CN113534407A

CN113534407A - Optical lens, camera module and electronic equipment

Info

Publication number: CN113534407A
Application number: CN202110738149.XA
Authority: CN
Inventors: 刘彬彬; 邹海荣; 李明
Original assignee: Jiangxi Jingchao Optical Co Ltd
Current assignee: Jiangxi Jingchao Optical Co Ltd
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2021-10-22
Anticipated expiration: 2041-06-30
Also published as: CN113534407B

Abstract

The invention discloses an optical lens, a camera module and electronic equipment, wherein the optical lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens which are sequentially arranged from an object side to an image side along an optical axis; the first lens element with positive refractive power, the second lens element with negative refractive power, the third lens element with positive refractive power, the eighth lens element with negative refractive power, and the optical lens assembly satisfy the following relationships: 2mm < SD82/FNO <3.5mm, SD82 is the maximum effective half aperture of the image side of the eighth lens, and FNO is the reciprocal of the relative aperture of the optical lens. The optical lens, the camera module and the electronic equipment provided by the invention can meet the light, thin and miniaturized design, have the characteristic of large aperture, meet the shooting requirement of large field angle, improve the image quality of the optical lens, improve the resolution and imaging definition of the optical lens and realize clear imaging.

Description

Optical lens, camera module and electronic equipment

Technical Field

The invention relates to the technical field of optical imaging, in particular to an optical lens, a camera module and electronic equipment.

Background

At present, with the development of the camera technology, people have higher and higher requirements on the imaging quality of the optical lens, and the optical lens is required to be lighter, thinner and smaller, and simultaneously has higher imaging quality. In order to achieve higher imaging quality, the optical lens needs to increase the number of lenses to correct aberrations. However, the increase in the number of lenses increases the difficulty of processing, molding and assembling the lenses, and increases the volume of the optical lens. Therefore, in the related art, under the design trend of light, thin and small optical lens, the image quality of the optical lens is poor, the resolution is low, and the imaging quality of the optical lens is not clear enough, so that it is difficult to meet the requirement of high-definition imaging of the optical lens.

Disclosure of Invention

The embodiment of the invention discloses an optical lens, a camera module and electronic equipment, which can realize the light, thin and miniaturized design of the optical lens, have the characteristic of a large aperture, meet the shooting requirement of a large field angle and realize clear imaging.

In order to achieve the above object, in a first aspect, the present invention discloses an optical lens including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens, which are arranged in order from an object side to an image side along an optical axis;

the first lens element with positive refractive power has a convex object-side surface at a paraxial region thereof and a concave image-side surface at a paraxial region thereof;

the second lens element with negative refractive power has a convex object-side surface at paraxial region and a concave image-side surface at paraxial region;

the third lens element with positive refractive power;

the fourth lens element with refractive power;

the fifth lens element with refractive power;

the sixth lens element with refractive power has a concave object-side surface at a paraxial region;

the seventh lens element with refractive power has a convex object-side surface at paraxial region;

the eighth lens element with negative refractive power has a concave image-side surface at a paraxial region, and at least one of an object-side surface and an image-side surface of the eighth lens element has at least one inflection point;

the optical lens satisfies the following relation:

2mm<SD82/FNO<3.5mm；

wherein SD82 is the maximum effective half aperture of the image side surface of the eighth lens element, and FNO is the f-number of the optical lens.

In the optical lens provided by the present application, the positive refractive power provided by the first lens element and the convex-concave surface design of the object-side surface and the image-side surface at the optical axis can effectively utilize the space of the optical lens to reduce the back focal length of the optical lens; meanwhile, the negative refractive power provided by the second lens element helps to dispose the lens element (the first lens element) with stronger refractive power at the object-side end of the optical lens, so as to avoid the situation that the lens element with stronger refractive power is difficult to process due to excessive distortion of the shape. The positive refractive power provided by the third lens is favorable for converging light rays entering the optical lens from the object side of the optical lens, so that the wide angle of the optical lens is reduced; the positive refractive power or the negative refractive power provided by the fourth lens element, the fifth lens element, the sixth lens element and the seventh lens element can properly distribute the focal power of the optical lens assembly, which is beneficial to correcting the aberration and enlarging the field angle. The negative refractive power and the concave surface design of the image side surface at the optical axis provided by the eighth lens element, and at least one of the object side surface and the image side surface of the eighth lens element is provided with an inflection point, so that the total length of the optical lens can be shortened, aberration can be corrected, the emergent angle of light can be suppressed, the receiving efficiency of the photosensitive chip can be improved, aberration can be further corrected, and the imaging quality can be improved. Simultaneously, the optical lens satisfies the following relational expression: when the diameter of the image side surface of the eighth lens element is 2mm < SD82/FNO <3.5mm, the diameter of the image side surface of the eighth lens element is not too large, which is beneficial for shortening the total length of the optical lens to realize the light and thin and miniaturized design of the optical lens, and is also beneficial for increasing the aperture of the optical lens to ensure that the optical lens has the characteristic of a large aperture, so that light rays which are emitted into the optical lens at a large angle can be grasped, the field angle range of the optical lens is enlarged, the light inlet quantity is greater, the image quality of the optical lens is improved, the resolution and the imaging definition of the optical lens are improved, the optical lens has a better imaging effect, and the high-definition imaging requirement of the optical lens by people is met; meanwhile, enough luminous flux can be obtained under a dim environment, dim light shooting conditions are improved, high-definition shooting effects of high image quality can be achieved, meanwhile, the method is suitable for shooting in dim light environments such as night scenes, rainy days and starry sky, and shooting experience of users is improved.

As an alternative implementation, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: 0.6< TTL/(ImgH × 2) < 0.8; wherein, TTL is a distance on the optical axis from the object-side surface of the first lens element to the imaging surface of the optical lens (i.e., a total optical length of the optical lens), and Imgh is a radius of an effective imaging circle on the imaging surface of the optical lens (i.e., a half-image height of the optical lens).

By controlling the ratio of the total optical length to the half-image height of the optical lens within a reasonable range, the optical lens is beneficial to being more compact in structure and ultrathin in characteristic on the premise that the optical lens has a larger image plane, and the design requirement of miniaturization is met.

As an alternative implementation, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: 0< SD11/SD82< 0.5; wherein SD11 is the maximum effective half aperture of the object side surface of the first lens.

By controlling the ratio of the maximum effective half aperture of the object side surface of the first lens to the maximum effective half aperture of the image side surface of the eighth lens within a reasonable range, the emergent angle of incident light can be reduced to a certain extent, astigmatism and field curvature of the optical lens can be effectively inhibited, and meanwhile, the first lens and the eighth lens can be guaranteed to be reasonable and moderate in structural size, so that the optical lens is compact in structure and meets the design requirement of miniaturization.

