CN116088148A

CN116088148A - Optical lens

Info

Publication number: CN116088148A
Application number: CN202310062537.XA
Authority: CN
Inventors: 谢雨辰; 庄林凡; 章彬炜
Original assignee: Jiangxi Lianyi Optics Co Ltd
Current assignee: Jiangxi Lianyi Optics Co Ltd
Priority date: 2023-01-16
Filing date: 2023-01-16
Publication date: 2023-05-09

Abstract

The invention discloses an optical lens, which sequentially comprises from an object side to an imaging surface along an optical axis: a diaphragm; the first lens with positive focal power has a convex object side surface and a concave image side surface; a second lens with negative focal power, wherein the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; a third lens element with positive refractive power having a convex object-side surface at a paraxial region and a convex image-side surface; a fourth lens with negative focal power, the object side surface of which is a concave surface; a fifth lens with positive focal power, wherein an object side surface of the fifth lens is a concave surface, and an image side surface of the fifth lens is a convex surface; a sixth lens element with positive refractive power having a convex object-side surface at a paraxial region and a convex image-side surface; the seventh lens element with negative optical power has a concave object-side surface at a paraxial region and a concave image-side surface at a paraxial region. The optical lens provided by the invention has the advantages of large aperture, large image height, short total length and high resolution quality by reasonably matching the focal power and the surface type combination of each lens.

Description

Optical lens

Technical Field

The invention relates to the technical field of imaging lenses, in particular to an optical lens.

Background

Currently, with the popularity of portable electronic devices (such as smartphones and cameras), and the popularity of social, video and live broadcast software, people have a higher and higher preference for photography, and optical lenses have become the standard of portable electronic devices, and even have become the primary index considered when consumers purchase portable electronic devices.

With the continuous development of mobile information technology, the requirements of consumers on imaging quality of mobile electronic products such as smart phones are higher, the application range is wider, the total length of the lens is required, the design of a large aperture is required to improve the luminous flux, and the imaging area is required to be larger to increase the number of pixels of the camera. Therefore, it is necessary to design an optical lens having a total length, a large aperture, a large image height and a good imaging quality.

Disclosure of Invention

Based on the above, the present invention aims to provide an optical lens having advantages of short total length, large aperture, large image height, high resolution quality, etc.

The embodiment of the invention realizes the aim through the following technical scheme.

The invention provides an optical lens, which sequentially comprises from an object side to an imaging surface along an optical axis: a diaphragm; a first lens with positive focal power, wherein the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; a second lens with negative focal power, wherein the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; a third lens element with positive refractive power, wherein the object-side surface of the third lens element is convex at a paraxial region, and the image-side surface of the third lens element is convex; a fourth lens with negative focal power, wherein the object side surface of the fourth lens is a concave surface; a fifth lens with positive focal power, wherein an object side surface of the fifth lens is a concave surface, and an image side surface of the fifth lens is a convex surface; a sixth lens element with positive refractive power having a convex object-side surface at a paraxial region and a convex image-side surface; a seventh lens having negative optical power, an object-side surface of the seventh lens being concave at a paraxial region, an image-side surface of the seventh lens being concave at a paraxial region; the optical lens satisfies the following conditional expression:

wherein ,/>

Representing the optical power of the object side of the sixth lens,>

representing the optical power of the image side of the sixth lens.

According to the optical lens provided by the invention, through reasonably matching the lens shape and focal power combination among seven lenses with specific refractive power, the structure is more compact while the high pixel and the large image height are met, the imaging requirement of a darker environment is met, the miniaturization of the lens and the balance of the high pixel are better realized, and the image capturing experience of a user can be effectively improved.

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

fig. 1 is a schematic structural diagram of an optical lens according to a first embodiment of the present invention;

FIG. 2 is a graph of axial chromatic aberration of an optical lens according to a first embodiment of the present invention, wherein the horizontal axis represents axial chromatic aberration values (in mm) and the vertical axis represents normalized pupil values;

FIG. 3 is a graph showing optical distortion of an optical lens according to a first embodiment of the present invention, wherein the horizontal axis represents the distortion percentage and the vertical axis represents the angle of view (in degrees);

