CN114296213B

CN114296213B - Optical lens, camera module and electronic equipment

Info

Publication number: CN114296213B
Application number: CN202111410384.0A
Authority: CN
Inventors: 华露; 杨健; 李明
Original assignee: Jiangxi Jingchao Optical Co Ltd
Current assignee: Jiangxi Jingchao Optical Co Ltd
Priority date: 2021-11-25
Filing date: 2021-11-25
Publication date: 2023-07-04
Anticipated expiration: 2041-11-25
Also published as: CN114296213A

Abstract

The invention discloses an optical lens, an image pickup 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 and the seventh lens have positive refractive power, the object side surfaces and the image side surfaces of the first lens and the second lens are respectively convex surfaces and concave surfaces at a paraxial region, the object side surface of the third lens is convex at the paraxial region, the image side surface of the fourth lens is convex at the paraxial region, the object side surface of the fifth lens is concave at the paraxial region, and the object side surface of the sixth lens is concave at the paraxial region; the seventh lens element has a convex object-side surface and a concave image-side surface at a paraxial region, and the eighth lens element has negative refractive power. The optical lens can realize miniaturized design of the optical lens while meeting high-quality imaging of the optical lens.

Description

Optical lens, camera module and electronic equipment

Technical Field

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

Background

Along with the progress of technology, electronic products with camera shooting function are rapidly developed, and consumers have higher and higher requirements on imaging quality of the electronic products, and meanwhile, the light, thin and miniaturized structural characteristics are also gradually becoming the development trend of optical lenses. However, as the pixel size of the photosensitive chip in the optical lens is continuously reduced, further design demands are put on miniaturization and high-quality imaging of the optical lens.

Disclosure of Invention

The embodiment of the invention discloses an optical lens, an imaging module and electronic equipment, which can realize miniaturized design of the optical lens while meeting high-quality imaging of the optical lens.

In order to achieve the above object, a first aspect of 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 disposed 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 and a concave image-side surface at a paraxial region; the second lens element with refractive power has a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region; the third lens element with refractive power has a convex object-side surface at a paraxial region; the fourth lens element with refractive power has a convex image-side surface at a paraxial region; the fifth lens element with refractive power has a concave object-side surface at a paraxial region; the sixth lens element with refractive power has a concave object-side surface at a paraxial region; the seventh lens element with positive refractive power has a convex object-side surface at a paraxial region, a concave image-side surface at a paraxial region, and at least one inflection point is disposed on each of the object-side surface and the image-side surface of the seventh lens element; the eighth lens element with negative refractive power has a convex object-side surface at a paraxial region, a concave image-side surface at a paraxial region, and at least one inflection point is disposed on each of the object-side surface and the image-side surface of the eighth lens element;

The optical lens satisfies the following relation: 1< TTL/ImgH <1.12; wherein TTL is a distance from an object side surface of the first lens element to an imaging surface of the optical lens element on the optical axis, and ImgH is a radius of a maximum effective imaging circle of the optical lens element.

According to the optical lens provided by the application, the first lens element has positive refractive power, the object side surfaces of the first lens element and the second lens element are convex surfaces at the optical axis, and the image side surfaces of the first lens element and the second lens element are concave surfaces at the optical axis, so that incident light rays with a large angle with the optical axis enter the optical lens element, the convergence of the light rays of the optical lens element is facilitated, the optical performance of the optical lens element is improved, in addition, as the surface types of the first lens element and the second lens element at the paraxial region are both convex-concave structures, and the object side surface of the third lens element is convex surfaces at the paraxial region, the surface type matching mode of the surface type structure is adopted, so that the surface type matching degree of a front lens element (namely the first lens element, the second lens element and the third lens element) can be increased, the incident angle of the incident light rays can be reduced, the chromatic aberration is further reduced, and the imaging quality of the optical lens element is improved. The surface design of the fourth lens and the fifth lens can be matched with the object side lens to further converge the incident light so as to compress the total length of the optical lens, and the refractive power provided by the sixth lens and the corresponding surface design can balance the aberration which is difficult to correct and is brought by each lens of the object side when converging the incident light, so that the correction pressure of the rear lens group is reduced. The object side surface and the image side surface of the seventh lens element and the eighth lens element are respectively provided with at least one inflection point, which is favorable for making the light rays of the edge view field obtain smaller light ray deflection angle, meanwhile, the positive refractive power of the seventh lens element is combined with the negative refractive power provided by the eighth lens element, the positive refractive power and the negative refractive power of the seventh lens element counteract the aberration generated by each other, and the object side surface and the image side surface of the seventh lens element are designed in a convex-concave surface mode at the optical axis, so that the light rays of the center view field can be further converged, the total length of the optical lens element can be shortened, the aberration can be corrected, the emergent angle of the light rays can be pressed, the light ray receiving efficiency of the photosensitive chip can be improved, the aberration can be further corrected, and the imaging quality can be improved.

Further, by making the optical lens satisfy the following relation: 1< TTL/ImgH <1.12, can control the total length of the optical lens, reduce the assembly sensitivity of the optical lens, and meanwhile, is beneficial to the balance between the miniaturized design and the large imaging surface of the optical lens, so that the optical lens also has the larger imaging surface under the condition of smaller size so as to be matched with a sensor with higher pixels, and further can shoot more details of an object.

As an alternative implementation manner, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: fno/tan (HFOV) <2; wherein FNO is the f-number of the optical lens and HFOV is half the maximum field angle of the optical lens. When the relation is satisfied, the optical lens is favorable for having larger luminous flux, improving the image plane brightness of the optical lens and improving the imaging definition, thereby improving the photosensitive performance of the image sensor and inhibiting the dark angle phenomenon; in addition, on the premise of enough luminous flux, the field of view range of the optical lens is not excessively compressed, so that the large field angle characteristic is realized, and the imaging quality of the optical lens is improved.