As an alternative implementation, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: (ET1+ ET7+ ET8)/(ET4+ ET5+ ET6) > 1;

wherein ET1 is a thickness from an effective diameter edge of an object-side surface of the first lens to an effective diameter edge of an image-side surface of the first lens in a direction parallel to an optical axis (i.e., an edge thickness of the first lens), ET4 is a thickness from an effective diameter edge of an object-side surface of the fourth lens to an effective diameter edge of an image-side surface of the fourth lens in a direction parallel to an optical axis (i.e., an edge thickness of the fourth lens), ET5 is a thickness from an effective diameter edge of an object-side surface of the fifth lens to an effective diameter edge of an image-side surface of the fifth lens in a direction parallel to an optical axis (i.e., an edge thickness of the fifth lens), ET6 is a thickness from an effective diameter edge of an object-side surface of the sixth lens to an effective diameter edge of an image-side surface of the sixth lens in a direction parallel to an optical axis (i.e., an edge thickness of the sixth lens), and ET7 is an effective diameter edge of an object-side surface of the seventh lens to an effective diameter edge of an image-side surface of the seventh lens ET8 is a thickness from an effective diameter edge of an object-side surface of the eighth lens to an effective diameter edge of an image-side surface of the eighth lens in a direction parallel to the optical axis (i.e., an edge thickness of the eighth lens).

The thicknesses of the edges of the first lens, the seventh lens, the eighth lens, the fourth lens, the fifth lens and the sixth lens are reasonably configured by limiting the relational expression, so that the reasonable configuration of the distance between the lenses is facilitated, light can smoothly enter the optical lens, and the miniaturization design of the optical lens is facilitated.

As an alternative implementation, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: 0.2< Yc82/f < 0.5; yc82 is a perpendicular distance between a first tangent point and the optical axis, the first tangent point is a tangent point of a tangent line perpendicular to the optical axis on the image-side surface of the eighth lens, and the first tangent point is not located on the optical axis.

The definition of the relational expression is beneficial to correcting the aberration of the optical lens and improving the peripheral relative illumination of the optical lens, so that the peripheral resolution of the optical lens is further enhanced, and the imaging quality of the optical lens is improved.

As an alternative implementation, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: 0.8< (| SAG81| + SAG82)/CT8< 3.5;

SAG81 is the distance from the intersection point of the object side surface of the eighth lens and the optical axis to the maximum effective radius of the object side surface of the eighth lens in the direction parallel to the optical axis, namely the rise of the object side surface of the eighth lens; SAG82 is the distance from the maximum effective radius of the image side surface of the eighth lens to the intersection point of the image side surface of the eighth lens and the optical axis in the direction parallel to the optical axis, namely the rise of the image side surface of the eighth lens, and CT8 is the thickness of the eighth lens on the optical axis.

Therefore, the relation is satisfied, the surface shape of the eighth lens element is not too curved or too flat, the focal length of the eighth lens element can be controlled properly, and meanwhile, the center thickness of the eighth lens element is matched within a proper range, so that the eighth lens element is prevented from being too thin or too thick, the incident angle of light on the imaging surface of the optical lens can be reduced, the sensitivity of the optical lens is reduced, and the optical performance of the optical lens is improved.

As an alternative implementation, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: 0.1< CT8/SD82< 0.2; wherein CT8 is the thickness of the eighth lens element on the optical axis.

Through the limitation of the relational expression, the ratio of the central thickness of the eighth lens to the maximum effective semi-caliber can be reasonably distributed, the surface shape of the eighth lens cannot be excessively bent or flattened, the focal length of the eighth lens can be properly controlled, and the eighth lens cannot be excessively thin or thick, so that the distortion and the curvature of field generated by the front lens group (the first lens to the seventh lens) can be favorably corrected; meanwhile, the sensitivity of the eighth lens is reduced, so that the molding processability of the eighth lens is improved, the processing of the eighth lens is facilitated, and the processing cost of the eighth lens is reduced.

As an alternative implementation manner, in an embodiment of the first aspect of the present invention, at least one of the object-side surface and the image-side surface of the seventh lens is provided with at least one inflection point, and the optical lens satisfies the following relation:

0.2< Yc82/SD82< 0.5; and/or

0.3<Yc72/SD72<0.8；

Yc82 is the perpendicular distance between a first tangent point and the optical axis, the first tangent point is the tangent point of a tangent line perpendicular to the optical axis on the image side surface of the eighth lens, and the first tangent point is not located on the optical axis; yc72 is the perpendicular distance of second tangent point and optical axis, the second tangent point be the tangent point of the tangent line of perpendicular to optical axis on the image side face of seventh lens, just the second tangent point is not located the optical axis, SD72 is the most effective half bore of the image side face of seventh lens.

Satisfying the above relation, the optical lens can be ensured to have a sufficient field angle, and is beneficial to effectively suppressing the angle of the light rays of the off-axis field incident on the photosensitive chip, thereby further correcting the aberration of the off-axis field and improving the imaging quality of the optical lens.

In a second aspect, the present invention discloses a camera module, which includes a photosensitive chip and the optical lens according to the first aspect, wherein the photosensitive chip is disposed on an image side of the optical lens. The camera module with the optical lens can meet the requirements of light, thin and small design, is favorable for enabling the optical lens to have the characteristic of a large aperture, has larger light inlet quantity, improves the painting texture of the optical lens, enables the optical lens to have better imaging effect, can also achieve enough luminous flux in a dim environment, and improves dim light shooting conditions, so that the shooting quality of the camera module in the dim light environment can be effectively improved, and the camera module is favorable for being suitable for shooting in dim light environments such as night scenes, rainy days, starry sky and the like.

In a third aspect, the invention further discloses an electronic device, which includes a housing and the camera module set according to the second aspect, and the camera module set is disposed on the housing. The electronic equipment with the camera module can meet the requirements of light, thin and small design, is favorable for enabling the optical lens to have the characteristic of a large aperture, has larger light inlet quantity, improves the painting texture of the optical lens, enables the optical lens to have better imaging effect, can also obtain enough luminous flux in a dark environment, and improves the dark light shooting condition, so that the shooting quality of the camera module in the dark light environment can be effectively improved, and the camera module is favorable for being suitable for shooting in the dark light environments such as night scenes, rainy days, starry sky and the like.

Compared with the prior art, the invention has the beneficial effects that:

according to the optical lens, the camera module and the electronic equipment provided by the embodiment of the invention, the optical lens adopts eight-piece type lenses, the number of the lenses is reasonable, the structure is ingenious, and the volume is small. By selecting a proper number of lenses and reasonably configuring the refractive power and the surface shape of each lens, the optical lens meets the following relational expression: when the diameter of the image side surface of the eighth lens is 2mm < SD82/FNO <3.5mm, the caliber of the image side surface of the eighth lens is not too large, the total length of the optical lens is favorably shortened, the light and thin and miniaturized design of the optical lens is realized, and the aperture of the optical lens is favorably increased, so that the optical lens has the characteristic of a large aperture, the light rays which are emitted into the optical lens at a large angle can be grasped, the field angle range of the optical lens is enlarged, the light entering quantity is larger, the image quality feeling of the optical lens is improved, the resolution and the imaging definition of the optical lens are improved, the optical lens has a better imaging effect, and the high-definition imaging requirement of the optical lens by people is met; meanwhile, enough luminous flux can be obtained under a dim environment, dim light shooting conditions are improved, high-definition shooting effects of high image quality can be achieved, meanwhile, the method is suitable for shooting in dim light environments such as night scenes, rainy days and starry sky, and shooting experience of users is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an optical lens disclosed in a first embodiment of the present application;

fig. 2 is a light ray spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%);

fig. 3 is a schematic structural diagram of an optical lens disclosed in the second embodiment of the present application;

fig. 4 is a light ray spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%);

fig. 5 is a schematic structural diagram of an optical lens disclosed in the third embodiment of the present application;

fig. 6 is a light ray spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%);

fig. 7 is a schematic structural diagram of an optical lens disclosed in a fourth embodiment of the present application;

fig. 8 is a light ray spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%);

fig. 9 is a schematic structural diagram of an optical lens disclosed in a fifth embodiment of the present application;

fig. 10 is a light ray spherical aberration diagram (mm), an astigmatism diagram (mm), and a distortion diagram (%);

fig. 11 is a schematic structural diagram of the camera module disclosed in the present application;

fig. 12 is a schematic structural diagram of an electronic device disclosed in the present application.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the present invention, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "center", "vertical", "horizontal", "lateral", "longitudinal", and the like indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These terms are used primarily to better describe the invention and its embodiments and are not intended to limit the indicated devices, elements or components to a particular orientation or to be constructed and operated in a particular orientation.