FIG. 4 is a graph showing a vertical chromatic aberration of an optical lens according to a first embodiment of the present invention, wherein a horizontal axis represents a vertical chromatic aberration value (unit: micrometers) and a vertical axis represents a viewing angle (unit: degrees);

fig. 5 is a schematic structural diagram of an optical lens according to a second embodiment of the present invention;

FIG. 6 is a graph showing axial chromatic aberration of an optical lens according to a second embodiment of the present invention;

FIG. 7 is a graph showing optical distortion of an optical lens according to a second embodiment of the present invention;

FIG. 8 is a graph of a vertical axis chromatic aberration curve of an optical lens according to a second embodiment of the present invention;

fig. 9 is a schematic structural diagram of an optical lens according to a third embodiment of the present invention;

fig. 10 is an axial chromatic aberration chart of an optical lens according to a third embodiment of the present invention:

FIG. 11 is a graph showing optical distortion of an optical lens according to a third embodiment of the present invention;

FIG. 12 is a graph of the vertical chromatic aberration of an optical lens according to a third embodiment of the present invention;

fig. 13 is a schematic structural diagram of an optical lens according to a fourth embodiment of the present invention;

fig. 14 is an axial chromatic aberration chart of an optical lens according to a fourth embodiment of the present invention:

FIG. 15 is a graph showing optical distortion of an optical lens according to a fourth embodiment of the present invention;

fig. 16 is a graph showing a vertical axis chromatic aberration curve of an optical lens according to a fourth embodiment of the present invention.

Detailed Description

In order that the objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Several embodiments of the invention are presented in the figures. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Like reference numerals refer to like elements throughout the specification.

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

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

The invention provides an optical lens, which sequentially comprises from an object side to an imaging surface along an optical axis: a diaphragm, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and plate glass;

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

The second lens has negative focal power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface.

The third lens has positive focal power, the object side surface of the third lens is convex at the paraxial region, and the image side surface of the third lens is convex.

The fourth lens has negative focal power, and the object side surface of the fourth lens is a concave surface.

The fifth lens has positive focal power, the object side surface of the fifth lens is concave, and the image side surface of the fifth lens is convex.

The sixth lens element has positive refractive power, wherein an object-side surface of the sixth lens element is convex at a paraxial region thereof, and an image-side surface of the sixth lens element is convex.

The seventh lens has negative focal power, an object side surface of the seventh lens is concave at a paraxial region, and an image side surface of the seventh lens is concave at the paraxial region.

Further, the optical lens satisfies the following conditional expression:

wherein ,

representing the optical power of the object side of the sixth lens,/>

Representing the optical power of the image side of the sixth lens. Meets the above range by reasonably distributing +.>

The optical lens has larger image height, larger aperture and higher imaging quality.

In some embodiments, the optical lens satisfies the following conditional expression:

2<f3/f<4；

wherein f3 represents the focal length of the third lens, and f represents the effective focal length of the optical lens. The range is satisfied, so that the third lens has proper positive focal power, the deflection degree of off-axis vision field rays in the third lens is reduced, the aberration of off-axis vision field is corrected, and the resolution quality of the optical lens is improved.

-12<f4/f<-7；

-2<f4/f5<-0.1；

wherein f4 represents a focal length of the fourth lens, f5 represents a focal length of the fifth lens, and f represents an effective focal length of the optical lens. The above range is satisfied, which is beneficial to correcting field curvature and improving the resolution quality of the optical lens.

5<f5/f<100；

wherein f5 represents a focal length of the fifth lens, and f represents an effective focal length of the optical lens. The range is satisfied, so that the fifth lens has proper positive focal power, the aberration of the system can be better corrected, and the resolution quality of the optical lens is improved.

0.8<f6/f<1.25；

where f6 denotes a focal length of the sixth lens, and f denotes an effective focal length of the optical lens. The above range is satisfied, so that the sixth lens element has a proper positive refractive power, which is advantageous for correcting spherical aberration and improving the resolution quality of the optical lens element.

-0.8<f7/f<-0.5；

-0.7<f7/f6<-0.4；

wherein f6 denotes a focal length of the sixth lens, f7 denotes a focal length of the seventh lens, and f denotes an effective focal length of the optical lens. The optical lens system meets the range, and is favorable for correcting the advanced aberration of the optical lens by reasonably matching the focal length proportion of the sixth lens and the seventh lens, so that the optical system has higher imaging quality of pixels.

