1063
					7	41.3828	4.9861	1.59	61.12
8	-8.6170	0.1167
					9	9.8631	2.9246	1.50	81.59
10	-16.4253	2.0069	1.85	23.79
					11	49.8612	0.3109
12	All-round	0.9539	1.52	64.21
					13	All-round	8.9311
IMA	All-round	-

TABLE 11

Flour mark

K

A

B

C

D

E

1

-0.9002

-1.7537E-03

-1.1604E-04

-2.3233E-07

2.6083E-07

-7.6044E-09

2

-1.1410

7.6326E-04

-1.4003E-04

-3.4479E-06

7.1643E-06

-5.4929E-08

7

2.9545

2.6259E-04

3.9089E-06

7.0093E-08

7.0490E-09

-7.9950E-11

8

-1.0179

-1.9934E-05

-1.5760E-06

5.8697E-07

-1.4809E-08

1.6002E-09

TABLE 12

In the present embodiment, TTL/F is 2.8995 between the total optical length TTL of the optical lens and the whole focal length F of the optical lens; the length TL of the lens group of the optical lens and the whole group focal length value F of the optical lens meet the condition that TL/F is 1.8438; 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 0.0142; the distance between the optical back focus BFL of the optical lens and the lens group length TL of the optical lens is 0.5726; a focal length value F2 of the second lens L2 and a focal length value F3 of the third lens L3 satisfy | F2/F3| ═ 0.8985; F5/F1.3293 is satisfied between the focal length value F5 of the fifth lens L5 and the focal length value F of the entire group of optical lenses; a combined focal length value F23 of the second lens L2 and the third lens L3 and a whole group focal length value F of the optical lens satisfy | F23/F | ═ 62.5311; a focal length value F4 of the fourth lens L4 and a focal length value F of the entire group of the optical lens satisfy | F4/F | > -1.3036; a focal length value F6 of the sixth lens L6 and a focal length value F of the entire group of the optical lens satisfy | F6/F | > -1.4755; a center distance d12 between an image side surface S2 of the first lens L1 and an object side surface S3 of the second lens L2 and an optical total length TTL of the optical lens satisfy d12/TTL of 0.0924; the center distance d34 between the image side surface S5 of the third lens L3 and the object side surface S7 of the fourth lens L4 and the center thickness T4 of the fourth lens L4 satisfy d34/T4 ═ 0.1151; the central distance d45 between the image side surface S8 of the fourth lens L4 and the object side surface S9 of the fifth lens L5 and the central thickness T4 of the fourth lens L4 satisfy d 12/T4-0.0234; a center curvature radius R42 of the image side surface S8 of the fourth lens L4 and a lens group length TL of the optical lens satisfy | R42/TL | ═ 0.4839; and the central radius of curvature R32 of the image-side surface S5 of the third lens L3 and the central radius of curvature R41 of the object-side surface S7 of the fourth lens L4 satisfy | (| R32| - | R41|)/(| R32| + | R41|) | > |, 0.1997.

Example 5

An optical lens according to embodiment 5 of the present application is described below with reference to fig. 5. 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. 5 shows a schematic structural diagram of an optical lens according to embodiment 5 of the present application.

As shown in fig. 5, 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 second lens L2 is a biconcave lens with negative optical power, and both the object-side surface S3 and the image-side surface S4 are concave.

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

The fourth lens L4 is a biconvex lens with positive optical power, and has both the object-side surface S8 and the image-side surface S9 convex.

The fifth lens L5 is a meniscus lens with positive power, with the object side S10 being concave and the image side S11 being convex.

The sixth lens L6 is a meniscus lens with negative power, and has a concave object-side surface S12 and a convex image-side surface S13.

Optionally, the optical lens may further include a filter L7 and/or a protective lens L7' having an object side S14 and an image side S15. 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 S15 in sequence and is finally imaged on the imaging plane IMA.

Table 13 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 5, where the radius of curvature R and the thickness T are both in units of millimeters (mm). The following table 14 shows the conic coefficients k and the high-order term coefficients A, B, C, D and E which can be used for the aspherical lens surfaces S1 to S2, S8 to S9 in example 5. Table 15 below shows the total optical length TTL of the optical lens, the entire group focal length value F of the optical lens, the maximum field angle FOV of the optical lens, the image height H corresponding to the maximum field angle of the optical lens, the maximum clear aperture D of the object-side surface S1 of the first lens L1 corresponding to the maximum field angle of the optical lens, the optical back focus BFL of the optical lens, the lens group length TL of the optical lens, the center thickness T4 of the fourth lens L4, the center distance D12 between the image-side surface S2 of the first lens L1 and the object-side surface S3 of the second lens L2, the center distance D589 between the image-side surface S5 of the third lens L3 and the object-side surface S8 of the fourth lens L4, the center distance D45 between the image-side surface S9 of the fourth lens L4 and the object-side surface S10 of the fifth lens L5, the center distances D45 between the image-side surfaces S8258 of the second lens L2 and the third lens L2F 2, The center radius of curvature R32 of the image-side surface S5 of the third lens L3, and the center radii of curvature R41 to R42 of the object-side surface S8 and the image-side surface S9 of the fourth lens L4.