Moreover, some of the above terms may be used to indicate other meanings besides the orientation or positional relationship, for example, the term "on" may also be used to indicate some kind of attachment or connection relationship in some cases. The specific meanings of these terms in the present invention can be understood by those skilled in the art as appropriate.

Furthermore, the terms "mounted," "disposed," "provided," "connected," and "connected" are to be construed broadly. For example, it may be a fixed connection, a removable connection, or a unitary construction; can be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements or components. The specific meanings of the above terms in the present invention can be understood by those of ordinary skill in the art according to specific situations.

Furthermore, the terms "first," "second," and the like, are used primarily to distinguish one device, element, or component from another (the specific nature and configuration may be the same or different), and are not used to indicate or imply the relative importance or number of the indicated devices, elements, or components. "plurality" means two or more unless otherwise specified.

The technical solution of the present invention will be further described with reference to the following embodiments and the accompanying drawings.

Referring to fig. 1, according to a first aspect of the present application, an optical lens 100 is disclosed, where the optical lens 100 includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8, which are disposed in order from an object side to an image side along an optical axis O. During imaging, light rays enter the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 in sequence from the object side of the first lens L1, and finally form an image on the imaging surface 101 of the optical lens 100. The first lens element L1, the second lens element L2, the third lens element L3, the fourth lens element L4, the fifth lens element L5, the sixth lens element L6, and the seventh lens element L7 have positive refractive power, negative refractive power, and positive refractive power, respectively, and the eighth lens element L8 has negative refractive power, respectively.

Further, the object-side surface S1 of the first lens element L1 can be convex at the paraxial region O, the image-side surface S2 of the first lens element L1 can be concave at the paraxial region O, the object-side surface S1 of the first lens element L1 can be convex at the circumference, and the image-side surface S2 of the first lens element L1 can be convex or concave at the circumference. The object-side surface S3 of the second lens element L2 can be convex at the paraxial region O, the image-side surface S4 of the second lens element L2 can be concave at the paraxial region O, the object-side surface S3 of the second lens element L2 can be convex at the circumference, and the image-side surface S4 of the second lens element L2 can be concave at the circumference. The object-side surface S5 of the third lens element L3 can be convex or concave at the paraxial region O, the image-side surface S6 of the third lens element L3 can be convex or concave at the paraxial region O, the object-side surface S5 of the third lens element L3 can be convex or concave at the circumference, and the image-side surface S6 of the third lens element L3 can be convex or concave at the circumference. The object-side surface S7 of the fourth lens element L4 can be convex or concave at the paraxial region O, the image-side surface S8 of the fourth lens element L4 can be convex or concave at the paraxial region O, the object-side surface S7 of the fourth lens element L4 can be concave at the circumference, and the image-side surface S8 of the fourth lens element L4 can be convex at the circumference. The object-side surface S9 of the fifth lens element L5 can be convex or concave at the paraxial region O, the image-side surface S10 of the fifth lens element L5 can be convex or concave at the paraxial region O, the object-side surface S9 of the fifth lens element L5 can be convex or concave at the circumference, and the image-side surface S10 of the fifth lens element L5 can be convex at the circumference. The object-side surface S11 of the sixth lens element L6 can be concave at the paraxial region O, the image-side surface S12 of the sixth lens element L6 can be convex or concave at the paraxial region O, the object-side surface S11 of the sixth lens element L6 can be concave at the circumference, and the image-side surface S12 of the sixth lens element L6 can be convex at the circumference. The object-side surface S13 of the seventh lens element L7 can be convex at the paraxial region O, the image-side surface S14 of the seventh lens element L7 can be convex or concave at the paraxial region O, the object-side surface S13 of the seventh lens element L7 can be concave at the circumference, and the image-side surface S14 of the seventh lens element L7 can be convex at the circumference. The object-side surface S15 of the eighth lens element L8 can be convex or concave at the paraxial region O, the image-side surface S16 of the eighth lens element L8 can be concave at the paraxial region O, and the object-side surface S15 and the image-side surface S16 of the eighth lens element L8 can be convex at the circumference.

Furthermore, at least one of the object-side surface S13 and the image-side surface S14 of the seventh lens element L7 is provided with at least one inflection point, and at least one of the object-side surface S15 and the image-side surface S16 of the eighth lens element L8 is provided with at least one inflection point, so that the total length of the optical lens 100 can be shortened, aberration can be corrected, the exit angle of light can be suppressed, the receiving efficiency of the photosensitive chip can be improved, aberration can be further corrected, and the imaging quality can be improved.

It is considered that the optical lens 100 is mostly applied to electronic devices such as smart phones and smart tablets. When the optical lens 100 is used as a camera of a smartphone, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 may be made of Plastic (e.g., Polycarbonate Plastic, PC Plastic for short), so that the optical lens 100 has a good optical effect and the overall weight of the optical lens 100 may be reduced. Meanwhile, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 may all be aspheric.

In addition, it is understood that, in other embodiments, when the optical lens 100 is applied to electronic devices such as an in-vehicle device, a driving recorder, or an automobile, the material of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 may also be plastic or glass, and each lens may also be an aspheric surface or a spherical surface.

In some embodiments, the optical lens 100 further includes a stop 102, and the stop 102 may be an aperture stop or a field stop, which may be disposed between the object side of the optical lens 100 and the object side S1 of the first lens L1. It is understood that, in other embodiments, the stop 102 may also be disposed between two adjacent lenses, for example, between the second lens L2 and the third lens L3, and the arrangement is adjusted according to the actual situation, which is not specifically limited in this embodiment.

In some embodiments, the optical lens 100 further includes a filter L9, such as an infrared filter, disposed between the image side surface S16 of the eighth lens element L8 and the image plane 101 of the optical lens 100, so as to filter out light in other bands, such as visible light, and only allow infrared light to pass through, and therefore, the optical lens 100 can be used as an infrared optical lens, that is, the optical lens 100 can image in a dark environment and other special application scenes and can obtain a better image effect.

In some embodiments, the optical lens 100 satisfies the following relationship: 2mm < SD82/FNO <3.5 mm; where SD82 is the maximum effective half aperture of the image-side surface S16 of the eighth lens element L8, and FNO is the f-number of the optical lens 100 (i.e., the reciprocal of the relative aperture of the optical lens 100). By controlling the ratio of the maximum effective half aperture of the image-side surface S16 of the eighth lens element L8 to the f-number of the optical lens 100 within a reasonable range, the aperture of the image-side surface S16 of the eighth lens element L8 is not too large, and the optical lens 100 can be guaranteed to have a compact structure, so that the optical lens 100 can satisfy the requirement of miniaturization and has the characteristic of a large aperture, so that the optical lens 100 can have a larger light incoming amount, the image quality of the optical lens 100 is improved, the resolution and the imaging definition of the optical lens 100 are improved, and the effective pixel area on the imaging surface of the optical lens 100 has good imaging quality.