As an alternative implementation manner, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: tan (HFOV)/(distim 10) >6.5; wherein HFOV is half of the maximum field angle of the optical lens and distime is the maximum optical distortion value of the optical lens. When the relation is satisfied, the deformation degree of the optical lens with the wide-angle characteristic in actual imaging is reduced, the aberration such as field curvature and distortion caused by the wide-angle characteristic is effectively restrained, meanwhile, the angle of incidence of off-axis view field rays on the image sensor can be effectively pressed by matching with the surface type design of each lens, the response efficiency of the image sensor is improved, the peripheral distortion of an image is corrected, the optical lens performance is guaranteed to be better, and the imaging quality of the optical lens is further improved.

As an alternative implementation manner, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: 1< f1/f <2; wherein f1 is the focal length of the first lens, and f is the effective focal length of the optical lens. When the refractive power of the first lens is configured within a reasonable range, that is, when the above relation is satisfied, the first lens can provide proper positive refractive power, so that reasonable convergence can be realized on incident light rays to compress the total length of the optical lens, meanwhile, the first lens can be prevented from generating aberration which is difficult to correct, and in addition, the positive refractive power of the first lens can also reasonably deflect light rays which are incident at a large angle relative to the optical axis, thereby being beneficial to expanding the angle of view of the optical lens, effectively reducing the head size of the optical lens, shortening the total length of the optical lens and providing enough space for improving the size of an imaging surface.

As an alternative implementation manner, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: 1.5< r72/f7<5.5; wherein f7 is the focal length of the seventh lens; r72 is the radius of curvature of the image side surface of the seventh lens at the optical axis. When the relation is satisfied, the shape of the seventh lens can be reasonably controlled, so that the seventh lens has proper deflection degree, under the condition of providing proper positive refractive power, the shape of the seventh lens is more controllable, and the design that the object side surface and the image side surface of the seventh lens are respectively convex and concave can be matched, so that the total length of the optical lens can be shortened, the miniaturization design is realized, in addition, the curvature and the reverse curvature of the image side surface of the seventh lens can be matched, the angle of incidence of off-axis view field rays to the eighth lens can be effectively pressed, the correction pressure of the eighth lens is reduced, the correction of peripheral distortion of an image generated by a front lens group is facilitated, in addition, the off-axis aberration can be corrected, the relative illuminance can be improved, and the imaging quality of the optical lens is improved.

As an alternative implementation manner, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: -2.5< r81/f8< -0.5; where r81 is a radius of curvature of the object side surface of the eighth lens element at the optical axis, and f8 is a focal length of the eighth lens element. When the relation is satisfied, the eighth lens element can provide reasonable negative refractive power, and the angle of incidence of the light rays with the off-axis view field on the image sensor can be effectively pressed by matching with the curvature and the inflection of the object side surface of the eighth lens element, so that the angle of incidence of the light rays on the imaging surface can be adjusted, the photosensitive chip can be matched better, the response efficiency of the image sensor can be improved, the peripheral distortion of the image can be corrected, the relative illuminance can be improved, the astigmatism of the optical lens can be corrected, and the distortion of the optical lens can be reduced.

As an alternative implementation manner, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: 1< r31/r22<5.5; wherein r31 is a radius of curvature of the object side surface of the third lens at the optical axis; r22 is the radius of curvature of the image side surface of the second lens at the optical axis. When the relation is satisfied, the object side surface of the third lens element and the image side surface of the second lens element have enough bending degrees of freedom, so that smooth transmission of light is facilitated, and aberration such as astigmatism and field curvature of the optical lens can be corrected. When the object-side surface of the third lens element is less than the lower limit of the above-mentioned relation, the object-side surface of the third lens element is not enough in bending degree of freedom, and the image-side surface of the second lens element is too bent, so that an aberration of an edge field of view is easily generated, which is not beneficial to correcting the aberration of the optical lens element; when the upper limit of the above relation is exceeded, the image-side bending degree of freedom of the second lens element is insufficient, the object-side surface of the third lens element is too curved, and the object-side surface of the third lens element is complex, which is not conducive to the processing and molding of the third lens element.

As an alternative implementation manner, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: at14/TTL is less than or equal to 0.11; wherein at14 is the sum of air gaps of the first lens to the fifth lens on the optical axis. By controlling the ratio of the sum of the air gaps between the first lens and the fifth lens to the total length of the optical lens, namely, when the relation is satisfied, the optical lens is favorable to have enough air gaps, and the stability and good imaging quality of the optical lens are ensured. Meanwhile, the total length of the optical lens is shortened, the miniaturization design is facilitated, the assembly difficulty of each lens can be reduced, and the assembly stability is improved.

As an alternative implementation manner, in an embodiment of the first aspect of the present invention, the optical lens satisfies the following relation: sd82/ct8<8.9; wherein sd82 is the maximum effective half-caliber of the image side surface of the eighth lens, and ct8 is the thickness of the eighth lens on the optical axis. When the relation is satisfied, the thickness of the eighth lens can be reasonably configured, and the lens surface can be reasonably configured, so that the large-angle light is incident on the image sensor, the large-image-plane characteristic of the optical lens is favorably realized, the chip with higher pixels is matched, the tolerance sensitivity of the eighth lens can be reduced, the structural arrangement pressure of the lens barrel can be reduced, and the forming and the assembly of the eighth lens are favorably realized. When the upper limit of the relation is exceeded, the outer diameter of the eighth lens is too large, so that the assembly stability of the eighth lens is reduced, defects are easily caused in the forming and assembling process, and the cost is increased.

In a second aspect, the present invention discloses an image capturing module, where the image capturing module includes a photosensitive chip and the optical lens described in the first aspect, and the photosensitive chip is disposed on an image side of the optical lens. The imaging module with the optical lens can improve imaging quality, reduce the total length of the optical lens, realize miniaturization design, reduce the sensitivity of the optical lens, and simultaneously, can also have a larger imaging surface to match with a photosensitive chip with higher pixels.

In a third aspect, the invention discloses an electronic device, which comprises a housing and the camera module set in the second aspect, wherein the camera module set is arranged on the housing. The electronic equipment with the camera module can improve the imaging quality of the optical lens, reduce the total length of the optical lens, realize miniaturized design and reduce the sensitivity of the optical lens, and simultaneously, the electronic equipment can also have a larger imaging surface so as to be matched with a photosensitive chip with higher pixels.

