CN113433659A

CN113433659A - Optical lens, camera module, electronic equipment and automobile

Info

Publication number: CN113433659A
Application number: CN202110726777.6A
Authority: CN
Inventors: 乐宇明; 蔡雄宇; 兰宾利; 赵迪
Original assignee: Tianjin OFilm Opto Electronics Co Ltd
Current assignee: Jiangxi Oufei Optics Co ltd
Priority date: 2021-06-29
Filing date: 2021-06-29
Publication date: 2021-09-24
Anticipated expiration: 2041-06-29
Also published as: CN113433659B

Abstract

The invention discloses an optical lens, a camera module, electronic equipment and an automobile, 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 negative refractive power; the second lens element with negative refractive power; the third lens element with positive refractive power; the fourth lens element with negative refractive power; the fifth lens element with positive refractive power, the sixth lens element with positive refractive power, the seventh lens element with negative refractive power, and the eighth lens element with positive refractive power; the optical lens satisfies the following relationship: -6< f1/f < -4, wherein f1 is the focal length of the first lens and f is the effective focal length of the optical lens. The optical lens, the camera module, the electronic equipment and the automobile provided by the invention can meet the light and thin and miniaturized design, and can grasp the light rays emitted into the optical lens at a large angle, thereby being beneficial to meeting the shooting requirement at a super-large angle and realizing high-pixel imaging.

Description

Optical lens, camera module, electronic equipment and automobile

Technical Field

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

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 meanwhile, the structural characteristics of lightness, thinness and miniaturization gradually become the development trend of the optical lens. In the related art, under the design trend of light, thin and small optical lens, the shooting angle of the optical lens is small, the resolution ratio is low, and shooting and clear imaging in a wide angle range are difficult to meet, so that the shooting requirement of a large field angle cannot be met.

Disclosure of Invention

The embodiment of the invention discloses an optical lens, a camera module, electronic equipment and an automobile, which can realize the light, thin and miniaturized design of the optical lens, have the characteristic of ultra-wide angle, and are beneficial to meeting the requirement of ultra-large-angle shooting and realizing high-pixel 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 has negative refractive power;

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

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

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

the fifth lens element with positive refractive power;

the sixth lens element with positive refractive power;

the seventh lens element with negative refractive power;

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

the optical lens satisfies the following relation:

-6<f1/f<-4；

wherein f1 is the focal length of the first lens, and f is the effective focal length of the optical lens.

In the optical lens provided by the application, the first lens is set as the negative lens, so that negative refractive power is provided for the optical lens, light rays emitted into the optical lens at a large angle can be captured, the field angle range of the optical lens can be enlarged, and the wide-angle design of the optical lens is facilitated; the negative refractive power provided by the second lens is matched to further expand the beam width, so that the beam which forms a large angle with the optical axis and is incident after being refracted by the first lens is effectively expanded, and the concave surface design of the image side surface of the second lens at the position close to the optical axis can ensure the incident angle of the light and avoid generating excessive aberration. The positive refractive power provided by the third lens is matched, so that the edge aberration is favorably corrected, the imaging resolving power is improved, meanwhile, the object side surface of the third lens is designed into a concave surface shape at the position of a dipped optical axis, the peripheral light is favorably converged, the phenomenon that stray light is caused due to the overlarge incident angle is avoided, and the image side surface of the third lens is designed into a convex surface shape at the position of the dipped optical axis, so that the aberration is favorably balanced, and the total length of the optical lens is favorably compressed. The negative refractive power provided by the fourth lens element and the concave surface design of the object side surface at the paraxial region can be matched, so that the ability of the second lens element for enlarging the beam width can be distributed, the width of an incident beam can be ensured, and the overlarge outer diameter of the fourth lens element can be avoided. The positive refractive power provided by the fifth lens is beneficial to reducing the deviation of the incident angle and the emergent angle of the light rays with different viewing fields, thereby reducing the sensitivity; the positive refractive power provided by the sixth lens element and the negative refractive power provided by the seventh lens element, and simultaneously, when the sixth lens element and the seventh lens element are bonded, that is, the sixth lens element and the seventh lens element form a bonded element, and the accumulated tolerance of the two lens elements is set to the tolerance of one integrated lens element by the arrangement of the bonded element, so that the eccentricity sensitivity of the lens elements can be reduced, the assembly sensitivity of the optical lens is reduced, the problem of difficulty in lens processing and manufacturing and lens assembly is solved, and the yield is improved. The positive refractive power provided by the eighth lens element and the convex design of the object-side surface and the image-side surface at the paraxial region are favorable for correcting the aberration of the optical lens system and improving the imaging resolution.