In some embodiments, the optical lens 100 satisfies the following relationship: 0.6< TTL/(ImgH × 2) < 0.8; wherein, TTL is a distance from the object-side surface S1 of the first lens element L1 to the image plane 101 of the optical lens system 100 on the optical axis O (i.e., the total optical length of the optical lens system 100), and Imgh is a radius of an effective image circle on the image plane 101 of the optical lens system 100 (i.e., a half-image height of the optical lens system 100).

By controlling the ratio of the total optical length to the half-image height of the optical lens 100 within a reasonable range, the optical lens 100 has a more compact structure and an ultrathin characteristic on the premise that the optical lens 100 has a larger image plane, and the design requirement of miniaturization is met; on the other hand, if the upper limit of the above relation is exceeded, the total optical length of the optical lens 100 becomes too long, which is disadvantageous for downsizing the optical lens 100.

In some embodiments, the optical lens 100 satisfies the following relationship: 0< SD11/SD82< 0.5; SD11 is the maximum effective half aperture of the object-side surface S1 of the first lens L1. By controlling the ratio of the maximum effective half aperture of the object-side surface S1 of the first lens L1 to the maximum effective half aperture of the image-side surface S16 of the eighth lens L8 within a reasonable range, the emergent angle of the incident light can be reduced to a certain extent, astigmatism and curvature of field of the optical lens 100 can be effectively suppressed, and meanwhile, the first lens L1 and the eighth lens L8 can be ensured to be reasonable and moderate in structural size, so that the optical lens 100 can be favorably realized to be compact in structure, and the miniaturized design requirements can be met.

It is understood that, when the stop 102 is disposed on the object-side surface S1 of the first lens L1, which belongs to a mid-set design, when the stop 102 is mid-set, the maximum effective half apertures of the first four lenses and the last four lenses of the optical lens 100 have certain symmetry, and the object-side surface S1 of the first lens L1 and the image-side surface S16 of the eighth lens L8 have corresponding symmetry in position. By satisfying the above relational expression, the ratio of the maximum effective radii of the two positions is controlled to be within 0.5, which is favorable for ensuring uniform distribution of the half apertures of the first lens L1 and the eighth lens L8, and the optical lens 100 can better correct aberrations while realizing the telephoto characteristic. In addition, the optical lens 100 can obtain a larger field angle, and can be matched with a photosensitive chip with higher pixels and a larger image plane, thereby realizing high-definition imaging. If the maximum effective half aperture of the object-side surface S1 of the first lens L1 is too large when the upper limit of the above relational expression is exceeded, the maximum effective half aperture of the image-side surface S16 of the eighth lens L8 is less symmetrical with the maximum effective half aperture, which is not favorable for realizing a telephoto characteristic and matching a photosensitive chip with a large image plane and high pixels, and affects the imaging quality.

In some embodiments, the optical lens 100 satisfies the following relationship: (ET1+ ET7+ ET8)/(ET4+ ET5+ ET6) > 1.

ET1 is a thickness from an effective diameter edge of the object-side surface S1 of the first lens L1 to an effective diameter edge of the image-side surface S2 of the first lens L1 in a direction parallel to the optical axis O (i.e., an edge thickness of the first lens L1), ET4 is a thickness from an effective diameter edge of the object-side surface S7 of the fourth lens L4 to an effective diameter edge of the image-side surface S8 of the fourth lens L4 in a direction parallel to the optical axis O (i.e., an edge thickness of the fourth lens L4), ET5 is a thickness from an effective diameter edge of the object-side surface S5 of the fifth lens L5 to an effective diameter edge of the image-side surface S5 of the fifth lens L5 in a direction parallel to the optical axis O (i.e., an edge thickness of the fifth lens L5), ET5 is a thickness from an effective diameter edge of the object-side surface S5 of the sixth lens L5 to an effective diameter edge of the image-side surface S5 of the sixth lens L5 in a direction parallel to the optical axis O (i.e., an edge thickness from an effective diameter edge of the seventh lens L5 of the image-side surface S5 of the seventh lens L5 in a direction parallel to the optical axis O (i.e., an edge thickness of the effective diameter edge of the seventh lens L5 of the effective diameter edge of the seventh lens L5) of the effective diameter edge of the seventh lens L5 of the effective diameter edge of the optical axis L5 of the fifth lens L5 of the optical axis L5 (i.e., an effective diameter edge of the lens L5) of the lens L5 is equal to the optical axis L5 in a thickness of the optical axis L5 (i.e., an effective diameter of the effective diameter edge of the optical axis L5 of the effective diameter edge of the lens L5 of the effective diameter edge of the effective diameter of the seventh lens L5 of the effective diameter of the lens L5 of the effective diameter edge of the lens L5 of the seventh lens L5 of the optical axis L5 of the effective diameter of the seventh lens L5 of the optical axis L5) ET8 is the thickness in the direction parallel to the optical axis O (i.e., the thickness of the edge of the seventh lens L7) from the effective diameter edge of the object-side surface S15 of the eighth lens L8 to the effective diameter edge of the image-side surface S16 of the eighth lens L8 (i.e., the thickness of the edge of the eighth lens L8).

Through the limitation of the above relational expression, the edge thicknesses of the first lens L1, the seventh lens L7, the eighth lens L8, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are reasonably configured, which is beneficial to reasonably configuring the distance between the lenses, so that the light can smoothly enter the optical lens 100, and the optical lens 100 can be miniaturized.

In some embodiments, the optical lens 100 satisfies the following relationship: 0.2< Yc82/f < 0.5; where Yc82 is a perpendicular distance from the optical axis O to a first tangent point on the image-side surface S16 of the eighth lens element L8, which is perpendicular to the optical axis O, and the first tangent point is not located on the optical axis O, that is, the first tangent point is a point on the image-side surface S16 of the eighth lens element L8 except for an intersection point with the optical axis O.

The above relation is used for limiting, which is beneficial to correcting the aberration of the optical lens 100 and improving the peripheral relative illumination of the optical lens 100, thereby further enhancing the peripheral resolution of the optical lens 100 and improving the imaging quality of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the following relationship: 0.8< (| SAG81| + SAG82)/CT8< 3.5.

Wherein SAG81 is the distance in the direction parallel to the optical axis O from the intersection of the object-side surface S15 of the eighth lens L8 and the optical axis O to the maximum effective radius of the object-side surface S15 of the eighth lens L8, i.e., the rise of the object-side surface S15 of the eighth lens L8; SAG82 is the distance in the direction parallel to the optical axis O from the intersection of the image-side surface S16 of the eighth lens L8 and the optical axis O to the maximum effective radius of the image-side surface S16 of the eighth lens L8, i.e., the rise of the image-side surface S16 of the eighth lens L8, and CT8 is the thickness of the eighth lens L8 on the optical axis O.

Satisfying the above relationship, the refractive power and the center thickness of the eighth lens element L8 can be controlled within a reasonable range, and the eighth lens element L8 is prevented from being too thin or too thick, so that the incident angle of light on the image plane 101 of the optical lens 100 can be reduced, the sensitivity of the optical lens 100 can be reduced, and the optical performance of the optical lens 100 can be improved.