-0.1<R31/R32<0；

-50<R32/f<-20；

wherein R31 represents a radius of curvature of an object side surface of the third lens, R32 represents a radius of curvature of an image side surface of the third lens, and f represents an effective focal length of the optical lens. The range is satisfied, the third lens adopts the biconvex positive lens, the tortuosity of light entering the third lens can be slowed down, the optical distortion of the optical lens can be corrected, and the integral imaging quality is improved.

-0.8<R61/R62<-0.2；

0.5<R61/f<1.2；

wherein R61 represents a radius of curvature of an object side surface of the sixth lens, R62 represents a radius of curvature of an image side surface of the sixth lens, and f represents an effective focal length of the optical lens. The object side surface and the image side surface of the sixth lens are reasonably controlled to meet the range, so that larger image height can be obtained, field curvature correction of an off-axis visual field can be facilitated, and imaging quality of an optical system can be improved.

0.14<BFL/TTL<0.16；

where BFL denotes a distance on the optical axis from the image side surface to the imaging surface of the seventh lens. The rear focal length of the optical system is reasonably distributed, so that the length of the optical system is reduced, meanwhile, the mounting interference between the lens and the chip is reduced, and the assembly yield is improved.

10mm<(f×IH)/f1<11.5mm；

wherein f represents the effective focal length of the optical lens, IH represents the real image height corresponding to the maximum field angle of the optical lens, and f1 represents the focal length of the first lens. Satisfying the above range, by reasonably controlling the value of (f×ih)/f 1, a larger imaging surface is facilitated, which means that a higher image resolution may be provided, so that the lens may match with a chip of a higher pixel, and an imaging effect of a high pixel is achieved.

Further, the optical lens satisfies the following conditional expression:

1.9<IH/f<2.1；

IH represents the real image height corresponding to the maximum field angle of the optical lens, and f represents the effective focal length of the optical lens. The range is satisfied, the IH/f value is reasonably controlled, the imaging surface of the lens is increased, the total length of the lens is shortened, and the miniaturization of the lens and the balance of a large image surface are realized.

0.21<CT1/∑CT<0.26；

0.06<CT12/CTb<0.11；

wherein, CT1 represents the center thickness of the first lens on the optical axis, ΣCT represents the sum of the center thicknesses of all lenses in the optical lens on the optical axis, CT12 represents the interval distance between the first lens and the second lens on the optical axis, and CTb represents the sum of the air interval distances of the seven lenses on the optical axis. The distribution of each lens can be more compact by reasonably distributing the ratio of the center thickness of the first lens to the center thickness of all lenses and the ratio of the first lens to the second lens to the space between all lenses, which is beneficial to shortening the total length of the lens and realizing the miniaturization of the lens.

1.6<IH/TTL<1.7；

0.52<∑CT/TTL<0.58；

wherein IH represents the real image height corresponding to the maximum field angle of the optical lens, ΣCT represents the sum of the thicknesses of the centers of all lenses in the optical lens on the optical axis, and TTL represents the total optical length of the optical lens. The above range is satisfied, and the ratio of the image height to the total length is reasonably distributed, so that the ratio of the central thicknesses of all lenses in the total length is favorable for shortening the total length of the lens while ensuring high imaging quality, and the miniaturization of the lens is realized.

0.25<R11/R12<0.35；

0.63<SAG11/(CT1+SAG12)<0.68；

wherein R11 represents a radius of curvature of an object side surface of the first lens, R12 represents a radius of curvature of an image side surface of the first lens, SAG11 represents a sagittal height of the object side surface of the first lens, SAG12 represents a sagittal height of the image side surface of the first lens, and CT1 represents a center thickness of the first lens on an optical axis. The range is satisfied, the surface curvature and the sagittal height of the first lens are reasonably controlled, the diameter of the entrance pupil is favorably increased, the f-number of the optical system is increased, and the large aperture performance is realized.

2<R21/R22<2.5；

wherein R21 represents a radius of curvature of the object side surface of the second lens, and R22 represents a radius of curvature of the image side surface of the second lens. The spherical aberration correction device meets the above range, is beneficial to smooth light passing through the second lens by reasonably controlling the surface shape of the second lens, corrects spherical aberration generated by excessive turning of the light through the first lens, and is beneficial to improving the imaging quality of an optical system.