Compared with the prior art, the invention has the beneficial effects that: the embodiment of the invention provides an optical lens, an imaging module and electronic equipment, wherein eight lenses are adopted in the optical lens, and the refractive power and the surface shape of each lens are reasonably configured, so that the optical lens meets the relation: 1< TTL/ImgH <1.12, can correct the aberration of the optical lens, improve the imaging quality of the optical lens, reduce the total length of the optical lens, reduce the sensitivity of the optical lens, and meanwhile, is beneficial to the balance between the miniaturized design and the large imaging surface of the optical lens, so that the optical lens also has a larger imaging surface under the condition of smaller size so as to be matched with a photosensitive chip with higher pixels, and further can shoot more details of an object.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed 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 other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

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

fig. 2 is a longitudinal spherical aberration diagram (mm), astigmatic curve diagram (mm) and distortion curve diagram (%) of an optical lens disclosed in the first embodiment of the present application;

FIG. 3 is a schematic view of an optical lens disclosed in a second embodiment of the present application;

fig. 4 is a longitudinal spherical aberration diagram (mm), astigmatic curve diagram (mm) and distortion curve diagram (%) of an optical lens disclosed in the second embodiment of the present application;

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

fig. 6 is a longitudinal spherical aberration diagram (mm), astigmatic curve diagram (mm) and distortion curve diagram (%) of an optical lens disclosed in a third embodiment of the present application;

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

Fig. 8 is a longitudinal spherical aberration diagram (mm), astigmatic curve diagram (mm) and distortion curve diagram (%) of an optical lens disclosed in a fourth embodiment of the present application;

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

fig. 10 is a longitudinal spherical aberration diagram (mm), astigmatic curve diagram (mm) and distortion curve diagram (%) of an optical lens disclosed in the fifth embodiment of the present application;

fig. 11 is a schematic structural view of an optical lens disclosed in a sixth embodiment of the present application;

fig. 12 is a longitudinal spherical aberration diagram (mm), astigmatic curve diagram (mm) and distortion curve diagram (%) of an optical lens disclosed in a sixth embodiment of the present application;

fig. 13 is a schematic structural view of an optical lens disclosed in a seventh embodiment of the present application;

fig. 14 is a longitudinal spherical aberration diagram (mm), astigmatic curve diagram (mm) and distortion curve diagram (%) of an optical lens disclosed in the seventh embodiment of the present application;

FIG. 15 is a schematic view of the structure of the camera module disclosed in the present application;

fig. 16 is a schematic structural view of an electronic device disclosed in the present application.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the present invention, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate an azimuth or a positional relationship based on that shown in the drawings. These terms are only used to better describe the present invention and its embodiments and are not intended to limit the scope of the indicated devices, elements or components to the particular orientations or to configure and operate in the particular orientations.

Also, some of the terms described above may be used to indicate other meanings in addition to orientation or positional relationships, for example, the term "upper" may also be used to indicate some sort of attachment or connection in some cases. The specific meaning of these terms in the present invention will be understood by those of ordinary skill in the art according to the specific circumstances.

Furthermore, the terms "mounted," "configured," "provided," "connected," and "connected" are to be construed broadly. For example, it may be a fixed connection, a removable connection, or a unitary construction; may 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 meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

Furthermore, the terms "first," "second," and the like, are used primarily to distinguish between different devices, elements, or components (the particular species and configurations may be the same or different), and are not used to indicate or imply the relative importance and number of devices, elements, or components indicated. Unless otherwise indicated, the meaning of "a plurality" is two or more.

The technical scheme of the invention will be further described with reference to the examples and the accompanying drawings.

Referring to fig. 1, according to a first aspect of the present application, an optical lens 100 is disclosed, 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 sequentially disposed from an object side to an image side along an optical axis O. During imaging, light enters 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 forms an image on the imaging surface 101 of the optical lens 100. The first lens element L1 with positive refractive power, the second lens element L2, the third lens element L3, the fourth lens element L4, the fifth lens element L5 and the sixth lens element L6 with positive refractive power (e.g., positive refractive power or negative refractive power), the seventh lens element L7 with positive refractive power, and the eighth lens element L8 with 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 at the paraxial region O, respectively; the object side surface S3 and the image side surface S4 of the second lens element L2 are respectively convex and concave at the paraxial region O; the object side surface S5 of the third lens element L3 is convex at a paraxial region O, and the image side surface S6 of the third lens element L3 is convex or concave at the paraxial region O; the object side surface S7 of the fourth lens element L4 is convex or concave at the paraxial region O, and the image side surface S8 of the fourth lens element L4 is convex at the paraxial region O; the object side surface S9 of the fifth lens element L5 is convex at the paraxial region O, and the image side surface S10 of the fifth lens element L5 is concave at the paraxial region O; the object side surface S11 of the sixth lens element L6 is convex at the paraxial region O, and the image side surface S12 of the sixth lens element L6 is concave at the paraxial region O; the object-side surface S13 and the image-side surface S14 of the seventh lens element L7 are convex and concave at the paraxial region O, respectively, and at least one inflection point is disposed in each of the object-side surface S13 and the image-side surface S14 of the seventh lens element L7. The object-side surface S15 and the image-side surface S16 of the eighth lens element L8 are convex and concave at the paraxial region O, respectively, and at least one inflection point is disposed in each of the object-side surface S15 and the image-side surface S16 of the eighth lens element L8.

