CN114002818B

CN114002818B - Optical system, camera module and electronic equipment

Info

Publication number: CN114002818B
Application number: CN202111346790.5A
Authority: CN
Inventors: 乐宇明; 兰宾利; 朱志鹏
Original assignee: Jiangxi Jingchao Optical Co Ltd
Current assignee: Jiangxi Jingchao Optical Co Ltd
Priority date: 2021-11-15
Filing date: 2021-11-15
Publication date: 2023-09-05
Anticipated expiration: 2041-11-15
Also published as: CN114002818A

Abstract

The invention relates to an optical system, an imaging module and electronic equipment. The optical system sequentially comprises from an object side to an image side along an optical axis: the first lens element with negative refractive power has a convex object-side surface and a concave image-side surface; the second lens element with negative refractive power has a convex object-side surface and a concave image-side surface; the third lens element with negative refractive power has a concave object-side surface and a concave image-side surface; the fourth lens element with positive refractive power has a convex object-side surface and a convex image-side surface; a diaphragm; the fifth lens element with positive refractive power has a convex object-side surface and a convex image-side surface; the object side surface and the image side surface of the sixth lens element with negative refractive power are concave; the seventh lens element with positive refractive power has a convex object-side surface and a convex image-side surface; and satisfies the following: 8.50mm < TTL/FNO < 10.50mm, TTL is the distance between the object side surface of the first lens and the imaging surface of the optical system on the optical axis, FNO is the f-number of the optical system. The optical design ensures the aperture of the diaphragm and simultaneously realizes wide-angle shooting.

Description

Optical system, camera module and electronic equipment

Technical Field

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

Background

With the continuous improvement of national requirements on road traffic safety and automobile safety, the effect of the looking-around camera in the vehicle is more and more remarkable, and the camera is continuously applied to an automobile auxiliary driving system. The camera is looked around, through the rational distribution of a plurality of optical systems in the automobile body, the aerial view picture of car top each direction is spliced together, makes the driver see the picture around the car clearly, can effectively avoid backing a car and roll, scratch the emergence of accidents such as bumper and wheel hub, simultaneously the camera can also discern parking passageway sign, curb and nearby vehicle, has guaranteed the travelling safety of car greatly.

However, the conventional vehicle-mounted annular lens has the defects of low illumination and the like because the aperture of the lens is small and the light entering amount of the lens is insufficient, and the problems of insufficient field angle and the like of the conventional vehicle-mounted annular lens.

Disclosure of Invention

Accordingly, it is necessary to provide an optical system, an imaging module, and an electronic apparatus for solving the problems of a small aperture of a photographing diaphragm and insufficient angle of view.

An optical system comprising, in order from an object side to an image side along an optical axis:

a first lens element with negative refractive power having a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region;

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

a third lens element with negative refractive power having a concave object-side surface and a concave image-side surface at a paraxial region;

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

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

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

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

and a diaphragm is arranged between the fourth lens and the fifth lens.

In the above optical design, the object side surface of the first lens element with negative refractive power is convex, and the image side surface of the first lens element with negative refractive power is concave, so that light rays are incident into the first lens element with a larger angle, the field angle of the optical system is increased, the shooting range of the optical system is effectively enlarged, and the design requirement of wide angle of the optical system is met; the object side surface of the second lens with negative refractive power is set to be a convex surface, and the image side surface of the second lens with negative refractive power is set to be a concave surface, so that light rays transmitted from the first lens can be incident to the second lens at a larger angle, the second lens can be ensured to reasonably receive the light rays, and the light rays smoothly transition in the second lens, thereby being beneficial to reducing edge aberration and reducing ghost image risks; the object side surface and the image side surface of the third lens with negative refractive power are both concave surfaces, so that the third lens can effectively receive light rays transmitted from the first lens and the second lens in sequence, and the field curvature astigmatism of the optical system is reduced; the object side surface and the image side surface of the fourth lens with positive refractive power are both convex, so that the positive refractive power of the fourth lens can be reasonably matched with the negative refractive powers of the first lens and the third lens, the positive refractive powers of the first lens and the third lens can be reasonably configured, the incidence angle of light rays entering an optical system is increased, the field angle is increased, in addition, the light rays can be better converged at a diaphragm by the fourth lens, the optical system is ensured to have a proper aperture, the phenomenon that the aperture of the aperture is too small is avoided, the light entering amount of the optical system is improved, the relative illuminance of the imaging surface is increased, and the brightness is improved; the object side surface and the image side surface of the fifth lens element with positive refractive power are both convex, so that the light quantity of the light rays of the rear lens group (namely the lens group formed by the fifth lens element and the seventh lens element) positioned on the image side of the diaphragm can be controlled to a certain extent, the relative illumination of the imaging surface is increased, and the brightness is improved; the object side surface and the image side surface of the sixth lens with negative refractive power are set to be concave surfaces, so that the negative refractive power of the sixth lens and the positive refractive power of the fifth lens are reasonably matched, chromatic aberration and tolerance sensitivity of an optical system are reduced, and imaging quality is improved; the object side surface and the image side surface of the seventh lens with positive refractive power are both convex, so that off-axis aberration generated by the optical system can be corrected, and the optical system can have enough back focal length, so that the relative illuminance of the imaging surface is improved, and the imaging quality is further optimized.

And the optical system satisfies the following conditional expression:

8.50mm＜TTL/FNO＜10.50mm；

wherein TTL is the distance between the object side surface of the first lens and the imaging surface of the optical system on the optical axis (i.e. the total optical length), and FNO is the f-number of the optical system.

When the above conditional expression is satisfied, the ratio relation between the total optical length of the optical system and the aperture number of the optical system is reasonably controlled, so that the aperture of the optical system is enlarged, and a large aperture effect is realized; the TTL/FNO is more than or equal to 10.50mm, so that the total optical length of the optical system is increased, which is not beneficial to the miniaturization design of the optical system and the production; TTL/FNO is less than or equal to 8.50mm, the aperture number of the aperture of the optical system is easily caused to be too large, the aperture of the optical system is reduced, the light incoming quantity is insufficient, the relative illuminance is reduced, the imaging quality is affected, and the imaging of a large aperture is not facilitated.