0.8<R51/R52<1.3；

1.15<SAG52/SAG51<1.4；

wherein R51 represents a radius of curvature of the object side surface of the fifth lens, R52 represents a radius of curvature of the image side surface of the fifth lens, SAG51 represents a sagittal height of the object side surface of the fifth lens, and SAG52 represents a sagittal height of the image side surface of the fifth lens. The range is satisfied, the focal power of the fifth lens is reduced by reasonably controlling the surface curvature and the sagittal height of the fifth lens, so that light can smoothly pass through the fifth lens, and meanwhile, the aberration of each view field is corrected, so that the imaging quality of an optical system is improved.

wherein ,

representing the optical power of the first lens, +.>

Representing the optical power of the second lens, +.>

Representing the optical power of the third lens, +.>

Representing the optical power of the fourth lens. Meets the above range by reasonably controlling the front four lensesThe focal power relation is favorable for increasing the focal length of the system, increasing the imaging area of the optical system and matching the chip with larger pixels.

F#<1.8；

wherein f# represents the F-number of the optical lens. The aperture of the system can be increased by meeting the range, the light entering quantity of the system is increased, and the sharpness of a shot picture is improved.

In some embodiments, the image side of the fourth lens is concave at the optical axis. In other embodiments, the image side of the fourth lens is convex at the optical axis. The image side surface of the fourth lens adopts different surface type collocations, so that the system can realize good imaging effect.

In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens each employ an aspherical lens. By adopting the aspheric lens, aberration can be effectively corrected, imaging quality is improved, and an optical performance product with higher cost performance is provided.

The invention is further illustrated in the following examples. In various embodiments, the thickness, radius of curvature, and material selection portion of each lens in the optical lens may vary, and for specific differences, reference may be made to the parameter tables of the various embodiments. The following examples are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following examples, and any other changes, substitutions, combinations or simplifications that do not depart from the gist of the present invention are intended to be equivalent substitutes within the scope of the present invention.

In various embodiments of the present invention, when an aspherical lens is used as the lens, the surface shape of the aspherical lens satisfies the following equation:

where z is the distance sagittal height from the aspherical surface vertex when the aspherical surface is at a position of height h in the optical axis direction, c is the paraxial curvature of the surface, k is the conic coefficient conic, and A2i is the aspherical surface type coefficient of the 2 i-th order.

First embodiment

Referring to fig. 1, a schematic structural diagram of an optical lens 100 according to a first embodiment of the present invention is shown, where the optical lens 100 includes, in order from an object side to an imaging surface S17 along an optical axis: stop ST, first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, sixth lens L6, seventh lens L7, and plate glass G1.

The first lens element L1 has positive refractive power, wherein an object-side surface S1 of the first lens element is convex, and an image-side surface S2 of the first lens element is concave;

the second lens L2 has negative focal power, the object side surface S3 of the second lens is a convex surface, and the image side surface S4 of the second lens is a concave surface;

the third lens element L3 with positive refractive power has a convex object-side surface S5 at a paraxial region and a convex image-side surface S6;

the fourth lens element L4 has negative refractive power, wherein an object-side surface S7 of the fourth lens element is concave, and an image-side surface S8 of the fourth lens element is concave at a paraxial region;

the fifth lens element L5 has positive refractive power, wherein an object-side surface S9 of the fifth lens element is concave, and an image-side surface S10 of the fifth lens element is convex;

the sixth lens element L6 with positive refractive power has a convex object-side surface S11 at a paraxial region and a convex image-side surface S12 at a paraxial region;

the seventh lens L7 has negative focal power, the object-side surface S13 of the seventh lens is concave at a paraxial region, and the image-side surface S14 of the seventh lens is concave at a paraxial region;

the object side surface of the plate glass G1 is S15, and the image side surface is S16.

The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all plastic aspheric lenses.

The relevant parameters of each lens in the optical lens 100 according to the first embodiment of the present invention are shown in table 1.

TABLE 1

The surface profile coefficients of the aspherical surfaces of the optical lens 100 in this embodiment are shown in table 2.

TABLE 2

In the present embodiment, graphs of axial chromatic aberration, optical distortion, and vertical chromatic aberration of the optical lens 100 are shown in fig. 2, 3, and 4, respectively.