In some embodiments, the optical lens 100 satisfies the following relationship: 0.1< CT8/SD82< 0.2.

Through the limitation of the relational expression, the ratio of the central thickness of the eighth lens L8 to the maximum effective semi-caliber can be reasonably distributed, the surface shape of the eighth lens L8 is not excessively bent or flattened, the focal length of the eighth lens L8 can be properly controlled, and the eighth lens L8 is not excessively thin or thick, so that the distortion and the curvature of field generated by the front lens group can be favorably corrected; meanwhile, the sensitivity of the eighth lens L8 is reduced, so that the molding processability of the eighth lens L8 is improved, the processing of the eighth lens L8 is facilitated, and the processing cost of the eighth lens L8 is reduced.

In some embodiments, the optical lens 100 satisfies the following relationship: 0.2< Yc82/SD82< 0.5; and/or, 0.3< Yc72/SD72< 0.8.

The Yc72 is a perpendicular distance between a second tangent point and the optical axis O, the second tangent point is a tangent point of a tangent line perpendicular to the optical axis O on the image-side surface S14 of the seventh lens L7, the second tangent point is not located on the optical axis O, and the SD72 is the maximum effective half-aperture of the image-side surface S14 of the seventh lens L7.

Satisfying the above relation, the optical lens 100 can have a sufficient field angle, and is beneficial to effectively suppressing the angle of the light rays of the off-axis field incident on the photosensitive chip, so that the aberration of the off-axis field can be further corrected, and the imaging quality of the optical lens 100 can be improved.

The optical lens 100 of the present embodiment will be described in detail with reference to specific parameters.

First embodiment

A schematic structural diagram of an optical lens 100 disclosed in the first embodiment of the present application is shown in fig. 1, where the optical lens 100 includes a stop 102, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter L9, which are arranged in order from an object side to an image side along an optical axis O. For materials of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8, reference may be made to the above detailed description, and details are not repeated here.

Further, the first lens element L1 has positive refractive power, the second lens element L2 has negative refractive power, the third lens element L3 has positive refractive power, the fourth lens element L4 has positive refractive power, the fifth lens element L5 has negative refractive power, the sixth lens element L6 has positive refractive power, the seventh lens element L7 has negative refractive power, and the eighth lens element L8 has negative refractive power.

Further, the object-side surface S1 and the image-side surface S2 of the first lens element L1 are convex and concave, respectively, at the paraxial region O; the object-side surface S1 and the image-side surface S2 of the first lens element L1 are convex at their circumferences. The object-side surface S3 and the image-side surface S4 of the second lens element L2 are convex and concave, respectively, at a paraxial region O; the object-side surface S3 and the image-side surface S4 of the second lens L2 are convex and concave, respectively, at the circumference. The object-side surface S5 and the image-side surface S6 of the third lens element L3 are convex and concave, respectively, at a paraxial region O; the object-side surface S5 and the image-side surface S6 of the third lens L3 are convex and concave, respectively, at the circumference. The object-side surface S7 and the image-side surface S8 of the fourth lens element L4 are concave and convex, respectively, at a paraxial region O; the object-side surface S7 and the image-side surface S8 of the four-lens L4 are concave and convex, respectively, at the circumference. The object-side surface S9 and the image-side surface S10 of the fifth lens element L5 are convex and concave, respectively, at a paraxial region O; the object-side surface S9 and the image-side surface S10 of the fifth lens L5 are concave and convex, respectively, at the circumference. The object-side surface S11 and the image-side surface S12 of the sixth lens element L6 are concave and convex, respectively, at a paraxial region O; the object-side surface S11 and the image-side surface S12 of the sixth lens element L6 are concave and convex, respectively, at the circumference. The object-side surface S13 and the image-side surface S14 of the seventh lens element L7 are convex and concave, respectively, at a paraxial region O; the object-side surface S13 and the image-side surface S14 of the seventh lens element L7 are concave and convex, respectively, at the circumference. The object-side surface S15 and the image-side surface S16 of the eighth lens element L8 are convex and concave, respectively, at a paraxial region O; the object-side surface S15 and the image-side surface S16 of the eighth lens element L8 are convex at their circumferences.

Specifically, other parameters of the optical lens 100 are given in table 1 below, taking as examples that the effective focal length f of the optical lens 100 is 7.5mm, the field angle FOV of the optical lens 100 is 77.5 °, the total optical length TTL of the optical lens 100 is 9.2mm, the aperture size FNO is 1.5, and the half-image height Imgh is 6.068 mm. The elements of the optical lens 100 from the object side to the image side along the optical axis O are arranged in the order of the elements from top to bottom in table 1. In the same lens, the surface with the smaller number of surfaces is the object side surface of the lens, and the surface with the larger number of surfaces is the image side surface of the lens, and for example, the numbers 2 and 3 correspond to the object side surface S1 and the image side surface S2 of the first lens L1, respectively. The Y radius in table 1 is the radius of curvature of the object-side or image-side surface of the respective surface number at the paraxial region O. The first value in the "thickness" parameter list of a lens is the thickness of the lens on the optical axis O, and the second value is the distance from the image-side surface to the back surface of the lens on the optical axis O. The numerical value of the stop 102 in the "thickness" parameter column is the distance on the optical axis O from the stop 102 to the vertex of the next surface (the vertex refers to the intersection point of the surface and the optical axis O), the direction from the object side to the image side of the last lens of the first lens L1 is the positive direction of the optical axis O, when the value is negative, it indicates that the stop 102 is disposed on the right side of the vertex of the next surface, and if the thickness of the stop 102 is a positive value, the stop 102 is disposed on the left side of the vertex of the next surface. It is understood that the units of the radius Y, thickness, and focal length in table 1 are all mm. And the reference wavelength of refractive index, Abbe number of each lens in Table 1 was 587.6nm, and the reference wavelength of focal length of each lens was 555 nm.

TABLE 1

In the first embodiment, the object-side surface and the image-side surface of any one of the first lens L1 through the eighth lens L8 are aspheric, and the surface shape x of each aspheric lens can be defined by, but is not limited to, the following aspheric formula:

wherein x is the rise of the distance from the aspheric surface vertex to the aspheric surface vertex 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 R of Y in table 1 above); k is a conic coefficient; ai is a correction coefficient corresponding to the high-order term of the ith aspheric term. Table 2 shows the high-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for the respective aspherical mirror surfaces S1-S16 in the first embodiment.

TABLE 2

Referring to fig. 2 (a), fig. 2 (a) shows a light spherical aberration curve of the optical lens 100 in the first embodiment at wavelengths of 470nm, 510nm, 555nm, 610nm and 650 nm. In fig. 2 (a), the abscissa in the X-axis direction represents the focus shift, and the ordinate in the Y-axis direction represents the normalized field of view. As can be seen from fig. 2 (a), the spherical aberration value of the optical lens 100 in the first embodiment is better, which illustrates that the imaging quality of the optical lens 100 in this embodiment is better.

Referring to fig. 2 (B), fig. 2 (B) is a diagram of astigmatism of light of the optical lens 100 in the first embodiment at a wavelength of 555 nm. Wherein the abscissa along the X-axis direction represents the focus offset and the ordinate along the Y-axis direction represents the image height in mm. The astigmatism curves represent the meridional image plane curvature T and the sagittal image plane curvature S, and it can be seen from (B) in fig. 2 that the astigmatism of the optical lens 100 is well compensated at a wavelength of 555 nm.