That is to say, by setting a suitable number of lenses and reasonably configuring the refractive power and the surface shape of each lens, the resolution and the imaging definition of the optical lens are favorably improved to meet the high-definition imaging requirement of the optical lens, and simultaneously, the optical lens meets the relation: when the power is 6< f1/f < -4 >, the lens (the first lens) close to the object side is set as a negative lens to provide negative refractive power for the optical lens, so that light rays emitted into the optical lens at large angles can be captured, and the field angle range of the optical lens is expanded; meanwhile, the sensitivity of the optical lens is reduced, and the miniaturization design of the optical lens is realized. When the optical lens system exceeds the upper limit of the relational expression, the focal length of the first lens element is too large, and the refractive power is too strong, so that the imaging surface of the optical lens system becomes sensitive due to the change of the first lens element during imaging, and a larger aberration is generated; when the refractive power of the first lens element is lower than the lower limit of the above relation, the refractive power of the first lens element is insufficient, which is not favorable for the light with large angle to enter the optical lens, and is not favorable for the wide angle and miniaturization design of the optical lens.

As an alternative implementation, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: 2< f3/CT3< 3.5;

wherein f3 is the focal length of the third lens element, and CT3 is the thickness of the third lens element on the optical axis.

Because the light rays are emitted from the first lens element and the second lens element with strong negative refractive power, the imaging surface of the optical lens system on which the marginal light rays are emitted is prone to generate large field curvature, and therefore, the third lens element with positive refractive power is arranged, so that marginal aberration can be corrected favorably, and imaging resolution is improved. By limiting the ratio of the focal length of the third lens to the central thickness of the third lens, the tolerance sensitivity of the central thickness of the third lens can be reduced, and the processing difficulty of the third lens is reduced, so that the production cost can be reduced, and the assembly yield of the optical lens is improved; meanwhile, the edge aberration of the optical lens is favorably corrected, and the imaging quality is improved. When the range of the above relational expression is exceeded, the correction of the aberration of the optical lens is not facilitated, resulting in a low image quality of the optical lens.

As an alternative implementation, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: -1.5< f14/f58< -0.5;

wherein f14 is a combined focal length of the first lens, the second lens, the third lens, and the fourth lens, and f58 is a combined focal length of the fifth lens, the sixth lens, the seventh lens, and the eighth lens.

Limited by the above relation, the front lens group (the first lens, the second lens, the third lens and the fourth lens) of the optical lens provides negative refractive power for the optical lens, which is beneficial for the large-angle light beam to penetrate and enter, so as to realize the wide-angle design of the optical lens and also beneficial for improving the brightness of the imaging surface of the optical lens; on one hand, the rear lens group (the fifth lens element, the sixth lens element, the seventh lens element and the eighth lens element) of the optical lens provides positive refractive power for the optical lens, which is beneficial to controlling the height of light rays emitted out of the optical lens so as to reduce the high-level aberration of the optical lens and reduce the outer diameter of each lens in the rear lens group; on the other hand, curvature of field generated by the front lens group can be corrected to reduce the influence on the resolving power of the optical lens and improve the imaging quality of the optical lens.

As an alternative implementation, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: -5< f67/(CT6-CT7) < -4;

wherein f67 is a combined focal length of the sixth lens and the seventh lens, CT6 is an optical thickness of the sixth lens, and CT7 is an optical thickness of the seventh lens.

By reasonably matching the central thickness relationship between the sixth lens element and the seventh lens element, the refractive powers of the two lens elements with a positive refractive power and a negative refractive power can be reasonably matched, thereby facilitating the mutual correction of aberrations, facilitating the sixth lens element and the seventh lens element to provide the minimum aberration contribution ratio for the optical lens, and facilitating the improvement of the imaging quality of the optical lens. And the image side surface of the sixth lens element is cemented with the object side surface of the seventh lens element, that is, the sixth lens element and the seventh lens element form a cemented element, so that the above relational expression is satisfied, thereby preventing the difference between the central thicknesses of the sixth lens element and the seventh lens element from being too large, facilitating the cementing of the sixth lens element and the seventh lens element, and simultaneously preventing the phenomena of large difference between the cold and heat deformations, easy cracking or degumming and the like of the sixth lens element and the seventh lens element under the environment with large variation of high and low temperature environments due to the too large difference between the central thicknesses of the sixth lens element and the seventh lens element, and thus being beneficial to reducing the risk of cracking of the cemented lens element under the conditions of high temperature or low temperature.

As an optional implementation manner, in an embodiment of the first aspect of the present invention, the optical lens further includes a diaphragm, and the optical lens satisfies the following relation: 50deg < (FOV x f)/(2 x Imgh) <60 deg;

wherein, the FOV is the maximum angle of view of the optical lens, and Imgh is half of the image height corresponding to the maximum angle of view of the optical lens.

The optical lens can be ensured to have large visual angle and large image surface characteristic by the limitation of the relational expression, so that the optical lens has good optical performance, the optical lens can meet the imaging requirement of high pixels, and the details of a shot object can be well captured.