In one embodiment, the image side surface of the fifth lens element abuts against the object side surface of the sixth lens element, which is favorable for reducing chromatic aberration of the optical system and correcting spherical aberration of the optical system, so that resolution of shooting and imaging of the optical system is improved, and imaging quality is better improved.

In one embodiment, the optical system further satisfies the following conditional expression:

2.00＜CT4/EPD＜3.50；

Wherein CT4 is the thickness of the fourth lens on the optical axis, EPD is the entrance pupil diameter of the optical system.

When the above conditional expression is satisfied, the aperture number of the optical system can be improved by reasonably controlling the ratio of the thickness of the fourth lens on the optical axis to the entrance pupil diameter of the optical system, which is beneficial to increasing the picture feel of the optical system, enhancing the presentation capability of details and obtaining a clear image.

5.00＜Rs1/SAGs1＜7.00；

wherein Rs1 is the radius of curvature of the object side surface of the first lens on the optical axis, and sag 1 is the sagittal height of the object side surface of the first lens (i.e. the distance from the intersection point of the object side surface of the first lens and the optical axis to the maximum effective caliber of the object side surface of the first lens in the direction of the optical axis).

When the above conditional expression is satisfied, by controlling the radius of curvature of the object side surface of the first lens and the sagittal height thereof, the first lens is ensured to provide proper negative refractive power for the optical system, and meanwhile, the first lens is also beneficial to controlling the first lens to have enough maximum effective caliber, so that the first lens is beneficial to grabbing light rays entering the optical system at a larger angle, thereby enlarging the shooting range of the optical system and increasing the angle of view; rs1/SAGs1 is larger than or equal to 7.00, the sagittal height of the object side surface of the first lens is too small, or the radius of curvature of the object side surface of the first lens is too large, so that the refractive power of the first lens is too small, and the increase of the angle of view is not facilitated; rs1/SAGs1 is less than or equal to 5.00, the sagittal height of the object side surface of the first lens is too large, so that the first lens is too bent and unfavorable for production, and the curvature radius of the object side surface of the first lens is too small, so that ghost images are easy to generate, the risk of the ghost images is increased, larger aberration is generated, and the imaging quality is reduced.

1.00＜CT4/f4＜2.00；

wherein CT4 is the thickness of the fourth lens on the optical axis, and f4 is the effective focal length of the fourth lens.

When the above conditional expression is satisfied, the positive refractive power of the fourth lens can be reasonably configured, so that the deflection angle of light rays in the optical system at the fourth lens can be effectively controlled, the sensitivity of the optical system is further reduced, and the resolution of shooting and imaging is improved; when CT4/f4 is more than or equal to 2.00, the focal length of the fourth lens is reduced, and the positive refractive power provided for the optical system is overlarge, so that the deflection angle of light rays in the optical system at the fourth lens is overlarge; when CT4/f4 is less than or equal to 1.00, the thickness of the fourth lens on the optical axis becomes smaller, so that the deflection angle of marginal rays at the fourth lens is too small, which is unfavorable for correcting the aberration of the optical system, and further the imaging quality of the optical system is reduced.

135.00°/mm＜FOV/f＜155.00°/mm；

wherein FOV is the maximum field angle of the optical system and f is the effective focal length of the optical system.

When the conditional expression is satisfied, the ratio relation of the maximum field angle of the optical system to the effective focal length is controlled, so that the larger field angle is obtained, the development of the optical system to the wide angle direction is facilitated, the deflection angle of emergent light rays can be reduced, the sensitivity of the optical system is reduced, the aberration of the optical system is effectively corrected, and the imaging quality is improved; when the FOV/f is more than or equal to 135.00 degrees/mm, the effective focal length of the optical system is too small, the tolerance sensitivity of the optical system is enhanced, the deflection angle of emergent light rays is not reduced, and the problem of dark angles of edges of the optical system is caused; when the FOV/f is 155.00 °/mm or less, the maximum field angle of the optical system is reduced, and details of the object cannot be captured at a large angle well, making it difficult to achieve a wide angle.

1.50＜SD2/SAGs3＜3.50；

wherein SD2 is half of the maximum effective caliber (i.e. the maximum effective half caliber) of the object side surface of the second lens, and sag 3 is the sagittal height of the object side surface of the second lens (i.e. the distance from the intersection point of the object side surface of the second lens and the optical axis to the maximum effective caliber of the object side surface of the second lens in the optical axis direction).

When the above conditional expression is satisfied, the ratio relation between the maximum effective half caliber of the object side surface of the second lens and the sagittal height of the image side surface of the second lens is controlled, so that the size of the maximum effective half caliber of the object side surface of the second lens can be effectively controlled, and meanwhile, the sagittal height of the image side surface of the second lens is controlled in a matched manner, so that the volume of the second lens can be compressed to a greater degree, the optical total length of an optical system can be shortened, the ghost image risk can be reduced, and the imaging quality is high; when SD2/SAGs3 is more than or equal to 3.50, the maximum effective half caliber of the object side surface of the second lens is not beneficial to shrinking, and the risk of ghost images occurring when light is incident to the second lens is increased; when SD2/SAGs3 is less than or equal to 1.50, the sagittal height of the image side surface of the second lens is too large, so that the volume of the second lens is not easy to compress, and the image side surface of the second lens is too bent, so that the processing difficulty of the second lens is high, and the processing cost is increased.

14°/mm＜CRA/|SAGs14|＜16°/mm；

where CRA is the chief ray incidence angle of the optical system at the maximum field of view, and sag 14 is the sagittal height of the image side surface of the seventh lens element (i.e., the distance from the intersection point of the image side surface of the seventh lens element and the optical axis to the maximum effective caliber of the image side surface thereof in the optical axis direction).

When the above conditional expression is satisfied, the sagittal height of the image side of the seventh lens is controlled, so that the image side of the seventh lens located in front of the imaging plane is not too curved, which is beneficial to the molding of the seventh lens, and the incident angle of the chief ray of the optical system at the maximum field of view is ensured to be large enough to enable more rays to be incident into the imaging plane, thereby increasing the relative illuminance of the imaging plane; when CRA/|SAGs 14|is less than or equal to 14.00 degrees/mm, the absolute value of the sagittal height of the image side surface of the seventh lens is too large, so that the seventh lens is too bent, the processing is not easy, the incidence angle of the chief ray of the optical system at the maximum view field is easy to be smaller, and the relative illumination of the imaging surface is smaller; when CRA/|SAGs 14|is not less than 16.00 degrees/mm, the incidence angle of the chief ray of the optical system at the maximum field of view is larger, and the chief ray is unfavorable for matching with an image sensor.