Watch 13

Flour mark	Radius of curvature R	Thickness T	Refractive index Nd	Abbe number Vd
					1	3.7869	0.9833	1.59	61.12
2	2.6400	2.5974
					3	-8.7250	0.6343	1.52	64.21
4	18.4362	0.3984
					5	-116.4196	3.1285	1.62	63.41
6	-6.7598	0.4409
					STO	All-round	-0.1948
8	15.3219	5.4928	1.59	61.12
					9	-8.0507	0.1166
10	-22.9223	1.9032	1.50	81.59
					11	-6.7636	0.4981
12	-8.5160	3.1701	1.85	23.79
					13	-38.0927	0.3106
14	All-round	0.9540	1.52	64.21
					15	All-round	7.5554
IMA	All-round	-

TABLE 14

Watch 15

TTL(mm)	27.9888	F2(mm)	-11.3268
				F(mm)	9.6300	F3(mm)	11.4439
D(mm)	6.9684	F4(mm)	9.8280
				H(mm)	8.7280	F5(mm)	18.5231
FOV(°)	56.0000	F6(mm)	-13.4939
				BFL(mm)	8.8199	F23(mm)	50.0426
TL(mm)	19.1689	R32(mm)	-6.7598
				T4(mm)	5.4928	R41(mm)	15.3219
d12(mm)	2.5974	R42(mm)	-8.0507
				d34(mm)	0.4409
d45(mm)	0.1166

In the present embodiment, TTL/F is 2.9064 between the total optical length TTL of the optical lens and the whole focal length F of the optical lens; the length TL of the lens group of the optical lens and the whole group focal length value F of the optical lens meet the condition that TL/F is 1.9905; 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 0.0143; the distance between the optical back focus BFL of the optical lens and the lens group length TL of the optical lens is 0.4601; a focal length value F2 of the second lens L2 and a focal length value F3 of the third lens L3 satisfy | F2/F3| ═ 0.9898; F5/F1.9235 is satisfied between the focal length value F5 of the fifth lens L5 and the focal length value F of the entire group of optical lenses; a combined focal length value F23 of the second lens L2 and the third lens L3 and a whole group focal length value F of the optical lens satisfy | F23/F | ═ 5.1965; a focal length value F4 of the fourth lens L4 and a focal length value F of the entire group of the optical lens satisfy | F4/F | > -1.0206; a focal length value F6 of the sixth lens L6 and a focal length value F of the entire group of the optical lens satisfy | F6/F | > -1.4012; a center distance d12 between an image side surface S2 of the first lens L1 and an object side surface S3 of the second lens L2 and an optical total length TTL of the optical lens satisfy d12/TTL 0.0928; the center distance d34 between the image side surface S5 of the third lens L3 and the object side surface S8 of the fourth lens L4 and the center thickness T4 of the fourth lens L4 satisfy d34/T4 ═ 0.0803; the center distance d45 between the image side surface S9 of the fourth lens L4 and the object side surface S10 of the fifth lens L5 and the center thickness T4 of the fourth lens L4 satisfy d12/T4 being 0.0212; a center curvature radius R42 of the image side surface S9 of the fourth lens L4 and a lens group length TL of the optical lens satisfy | R42/TL | ═ 0.4200; and the central radius of curvature R32 of the image-side surface S5 of the third lens L3 and the central radius of curvature R41 of the object-side surface S8 of the fourth lens L4 satisfy | (| R32| - | R41|)/(| R32| + | R41|) | > |, 0.1830.

In summary, examples 1 to 5 each satisfy the relationship shown in table 16 below.

TABLE 16

Conditions/examples	1	2	3	4	5
						TTL/F	2.8783	2.9313	2.9391	2.8995	2.9064
TL/F	1.7173	1.6220	1.6902	1.8438	1.9905
						D/H/FOV	0.0183	0.0163	0.0168	0.0142	0.0143
BFL/TL	0.6760	0.8072	0.7389	0.5726	0.4601
						\|F2/F3\|	0.9293	0.9530	0.9426	0.8985	0.9898
F5/F	1.2789	1.2856	1.2674	1.3293	1.9235
						\|F23/F\|	11.1802	8.7476	9.2295	62.5311	5.1965
\|F4/F\|	1.2952	1.2822	1.3306	1.3036	1.0206
						\|F6/F\|	1.7607	1.7636	1.7628	1.4755	1.4012
d12/TTL	0.1157	0.1134	0.1168	0.0924	0.0928
						d34/T4	0.1449	0.0844	0.1233	0.1151	0.0803
d45/T4	0.0504	0.0506	0.0509	0.0234	0.0212
						\|R42/TL\|	0.6708	0.6788	0.6932	0.4839	0.4200
\|(\|R32\|-\|R41\|)/(\|R32\|+\|R41\|)\|	0.2526	0.2277	0.2192	0.1997	0.1830