As an optional implementation manner, in an embodiment of the first aspect of the present invention, the optical lens further includes a diaphragm, and the optical lens satisfies the following relation: 1.5< TTL/DOS < 2;

wherein, TTL is a distance on an optical axis from an object-side surface of the first lens element to an image plane of the optical lens, and DOS is a distance on the optical axis from the object-side surface of the first lens element to the diaphragm.

The optical lens is defined through the relational expression, so that the structure of the optical lens is more compact, and the design requirement of miniaturization is met. When the lower limit of the relation is exceeded, large-angle light rays are easily difficult to enter the optical lens, so that the object space imaging range of the optical lens is reduced, and the wide angle is not favorably realized; when the optical length exceeds the upper limit of the relation, the total optical length of the optical lens (i.e., the distance from the object-side surface of the first lens element to the image plane of the optical lens on the optical axis) is too long, which is not favorable for the miniaturization of the optical lens.

As an alternative implementation, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: -8.8< CT4/Sags7< -2.8;

wherein CT4 is the thickness of the fourth lens on the optical axis, and Sags7 is the distance from the maximum clear aperture of the object-side surface of the fourth lens to the point on the optical axis of the object-side surface of the fourth lens in the direction parallel to the optical axis (the rise value of the object-side surface of the fourth lens).

By controlling the ratio of the central thickness of the fourth lens element to the rise of the object-side surface of the fourth lens element, the fourth lens element can have a high refractive power, and the manufacturing difficulty of the fourth lens element due to the excessive central thickness or the excessive bending of the object-side surface of the fourth lens element can be avoided, so that the production cost of the fourth lens element can be reduced. When the lower limit of the relational expression is exceeded, the image side surface of the fourth lens is too curved, so that the processing difficulty of the fourth lens is increased, and the production cost of the fourth lens is increased; meanwhile, the surface of the object side surface of the fourth lens is too curved, so that edge aberration is easily generated, and the image quality of the optical lens is not favorably improved. On the other hand, if the thickness exceeds the upper limit of the above relational expression, the thickness of the fourth lens element becomes too large, which is disadvantageous in weight reduction and size reduction of the optical lens system.

As an alternative implementation, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: -5.6< (Rs7+ Rs8)/(Rs7-Rs8) < -2.6;

wherein Rs7 is a radius of curvature of an object-side surface of the fourth lens element at an optical axis, and Rs8 is a radius of curvature of an image-side surface of the fourth lens element at the optical axis.

Since the smaller the curvature radius of the fourth lens element, the more curved the surface of the fourth lens element, the more favorable the light beam that is deflected and diverged by the object-side surface of the fourth lens element is to be converged and transmitted to the image plane, when the above relation is satisfied, the more favorable the edge aberration of the optical lens is to be corrected, the more favorable the astigmatism is suppressed, and the angle at which the principal ray of the peripheral angle of view enters the image plane is reduced. When the range of the relation is exceeded, the correction of the edge aberration of the optical lens is not facilitated, and the probability of generating the ghost image or the intensity of the ghost image may be increased, which affects the imaging quality.

As an alternative implementation, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: 2.5< f8/f < 3.5;

wherein f8 is the focal length of the eighth lens.

The eighth lens element provides positive refractive power for the optical lens, and the limitation of the relational expression is favorable for correcting the aberration of the optical lens, reducing the eccentricity sensitivity, correcting the aberration of the optical lens and improving the imaging resolution of the optical lens. When the range of the relation is exceeded, the aberration of the optical lens is not corrected favorably, so that the imaging quality of the optical lens is low.

In a second aspect, the present invention discloses a camera module, which includes a photosensitive element and the optical lens of the first aspect, wherein the photosensitive element is disposed at an image side of the optical lens. The camera module with the optical lens can meet the light and thin and miniaturized design, and can grasp the light rays emitted into the optical lens at a large angle, so that the camera module is favorable for meeting the shooting requirement of a large field angle and realizing clear imaging.

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 light and thin and miniaturized design, and can grasp the light rays emitted into the optical lens at a large angle, so that the shooting requirement of a large field angle can be met, and clear imaging can be realized.

In a fourth aspect, the invention further discloses an automobile, which comprises an automobile body and the camera module set in the second aspect, wherein the camera module set is arranged on the automobile body. The automobile with the camera module is beneficial to obtaining environmental information around an automobile body, and meanwhile shooting and clear imaging within a wide angle range can be realized, so that better driving early warning is provided for driving of a driver.