An image pickup module comprises an image sensor and any one of the optical systems, wherein the image sensor is arranged on the image side of the optical system. By adopting the optical system, the camera module can realize the shooting requirements of large aperture and wide angle.

An electronic device comprises a fixing piece and the camera shooting module, wherein the camera shooting module is arranged on the fixing piece. When the electronic equipment is used for shooting scenes, the shooting requirements of large aperture and wide angle can be realized.

Drawings

Fig. 1 is a schematic structural diagram of an optical system according to a first embodiment of the present application;

FIG. 2 includes a longitudinal spherical aberration, astigmatism and distortion curves of the optical system in the first embodiment;

FIG. 3 is a schematic diagram of an optical system according to a second embodiment of the present application;

FIG. 4 includes longitudinal spherical aberration, astigmatism and distortion plots of the optical system in a second embodiment;

FIG. 5 is a schematic diagram of an optical system according to a third embodiment of the present application;

FIG. 6 includes longitudinal spherical aberration, astigmatism and distortion plots of the optical system in a third embodiment;

fig. 7 is a schematic structural diagram of an optical system according to a fourth embodiment of the present application;

FIG. 8 includes a longitudinal spherical aberration, astigmatism and distortion plots of the optical system in a fourth embodiment;

fig. 9 is a schematic structural view of an optical system according to a fifth embodiment of the present application;

FIG. 10 includes a longitudinal spherical aberration, astigmatism and distortion curves of the optical system in a fifth embodiment;

FIG. 11 is a schematic structural diagram of an image capturing module according to an embodiment of the present application;

fig. 12 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

In the description of the present application, it should be understood that the terms "center," "longitudinal," "transverse," "length," "thickness," "upper," "front," "rear," "axial," "radial," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate description of the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be configured and operated in a particular orientation, and thus should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. 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.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Referring to fig. 1, in an embodiment of the present application, the optical system 10 includes, in order from an object side to an image side along an optical axis 101, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a stop STO, a fifth lens L5, a sixth lens L6, and a seventh lens L7. The lenses in the optical system 10 are coaxially arranged, i.e. the optical axes of the lenses are all on the same line, which may be the optical axis 101 of the optical system 10. Each lens in the optical system 10 is mounted in a lens barrel to be assembled into an imaging lens.

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

The first lens element L1 has an object-side surface S1 and an image-side surface S2, the second lens element L2 has an object-side surface S3 and an image-side surface S4, the third lens element L3 has an object-side surface S5 and an image-side surface S6, the fourth lens element L4 has an object-side surface S7 and an image-side surface S8, the fifth lens element L5 has an object-side surface S9 and an image-side surface S10, the sixth lens element L6 has an object-side surface S11 and an image-side surface S12, and the seventh lens element L7 has an object-side surface S13 and an image-side surface S14. The optical system 10 further has an imaging plane Si located on the image side of the seventh lens L7, and the light from the object on the object plane of the optical system 10 can be condensed on the imaging plane Si after being adjusted by the respective lenses of the optical system 10. In general, the imaging plane Si of the optical system 10 coincides with the photosurface of the image sensor.

In the embodiment of the application, the object-side surface S1 of the first lens element L1 is convex at the paraxial region 101, and the image-side surface is concave at the paraxial region 101; the object side surface S3 of the second lens element L2 is convex at the paraxial region 101, and the image side surface S4 is concave at the paraxial region 101; the object-side surface S5 and the image-side surface S6 of the third lens element L3 are concave at the paraxial region 101; the object-side surface S7 and the image-side surface S8 of the fourth lens element L4 are convex at the paraxial region 101; the object-side surface S9 and the image-side surface S10 of the fifth lens element L5 are convex at the paraxial region 101; the object-side surface S11 and the image-side surface S12 of the sixth lens element L6 are concave at the paraxial region 101; the object-side surface S13 and the image-side surface S14 of the seventh lens element L7 are convex at the paraxial region 101. When describing that the lens surface has a certain profile at the paraxial region, i.e. the lens surface has such a profile near the optical axis 101, the lens surface may have the same profile or an opposite profile in the region near the maximum effective aperture.

The stop STO is an aperture stop, and is disposed between the fourth lens L4 and the fifth lens L5, and is used for limiting the incident light amount of the system, and meanwhile, can also inhibit aberration and stray light to a certain extent. The diaphragm may be a single light-blocking member fitted between the lenses or may be formed by some kind of clamping member that secures the lenses. In some embodiments, the stop STO is located on the object side and remains fixed relative to the imaging plane Si of the system.

By the lens design, the object side surface S1 of the first lens element L1 with negative refractive power is convex, and the image side surface S2 is concave, so that light is incident into the first lens element L1 at a larger angle, thereby increasing the angle of view of the optical system 10, effectively expanding the shooting range of the optical system 10, and realizing the design requirement of wide angle of the optical system 10; the object side surface S3 of the second lens element L2 with negative refractive power is convex, and the image side surface S4 is concave, so that the light transmitted from the first lens element L1 can be incident on the second lens element L2 at a larger angle, and the second lens element L2 can reasonably receive the light; the object-side surface S5 and the image-side surface S6 of the third lens element L3 with negative refractive power are concave, so that the third lens element L3 can effectively receive the light transmitted from the first lens element L1 and the second lens element L2 in sequence, thereby being beneficial to reducing the field curvature astigmatism of the optical system 10; the object side surface S7 and the image side surface S8 of the fourth lens element L4 with positive refractive power are both convex, so that the positive refractive power of the fourth lens element L4 can reasonably cooperate with the negative refractive powers of the first lens element L1 to the third lens element L3, thereby being beneficial to reasonably configuring the negative refractive powers of the first lens element L1 to the third lens element L3, increasing the incident angle of light rays to the optical system 10, increasing the angle of view, and in addition, the fourth lens element L4 can better collect light rays at the stop STO to ensure that the optical system 10 has a proper aperture, avoiding the phenomenon of excessively small aperture of the aperture, being beneficial to improving the light incoming amount of the optical system 10, increasing the relative illuminance of the imaging surface Si and improving the brightness; the object side surface S9 and the image side surface S10 of the fifth lens element L5 with positive refractive power are both convex, so that the light amount of the light beam of the rear lens group (i.e., the lens group formed by the fifth lens element L5 and the seventh lens element L7) positioned at the image side of the stop STO can be controlled to a certain extent, the relative illuminance of the imaging surface Si can be increased, and the brightness can be improved; the object side surface S11 and the image side surface S12 of the sixth lens element L6 with negative refractive power are concave, so that the negative refractive power of the sixth lens element L6 and the positive refractive power of the fifth lens element L5 can be reasonably matched, the chromatic aberration and the tolerance sensitivity of the optical system 10 can be reduced, and the imaging quality can be improved; the object-side surface S13 and the image-side surface S14 of the seventh lens element L7 with positive refractive power are convex, which is beneficial to correcting the off-axis aberration generated by the optical system 10, and is beneficial to enabling the optical system 10 to have a sufficient back focal length, so as to further improve the relative illuminance of the imaging surface Si and further optimize the imaging quality.