Fig. 2 shows an axial chromatic aberration curve of the optical lens 100 in this embodiment, which represents aberrations of different wavelengths in the optical axis direction, and it can be seen from the figure that the axial chromatic aberration of different wavelengths is controlled within ±0.035mm, which indicates that the axial chromatic aberration of the optical lens 100 is well corrected.

Fig. 3 shows an optical F-Tan (θ) distortion curve of the optical lens 100 of the present embodiment, which represents distortions at different image heights on the imaging plane, and it can be seen from the figure that the optical distortion is controlled within 2%, which indicates that the distortion of the optical lens 100 is well corrected.

Fig. 4 shows a paraxial color difference curve of the optical lens 100 of the present embodiment, which represents the paraxial color difference value between the light with different wavelengths and the dominant wavelength, and it can be seen from the figure that the paraxial color difference value of different wavelengths is within ±2 μm, which indicates that the paraxial color difference of the optical lens 100 is well corrected.

Second embodiment

Referring to fig. 5, a schematic structural diagram of an optical lens 200 according to a second embodiment of the present invention is shown, and the optical lens 200 according to the present embodiment is substantially the same as the first embodiment, and the main differences are that: the image side surface S8 of the fourth lens element is convex at a paraxial region, and the curvature radius, lens thickness, pitch, and the like of each lens element are different.

The relevant parameters of each lens in the optical lens 200 according to the second embodiment of the present invention are shown in table 3.

TABLE 3 Table 3

The surface profile coefficients of the aspherical surfaces of the optical lens 200 in this embodiment are shown in table 4.

TABLE 4 Table 4

In the present embodiment, graphs of axial chromatic aberration, optical distortion, and vertical chromatic aberration of the optical lens 200 are shown in fig. 6, 7, and 8, respectively. It can be seen from fig. 6 that the axial chromatic aberration of all wavelengths is controlled within ±0.04mm, indicating that the axial chromatic aberration of the optical lens 200 is well corrected. As can be seen from fig. 7, the optical distortion is controlled to be within 2%, which means that the distortion of the optical lens 200 is well corrected. As can be seen from fig. 8, the vertical chromatic aberration of each wavelength is within ±2 μm, indicating that the vertical chromatic aberration of the optical lens 200 is well corrected.

Third embodiment

Referring to fig. 9, a schematic diagram of an optical lens 300 according to a third embodiment of the present invention is shown, and the optical lens 300 of the present embodiment is substantially the same as the first embodiment described above, and the difference is mainly that the radius of curvature, the lens thickness, the pitch, etc. of each lens surface are different.

The relevant parameters of each lens in the optical lens 300 according to the third embodiment of the present invention are shown in table 5.

TABLE 5

The surface profile coefficients of the aspherical surfaces of the optical lens 300 in this embodiment are shown in table 6.

TABLE 6

In the present embodiment, graphs of axial chromatic aberration, optical distortion, and vertical chromatic aberration of the optical lens 300 are shown in fig. 10, 11, and 12, respectively. As can be seen from fig. 10, the axial chromatic aberration of all wavelengths is controlled within ±0.035mm, which indicates that the axial chromatic aberration of the optical lens 300 is well corrected. As can be seen from fig. 11, the optical distortion is controlled to be within 2.0%, which means that the distortion of the optical lens 300 is well corrected. As can be seen from fig. 12, the vertical chromatic aberration of each wavelength is within ±2 μm, indicating that the vertical chromatic aberration of the optical lens 300 is well corrected.

Fourth embodiment

Referring to fig. 13, a schematic diagram of an optical lens 400 according to a fourth embodiment of the present invention is shown, and the optical lens 400 according to the present embodiment is substantially the same as the first embodiment described above, and is mainly different in the radius of curvature, lens thickness, pitch, etc. of each lens surface.

The parameters related to each lens in the optical lens 400 according to the fourth embodiment of the present invention are shown in table 7.

TABLE 7

The surface profile coefficients of the aspherical surfaces of the optical lens 400 in this embodiment are shown in table 8.

TABLE 8

In the present embodiment, graphs of axial chromatic aberration, optical distortion, and vertical chromatic aberration of the optical lens 400 are shown in fig. 14, 15, and 16, respectively. It can be seen from fig. 14 that the axial chromatic aberration of all wavelengths is controlled within ±0.06mm, indicating that the axial chromatic aberration of the optical lens 400 is well corrected. As can be seen from fig. 15, the optical distortion is controlled to be within 2%, which means that the distortion of the optical lens 400 is well corrected. As can be seen from fig. 16, the vertical chromatic aberration of each wavelength is within ±2 μm, indicating that the vertical chromatic aberration of the optical lens 400 is well corrected.