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

in the optical lens, the camera module, the electronic device and the automobile provided by the embodiment of the invention, the optical lens adopts eight-piece lenses, the number of the used lenses is relatively small, the light, thin and miniaturized design of the optical lens is favorably realized, the refractive power and the surface shape of each lens are designed, and the optical lens meets the relation: when the power is 6< f1/f < -4 >, the large-angle light rays emitted into the optical lens can be grasped, the field angle range of the optical lens can be enlarged, and the resolution and the imaging definition of the optical lens can be improved, so that the high-definition imaging requirement of people on the optical lens can be met; meanwhile, the sensitivity of the optical lens is reduced, and the miniaturization design of the optical lens is realized. When the optical lens system exceeds the upper limit of the relational expression, the focal length of the first lens element is too large, and the refractive power is too strong, so that the imaging surface of the optical lens system becomes sensitive due to the change of the first lens element during imaging, and larger aberration is generated; when the refractive power of the first lens element is lower than the lower limit of the above relation, the refractive power of the first lens element is insufficient, which is not favorable for the light with large angle to enter the optical lens, and is not favorable for the wide angle and miniaturization design of the optical lens.

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 diagram of an electronic device disclosed herein;

fig. 13 is a schematic structural view of an automobile 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 optical lens 100, and are finally imaged on the imaging surface 101 of the optical lens 100. The first lens element L1 with negative refractive power, the second lens element L2 with negative refractive power, the third lens element L3 with positive refractive power, the fourth lens element L4 with negative refractive power, the fifth lens element L5 with positive refractive power, the sixth lens element L6 with positive refractive power, the seventh lens element L7 with negative refractive power, and the eighth lens element L8 with positive refractive power.

Further, the object-side surface S1 of the first lens element L1 can be convex or concave at the paraxial region O, and the image-side surface S2 of the first lens element L1 can be concave or convex at the paraxial region O; the object-side surface S3 of the second lens element L2 can be convex or concave at the paraxial region O, and the image-side surface S4 of the second lens element L2 can be concave at the paraxial region O; 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 S7 of the fourth lens element L4 can be 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 S9 of the fifth lens element L5 can be convex or concave at the paraxial region O, and 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 S11 of the sixth lens element L6 can be convex or concave at the paraxial region O, and 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 S13 of the seventh lens element L7 can be convex or concave at the paraxial region O, and 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 S15 and the image-side surface S16 of the eighth lens element L8 may both be convex at the paraxial region O.

Further, 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 glass lenses, plastic lenses, or the like. Meanwhile, the aforementioned first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, sixth lens L6, seventh lens L7, and eighth lens L8 may be spherical lenses or aspherical lenses.

In some embodiments, the optical lens 100 further includes a stop 102, and the stop 102 may be an aperture stop 102 or a field stop 102, which may be disposed between the fourth lens L4 and the fifth lens L5. For example, the stop 102 may be disposed between the image-side surface S8 of the fourth lens L4 and the object-side surface S9 of the fifth lens L5. It is understood that, in other embodiments, the stop 102 may be disposed between other lenses or between the object side of the optical lens 100 and the object side S1 of the first lens L1, and the setting is adjusted according to practical situations, which is not limited in this embodiment.

In some embodiments, in order to improve the imaging quality, the optical lens 100 further includes a protective glass L10, the protective glass L10 is disposed between the image-side surface S16 of the eighth lens L8 and the imaging surface 101 of the optical lens 100, and the protective glass L10 is used for protecting the eighth lens L8.

Further, the optical lens 100 may further include a filter L9, such as an infrared filter, disposed between the image-side surface S16 of the eighth lens L8 and the protective glass L10, so as to filter out light rays in other wavelength bands, such as infrared light, and only allow visible light to pass through; the optical lens 100 can also filter out light in other bands, such as visible light, and only let infrared light pass through, so that the optical lens 100 can be used as an infrared optical lens, that is, the optical lens 100 can also 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: -6< f1/f < -4; where f1 is the focal length of the first lens element L1, and f is the effective focal length of the optical lens system 100. The lens (the first lens element L1) near the object side of the optical lens 100 is a negative lens element, which provides negative refractive power for the optical lens 100, so as to capture light rays incident into the optical lens 100 at a large angle and expand the field angle range of the optical lens 100; and is also advantageous in reducing the sensitivity of the optical lens 100 and in achieving a compact design of the optical lens 100. When the upper limit of the above relation is exceeded, the focal length of the first lens element L1 is too large, and the refractive power is too strong, so that the imaging surface 101 of the optical lens system 100 becomes sensitive due to the change of the first lens element L1 during imaging, and a large aberration is generated; when the refractive power of the first lens element L1 is lower than the lower limit of the above relation, it is not favorable for the large-angle light to enter the optical lens 100, and therefore it is not favorable for the wide-angle and compact design of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the following relationship: 2< f3/CT3< 3.5; wherein f3 is the focal length of the third lens element L3, and CT3 is the thickness of the third lens element L3 on the optical axis O.