In the embodiment of the present application, and the optical system 10 satisfies the conditional expression:

8.50mm＜TTL/FNO＜10.50mm；

wherein TTL is the distance (i.e. the total optical length) between the object side surface S1 of the first lens L1 and the imaging surface Si of the optical system 10 on the optical axis 101, and FNO is the f-number of the optical system 10. For example, in some embodiments, the numerical values of the above conditional expression are specifically: 8.523mm, 8.635mm, 8.671mm, 8.946mm, 9.384mm, 9.388mm, 9.386mm, 9.396mm, 9.426mm or 10.327mm.

When the above conditional expression is satisfied, the ratio relationship between the total optical length of the optical system 10 and the f-number of the optical system 10 is reasonably controlled, which is favorable for enlarging the aperture of the optical system 10 and realizing a large aperture effect; the TTL/FNO is more than or equal to 10.50mm, which leads to the increase of the total optical length of the optical system 10, and is unfavorable for the miniaturization design of the optical system 10 and the production; TTL/FNO is less than or equal to 8.50mm, the aperture number of the aperture of the optical system 10 is easily caused to be too large, the aperture of the optical system 10 is reduced, the light incoming quantity is insufficient, the relative illuminance is reduced, the imaging quality is affected, and the imaging of a large aperture is not facilitated.

Preferably, in some embodiments, the image side surface of the fifth lens element L5 abuts against the object side surface S11 of the sixth lens element L6, which is beneficial to reducing chromatic aberration of the optical system 10 and correcting spherical aberration of the optical system 10, so as to improve resolution of photographing imaging of the optical system 10 and better improve imaging quality.

It should be noted that, in some embodiments, at least one lens in the optical system 10 has an aspherical surface type, and when at least one side surface (object side surface or image side surface) of the lens is aspherical, the lens may be said to have an aspherical surface type. Specifically, the object side surface and the image side surface of each lens can be designed to be aspherical. The aspheric surface profile arrangement can further help the optical system 10 to more effectively eliminate aberrations, ghost images, astigmatism, chromatic aberrations, spherical aberration, etc., improving imaging quality. Of course, in other embodiments, at least one lens of the optical system 10 may have a spherical surface shape, and the design of the spherical surface shape may reduce the difficulty of manufacturing the lens and reduce the manufacturing cost. It should be noted that there may be some deviation in the ratio of the dimensions of the thickness, surface curvature, etc. of each lens in the drawings. It should also be noted that when the object side or image side of a lens is aspheric, the surface may have a curvature, and the shape of the surface from center to edge will change.

Preferably, in one embodiment, the object-side surface S3 and the image-side surface S4 of the second lens element L2 are aspheric, so that the large-angle light of the first lens element L1 can be reasonably incident into the second lens element L2, and the ghost image risk can be reduced while the edge aberration is reduced.

Preferably, in one embodiment, the object side surface and the image side surface of the third lens element L3 are aspheric, so as to more effectively correct the astigmatism of the optical system 10.

Preferably, in one of the embodiments, the object-side surface and the image-side surface of the fifth lens element L5 are aspheric, which is more beneficial to reducing chromatic aberration of the optical system 10 and correcting spherical aberration of the optical system 10.

Preferably, in one embodiment, the object side surface and the image side surface of the sixth lens element L6 are aspheric, so as to further reduce chromatic aberration of the optical system and improve imaging quality.

Preferably, in one embodiment, the object side surface and the image side surface of the seventh lens element L7 are aspheric, so that the off-axis aberration of the optical system 10 can be effectively controlled, and the imaging quality can be improved.

Preferably, in one of the embodiments, the fifth lens L5 and the sixth lens L6 are provided as cemented lenses.

Through the above-mentioned cemented lens arrangement, be favorable to reducing the chromatic aberration and the correction spherical aberration of optical system 10, be favorable to improving the shooting resolution of optical system 10, realized the function of high pixel shooting, thereby improve imaging quality, in addition, be favorable to shortening the optical overall length of optical system 10, make the process of installing at optical system 10 of fifth lens L5 and sixth lens L6 simpler simultaneously, reduce the installation degree of difficulty, and be favorable to reducing the tolerance sensitivity between fifth lens L5 and the sixth lens L6. Of course, in other embodiments, the fifth lens L5 and the sixth lens L6 may be disposed at a relative interval.

In addition, in some embodiments, the optical system 10 further satisfies at least one of the following relationships, and when any of the conditional expressions is satisfied, the corresponding technical effects can be achieved:

CT4/EPD is more than 2.00 and less than 3.50; wherein, CT4 is the thickness of the fourth lens L4 on the optical axis 101, and EPD is the entrance pupil diameter of the optical system 10. For example, in some embodiments, the numerical values of the above conditional expression are specifically: 2.132, 2.235, 2.631, 2.803, 2.909, 2.940, 2.965, 2.975, 2.987 or 3.288.