The present application also provides an imaging apparatus that may include the optical lens according to the above-described embodiment of the present application and an imaging element for converting an optical image formed by the optical lens into an electrical signal. The imaging element may be a photo-coupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The imaging device may be a stand-alone imaging device such as a range finding camera or may be an imaging module integrated on a device such as a range finding device.

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

Claims

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

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, and the object side surface of the second lens is a concave surface;

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

the sixth lens has negative focal power, the object side surface of the sixth lens is a concave surface,

wherein, the optical lens has six lenses with focal power,

wherein, the total optical length TTL of the optical lens and the whole group of focal length values F of the optical lens satisfy: TTL/F is less than or equal to 3.5.

2. An optical lens barrel according to claim 1, wherein the image side surface of the second lens element is convex or concave.

3. An optical lens barrel according to claim 1, wherein the object side surface of the third lens is convex or concave.

4. An optical lens barrel according to claim 1, wherein the object side surface of the fifth lens element is convex or concave.

5. An optical lens barrel according to claim 1, wherein the image side surface of the sixth lens element is convex or concave.

6. An optical lens according to claim 1, wherein the second lens and the third lens are cemented to each other to form a first cemented lens.

7. An optical lens barrel according to claim 6, wherein the fifth lens and the sixth lens are cemented to each other to form a second cemented lens.

8. An optical lens according to claim 1, characterized in that the first lens and the fourth lens are both aspherical lenses.

9. An optical lens according to any one of claims 1 to 8, wherein a lens group length TL of the optical lens and a total group focal length value F of the optical lens satisfy: TL/F is less than or equal to 2.5.

10. An optical lens according to any one of claims 1 to 8, wherein the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface of the first lens corresponding to the maximum field angle of the optical lens, and the image height H corresponding to the maximum field angle of the optical lens satisfy: (D is multiplied by 180 degrees) and/(h is multiplied by FOV) is less than or equal to 4.5.

11. An optical lens according to any of claims 1-8, characterized in that between an optical back focus BFL of the optical lens and a lens group length TL of the optical lens satisfies: BFL/TL is more than or equal to 0.2.

12. An optical lens according to any one of claims 1 to 8, characterized in that a focal length value F2 of the second lens and a focal length value F3 of the third lens satisfy: the ratio of F2 to F3 is less than or equal to 1.5.

13. An optical lens according to any one of claims 1 to 8, characterized in that the focal length value F5 of the fifth lens and the entire group of focal length values F of the optical lens satisfy: F5/F is less than or equal to 2.5.

14. An optical lens according to any one of claims 1 to 8, characterized in that a combined focal length value F23 of the second lens and the third lens and a full set of focal length values F of the optical lens satisfy: and | F23/F | ≧ 3.

15. An optical lens according to any one of claims 1 to 8, characterized in that the focal length value F4 of the fourth lens and the entire group of focal length values F of the optical lens satisfy: the ratio of F4/F is less than or equal to 1.7.

16. An optical lens according to any one of claims 1 to 8, characterized in that a focal length value F6 of the sixth lens and a full group focal length value F of the optical lens satisfy: i F6/F | ≧ 1.0.

17. An optical lens barrel according to any one of claims 1 to 8, wherein the central radius of curvature R32 of the image side surface of the third lens and the central radius of curvature R41 of the object side surface of the fourth lens satisfy: and | (| R32| - | R41|)/(| R32| + | R41|) | is less than or equal to 0.6.

18. An optical lens element according to any one of claims 1 to 8, wherein a center distance d12 between an image side surface of the first lens element and an object side surface of the second lens element and an overall optical length TTL of the optical lens element satisfy: d12/TTL is more than or equal to 0.05.

19. An optical lens barrel according to any one of claims 1 to 8, wherein a center distance d34 between an image side surface of the third lens and an object side surface of the fourth lens and a center thickness T4 of the fourth lens satisfy: d34/T4 is less than or equal to 0.3.

20. An optical lens barrel according to any one of claims 1 to 8, wherein a center distance d45 between an image side surface of the fourth lens and an object side surface of the fifth lens and a center thickness T4 of the fourth lens satisfy: d45/T4 is less than or equal to 0.2.