Table 9 is an optical characteristic corresponding to the above four embodiments, and mainly includes an effective focal length F, an f#, an optical total length TTL, a maximum field angle 2θ, and a corresponding image height IH of the system, and a numerical value corresponding to each of the above conditional expressions.

TABLE 9

In summary, the optical lens provided by the invention adopts seven lenses with specific focal power, and the lens has a compact structure through specific surface shape collocation and reasonable focal power distribution, so that the miniaturization of the lens is realized; meanwhile, the lens also has a larger aperture, so that the imaging requirement of a bright and dark environment is met; the image height of the lens reaches more than 10.7mm, so that the requirements of a large image plane and high pixels are met, and the lens can be matched with a 1/1.56 inch CMOS chip for clear imaging; therefore, the optical lens provided by the invention has the advantages of large aperture, large image height, short total length and high resolution quality.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above examples merely represent a few embodiments of the present invention, which are described in more detail and are not to be construed as limiting the scope of the present invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of the invention should be assessed as that of the appended claims.

Claims

1. An optical lens comprising, in order from an object side to an image side along an optical axis:

a diaphragm;

a first lens with positive focal power, wherein the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface;

a second lens with negative focal power, wherein the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface;

a third lens element with positive refractive power, wherein the object-side surface of the third lens element is convex at a paraxial region, and the image-side surface of the third lens element is convex;

a fourth lens with negative focal power, wherein the object side surface of the fourth lens is a concave surface;

a fifth lens with positive focal power, wherein an object side surface of the fifth lens is a concave surface, and an image side surface of the fifth lens is a convex surface;

a sixth lens element with positive refractive power having a convex object-side surface at a paraxial region and a convex image-side surface;

a seventh lens having negative optical power, an object-side surface of the seventh lens being concave at a paraxial region, an image-side surface of the seventh lens being concave at a paraxial region;

the optical lens satisfies the following conditional expression:

wherein ,

representing the optical power of the object side of the sixth lens,>

representing the optical power of the image side of the sixth lens.

2. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

2<f3/f<4；

wherein f3 represents the focal length of the third lens, and f represents the effective focal length of the optical lens.

3. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

-12<f4/f<-7；

-2<f4/f5<-0.1；

wherein f4 represents a focal length of the fourth lens, f5 represents a focal length of the fifth lens, and f represents an effective focal length of the optical lens.

4. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

5<f5/f<100；

wherein f5 represents a focal length of the fifth lens, and f represents an effective focal length of the optical lens.

5. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

0.8<f6/f<1.25；

where f6 denotes a focal length of the sixth lens, and f denotes an effective focal length of the optical lens.

6. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

-0.8<f7/f<-0.5；

-0.7<f7/f6<-0.4；

wherein f6 denotes a focal length of the sixth lens, f7 denotes a focal length of the seventh lens, and f denotes an effective focal length of the optical lens.

7. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

-0.1<R31/R32<0；

-50<R32/f<-20；

wherein R31 represents a radius of curvature of an object side surface of the third lens, R32 represents a radius of curvature of an image side surface of the third lens, and f represents an effective focal length of the optical lens.

8. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

-0.8<R61/R62<-0.2；

0.5<R61/f<1.2；

wherein R61 represents a radius of curvature of an object side surface of the sixth lens, R62 represents a radius of curvature of an image side surface of the sixth lens, and f represents an effective focal length of the optical lens.

9. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

0.14<BFL/TTL<0.16；

wherein BFL represents the distance between the image side surface of the seventh lens and the imaging surface on the optical axis, and TTL represents the total optical length of the optical lens.

10. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

10mm<(f×IH)/f1<11.5mm；

wherein f represents the effective focal length of the optical lens, IH represents the real image height corresponding to the maximum field angle of the optical lens, and f1 represents the focal length of the first lens.

11. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

1.9<IH/f<2.1；

wherein IH represents the real image height corresponding to the maximum field angle of the optical lens, and f represents the effective focal length of the optical lens.