As can be seen from the above, the first lens element L1 of the optical lens 100 has positive refractive power, the object-side surfaces of the first lens element L1 and the second lens element L2 are both convex at the optical axis O, and the image-side surfaces of the first lens element L1 and the second lens element L2 are both concave at the optical axis O, so that incident light rays with a large angle with the optical axis enter the optical lens 100, which is beneficial to converging light rays of the optical lens 100, and the optical performance of the optical lens 100 is improved. The surface designs of the fourth lens element L4 and the fifth lens element L5 can be used in combination with the object-side lens element to further converge the incident light beam, so as to compress the overall length of the optical lens assembly 100, and the refractive power and the corresponding surface designs provided by the sixth lens element L6 can balance the aberration of the object-side lens elements, which is difficult to correct when converging the incident light beam, and reduce the correction pressure of the rear lens assembly. The object side surface and the image side surface of the seventh lens element L7 and the eighth lens element L8 are respectively provided with at least one inflection point, which is favorable for making the light rays of the marginal view field obtain smaller light ray deflection angle, meanwhile, the positive refractive power of the seventh lens element L7 combined with the negative refractive power provided by the eighth lens element L8 counteracts the aberration generated by the positive refractive power and the negative refractive power, and the convex-concave surface type design of the object side surface S15 and the image side surface S16 at the optical axis O can further converge the light rays of the central view field, shorten the total length of the optical lens element 100, correct the aberration, suppress the emergent angle of the light rays, improve the light ray receiving efficiency of the photosensitive chip, further correct the aberration and improve the imaging quality.

In some embodiments, the optical lens 100 may be applied to electronic devices such as a smart phone and a smart tablet, and the 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 may be plastic, so that the optical lens 100 has good optical effects and good portability. In addition, the plastic material is easier to process the lens, so that the processing cost of the optical lens 100 can be reduced.

In some embodiments, the optical lens 100 further includes a diaphragm 102, and the diaphragm 102 may be an aperture diaphragm or a field diaphragm, 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 to be understood that in other embodiments, the diaphragm 102 may 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 particularly limited in this embodiment.

In some embodiments, the optical lens 100 further includes an optical filter L9, such as an infrared optical filter, disposed between the image side surface S16 of the eighth lens element L8 and the imaging surface 101 of the optical lens 100, so as to filter out light rays of other wavelength bands, such as visible light, and only allow infrared light to pass through, so that the optical lens 100 can be used as an infrared optical lens, i.e., the optical lens 100 can also image in a dim environment and other special application scenarios and obtain better image effects.

In some embodiments, the optical lens 100 satisfies the following relationship: 1< TTL/ImgH <1.12, can control the total length of the optical lens 100, reduce the assembly sensitivity of the optical lens 100, and meanwhile, is beneficial to the balance between the miniaturized design and the large imaging surface 101 of the optical lens 100, so that the optical lens 100 also has the large imaging surface 101 under the condition of smaller size so as to be matched with a sensor with higher pixels, and further can shoot more details of an object.

In some embodiments, optical lens 100 satisfies the following relationship fno/tan (HFOV) <2; where FNO is the f-number of optical lens 100 and HFOV is half the maximum field angle of optical lens 100. When the relation is satisfied, the optical lens 100 is favorable for having larger luminous flux, improving the image plane brightness of the optical lens 100 and improving the imaging definition, thereby improving the photosensitive performance of the photosensitive chip and inhibiting the dark angle phenomenon; in addition, on the premise of having enough luminous flux, the field of view range of the optical lens 100 is not excessively compressed, which is beneficial to realizing the characteristic of large field angle and improving the imaging quality of the optical lens 100.

In some embodiments, optical lens 100 satisfies the following relationship tan (HFOV)/(distim 10) >6.5; wherein HFOV is half the maximum field angle of optical lens 100 and distime is the maximum optical distortion value of optical lens 100. When the above relation is satisfied, the deformation degree of the optical lens 100 with the wide-angle characteristic in actual imaging is reduced, aberration such as field curvature and distortion caused by the wide-angle characteristic is effectively inhibited, meanwhile, the angle of incidence of off-axis view field light on the photosensitive chip can be effectively pressed by matching with the surface design of each lens, the response efficiency of the photosensitive chip is improved, the peripheral distortion of an image is corrected, the performance of the optical lens 100 is guaranteed to be better, and the imaging quality of the optical lens 100 is further improved.

In some embodiments, the optical lens 100 satisfies the following relationship 1< f1/f <2; where f1 is the focal length of the first lens L1, and f is the effective focal length of the optical lens 100. When the refractive power of the first lens element L1 is configured within a reasonable range, that is, when the above-mentioned relational expression is satisfied, the first lens element L1 can provide a proper positive refractive power, so as to reasonably converge incident light rays to compress the total length of the optical lens element, and meanwhile, can prevent the first lens element from generating aberration which is difficult to correct.

In some embodiments, the optical lens 100 satisfies the following relationship 1.5< r72/f7<5.5; wherein f7 is the focal length of the seventh lens L7; r72 is a radius of curvature of the image-side surface of the seventh lens element L7 at the optical axis O. When the above relation is satisfied, the shape of the seventh lens element L7 can be reasonably controlled, so that the seventh lens element L7 has a proper degree of refractive error, and the shape of the seventh lens element L7 is more controllable when a proper positive refractive power is provided, and the design of the object-side surface S13 and the image-side surface S14 of the seventh lens element L7, which are convex and concave, respectively, can shorten the total length of the optical lens 100, thereby realizing a miniaturized design, and in addition, the curvature and the curvature-back of the image-side surface S14 of the seventh lens element L7 can effectively suppress the angle of incidence of the off-axis field light ray to the eighth lens element L8, thereby reducing the correction pressure of the eighth lens element L8, and being beneficial to correcting the peripheral distortion of the image generated by the front lens element group, and in addition, correcting the off-axis aberration and improving the relative illuminance, thereby improving the imaging quality of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the following relationship-2.5 < r81/f8< -0.5; where r81 is a radius of curvature of the object side surface S15 of the eighth lens element L8 at the optical axis O, and f8 is a focal length of the eighth lens element L8. When the above relation is satisfied, the eighth lens element L8 is favorable to providing a reasonable negative refractive power, and the angle of incidence of the off-axis field light on the photosensitive chip can be effectively suppressed by matching the curvature and the inflection of the object side surface S15 of the eighth lens element L8, so as to adjust the angle of incidence of the light on the imaging plane 101, better match the photosensitive chip, and simultaneously, be favorable to correcting the astigmatism of the optical lens 100 and reduce the distortion of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the following relationship 1< r31/r22<5.5; wherein r31 is a radius of curvature of the object side surface S5 of the third lens element L3 at the optical axis O; r22 is the radius of curvature of the image-side surface of the second lens element L2 at the optical axis O. When the above relation is satisfied, the object side surface S5 of the third lens element L3 and the image side surface S4 of the second lens element L2 have enough bending degrees of freedom, which is beneficial to smooth transmission of light and correction of aberrations such as astigmatism and curvature of field of the optical lens 100. When the object-side surface S5 of the third lens element L3 is less than the lower limit of the above-mentioned relationship, the image-side surface S4 of the second lens element L2 is too curved to generate fringe field-of-view aberration, which is not beneficial to correcting the aberration of the optical lens assembly 100; when the upper limit of the above relation is exceeded, the bending degree of freedom of the image side surface S4 of the second lens element L2 is insufficient, the object side surface S5 of the third lens element L3 is too curved, and the image side surface S5 of the third lens element L3 is complex in shape, which is not conducive to the processing and molding of the third lens element L3.