Since the light beams are emitted from the first lens element L1 and the second lens element L2 with strong negative refractive power, the edge light beams incident on the image plane 101 of the optical lens 100 are likely to generate large curvature of field, and therefore, the third lens element L3 with positive refractive power is beneficial to correcting the edge aberration of the optical lens 100 and improving the imaging resolution. By defining the ratio of the focal length of the third lens L3 to the center thickness of the third lens L3, the tolerance sensitivity of the center thickness of the third lens L3 can be reduced, the processing difficulty of the third lens L3 can be reduced, the production cost can be reduced, and the assembly yield of the optical lens 100 can be improved; meanwhile, the aberration of the optical lens 100 can be corrected, and the imaging quality can be improved. When the range of the above relation is exceeded, the correction of the edge aberration of the optical lens 100 is not favorable, resulting in a low image quality of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the following relationship: -1.5< f14/f58< -0.5; wherein f14 is a combined focal length of the first lens L1, the second lens L2, the third lens L3 and the fourth lens L4, and f58 is a combined focal length of the fifth lens L5, the sixth lens L6, the seventh lens L7 and the eighth lens L8.

Defined by the above relation, the front lens group (the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4) of the optical lens 100 provides negative refractive power for the optical lens 100, which is beneficial for the transmission and incidence of the high-angle light beams, so as to realize the wide-angle design of the optical lens 100, and is also beneficial for improving the brightness of the imaging surface 101 of the optical lens 100; on the one hand, the rear lens group (the fifth lens L5, the sixth lens L6, the seventh lens L7 and the eighth lens L8) of the optical lens 100 provides positive refractive power for the optical lens 100, which is beneficial to controlling the height of the light rays emitted out of the optical lens 100 so as to reduce the high-level aberration of the optical lens 100 and reduce the outer diameter of each lens in the rear lens group; on the other hand, curvature of field generated by the front lens group can be corrected to reduce the influence on the resolving power of the optical lens 100, and improve the imaging quality of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the following relationship: -5< f67/(CT6-CT7) < -4; wherein f67 is the combined focal length of the sixth lens L6 and the seventh lens L7, CT6 is the thickness of the sixth lens L6 on the optical axis O, and CT7 is the thickness of the seventh lens L7 on the optical axis O.

By reasonably matching the central thickness relationship between the sixth lens element L6 and the seventh lens element L7, the refractive powers of the two lens elements with a positive refractive power and a negative refractive power can be reasonably matched, so as to facilitate mutual aberration correction, and facilitate the sixth lens element L6 and the seventh lens element L7 to provide the minimum aberration contribution ratio for the optical lens 100, thereby facilitating improvement of the imaging quality of the optical lens 100. Moreover, since the image-side surface S12 of the sixth lens L6 is cemented with the object-side surface S13 of the seventh lens L7, that is, the sixth lens L6 and the seventh lens L7 form a cemented element, by satisfying the above relational expression, it is possible to avoid an excessive difference in the center thicknesses of the sixth lens L6 and the seventh lens L7, which facilitates the cementing between the sixth lens L6 and the seventh lens L7, and at the same time, it is possible to avoid a large difference in the amounts of cold and heat deformation caused by the excessive difference in the center thicknesses of the sixth lens L6 and the seventh lens L7 in an environment with a large change in high and low temperature environments, which is likely to cause phenomena such as cementing cracks or degumming, thereby being beneficial to reducing the risk of cracking of the cemented lens under high temperature or low temperature conditions.

In some embodiments, the optical lens 100 satisfies the following relationship: 50deg < (FOV x f)/(2 x Imgh) <60 deg; here, FOV is the maximum angle of view of the optical lens 100, and Imgh is half the image height corresponding to the maximum angle of view of the optical lens 100. By the limitation of the relational expression, the optical lens 100 can be ensured to have a large viewing angle and a large image plane characteristic, so that the optical lens 100 has good optical performance, the optical lens 100 can meet the imaging requirement of high pixels, and the details of a shot object can be well captured.

In some embodiments, the optical lens 100 satisfies the following relationship: 1.5< TTL/DOS < 2; 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, and DOS is a distance from the object-side surface S1 of the first lens element L1 to the stop 102 on the optical axis O.

The limitation of the relational expression is beneficial to making the structure of the optical lens 100 more compact and meeting the design requirement of miniaturization. When the lower limit of the above relation is exceeded, it is easy to cause that large-angle light is difficult to enter the optical lens 100, so that the object space imaging range of the optical lens 100 is reduced, and the realization of wide angle is not facilitated; if the upper limit of the relation is exceeded, the total optical length of the optical lens 100 (i.e. the distance from the object-side surface S1 of the first lens element L1 to the image plane 102 of the optical lens 100 on the optical axis O) is too long, which is not favorable for the miniaturization of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the following relationship: -8.8< CT4/Sags7< -2.8; where CT4 is the thickness of the fourth lens L4 on the optical axis O, and Sags7 is the distance from the maximum clear aperture of the object-side surface S7 of the fourth lens L4 to a point on the optical axis O of the object-side surface S4 of the fourth lens L4 (the rise value of the object-side surface S7 of the fourth lens L4) in the direction parallel to the optical axis O.