Referring to fig. 2 (C), fig. 2 (C) is a distortion curve diagram of the optical lens 100 in the first embodiment at a wavelength of 555 nm. Wherein the abscissa along the X-axis direction represents distortion and the ordinate along the Y-axis direction represents image height in mm. As can be seen from (C) in fig. 2, the distortion of the optical lens 100 is well corrected at a wavelength of 555 nm.

Second embodiment

Referring to fig. 3, fig. 3 is a schematic structural diagram of an optical lens 100 according to a second embodiment of the present application. The optical lens 100 includes a stop 102, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter L9, which are disposed in this order from the object side to the image side along the optical axis O. For materials of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8, reference may be made to the above detailed description, and details are not repeated here.

Further, in the second embodiment, the refractive power of each lens element is different from that of each lens element in the first embodiment in that: the seventh lens element L7 has positive refractive power. Meanwhile, in the second embodiment, the surface shape of each lens is different from that of each lens in the first embodiment in that: the object-side surface S5 and the image-side surface S6 of the third lens element L3 are concave and convex, respectively, at the paraxial region O, the object-side surface S9 and the image-side surface S10 of the fifth lens element L5 are concave and convex, respectively, at the paraxial region O, the object-side surface S11 and the image-side surface S12 of the sixth lens element L6 are concave, and the object-side surface S13 and the image-side surface S14 of the seventh lens element L7 are convex, respectively.

In the second embodiment, the effective focal length f of the optical lens 100 is 7.36mm, the FOV of the field angle of the optical lens 100 is 78 °, the total optical length TTL of the optical lens 100 is 9.16mm, the aperture size FNO is 1.5, and the half-image height Imgh is 6.068mm, for example.

Other parameters in the second embodiment are given in the following table 3, and the definitions of the parameters can be obtained from the description of the foregoing embodiments, which are not repeated herein. It is understood that the units of the radius Y, thickness, and focal length in table 3 are all mm. And the reference wavelengths of the refractive index and the abbe number of each lens in table 3 are 587.6nm, and the reference wavelength of the focal length of each lens is 555 nm.

TABLE 3

In the second embodiment, table 4 gives the high-order term coefficients that can be used for each aspherical mirror surface in the second embodiment, wherein each aspherical mirror surface type can be defined by the formula given in the first embodiment.

TABLE 4

Further, referring to fig. 4 (a), a light spherical aberration curve chart of the optical lens 100 in the second embodiment at wavelengths of 470nm, 510nm, 555nm, 610nm and 650nm is shown. In fig. 4 (a), the abscissa in the X-axis direction represents the focus shift, and the ordinate in the Y-axis direction represents the normalized field of view. As can be seen from (a) in fig. 4, the spherical aberration value of the optical lens 100 in the second embodiment is better, which illustrates that the imaging quality of the optical lens 100 in the present embodiment is better.

Referring to fig. 4 (B), fig. 4 (B) is a diagram of astigmatism of light of the optical lens 100 in the second embodiment at a wavelength of 555 nm. Wherein the abscissa along the X-axis direction represents the focus offset and the ordinate along the Y-axis direction represents the image height in mm. The astigmatism curves represent the meridional imaging plane curvature T and the sagittal imaging plane curvature S, and it can be seen from (B) in fig. 4 that the astigmatism of the optical lens 100 is well compensated at a wavelength of 555 nm.

Referring to fig. 4 (C), fig. 4 (C) is a distortion curve diagram of the optical lens 100 in the second embodiment at a wavelength of 555 nm. Wherein the abscissa along the X-axis direction represents distortion and the ordinate along the Y-axis direction represents image height in mm. As can be seen from (C) in fig. 4, the distortion of the optical lens 100 is well corrected at a wavelength of 555 nm.

Third embodiment

Referring to fig. 5, fig. 5 is a schematic structural diagram of an optical lens 100 according to a third embodiment of the present application. The optical lens 100 includes a stop 102, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter L9, which are disposed in this order from the object side to the image side along the optical axis O. For materials of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8, reference may be made to the above detailed description, and details are not repeated here.

Further, in the third embodiment, the refractive power of each lens element is different from that of each lens element in the first embodiment in that: the fourth lens element L4 has negative refractive power. Meanwhile, in the third embodiment, the surface shape of each lens is different from that of each lens in the first embodiment in that: the object-side surface S1 and the image-side surface S2 of the first lens element L1 are respectively convex and concave at the circumference, the object-side surface S5 and the image-side surface S6 of the third lens element L3 are respectively concave and convex at the paraxial region O, the object-side surface S5 and the image-side surface S6 of the third lens element L3 are respectively concave and convex at the circumference, the object-side surface S7 and the image-side surface S8 of the fourth lens element L4 are both concave at the paraxial region O, and the object-side surface S9 and the image-side surface S10 of the fifth lens element L5 are respectively concave and convex at the paraxial region O.

In the third embodiment, the effective focal length f of the optical lens 100 is 7.19mm, the FOV of the field angle of the optical lens 100 is 79 °, the total optical length TTL of the optical lens 100 is 9.64mm, the aperture size FNO is 1.68, and the half-image height Imgh is 6.068mm, for example.

Other parameters in the third embodiment are shown in the following table 5, and the definitions of the parameters can be obtained from the description of the foregoing embodiments, which are not repeated herein. It is understood that the units of the radius Y, thickness, and focal length in table 5 are mm. And the reference wavelengths of the refractive index and the abbe number of each lens in table 5 are 587.6nm, and the reference wavelength of the focal length of each lens is 555 nm.

TABLE 5

In the third embodiment, table 6 gives the high-order term coefficients that can be used for each aspherical mirror surface in the third embodiment, wherein each aspherical mirror surface type can be defined by the formula given in the first embodiment.

TABLE 6

Further, referring to fig. 6 (a), a light spherical aberration curve chart of the optical lens 100 in the third embodiment at wavelengths of 470nm, 510nm, 555nm, 610nm and 650nm is shown. In fig. 6 (a), the abscissa in the X-axis direction represents the focus shift, and the ordinate in the Y-axis direction represents the normalized field of view. As can be seen from (a) in fig. 6, the spherical aberration value of the optical lens 100 in the third embodiment is better, which illustrates that the imaging quality of the optical lens 100 in this embodiment is better.

Referring to fig. 6 (B), fig. 6 (B) is a diagram of astigmatism of light of the optical lens 100 in the third embodiment at a wavelength of 555 nm. Wherein the abscissa along the X-axis direction represents the focus offset and the ordinate along the Y-axis direction represents the image height in mm. The astigmatism curves represent the meridional imaging plane curvature T and the sagittal imaging plane curvature S, and it can be seen from (B) in fig. 6 that the astigmatism of the optical lens 100 is well compensated at a wavelength of 555 nm.

Referring to fig. 6 (C), fig. 6 (C) is a distortion curve diagram of the optical lens 100 in the third embodiment at a wavelength of 555 nm. Wherein the abscissa along the X-axis direction represents distortion and the ordinate along the Y-axis direction represents image height in mm. As can be seen from (C) in fig. 6, the distortion of the optical lens 100 is well corrected at a wavelength of 555 nm.