In some embodiments, the optical lens 100 satisfies the following relationship at 14/TTL.ltoreq.0.11; wherein at14 is the sum of the air gaps of the first lens L1 to the fifth lens L5 on the optical axis O. By controlling the ratio of the sum of the air gaps between the first lens L1 and the fifth lens L5 to the total length of the optical lens 100, that is, when the above relation is satisfied, it is advantageous for the optical lens 100 to have a sufficient air gap, so as to ensure the stability and good imaging quality of the optical lens 100. Meanwhile, the overall length of the optical lens 100 is shortened, the miniaturization design is facilitated, the assembly difficulty of each lens can be reduced, and the assembly stability is improved.

In some embodiments, the optical lens 100 satisfies the following relationship sd82/ct8<8.9; here, sd82 is the maximum effective half-caliber of the image side surface of the eighth lens element L8, and ct8 is the thickness of the eighth lens element L8 on the optical axis O. When the above relation is satisfied, the thickness of the eighth lens L8 can be reasonably configured, and the lens surface can be reasonably configured, so that a large-angle light is incident on the photosensitive chip, which is favorable for realizing the large image surface feature of the optical lens 100 to match with a chip with a higher pixel, and in addition, the tolerance sensitivity of the eighth lens can be reduced, the pressure of the structural arrangement of the lens barrel can be reduced, and the molding and assembly of the eighth lens L8 are favorable. When the upper limit of the above relation is exceeded, the outer diameter of the eighth lens L8 is too large, so that the assembly stability of the eighth lens L8 is reduced, defects are easily caused in the molding and assembling process, and the cost is increased.

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

First embodiment

As shown in fig. 1, a schematic structural diagram of an optical lens 100 according to a first embodiment of the present application is shown in fig. 1, wherein 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 sequentially disposed from an object side to an image side along an optical axis O, the first lens L1 has positive refractive power, the second lens L2 has negative refractive power, the third lens L3 and the fourth lens L4 have positive refractive power, the fifth lens L5 and the sixth lens L6 have negative refractive power, and the seventh lens L7 has positive refractive power, and the eighth lens 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 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 at the paraxial region O, the object-side surface S5 and the image-side surface S6 of the third lens element L3 are convex 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 at the paraxial region O, the object-side surface S9 and the image-side surface S10 of the fifth lens element L5 are concave 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 convex at the paraxial region O, the object-side surface S13 and the image-side surface S14 of the seventh lens element L7 are convex and concave at the paraxial region O, and the object-side surface S15 and the image-side surface S16 of the eighth lens element L8 are convex and concave at the paraxial region O. The object-side surface S1 and the image-side surface S2 of the first lens element L1 are concave and convex at the circumference, the object-side surface S3 and the image-side surface S4 of the second lens element L2 are convex and concave at the circumference, the object-side surface S5 and the image-side surface S6 of the third lens element L3 are convex at the circumference, the object-side surface S7 and the image-side surface S8 of the fourth lens element L4 are concave at the circumference, the object-side surface S9 and the image-side surface S10 of the fifth lens element L5 are convex and concave at the circumference, the object-side surface S11 and the image-side surface S12 of the sixth lens element L6 are convex and concave at the circumference, the object-side surface S13 and the image-side surface S14 of the seventh lens element L7 are convex and concave at the circumference, and the object-side surface S15 and the image-side surface S16 of the eighth lens element L8 are concave and convex at the circumference. It is noted that the object side surface and the image side surface of the seventh lens element L7 and the eighth lens element L8 each have inflection points.

Specifically, taking the effective focal length f= 4.738mm of the optical lens 100, the maximum field angle fov=96.35° of the optical lens 100, the optical total length ttl=5.8 mm of the optical lens 100, and the aperture size fno=2.1 as an example, other parameters of the optical lens 100 are given in table 1 below. The elements from the object side to the image side are sequentially arranged in the order of the elements from top to bottom in table 1 along the optical axis O of the optical lens 100. In the same lens element, the surface with smaller surface number is the object side surface of the lens element, and the surface with larger surface number is the image side surface of the lens element, and the surface numbers 2 and 3 correspond to the object side surface S1 and the image side surface S2 of the first lens element L1, respectively. The radius Y in table 1 is the radius of curvature of the object or image side of the corresponding surface number at the paraxial region O. The first value in the "thickness" parameter array of the lens is the thickness of the lens on the optical axis O, and the second value is the distance from the image side surface of the lens to the latter surface on the optical axis O. The value of the aperture 102 in the "thickness" parameter row is the distance between the aperture 102 and the vertex of the subsequent surface (the vertex refers to the intersection point of the surface and the optical axis O) on the optical axis O, and the direction from the object side surface of the first lens L1 to the image side surface of the last lens is the positive direction of the optical axis O by default, when the value is negative, it indicates that the aperture 102 is disposed on the image side of the vertex of the subsequent surface, and when the thickness of the aperture 102 is positive, the aperture 102 is on the object side of the vertex of the subsequent surface. It is understood that the units of Y radius, thickness, and focal length in Table 1 are all mm. And the reference wavelength of the effective focal length of the lens in table 1 is 555nm, and the reference wavelength of the refractive index and abbe number of the lens material is 587.6nm.