By controlling the ratio of the center thickness of the fourth lens element L4 to the rise of the object-side surface S7 of the fourth lens element L4, the manufacturing difficulty of the fourth lens element L4 due to the excessive center thickness of the fourth lens element L4 or the excessive curvature of the object-side surface S7 can be avoided while the high refractive power of the fourth lens element L4 is satisfied, so that the manufacturing cost of the fourth lens element L4 can be reduced. When the lower limit of the above relation is exceeded, the image-side surface S8 of the fourth lens L4 is excessively curved, resulting in an increase in the difficulty of processing the fourth lens L4 and an increase in the production cost of the fourth lens L4; meanwhile, since the surface of the object-side surface S7 of the fourth lens element L4 is too curved, edge aberration is likely to occur, which is not favorable for improving the image quality of the optical lens system 100. On the other hand, if the thickness exceeds the upper limit of the above relational expression, the thickness of the fourth lens element L4 becomes too large, which is disadvantageous in weight reduction and size reduction of the optical lens system 100.

In some embodiments, the optical lens 100 satisfies the following relationship: -5.6< (Rs7+ Rs8)/(Rs7-Rs8) < -2.6; wherein Rs7 is a curvature radius of the object-side surface S7 of the fourth lens element L4 along the optical axis O, and Rs8 is a curvature radius of the image-side surface S8 of the fourth lens element L4 along the optical axis O.

Since the smaller the curvature radius of the fourth lens element L4, the more curved the surface of the fourth lens element L4, the more beneficial the light beam that is deflected and diverged by the object-side surface S7 of the fourth lens element L4 is to be converged and transmitted to the image plane 101 of the optical lens 100, when the above relational expression is satisfied, it is advantageous to correct the peripheral aberration of the optical lens 100, suppress the occurrence of astigmatism, and reduce the angle at which the principal ray of the peripheral angle of view enters the image plane 102. When the range of the relationship is exceeded, the correction of the edge aberration of the optical lens 100 is not facilitated, and the probability of generating the ghost or the intensity of the ghost may be increased, which affects the imaging quality.

In some embodiments, the optical lens 100 satisfies the following relationship: 2.5< f8/f < 3.5; where f8 is the focal length of the eighth lens L8. Since the eighth lens element L8 provides positive refractive power for the optical lens 100, the aberration of the optical lens 100 can be corrected and the decentering sensitivity can be reduced by the limitation of the above relation, and the aberration of the optical lens 100 can be corrected and the imaging resolution of the optical lens 100 can be improved. When the range of the relationship is exceeded, the aberration of the optical lens 100 is not corrected, so that the imaging quality of the optical lens 100 is low.

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

First embodiment

As shown in fig. 1, a schematic structural diagram of an optical lens 100 disclosed in the first embodiment of the present application is that the optical lens 100 includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a stop 102, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter L9, and a protective glass L10, which are sequentially disposed from an object side to an image side along an optical axis O. For refractive power of 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, the seventh lens element L7 and the eighth lens element L8, reference is made to the above detailed description, which is not repeated herein.

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 S3 and the image-side surface S4 of the second lens element L2 are convex and concave, respectively, at the paraxial region O. 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 S7 and the image-side surface S8 of the fourth lens element L4 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 convex at the paraxial region O. The object-side surface S11 and the image-side surface S12 of the sixth lens element L6 are convex at the paraxial region O. The object-side surface S13 and the image-side surface S14 of the seventh lens element L7 are concave at the paraxial region O. The object-side surface S15 and the image-side surface S16 of the eighth lens element L8 are convex at the paraxial region O.

Alternatively, the image-side surface S12 of the sixth lens L6 may be cemented with the object-side surface S13 of the seventh lens L7, so that the sixth lens L6 and the seventh lens L7 form a cemented lens. The object-side surface S7 and the image-side surface S8 of the fourth lens L4 and the object-side surface S15 and the image-side surface S16 of the eighth lens L8 are aspheric, and the object-side surface and the image-side surface of the first lens L1, the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are spherical. Meanwhile, the first lens element L1 to the eighth lens element L8 are made of glass.