Fourth embodiment

Fig. 7 is a schematic structural diagram of an optical lens 100 according to a fourth embodiment of the present disclosure. The optical lens 100 includes a stop 102, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter L9, which are disposed in this order from the object side to the image side along the optical axis O. For materials of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8, reference may be made to the above detailed description, and details are not repeated here.

Further, in the fourth embodiment, the refractive power of each lens element differs from that of each lens element in the first embodiment in that: the fourth lens element L4 with negative refractive power, the fifth lens element L5 with positive refractive power, the sixth lens element L6 with negative refractive power and the seventh lens element L7 with positive refractive power. Meanwhile, in the fourth embodiment, the surface shape of each lens is different from that of each lens in the first embodiment in that: the object-side surface S5 and the image-side surface S6 of the third lens element L3 are both convex at their circumferences, the object-side surface S9 and the image-side surface S10 of the fifth lens element L5 are both convex at their paraxial regions O, and the object-side surface S9 and the image-side surface S10 of the fifth lens element L5 are both convex at their circumferences.

In the fourth embodiment, the focal length f of the optical lens 100 is 7.1mm, the FOV of the field angle of the optical lens 100 is 80 °, the total optical length TTL of the optical lens 100 is 8.77mm, the aperture size FNO is 1.63, and the half-image height Imgh is 6.068mm, for example.

Other parameters in the fourth embodiment are shown in the following table 7, and the definitions of the parameters can be obtained from the description of the foregoing embodiments, which are not repeated herein. It is understood that the units of the radius Y, thickness, and focal length in table 7 are mm. And the reference wavelengths of the refractive index and the abbe number of each lens in table 7 are 587.6nm, and the reference wavelength of the focal length of each lens is 555 nm.

TABLE 7

In the fourth embodiment, table 8 gives the high-order term coefficients that can be used for each aspherical mirror surface in the fourth embodiment, wherein each aspherical mirror surface type can be defined by the formula given in the first embodiment.

TABLE 8

Further, referring to fig. 8 (a), a light spherical aberration curve chart of the optical lens 100 in the fourth embodiment at wavelengths of 470nm, 510nm, 555nm, 610nm and 650nm is shown. In fig. 8 (a), the abscissa in the X-axis direction represents the focus shift, and the ordinate in the Y-axis direction represents the normalized field of view. As can be seen from (a) in fig. 8, the spherical aberration value of the optical lens 100 in the fourth embodiment is better, which illustrates that the imaging quality of the optical lens 100 in this embodiment is better.

Referring to fig. 8 (B), fig. 8 (B) is a diagram of astigmatism of light of the optical lens 100 in the fourth embodiment at a wavelength of 555 nm. Wherein the abscissa along the X-axis direction represents the focus offset and the ordinate along the Y-axis direction represents the image height in mm. The astigmatism curves represent the meridional imaging plane curvature T and the sagittal imaging plane curvature S, and it can be seen from (B) in fig. 8 that the astigmatism of the optical lens 100 is well compensated at a wavelength of 555 nm.

Referring to fig. 8 (C), fig. 8 (C) is a distortion curve diagram of the optical lens 100 in the fourth embodiment at a wavelength of 555 nm. Wherein the abscissa along the X-axis direction represents distortion and the ordinate along the Y-axis direction represents image height in mm. As can be seen from (C) in fig. 8, the distortion of the optical lens 100 is well corrected at a wavelength of 555 nm.

Fifth embodiment

Fig. 9 is a schematic structural diagram of an optical lens 100 according to a fifth embodiment of the present application. The optical lens 100 includes a stop 102, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter L9, which are disposed in this order from the object side to the image side along the optical axis O. For materials of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8, reference may be made to the above detailed description, and details are not repeated here.

Further, in the fifth embodiment, the refractive power of each lens element differs from that of each lens element in the first embodiment in that: the fourth lens element L4 with negative refractive power, the fifth lens element L5 with positive refractive power, the sixth lens element L6 with negative refractive power and the seventh lens element L7 with positive refractive power. Meanwhile, in the fifth embodiment, the surface shape of each lens is different from that of each lens in the first embodiment in that: the object-side surface S1 and the image-side surface S2 of the first lens element L1 are respectively convex and concave at the circumference, the object-side surface S5 and the image-side surface S6 of the third lens element L3 are respectively concave and convex at the circumference, the object-side surface S7 and the image-side surface S8 of the fourth lens element L4 are respectively convex and concave at the paraxial region O, the object-side surface S9 and the image-side surface S10 of the fifth lens element L5 are respectively concave and convex at the paraxial region O, the object-side surface S13 and the image-side surface S14 of the seventh lens element L5 are both convex at the paraxial region O, and the object-side surface S15 and the image-side surface S16 of the eighth lens element L8 are both concave at the paraxial region O.

In the fifth embodiment, the focal length f of the optical lens 100 is 6.72mm, the FOV of the field angle of the optical lens 100 is 82.5 °, the total optical length TTL of the optical lens 100 is 8.12mm, the aperture size FNO is 1.77, and the half-image height Imgh is 6.068mm, for example.

The other parameters in the fifth embodiment are shown in the following table 9, and the definitions of the parameters can be obtained from the foregoing description, which is not repeated herein. It is understood that the units of the radius Y, thickness, and focal length in table 9 are mm. And the reference wavelengths of the refractive index and the abbe number of each lens in table 9 are 587.6nm, and the reference wavelength of the focal length of each lens is 555 nm.

TABLE 9

In the fifth embodiment, table 10 gives the high-order term coefficients that can be used for each aspherical mirror surface in the fifth embodiment, wherein each aspherical mirror surface type can be defined by the formula given in the first embodiment.

Watch 10

Further, please refer to fig. 10 (a), which shows a light spherical aberration curve of the optical lens 100 in the fifth embodiment at wavelengths of 470nm, 510nm, 555nm, 610nm and 650 nm. In fig. 10 (a), the abscissa in the X-axis direction represents the focus shift, and the ordinate in the Y-axis direction represents the normalized field of view. As can be seen from (a) in fig. 10, the spherical aberration value of the optical lens 100 in the fifth embodiment is better, which illustrates that the imaging quality of the optical lens 100 in this embodiment is better.

Referring to fig. 10 (B), fig. 10 (B) is a diagram of astigmatism of light of the optical lens 100 in the fifth embodiment at a wavelength of 555 nm. Wherein the abscissa along the X-axis direction represents the focus offset and the ordinate along the Y-axis direction represents the image height in mm. The astigmatism curves represent the meridional image plane curvature T and the sagittal image plane curvature S, and it can be seen from (B) in fig. 10 that the astigmatism of the optical lens 100 is well compensated at a wavelength of 555 nm.

Referring to fig. 10 (C), fig. 10 (C) is a distortion curve diagram of the optical lens 100 in the fifth embodiment at a wavelength of 555 nm. Wherein the abscissa along the X-axis direction represents distortion and the ordinate along the Y-axis direction represents image height in mm. As can be seen from (C) in fig. 10, the distortion of the optical lens 100 is well corrected at a wavelength of 555 nm.

Referring to table 11, table 11 summarizes ratios of the relations in the first embodiment to the fifth embodiment of the present application.