TABLE 1

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

wherein x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at the position with the height h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c=1/R (i.e., paraxial curvature c is the inverse of the radius R of Y in table 1 above); k is a conic coefficient; ai is a correction coefficient corresponding to the i-th higher term of the aspherical surface. Table 2 shows the higher order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for each of the aspherical mirrors S1-S16 in the first embodiment.

TABLE 2

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

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

Referring to fig. 2 (C), fig. 2 (C) is a graph showing a distortion curve of the optical lens 100 at a wavelength of 555nm in the first embodiment. 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 fig. 2 (C), the distortion of the optical lens 100 is well corrected at a wavelength of 555 nm.

Second embodiment

As shown in fig. 3, 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 sequentially disposed from an object side to an image side along an optical axis O, and the refractive powers of the respective lenses are identical to those of the respective lenses in the first embodiment.

Further, in the second embodiment, the surface type of each lens differs from that in the first embodiment in that: the object-side surface S5 and the image-side surface S6 of the third lens element L3 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 S5 and the image-side surface S6 of the third lens element L3 are respectively concave and convex at the circumferential region, the object-side surface S9 and the image-side surface S10 of the fifth lens element L5 are respectively concave at the circumferential region, and the object-side surface S11 and the image-side surface S12 of the sixth lens element L6 are respectively convex at the circumferential region. It is noted that the object side surface and the image side surface of the seventh lens element L7 and the eighth lens element L8 each have inflection points.

Specifically, taking the effective focal length f= 4.601mm of the optical lens 100, the maximum field angle fov=97.85° of the optical lens 100, the total optical length ttl= 5.999mm of the optical lens 100, and the aperture size fno=1.73 as an example, other parameters of the optical lens 100 are given in table 3 below, and the definition of each parameter can be derived from the description of the foregoing embodiments. It is understood that the units of Y radius, thickness, and focal length in Table 3 are all mm. And the reference wavelength of the effective focal length of the lens in table 3 is 555nm, and the reference wavelength of the refractive index and abbe number of the lens material is 587.6nm.

TABLE 3 Table 3

In the second embodiment, table 4 gives the higher order coefficients that can be used for each aspherical mirror in the second embodiment, where each aspherical mirror shape can be defined by the formula given in the first embodiment.

TABLE 4 Table 4

Referring to fig. 4, as shown in fig. 4, the longitudinal spherical aberration, astigmatism and distortion of the optical lens 100 are well controlled by the (a) longitudinal spherical aberration diagram, the (B) astigmatic curve diagram and the (C) distortion curve diagram, so that the optical lens 100 of the embodiment has good imaging quality. In addition, the wavelengths corresponding to the curves in fig. 4 (a), 4 (B) and 4 (C) may refer to the contents described in the first embodiment in fig. 2 (a), 2 (B) and 2 (C), and will not be repeated here.

Third embodiment

As shown in fig. 5, 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 sequentially disposed from an object side to an image side along an optical axis O, and the refractive powers of the respective lenses are identical to those of the respective lenses in the first embodiment.

Further, in the third embodiment, the surface type of each lens differs from that in the first embodiment in that: the object-side surface S9 and the image-side surface S10 of the fifth lens element L5 are concave at the circumference. It is noted that the object side surface and the image side surface of the seventh lens element L7 and the eighth lens element L8 each have inflection points.

Specifically, taking the effective focal length f= 4.368mm of the optical lens 100, the maximum field angle fov=101° of the optical lens 100, the total optical length ttl=5.44 mm of the optical lens 100, and the aperture size fno=2.2 as an example, other parameters of the optical lens 100 are given in table 5 below, and the definition of each parameter can be derived from the description of the foregoing embodiments. It is understood that the units of Y radius, thickness, and focal length in Table 5 are all mm. And the reference wavelength of the effective focal length of the lens in table 5 is 555nm, and the reference wavelength of the refractive index and abbe number of the lens material is 587.6nm.

TABLE 5

In a third embodiment, table 6 gives the higher order coefficients that can be used for each of the aspherical mirror surfaces in the third embodiment, where each of the aspherical surface profiles can be defined by the formula given in the first embodiment.

TABLE 6

Referring to fig. 6, as can be seen from the (a) longitudinal spherical aberration diagram, (B) astigmatic curve diagram and (C) distortion diagram in fig. 6, the longitudinal spherical aberration, astigmatism and distortion of the optical lens 100 are well controlled, so that the optical lens 100 of the embodiment has good imaging quality. In addition, regarding the wavelengths corresponding to the curves in fig. 6 (a), 6 (B) and 6 (C), reference may be made to what is described in the first embodiment with respect to fig. 2 (a), 2 (B) and 2 (C), and the description thereof will be omitted here.

Fourth embodiment

As shown in fig. 7, a schematic structural diagram of an optical lens 100 disclosed in a fourth 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 sequentially disposed from an object side to an image side along an optical axis O, and refractive powers of the respective lenses differ from those of the first embodiment in that: the sixth lens element L6 with positive refractive power.

Further, in the fourth embodiment, the surface type of each lens differs from that in the first embodiment in that: the object-side surface S1 and the image-side surface S2 of the first lens element L1 are concave at the circumference, the object-side surface S5 and the image-side surface S6 of the third lens element L3 are convex and concave at the circumference, the object-side surface S9 and the image-side surface S10 of the fifth lens element L5 are concave at the circumference, and the object-side surface S11 and the image-side surface S12 of the sixth lens element L6 are convex at the circumference. It is noted that the object side surface and the image side surface of the seventh lens element L7 and the eighth lens element L8 each have inflection points.

Specifically, taking the effective focal length f= 4.738mm of the optical lens 100, the maximum field angle fov= 96.202 of the optical lens 100, the total optical length ttl=5.9 mm of the optical lens 100, and the aperture size fno=2.05 as examples, other parameters of the optical lens 100 are given in the following table 7, and the definition of each parameter can be derived from the description of the foregoing embodiments. It is understood that the units of Y radius, thickness, and focal length in Table 7 are all mm. And the reference wavelength of the effective focal length of the lens in table 7 is 555nm, and the reference wavelength of the refractive index and abbe number of the lens material is 587.6nm.

TABLE 7

In the fourth embodiment, table 8 gives the higher order coefficients that can be used for each aspherical mirror in the fourth embodiment, where each aspherical mirror shape can be defined by the formula given in the first embodiment.