When the above conditional expression is satisfied, by reasonably controlling the ratio of the thickness of the fourth lens L4 on the optical axis 101 to the entrance pupil diameter of the optical system 10, the f-number of the optical system 10 can be increased, which is beneficial to increasing the visual sense of the optical system 10, enhancing the presentation capability of details, and obtaining a clear image.

5.00＜Rs1/SAGs1＜7.00；

Wherein Rs1 is the radius of curvature of the object-side surface S1 of the first lens element L1 on the optical axis 101, and sag 1 is the sagittal height of the object-side surface S1 of the first lens element L1 (i.e., the distance from the intersection point of the object-side surface S1 of the first lens element L1 and the optical axis 101 to the maximum effective aperture of the object-side surface thereof is in the direction of the optical axis 101). For example, in some embodiments, the numerical values of the above conditional expression are specifically: 5.827, 5.864, 5.931, 5.988, 6.058, 6.141, 6.183, 6.217, 6.236 or 6.255.

When the above conditional expression is satisfied, by controlling the radius of curvature of the object-side surface S1 of the first lens element L1 and the sagittal height thereof, the first lens element L1 is ensured to provide the optical system 10 with a proper negative refractive power, and the first lens element L1 is advantageously controlled to have a sufficient maximum effective aperture, so that the first lens element L1 is advantageously used to grasp the light incident into the optical system 10 at a relatively large angle, thereby enlarging the photographing range of the optical system 10 and increasing the angle of view; rs1/SAGs1 is larger than or equal to 7.00, the sagittal height of the object side surface S1 of the first lens element L1 is too small, or the radius of curvature of the object side surface S1 of the first lens element L1 is too large, so that the refractive power of the first lens element L1 is too small, which is not beneficial to increasing the angle of view; and Rs1/SAGs1 is less than or equal to 5.00, the sagittal height of the object side S1 of the first lens L1 is too large, so that the first lens L1 is too bent, ghost images are easy to generate, the risk of the ghost images is increased, larger aberration is generated, and the imaging quality is reduced.

1.00＜CT4/f4＜2.00；

Wherein CT4 is the thickness of the fourth lens L4 on the optical axis 101, and f4 is the effective focal length of the fourth lens L4. For example, in some embodiments, the numerical values of the above conditional expression are specifically: 1.118, 1.194, 1.280, 1.356, 1.409, 1.413, 1.418, 1.427, 1.667 or 1.896.

When the above conditional expression is satisfied, the positive refractive power of the fourth lens L4 can be reasonably configured, so as to effectively control the deflection angle of the light ray in the optical system 10 at the fourth lens L4, thereby reducing the sensitivity of the optical system 10 and improving the resolution of shooting and imaging; when CT4/f4 is more than or equal to 2.00, the focal length of the fourth lens L4 becomes smaller, and the positive refractive power provided for the optical system 10 is overlarge, so that the deflection angle of light rays in the optical system 10 at the fourth lens L4 is overlarge; when CT4/f4 is less than or equal to 1.00, the thickness of the fourth lens L4 on the optical axis 101 becomes smaller, resulting in too small deflection angle of the marginal ray at the fourth lens L4, which is unfavorable for correcting the aberration of the optical system 10, and further reduces the imaging quality of the optical system 10.

135.00°/mm＜FOV/f＜155.00°/mm；

Where FOV is the maximum field angle of the optical system 10 and f is the effective focal length of the optical system 10. For example, in some embodiments, the numerical values of the above conditional expression are specifically: 137.331 DEG/mm, 138.412 DEG/mm, 140.894 DEG/mm, 143.262 DEG/mm, 144.286 DEG/mm, 146.377 DEG/mm, 147.445 DEG/mm, 149.841 DEG/mm, 150.557 DEG/mm or 152.446 DEG/mm.

When the above conditional expression is satisfied, by controlling the ratio relationship between the maximum field angle of the optical system 10 and the effective focal length thereof, a larger field angle is obtained, which is beneficial to the development of the optical system 10 in the wide-angle direction, and simultaneously, the deflection angle of the emergent light can be reduced, which is beneficial to the reduction of the sensitivity of the optical system 10, and the aberration of the optical system 10 is effectively corrected, thereby the imaging quality is improved; when the FOV/f is more than or equal to 135.00 degrees/mm, the effective focal length of the optical system 10 is too small, the tolerance sensitivity of the optical system 10 is enhanced, the deflection angle of emergent rays is not reduced, and the problem of dark corners of the edge of the optical system 10 is caused; when FOV/f is 155.00 °/mm or less, the maximum field angle of the optical system 10 is reduced, and details of the object cannot be captured at a large angle well, making it difficult to achieve a wide angle.

1.50＜SD2/SAGs3＜3.50；

Where SD2 is half of the maximum effective caliber (i.e., the maximum effective half caliber) of the object-side surface S3 of the second lens element L2, and sag 3 is the sagittal height of the object-side surface S3 of the second lens element L2 (i.e., the distance from the intersection point of the object-side surface S3 of the second lens element L2 and the optical axis 101 to the maximum effective caliber of the object-side surface in the direction of the optical axis 101). For example, in some embodiments, the numerical values of the above conditional expression are specifically: 1.646, 1.843, 1.978, 2.038, 2.242, 2.432, 2.473, 2.509, 2.807 or 3.135.

When the above condition is satisfied, the ratio of the maximum effective half-caliber of the object side surface S3 of the second lens element L2 to the sagittal height of the object side surface S3 thereof is controlled, so that the size of the maximum effective half-caliber of the object side surface S3 of the second lens element L2 can be effectively controlled, and the sagittal height of the image side surface of the second lens element L2 is cooperatively controlled, so that the volume of the second lens element L2 can be compressed to a greater extent, which is beneficial to shortening the total optical length of the optical system 10, reducing the ghost image risk and improving the imaging quality; when SD2/SAGs3 is more than or equal to 3.50, the maximum effective half caliber of the object side surface S3 of the second lens L2 is not reduced, and the risk of ghost images occurring when light is incident to the second lens L2 is increased; when SD2/SAGs3 is less than or equal to 1.50, the sagittal height of the image side of the second lens L2 is too large, which is not beneficial to compressing the volume of the second lens L2, and the image side of the second lens L2 is too curved, so that the processing difficulty of the second lens L2 is high, and the processing cost is increased.