TABLE 11

Relation/embodiment	First embodiment	Second embodiment	Third embodiment	Fourth embodiment	Fifth embodiment
						2<SD82/FNO)<3.5 (Unit: mm)	3.420	3.433	2.957	2.957	2.847
0.6<TTL/(ImgH*2)<0.8	0.758	0.755	0.723	0.723	0.669
						0<SD11/SD82<0.5	0.460	0.452	0.161	0.102	0.375
(ET1+ET7+ET8)/(ET4+ET5+ET6)>1	1.498	2.050	1.431	1.278	1.525
						0.2<Yc82/f<0.5	0.267	0.326	0.348	0.261	0.313
0.8<(\|SAG81\|+SAG82)/CT8<3.5	0.911	1.244	0.835	3.150	2.170
						0.1<CT8/SD82<0.2	0.186	0.191	0.161	0.102	0.134
0.2<Yc82/SD82<0.5	0.390	0.466	0.476	0.384	0.417
						0.3<Yc72/SD72<0.8	0.608	0.605	0.648	0.653	0.466

Referring to fig. 11, the present application further discloses a camera module 200, which includes a photo sensor 201 and the optical lens 100 according to any of the first to fifth embodiments, wherein the photo sensor 201 is disposed at an image side of the optical lens 100. The optical lens 100 may be configured to receive a light signal of a subject and project the light signal to the light sensing chip 201, and the light sensing chip 201 may be configured to convert the light signal corresponding to the subject into an image signal. And will not be described in detail herein. It can be understood that the camera module 200 having the optical lens 100 can make the optical lens 100 have the characteristic of a large aperture while meeting the requirements of light, thin and miniaturized design, and has a larger light-entering amount, so as to improve the painting quality of the optical lens 100, so that the optical lens 100 has a better imaging effect, and can also obtain sufficient luminous flux in a dim environment, thereby improving the dark light shooting condition, so as to effectively improve the shooting quality of the camera module in the dark light environment, and be beneficial to being suitable for shooting in dark light environments such as night scenes, rainy days, starry sky, and the like. Since the above technical effects have been described in detail in the embodiments of the optical lens 100, they are not described herein again.

Referring to fig. 12, the present application further discloses an electronic device, where the electronic device 300 includes a housing 301 and the camera module 200 as described above, and the camera module 200 is disposed on the housing 301 to obtain image information. The electronic device 300 may be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, a smart watch, a monitor, and the like. It can be understood that the electronic device 300 having the camera module 200 also has all the technical effects of the optical lens 100. That is, the electronic device 300 can satisfy the light, thin and miniaturized design of the optical lens 100, and at the same time, can satisfy the light, thin and miniaturized design, and is beneficial to making the optical lens have the characteristic of a large aperture, so as to have a larger light incoming amount, improve the painting texture of the optical lens 100, make the optical lens 100 have a better imaging effect, and at the same time, can also achieve sufficient luminous flux in a dim environment, and improve the dim light shooting condition, thereby effectively improving the shooting quality of the camera module in the dim light environment, and being beneficial to being suitable for shooting in dim light environments such as night scenes, rainy days, starry sky, and the like. Since the above technical effects have been described in detail in the embodiments of the optical lens 100, they are not described herein again.

The optical lens, the camera module and the electronic device disclosed by the embodiment of the invention are described in detail, a specific example is applied in the description to explain the principle and the implementation mode of the invention, and the description of the embodiment is only used for helping to understand the optical lens, the camera module and the electronic device and the core idea thereof; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

1. An optical lens includes a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, a seventh lens element, and an eighth lens element, which are disposed in this order from an object side to an image side along an optical axis;

the third lens element with positive refractive power;

the fourth lens element with refractive power;

the fifth lens element with refractive power;

the optical lens satisfies the following relation:

2mm<SD82/FNO<3.5mm；

2. An optical lens according to claim 1, wherein the optical lens satisfies the following relation:

0.6<TTL/(ImgH*2)<0.8；

wherein TTL is a distance on the optical axis from the object-side surface of the first lens element to the imaging surface of the optical lens, and Imgh is a radius of an effective imaging circle on the imaging surface of the optical lens.

3. An optical lens according to claim 1, wherein the optical lens satisfies the following relation:

0<SD11/SD82<0.5；

wherein SD11 is the maximum effective half aperture of the object side surface of the first lens.

4. An optical lens according to claim 1, wherein the optical lens satisfies the following relation:

(ET1+ET7+ET8)/(ET4+ET5+ET6)>1；

wherein ET1 is a thickness of an effective diameter edge of an object-side surface of the first lens to an effective diameter edge of an image-side surface of the first lens in a direction parallel to an optical axis, ET4 is a thickness of an effective diameter edge of an object-side surface of the fourth lens to an effective diameter edge of an image-side surface of the fourth lens in a direction parallel to the optical axis, ET5 is a thickness of an effective diameter edge of an object-side surface of the fifth lens to an effective diameter edge of an image-side surface of the fifth lens in a direction parallel to the optical axis, ET6 is a thickness of an effective diameter edge of an object-side surface of the sixth lens to an effective diameter edge of an image-side surface of the sixth lens in a direction parallel to the optical axis, ET7 is a thickness of an effective diameter edge of an object-side surface of the seventh lens to an effective diameter edge of an image-side surface of the seventh lens in a direction parallel to the optical axis, and ET8 is a thickness of an effective diameter edge of an object-side surface of the eighth lens to an effective diameter edge of an image-side surface of the eighth lens in a direction parallel to the optical axis Thickness in the direction of (a).

5. An optical lens according to claim 1, wherein the optical lens satisfies the following relation:

0.2<Yc82/f<0.5；

the Yc82 is a perpendicular distance between a first tangent point and the optical axis, the first tangent point is a tangent point of a tangent line perpendicular to the optical axis on the image-side surface of the eighth lens element, the first tangent point is not on the optical axis, and f is an effective focal length of the optical lens.

6. An optical lens according to claim 1, wherein the optical lens satisfies the following relation:

0.8<(|SAG81|+SAG82)/CT8<3.5；

SAG81 is the distance from the intersection point of the object side surface of the eighth lens and the optical axis to the maximum effective radius of the object side surface of the eighth lens in the direction parallel to the optical axis; SAG82 is the distance from the intersection point of the image side surface of the eighth lens and the optical axis to the maximum effective radius of the image side surface of the eighth lens in the direction parallel to the optical axis, and CT8 is the thickness of the eighth lens on the optical axis.

7. An optical lens according to claim 1, wherein the optical lens satisfies the following relation:

0.1<CT8/SD82<0.2；

wherein CT8 is the thickness of the eighth lens element on the optical axis.

8. An optical lens barrel according to claim 1, wherein at least one of the object side surface and the image side surface of the seventh lens element is provided with at least one inflection point, and the optical lens barrel satisfies the following relation:

0.2< Yc82/SD82< 0.5; and/or

0.3<Yc72/SD72<0.8；

The Yc82 is a perpendicular distance between a first tangent point and the optical axis, the first tangent point is a tangent point of a tangent line perpendicular to the optical axis on the image-side surface of the eighth lens element, the first tangent point is not on the optical axis, the Yc72 is a perpendicular distance between a second tangent point and the optical axis, the second tangent point is a tangent point of a tangent line perpendicular to the optical axis on the image-side surface of the seventh lens element, the second tangent point is not on the optical axis, and the SD72 is the maximum effective half aperture of the image-side surface of the seventh lens element.

9. A camera module, comprising a photo sensor chip and the optical lens of any one of claims 1-8, wherein the photo sensor chip is disposed on an image side of the optical lens.

10. An electronic device, comprising a housing and the camera module of claim 9, wherein the camera module is disposed in the housing.