Specifically, taking as an example that the effective focal length f of the optical lens 100 is 2.24mm, the aperture size FNO of the optical lens 100 is 1.8, and the field angle FOV is 195 °, other parameters of the optical lens 100 are given in table 1 below. 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 surface number is the object side surface of the lens, and the surface with the larger surface number is the image side surface of the lens, and for example, the surface numbers 1 and 2 correspond to the object side surface S1 and the image side surface S2 of the first lens L1, respectively. The radius Y in table 1 is the radius of curvature of the object-side surface or the image-side surface of the corresponding surface number at the optical axis 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. The reference wavelength of the refractive index and Abbe number of each lens in Table 1 was 587.56nm, and the reference wavelength of the effective focal length was 542.02 nm.

TABLE 1

In the first embodiment, the object-side surface S7 and the image-side surface S8 of the fourth lens L4 and the object-side surface S15 and the image-side surface S16 of the eighth lens L8 are both aspheric surfaces, and the surface type x of the fourth lens L4 and the eighth lens L8 can be defined by, but is not limited to, the following aspheric surface 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 coefficients of high-order terms A4, A6, a8, a10, a12, a14, a16, a18 and a20 that can be used for the object-side surface S7, the image-side surface S8 of the fourth lens L4 and the object-side surface S15 and the image-side surface S16 of the eighth lens L8 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 465.6100nm, 500.4800nm, 542.0200nm, 590.8600nm and 642.7300 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 542.0200 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 542.0200 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 542.0200 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 542.0200 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 first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a stop 102, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter L9, and a cover glass L10, which are disposed in order from the object side to the image side along an optical axis O. The refractive power and material of 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, the seventh lens element L7 and the eighth lens element L8 can be found in the above embodiments, and are not described herein again.

Further, the surface shapes 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 can be referred to the description of the first embodiment, and are not repeated herein.

In the second embodiment, the effective focal length f of the optical lens 100 is 2.27mm, the aperture size FNO of the optical lens 100 is 1.8, and the FOV of the field angle is 195 ° as an 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. The reference wavelength of the refractive index and Abbe number of each lens in Table 3 was 587.56nm, and the reference wavelength of the effective focal length was 542.02 nm.

TABLE 3

In the second embodiment, table 4 gives the high-order term coefficients of the respective aspherical mirror surfaces of the fourth lens L4 and the eighth lens L8 usable in the second embodiment, wherein the respective aspherical mirror surfaces of the fourth lens L4 and the eighth lens L8 may be defined by the formulas given in the first embodiment.

TABLE 4

Further, please refer to fig. 4 (a), which shows a light spherical aberration curve chart of the optical lens 100 in the second embodiment at 465.6100nm, 500.4800nm, 542.0200nm, 590.8600nm and 642.7300 nm. 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 542.0200 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. 4 that the astigmatism of the optical lens 100 is well compensated at a wavelength of 542.0200 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 542.0200 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 542.0200 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 first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a stop 102, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter L9, and a cover glass L10, which are disposed in order from the object side to the image side along an optical axis O. The refractive power and material of 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, the seventh lens element L7 and the eighth lens element L8 can be found in the above embodiments, and are not described herein again.

In the third embodiment, the effective focal length f of the optical lens 100 is 2.29mm, the aperture size FNO of the optical lens 100 is 2.0, and the FOV of the field angle is 195 ° are taken as examples.

Other parameters in the third embodiment are shown in the following table 5, 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 5 are mm. The reference wavelength of the refractive index and Abbe number of each lens in Table 5 was 587.56nm, and the reference wavelength of the effective focal length was 542.02 nm.

TABLE 5

In the third embodiment, table 6 gives the high-order term coefficients of the respective aspherical mirror surfaces usable for the fourth lens L4 and the eighth lens L8 in the third embodiment, wherein the respective aspherical mirror surfaces of the fourth lens L4 and the eighth lens L8 may be defined by the formulas given in the first embodiment.

TABLE 6

Further, please refer to fig. 6 (a), which shows a light spherical aberration curve of the optical lens 100 in the third embodiment at 465.6100nm, 500.4800nm, 542.0200nm, 590.8600nm and 642.7300 nm. 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 542.0200 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. 6 that the astigmatism of the optical lens 100 is well compensated at a wavelength of 542.0200 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 542.0200 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 542.0200 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 first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a stop 102, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter L9, and a cover glass L10, which are disposed in order from the object side to the image side along an optical axis O. The refractive power and material of 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, the seventh lens element L7 and the eighth lens element L8 can be found in the above embodiments, and are not described herein again.

In the fourth embodiment, the focal length f of the optical lens 100 is 2.35mm, the aperture size FNO of the optical lens 100 is 2.2, and the FOV of the angle of view is 195 ° are taken as examples.

Other parameters in the fourth embodiment are shown in the following table 7, 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 7 are mm. The reference wavelength of the refractive index and Abbe number of each lens in Table 5 was 587.56nm, and the reference wavelength of the effective focal length was 542.02 nm.