TABLE 8

Referring to fig. 8, as shown in fig. 8, the longitudinal spherical aberration, astigmatism and distortion of the optical lens 100 are well controlled, so that the optical lens 100 of the embodiment has good imaging quality. In addition, regarding the wavelengths corresponding to the curves in fig. 8 (a), 8 (B) and 8 (C), reference may be made to what is described in the first embodiment with respect to fig. 2 (a), 2 (B) and 2 (C), and the description thereof will be omitted here.

Fifth embodiment

As shown in fig. 9, a schematic structural diagram of an optical lens 100 disclosed in 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 sequentially disposed from an object side to an image side along an optical axis O, and the refractive powers of the respective lenses differ from those of the first embodiment in that: the third lens element L3 with negative refractive power, and the fifth lens element L5 with positive refractive power.

Further, in the fifth embodiment, the surface type of each lens differs from that in the first embodiment in that: the object-side surface S5 and the image-side surface S6 of the third lens element L3 are convex and concave at the paraxial region O, the object-side surface S7 and the image-side surface S8 of the fourth lens element L4 are convex 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 at the paraxial region O, the object-side surface S3 and the image-side surface S4 of the second lens element L2 are concave at the circumferential region, the object-side surface S5 and the image-side surface S6 of the third lens element L3 are concave and convex at the circumferential region, the object-side surface S9 and the image-side surface S10 of the fifth lens element L5 are concave at the circumferential region, and the object-side surface S11 and the image-side surface S12 of the sixth lens element L6 are convex at the circumferential region. It is noted that the object side surface and the image side surface of the seventh lens element L7 and the eighth lens element L8 each have inflection points.

Specifically, taking the effective focal length f= 4.707mm of the optical lens 100, the maximum field angle fov= 96.808 ° of the optical lens 100, the total optical length ttl=5.85 mm of the optical lens 100, and the aperture size fno=2.15 as examples, other parameters of the optical lens 100 are given in the following table 9, and the definition of each parameter can be derived from the description of the foregoing embodiments. It is understood that the units of Y radius, thickness, and focal length in Table 9 are all mm. And the reference wavelength of the effective focal length of the lens in table 9 is 555nm, and the reference wavelength of the refractive index and abbe number of the lens material is 587.6nm.

TABLE 9

In the fifth embodiment, table 10 gives the higher order coefficients that can be used for each aspherical mirror surface in the fifth embodiment, where each aspherical surface profile can be defined by the formula given in the first embodiment.

Table 10

Referring to fig. 10, as can be seen from the (a) longitudinal spherical aberration diagram, (B) astigmatic curve diagram and (C) distortion diagram in fig. 10, the longitudinal spherical aberration, astigmatism and distortion of the optical lens 100 are well controlled, so that the optical lens 100 of the embodiment has good imaging quality. In addition, regarding the wavelengths corresponding to the curves in fig. 10 (a), 10 (B) and 10 (C), reference may be made to what is described in the first embodiment with respect to fig. 2 (a), 2 (B) and 2 (C), and the description thereof will be omitted here.

Sixth embodiment

As shown in fig. 11, a schematic structural diagram of an optical lens 100 disclosed in a sixth 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 sequentially disposed from an object side to an image side along an optical axis O, and the refractive powers of the respective lenses differ from those of the first embodiment in that: the second lens element L2 with positive refractive power.

Further, in the sixth embodiment, the surface type of each lens differs from that in the first embodiment in that: the object-side surface S5 and the image-side surface S6 of the third lens element L3 are 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 concave and convex at the paraxial region O, the object-side surface S11 and the image-side surface S12 of the sixth lens element L6 are concave at the paraxial region O, the object-side surface S1 and the image-side surface S2 of the first lens element L1 are concave at the circumference, the object-side surface S5 and the image-side surface S6 of the third lens element L3 are convex and concave at the circumference, the object-side surface S9 and the image-side surface S10 of the fifth lens element L5 are concave at the circumference, and the object-side surface S11 and the image-side surface S12 of the sixth lens element L6 are convex at the circumference. It is noted that the object side surface and the image side surface of the seventh lens element L7 and the eighth lens element L8 each have inflection points.

Specifically, taking the effective focal length f= 4.592mm of the optical lens 100, the maximum field angle fov= 98.056 of the optical lens 100, the total optical length ttl=5.95 mm of the optical lens 100, and the aperture size fno=1.85 as examples, other parameters of the optical lens 100 are given in the following table 11, and the definition of each parameter can be derived from the description of the foregoing embodiments. It is understood that the units of Y radius, thickness, and focal length in Table 11 are all mm. And the reference wavelength of the effective focal length of the lens in table 11 is 555nm, and the reference wavelength of the refractive index and abbe number of the lens material is 587.6nm.

TABLE 11

In the sixth embodiment, table 12 gives the higher order coefficients that can be used for each aspherical mirror in the sixth embodiment, where each aspherical mirror shape can be defined by the formula given in the first embodiment.

Table 12

Referring to fig. 12, as can be seen from the (a) longitudinal spherical aberration diagram, (B) astigmatic curve diagram and (C) distortion diagram in fig. 12, the longitudinal spherical aberration, astigmatism and distortion of the optical lens 100 are well controlled, so that the optical lens 100 of the embodiment has good imaging quality. In addition, regarding the wavelengths corresponding to the curves in fig. 12 (a), 12 (B) and 12 (C), reference may be made to what is described in the first embodiment with respect to fig. 2 (a), 2 (B) and 2 (C), and the description thereof will be omitted here.

Seventh embodiment

As shown in fig. 13, a schematic structural diagram of an optical lens 100 disclosed in a seventh 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 sequentially disposed from an object side to an image side along an optical axis O, and the refractive powers of the respective lenses differ from those of the first embodiment in that: the fourth lens element L4 with negative refractive power.