14.00°/mm＜CRA/|SAGs14|＜16.00°/mm；

Where CRA is the chief ray incident angle of the optical system 10 at the maximum field of view, and sag 14 is the sagittal height of the image side surface of the seventh lens L7 (i.e., the distance from the intersection point of the image side surface of the seventh lens L7 and the optical axis 101 to the maximum effective caliber of the image side surface thereof in the direction of the optical axis 101). For example, in some embodiments, the numerical values of the above conditional expression are specifically: 15.932 DEG/mm, 15.474 DEG/mm, 15.169 DEG/mm, 15.087 DEG/mm, 14.930 DEG/mm, 14.790 DEG/mm, 14.533 DEG/mm, 14.324 DEG/mm, 14.227 DEG/mm or 14.066 DEG/mm.

When the above conditional expression is satisfied, by controlling the sagittal height of the image side surface of the seventh lens L7, the surface shape of the image side surface of the seventh lens L7 can be effectively controlled, so that the image side surface of the seventh lens L7 located in front of the imaging surface Si is not too curved, which is beneficial to the molding of the seventh lens L7, and the chief ray incident angle of the optical system 10 at the maximum field of view is ensured to be large enough to enable more rays to be incident into the imaging surface Si, thereby increasing the relative illuminance of the imaging surface Si; when CRA/|SAGs 14|is less than or equal to 14.00 degrees/mm, the absolute value of the sagittal height of the image side surface of the seventh lens is too large, so that the seventh lens is too bent, the processing is not easy, the incidence angle of the chief ray of the optical system at the maximum view field is easy to be smaller, and the relative illumination of the imaging surface is smaller; when CRA/|SAGs 14|is not less than 16.00 degrees/mm, the incidence angle of the chief ray of the optical system at the maximum field of view is larger, and the chief ray is unfavorable for matching with an image sensor.

It should be noted that the reference wavelengths of the effective focal lengths in the above relational conditions are 536nm, and the effective focal length refers to at least the value of the corresponding lens or lens group at the paraxial region. And the above relational conditions and the technical effects thereof are directed to the six-piece optical system 10 having the above lens design. If the lens design (lens number, refractive power configuration, surface configuration, etc.) of the optical system 10 cannot be ensured, it is difficult to ensure that the optical system 10 still has the corresponding technical effects while satisfying these relationships, and even significant degradation of the image capturing performance may occur.

In some embodiments, at least one lens of the optical system 10 is made of Plastic (PC), which may be polycarbonate, gum, or the like. In some embodiments, the material of at least one lens in the optical system 10 is Glass (GL). The lens with plastic material can reduce the production cost of the optical system 10, while the lens with glass material can withstand higher or lower temperature and has excellent optical effect and better stability. In some embodiments, at least two lenses of different materials may be disposed in the optical system 10, for example, a combination of glass lenses and plastic lenses may be used, but the specific configuration relationship may be determined according to practical needs, which is not meant to be exhaustive.

In some embodiments, the optical system 10 includes a filter 110, and the filter 110 is disposed on the image side of the fifth lens L5 and the imaging plane Si of the system. Specifically, the filter 110 is an infrared cut filter, which is used to filter infrared light, and prevent the infrared light from reaching the imaging surface Si of the system, thereby preventing the infrared light from interfering with normal imaging. The filter 110 may be assembled with each lens as part of the optical system 10. In other embodiments, the optical filter 110 is not a component of the optical system 10, and the optical filter 110 may be installed between the optical system 10 and the image sensor when the optical system 10 and the image sensor are assembled into the image capturing module. In other embodiments, the filtering effect of the infrared light can also be achieved by providing a filtering coating on at least one of the first lens L1 to the seventh lens L7.

The optical system 10 of the present application is illustrated by the following more specific examples:

first embodiment

Referring to fig. 1, in the first embodiment, the optical system 10 includes, in order from an object side to an image side, a first lens element L1 with negative refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with negative refractive power, a fourth lens element L4 with positive refractive power, a stop STO, a fifth lens element L5 with positive refractive power, a sixth lens element L6 with negative refractive power, and a seventh lens element L7 with positive refractive power.

The surface profile of each lens surface in the optical system 10 is as follows:

the object side surface S1 of the first lens element L1 is convex at a paraxial region, and the image side surface S2 is concave at a paraxial region;

the object side surface S3 of the second lens element L2 is convex at a paraxial region, and the image side surface S4 is concave at a paraxial region;

the object side surface S5 of the third lens element L3 is concave at a paraxial region, and the image side surface S6 is concave at a paraxial region;

the fourth lens element L4 has a convex object-side surface S7 at a paraxial region and a convex image-side surface S8 at a paraxial region;

the fifth lens element L5 has a convex object-side surface S9 at a paraxial region and a convex image-side surface S10 at a paraxial region;

the object side surface S11 of the sixth lens element L6 is concave at a paraxial region, and the image side surface S12 is concave at a paraxial region;

the object-side surface S13 of the seventh lens element L7 is convex at a paraxial region, and the image-side surface S14 is convex at a paraxial region.

In the embodiments of the present application, when describing that the lens surface has a certain profile at the paraxial region, it means that the lens surface has the certain profile near the optical axis 101.

Specifically, the object side surface and the image side surface of each lens in the first lens element L1 and the fourth lens element L4 are spherical surfaces, and are made of glass; the object side surface and the image side surface of each lens in the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are aspheric, and the materials of the lenses are plastics.

In addition, the fifth lens L5 and the sixth lens L6 together form a cemented lens.

The various lens parameters of the optical system 10 in this embodiment are presented in table 1 below. The elements from the object side to the image side of the optical system 10 are sequentially arranged in the order from top to bottom of table 1, wherein the aperture stop STO characterizes the aperture stop. The filter 110 may be part of the optical system 10 or may be removable from the optical system 10, but the overall optical length of the optical system 110 remains the same after the filter 110 is removed. The infrared filter 110 is used for filtering infrared light. The radius Y in table 1 is the radius of curvature of the corresponding surface of the lens at the optical axis 101 and in the Y direction. The absolute value of the first value of the lens in the "thickness" parameter row is the thickness of the lens on the optical axis 101, and the absolute value of the second value is the distance from the image side of the lens to the subsequent optical element (lens or diaphragm) on the optical axis 101, wherein the thickness parameter of the diaphragm represents the distance from the diaphragm surface to the object side of the adjacent lens on the optical axis 101. The refractive index, abbe number, of each lens in the table is 587.6nm, the focal length (effective focal length) is 538nm, and the Y radius, thickness, focal length (effective focal length) are all in millimeters (mm). In addition, the parameter data and the lens surface type structure used for the relational computation in the following embodiments are based on the data in the lens parameter table in the corresponding embodiments.