21. An optical lens barrel according to any one of claims 1 to 8, wherein a central radius of curvature R42 of an image side surface of the fourth lens and a lens group length TL of the optical lens satisfy: and the | R42/TL | is more than or equal to 0.2.

22. 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,

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

wherein the optical lens has six lenses having focal power, an

23. An optical lens barrel according to claim 22, wherein the second lens and the third lens are cemented to each other to form a first cemented lens.

24. An optical lens barrel according to claim 23, wherein the fifth lens and the sixth lens are cemented to each other to form a second cemented lens.

25. An optical lens barrel according to claim 22, wherein the second lens has both an object side surface and an image side surface which are concave.

26. An optical lens barrel according to claim 22, wherein the second lens element has a concave object-side surface and a convex image-side surface.

27. An optical lens barrel according to claim 22, wherein the object side surface and the image side surface of the third lens are convex.

28. An optical lens barrel according to claim 22, wherein the third lens element has a concave object-side surface and a convex image-side surface.

29. An optical lens barrel according to claim 22, wherein the object side surface and the image side surface of the fifth lens are convex.

30. An optical lens barrel according to claim 22, wherein the fifth lens element has a concave object-side surface and a convex image-side surface.

31. An optical lens barrel according to claim 22, wherein the sixth lens element has a concave object-side surface and a convex image-side surface.

32. An optical lens barrel according to claim 22, wherein the object side surface and the image side surface of the sixth lens element are both concave.

33. An optical lens element according to any one of claims 22-32, characterized in that the first and fourth lens elements are both aspherical lenses.

34. An optical lens element according to any one of claims 22-32, wherein the length TL of the lens group of the optical lens element and the value F of the total group focal length of the optical lens element satisfy: TL/F is less than or equal to 2.5.

35. An optical lens element according to any of claims 22-32, wherein the maximum field angle FOV of the optical lens, the maximum clear aperture D of the object-side surface of the first lens element corresponding to the maximum field angle of the optical lens element, and the image height H corresponding to the maximum field angle of the optical lens element satisfy: (D is multiplied by 180 degrees) and/(h is multiplied by FOV) is less than or equal to 4.5.

36. An optical lens according to any of claims 22-32, characterized in that between an optical back focus BFL of the optical lens and a lens group length TL of the optical lens satisfies: BFL/TL is more than or equal to 0.2.

37. An optical lens element according to any of claims 22-32, characterized in that between the focal value F2 of the second lens and the focal value F3 of the third lens, it is satisfied that: the ratio of F2 to F3 is less than or equal to 1.5.

38. An optical lens element according to any one of claims 22-32, characterized in that the focal length value F5 of the fifth lens element and the entire group of focal length values F of the optical lens element satisfy: F5/F is less than or equal to 2.5.

39. An optical lens element according to any one of claims 22-24, characterized in that the combined focal length value F23 of the second and third lens elements and the entire set of focal length values F of the optical lens element satisfy: and | F23/F | ≧ 3.

40. An optical lens element according to any one of claims 22-32, characterized in that the focal length value F4 of the fourth lens element and the entire set of focal length values F of the optical lens element satisfy: the ratio of F4/F is less than or equal to 1.7.

41. An optical lens element according to any one of claims 22-32, characterized in that the focal length value F6 of the sixth lens element and the entire group of focal length values F of the optical lens element satisfy: i F6/F | ≧ 1.0.

42. An optical lens element according to any one of claims 22 to 32, wherein the central radius of curvature R32 of the image side of the third lens element and the central radius of curvature R41 of the object side of the fourth lens element satisfy: and | (| R32| - | R41|)/(| R32| + | R41|) | is less than or equal to 0.6.

43. An optical lens element according to any one of claims 22 to 32, wherein a center distance d12 between an image side surface of the first lens element and an object side surface of the second lens element and an overall optical length TTL of the optical lens element satisfy: d12/TTL is more than or equal to 0.05.

44. An optical lens element according to any one of claims 22-32, characterized in that a center distance d34 between an image side surface of the third lens element and an object side surface of the fourth lens element and a center thickness T4 of the fourth lens element satisfy: d34/T4 is less than or equal to 0.3.

45. An optical lens element according to any one of claims 22-32, characterized in that a center distance d45 between an image-side surface of the fourth lens element and an object-side surface of the fifth lens element and a center thickness T4 of the fourth lens element satisfy: d45/T4 is less than or equal to 0.2.

46. An optical lens barrel according to any one of claims 22 to 32, wherein a central radius of curvature R42 of an image side surface of the fourth lens and a lens group length TL of the optical lens satisfy: and the | R42/TL | is more than or equal to 0.2.

47. An imaging apparatus comprising the optical lens of claim 1 or 22 and an imaging element for converting an optical image formed by the optical lens into an electric signal.