Further, in the seventh embodiment, the surface type of each lens differs from that in the first embodiment in that: the object-side surface S3 and the image-side surface S4 of the second lens element L2 are concave at the circumference, the object-side surface S9 and the image-side surface S10 of the fifth lens element L5 are concave at the circumference, the object-side surface S11 and the image-side surface S12 of the sixth lens element L6 are convex at the circumference, the object-side surface S13 and the image-side surface S14 of the seventh lens element L7 are concave at the circumference, and the object-side surface S15 and the image-side surface S16 of the eighth lens element L8 are convex at the circumference. It is noted that the object side surface and the image side surface of the seventh lens element L7 and the eighth lens element L8 each have inflection points.

Specifically, taking the effective focal length f= 4.542mm of the optical lens 100, the maximum field angle fov= 98.598 of the optical lens 100, the total optical length ttl=5.65 mm of the optical lens 100, and the aperture size fno=2.2 as an example, other parameters of the optical lens 100 are given in the following table 13, and the definition of each parameter can be derived from the description of the foregoing embodiments. It is understood that the units of Y radius, thickness, and focal length in Table 13 are all mm. And the reference wavelength of the effective focal length of the lens in table 13 is 555nm, and the reference wavelength of the refractive index and abbe number of the lens material is 587.6nm.

TABLE 13

In the seventh embodiment, table 14 gives the higher order coefficients that can be used for each aspherical mirror in the seventh embodiment, where each aspherical mirror shape can be defined by the formula given in the first embodiment.

TABLE 14

Referring to fig. 14, as shown in fig. 14, the longitudinal spherical aberration, astigmatism and distortion of the optical lens 100 are well controlled by the (a) longitudinal spherical aberration diagram, the (B) astigmatic curve diagram and the (C) distortion curve diagram, so that the optical lens 100 of the embodiment has good imaging quality. In addition, regarding the wavelengths corresponding to the curves in fig. 14 (a), 14 (B) and 14 (C), reference may be made to what is described in the first embodiment with respect to fig. 2 (a), 2 (B) and 2 (C), and the description thereof will be omitted here.

Referring to table 15, table 15 is a summary of the ratios of the relationships in the first embodiment to the seventh embodiment of the present application.

TABLE 15

Referring to fig. 15, the invention discloses an image capturing module 200, wherein the image capturing module 200 includes a photosensitive chip 201 and the optical lens 100, and the photosensitive chip 201 is disposed on an image side of the optical lens 100. The optical lens 100 may be used to receive an optical signal of a subject and project the optical signal to the photo-sensing chip 201, and the photo-sensing chip 201 may be used to convert the optical signal corresponding to the subject into an image signal. The image pickup module 200 with the optical lens 100 can improve the imaging quality of the optical lens 100, reduce the total length of the optical lens 100, realize miniaturization design, reduce the sensitivity of the optical lens 100, and simultaneously can also have a larger imaging surface to match a photosensitive chip with higher pixels.

Referring to fig. 16, the invention discloses an electronic device 300, wherein the electronic device 300 includes a housing 301 and the camera module 200, 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, etc. The electronic device 300 with the image capturing module 200 can improve the imaging quality of the optical lens 100, reduce the total length of the optical lens 100, realize a miniaturized design, reduce the sensitivity of the optical lens 100, and simultaneously can also have a larger imaging surface to match with a photosensitive chip with higher pixels.

The optical lens, the camera module and the electronic device disclosed in the embodiments of the present invention are described in detail, and specific examples are applied to the description of the principles and the implementation modes of the present invention, and the description of the above embodiments is only used to help understand the optical lens, the camera module, the electronic device and the core ideas thereof; meanwhile, as those skilled in the art will vary in the specific embodiments and application scope according to the idea of the present invention, the present disclosure should not be construed as limiting the present invention in summary.

Claims

1. An optical lens, characterized in that the optical lens has eight lens elements with refractive power, and the eight lens elements include 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 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 and a concave image-side surface at a paraxial region;

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

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

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

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

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

the seventh lens element with positive refractive power has a convex object-side surface at a paraxial region, a concave image-side surface at a paraxial region, and at least one inflection point is disposed on each of the object-side surface and the image-side surface of the seventh lens element;

The eighth lens element with negative refractive power has a convex object-side surface at a paraxial region, a concave image-side surface at a paraxial region, and at least one inflection point is disposed on each of the object-side surface and the image-side surface of the eighth lens element;

the optical lens satisfies the following relation:

1< TTL/ImgH <1.12,1.508 +.fno/tan (HFOV) <2,1< f1/f +.1.53, and-2.04 +.r81/f8 < -0.5;

wherein TTL is a distance from an object side surface of the first lens element to an imaging surface of the optical lens element on the optical axis, imgH is a radius of a maximum effective imaging circle of the optical lens element, FNO is an f-number of the optical lens element, HFOV is a half of a maximum field angle of the optical lens element, f1 is a focal length of the first lens element, f is an effective focal length of the optical lens element, r81 is a radius of curvature of the object side surface of the eighth lens element at the optical axis, and f8 is a focal length of the eighth lens element.

2. The optical lens of claim 1, wherein the optical lens satisfies the following relationship:

1.5<r72/f7<5.5；

wherein f7 is the focal length of the seventh lens; r72 is the radius of curvature of the image side surface of the seventh lens at the optical axis.

3. The optical lens of claim 1, wherein the optical lens satisfies the following relationship:

1<r31/r22<5.5；

Wherein r31 is a radius of curvature of the object side surface of the third lens at the optical axis; r22 is the radius of curvature of the image side surface of the second lens at the optical axis.

4. The optical lens of claim 1, wherein the optical lens satisfies the following relationship:

at14/TTL≤0.11；

wherein at14 is the sum of air gaps of the first lens to the fifth lens on the optical axis.

5. The optical lens of claim 1, wherein the optical lens satisfies the following relationship:

sd82/ct8<8.9；

wherein sd82 is the maximum effective half-caliber of the image side surface of the eighth lens, and ct8 is the thickness of the eighth lens on the optical axis.

6. An imaging module, wherein the imaging module comprises a photosensitive chip and the optical lens according to any one of claims 1 to 5, and the photosensitive chip is disposed on an image side of the optical lens.

7. An electronic device, comprising a housing and the camera module of claim 6, wherein the camera module is disposed on the housing.