TABLE 1

As is clear from table 1, the optical system 10 in the first embodiment has an effective focal length f of 1.41mm, an f-number FNO of 1.80, a maximum field angle FOV of 202 °, an optical total length TTL of 16.90mm, a large field angle, a large aperture, and a good imaging effect. When the image sensor is assembled, the FOV can also be understood as the maximum field angle of the optical system 10 in the diagonal direction of the rectangular effective pixel area of the corresponding image sensor.

Table 2 below presents the aspherical coefficients of the corresponding lens surfaces in table 1, where k is a conic coefficient and Ai is a coefficient corresponding to the i-th order higher order term in the aspherical surface type formula.

TABLE 2

The surface type calculation of the aspherical surface can refer to an aspherical surface formula:

where Z is the sagittal height of the corresponding position of the lens surface, r is the distance from the corresponding position of the lens surface to the optical axis, c is the curvature of the lens surface at the optical axis 101, k is the conic coefficient, ai is the coefficient corresponding to the i-th order higher order term. It should be noted that the actual planar shape of the lens is not limited to the shape shown in the drawings, which are not drawn to scale, and may differ from the actual planar structure of the lens to some extent.

In the first embodiment, the optical system 10 satisfies the following relationships:

Fig. 2 includes a longitudinal spherical aberration curve, an astigmatic curve, and a distortion curve of the optical system 10 in the first embodiment, wherein the reference wavelength of the astigmatic curve and the distortion curve is 536nm, and the reference wavelengths of the astigmatic curve and the distortion curve are the same in other embodiments.

The longitudinal spherical aberration plot (Longitudinal Spherical Aberration) exhibits a focus offset of light rays of different wavelengths after passing through the lens. The ordinate of the longitudinal spherical aberration plot represents the normalized pupil coordinates (Normalized Pupil Coordinator) from the pupil center to the pupil edge, and the abscissa represents the distance (in mm) from the imaging plane to the intersection of the light ray and the optical axis. As can be seen from the longitudinal spherical aberration graph, the degree of focus deviation of the light rays of each wavelength in the first embodiment tends to be uniform, and the diffuse spots or the halos in the imaging picture are effectively suppressed.

An astigmatic diagram (Astigmatic Field Curves) in which the abscissa along the X-axis represents the focus offset (in mm) and the ordinate along the Y-axis represents the field angle (in °), the S-curve in the diagram representing the sagittal field curve at 536m and the T-curve representing the meridional field curve at 536 nm. As can be seen from the figure, the curvature of field of the optical system is smaller, the curvature of field of the image plane is effectively suppressed, the curvature of sagittal field and curvature of meridional field under each field of view have smaller phase difference, and the astigmatism of each field of view is better controlled, so that the center to the edge of the field of view of the optical system 10 have clear imaging.

Distortion curve (Distortion) wherein the abscissa along the X-axis represents Distortion and the ordinate along the Y-axis represents field angle (in °), the Distortion curve represents Distortion magnitude values corresponding to different field angle positions, and the degree of Distortion of the optical system 10 is well controlled.

Second embodiment

Referring to fig. 3, in the second embodiment, the optical system 10 includes, in order from the object side to the image side, a first lens element L1 with negative refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with negative refractive power, a fourth lens element L4 with positive refractive power, a stop STO, a fifth lens element L5 with positive refractive power, a sixth lens element L6 with negative refractive power, and a seventh lens element L7 with positive refractive power.

In the present embodiment, the object-side surface and the image-side surface of each of the first lens element L1 and the fourth lens element L4 are spherical, and are made of glass; the object side surface and the image side surface of each lens in the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are aspheric, and the materials of the lenses are plastics. In addition, the fifth lens L5 and the sixth lens L6 together form a cemented lens.

In addition, the parameters of each lens of the optical system 10 in the second embodiment are shown in tables 3 and 4, wherein the definitions of each structure and parameter can be obtained in the first embodiment, and the description thereof is omitted herein.

TABLE 3 Table 3

TABLE 4 Table 4

The optical system 10 in this embodiment satisfies the following relationship:

as can be seen from the aberration diagrams in fig. 4, the longitudinal spherical aberration, the field curvature, the astigmatism and the distortion of the optical system 10 are well controlled, wherein the focal offset corresponding to the longitudinal spherical aberration at each wavelength is smaller, the curvature of the image plane is well suppressed, the astigmatism is reasonably regulated, and the distortion is very effectively suppressed.

Third embodiment

Referring to fig. 5, in the third embodiment, the optical system 10 includes, in order from the object side to the image side, a first lens element L1 with negative refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with negative refractive power, a fourth lens element L4 with positive refractive power, a stop STO, a fifth lens element L5 with positive refractive power, a sixth lens element L6 with negative refractive power, and a seventh lens element L7 with positive refractive power.

In addition, the parameters of each lens of the optical system 10 in the third embodiment are shown in tables 5 and 6, wherein the definitions of each structure and parameter can be obtained in the first embodiment, and the description thereof is omitted herein.