TABLE 7

In the fourth embodiment, table 8 gives high-order term coefficients of respective aspherical mirror surfaces usable for the fourth lens L4 and the eighth lens L8 in the fourth embodiment, wherein respective aspherical mirror surfaces of the fourth lens L4 and the eighth lens L8 may be defined by the formulas given in the first embodiment.

TABLE 8

Further, please refer to fig. 8 (a), which shows a light spherical aberration curve of the optical lens 100 in the fourth embodiment at 465.6100nm, 500.4800nm, 542.0200nm, 590.8600nm and 642.7300 nm. 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 542.0200 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. 8 that the astigmatism of the optical lens 100 is well compensated at a wavelength of 542.0200 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 542.0200 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 542.0200 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 first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a stop 102, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter L9, and a cover glass L10, which are disposed in order from the object side to the image side along an optical axis O. The refractive power and material of 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, the seventh lens element L7 and the eighth lens element L8 can be found in the above embodiments, and are not described herein again.

In the fifth embodiment, 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 S3 and the image-side surface S4 of the second lens element L2 may be concave at the paraxial region O. 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 S7 and the image-side surface S8 of the fourth lens element L4 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 convex at the paraxial region O. The object-side surface S11 and the image-side surface S12 of the sixth lens element L6 are convex at the paraxial region O. The object-side surface S13 and the image-side surface S14 of the seventh lens element L7 are concave at the paraxial region O. The object-side surface S15 and the image-side surface S16 of the eighth lens element L8 are convex at the paraxial region O.

In the fifth embodiment, the focal length f of the optical lens 100 is 2.46mm, the aperture size FNO of the optical lens 100 is 2.24, and the FOV of the field angle is 195 ° are taken as examples.

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. In table 6, the reference wavelength of the refractive index and abbe number of each lens is 587.56nm, and the reference wavelength of the effective focal length is 587.56 nm.

TABLE 9

In the fifth embodiment, table 10 gives high-order term coefficients of respective aspherical mirror surfaces usable for the fourth lens L4 and the eighth lens L8 in the fourth embodiment, wherein respective aspherical mirror surfaces of the fourth lens L4 and the eighth lens L8 may be defined by the formulas 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 465.6100nm, 500.4800nm, 542.0200nm, 590.8600nm and 642.7300 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 542.0200 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 542.0200 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 542.0200 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 542.0200 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

Referring to fig. 11, the present application further discloses a camera module 200, which includes a photosensitive element 201 and the optical lens 100 according to any of the first to fifth embodiments, wherein the photosensitive element 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 element 201, and the light sensing element 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 has all the technical effects of the optical lens 100, that is, the optical lens 100 has a super-wide angle while meeting the light, thin and miniaturized design, and is beneficial to meeting the shooting requirement of a large field angle and realizing clear imaging. 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, an unmanned aerial vehicle, 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 optical lens 100 has a super-wide angle while satisfying a thin and compact design, and is advantageous for satisfying a large field angle of view and realizing sharp imaging. 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. 13, the present application further discloses an automobile, in which the automobile 400 includes an automobile body 401 and the camera module 200 as described above, and the camera module 200 is disposed on the automobile body 401 to obtain image information. It can be understood that the automobile having the camera module described above also has all the technical effects of the optical lens 100 described above. Namely, the automobile 400 can be facilitated to acquire the environmental information around the automobile body 401, and meanwhile shooting and clear imaging in a wide angle range can be realized, so that better driving early warning is provided for the driver to drive. 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, the electronic device and the automobile 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, the electronic device and the automobile 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 first lens element has negative refractive power;

the fifth lens element with positive refractive power;

the sixth lens element with positive refractive power;

the seventh lens element with negative refractive power;

the optical lens satisfies the following relation:

-6<f1/f<-4；

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

2<f3/CT3<3.5；

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

-1.5<f14/f58<-0.5；

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

-5<f67/(CT6-CT7)<-4；

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

50deg<(FOV*f)/(2*Imgh)<60deg；

6. An optical lens according to claim 1, characterized in that the optical lens further comprises a diaphragm, the optical lens satisfying the following relation:

1.5<TTL/DOS<2；

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

-8.8<CT4/Sags7<-2.8；

wherein CT4 is the thickness of the fourth lens element on the optical axis, and Sags7 is the distance between the maximum clear aperture of the object-side surface of the fourth lens element and the point on the optical axis of the object-side surface of the fourth lens element in the direction parallel to the optical axis.

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

-5.6<(Rs7+Rs8)/(Rs7-Rs8)<-2.6；

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

2.5<f8/f<3.5；

wherein f8 is the focal length of the eighth lens.

10. A camera module, comprising the optical lens of any one of claims 1 to 9 and a photosensitive element, wherein the photosensitive element is disposed on an image side of the optical lens.

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

12. An automobile, characterized in that the automobile comprises an automobile body and the camera module group according to claim 10, wherein the camera module group is arranged on the automobile body.