TABLE 5

TABLE 6

Face number	S3	S4	S5	S6	S9
						k	-4.791E-01	-4.748E-01	9.506E-01	-4.260E+01	-4.612E+00
A4	-7.219E-04	-1.676E-02	1.456E-02	1.448E-02	-1.091E-02
						A6	-7.222E-05	4.872E-02	-3.066E-02	-1.796E-02	4.548E-02
A8	-7.262E-04	-6.422E-02	5.640E-02	4.295E-02	-1.551E-01
						A10	4.029E-04	4.722E-02	-5.342E-02	-4.685E-02	3.186E-01
A12	-1.033E-04	-2.110E-02	3.090E-02	2.988E-02	-4.065E-01
						A14	2.520E-05	5.849E-03	-1.120E-02	-1.149E-02	4.237E-01
A16	-1.320E-06	-4.681E-04	2.479E-03	2.589E-03	-1.566E-01
						A18	6.297E-08	8.543E-05	-3.061E-04	-3.095E-04	4.210E-02
A20	-1.274E-09	-2.943E-06	1.615E-05	1.475E-05	-4.822E-03

Face number	S11	S12	S13	S14
						k	-8.612E-02	-4.247E+01	-1.830E+01	-5.685E+00
A4	-1.875E-01	6.434E-03	5.512E-03	-7.249E-03
						A6	1.225E-01	-2.233E-02	-1.240E-02	-1.045E-02
A8	-9.531E-02	3.063E-02	7.053E-03	1.218E-02
						A10	1.631E-01	-1.954E-02	-1.192E-03	-7.645E-03
A12	-2.153E-01	6.858E-03	-5.147E-04	2.924E-03
						A14	1.479E-01	-1.280E-03	4.215E-04	-6.965E-04
A16	-5.185E-02	9.294E-05	-7.220E-05	1.013E-04
						A18	8.369E-03	4.649E-06	7.714E-06	-8.263E-06
A20	-3.949E-04	-8.051E-07	-3.267E-07	2.915E-07

The optical system 10 in this embodiment satisfies the following relationship:

as can be seen from the aberration diagrams in fig. 6, the longitudinal spherical aberration, the field curvature, the astigmatism and the distortion of the optical system 10 are well controlled, wherein the focal offset corresponding to the longitudinal spherical aberration at each wavelength is smaller, the curvature of the image plane is well suppressed, the astigmatism is reasonably regulated, and the distortion is very effectively suppressed.

Fourth embodiment

Referring to fig. 7, in the fourth embodiment, the optical system 10 includes, in order from the object side to the image side, a first lens element L1 with negative refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with negative refractive power, a fourth lens element L4 with positive refractive power, a stop STO, a fifth lens element L5 with positive refractive power, a sixth lens element L6 with negative refractive power, and a seventh lens element L7 with positive refractive power.

In addition, the parameters of each lens of the optical system 10 in the fourth embodiment are given in tables 7 and 8, wherein the definition of each structure and parameter can be obtained in the first embodiment, and the description thereof is omitted herein.

TABLE 7

TABLE 8

As can be seen from the aberration diagrams in fig. 8, the longitudinal spherical aberration, the field curvature, the astigmatism and the distortion of the optical system 10 are well controlled, wherein the focal offset corresponding to the longitudinal spherical aberration at each wavelength is smaller, the curvature of the image plane is well suppressed, the astigmatism is reasonably regulated, and the distortion is very effectively suppressed.

Fifth embodiment

Referring to fig. 9, in the fifth embodiment, the optical system 10 includes, in order from the object side to the image side, a first lens element L1 with negative refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with negative refractive power, a fourth lens element L4 with positive refractive power, a stop STO, a fifth lens element L5 with positive refractive power, a sixth lens element L6 with negative refractive power, and a seventh lens element L7 with positive refractive power.

In addition, the parameters of each lens of the optical system 10 in the fifth embodiment are shown in tables 9 and 10, wherein the definition of each structure and parameter can be obtained in the first embodiment, and the description thereof is omitted herein.

TABLE 9

Table 10

Face number	S3	S4	S5	S6	S9
						k	-2.517E-01	-9.833E-01	5.059E+00	-1.372E+01	-5.638E+00
A4	1.511E-03	-1.107E-02	1.007E-02	1.708E-02	-8.041E-03
						A6	-2.624E-03	3.825E-02	-2.546E-02	-3.126E-02	3.319E-02
A8	4.331E-04	-5.685E-02	4.825E-02	6.752E-02	-1.297E-01
						A10	9.260E-05	4.446E-02	-4.486E-02	-7.391E-02	2.896E-01
A12	-4.923E-05	-2.075E-02	2.544E-02	4.898E-02	-3.896E-01
						A14	9.019E-06	6.000E-03	-9.048E-03	-2.008E-02	3.206E-01
A16	-8.729E-07	-1.044E-03	1.965E-03	4.958E-03	-1.578E-01
						A18	4.443E-08	9.889E-05	-2.379E-04	-4.724E-04	4.255E-02
A20	-9.382E-10	-3.843E-06	1.229E-05	3.844E-05	-4.833E-03

Face number	S11	S12	S13	S14
						k	-2.403E-01	-2.366E+01	-1.950E+01	-3.635E+00
A4	-1.045E-01	7.175E-03	7.528E-03	-8.104E-03
						A6	-2.363E-01	-2.797E-02	-1.857E-02	-7.257E-03
A8	8.119E-01	3.956E-02	1.261E-02	7.211E-03
						A10	-1.226E+00	-2.693E-02	-4.108E-03	-3.860E-03
A12	1.118E+00	1.078E-02	7.323E-04	1.222E-03
						A14	-6.541E-01	-2.654E-03	6.182E-05	-2.277E-04
A16	2.395E-01	3.957E-04	-2.975E-05	2.394E-05
						A18	-4.955E-02	-3.288E-05	3.649E-06	-1.255E-06
A20	4.397E-03	1.164E-06	-1.568E-07	2.470E-08

The optical system 10 in this embodiment satisfies the following relationship:

as can be seen from the aberration diagrams in fig. 10, the longitudinal spherical aberration, the field curvature, the astigmatism and the distortion of the optical system 10 are all well controlled, wherein the focal offset corresponding to the longitudinal spherical aberration at each wavelength is smaller, the curvature of the image plane is well suppressed, the astigmatism is reasonably regulated, and the distortion is very effectively suppressed.

In the above first to fifth embodiments, the optical system 10 not only meets the design requirement of wide angle but also has the optical characteristics of large aperture through the corresponding refractive power, physical parameters and surface design, but also can effectively suppress the longitudinal spherical aberration, field curvature, astigmatism and distortion aberration of the optical system 10, thereby having high quality imaging effect.

In addition, referring to fig. 11, some embodiments of the present application further provide an image capturing module 20, where the image capturing module 20 may include the optical system 10 and the image sensor 210 according to any of the above embodiments, and the image sensor 210 is disposed on the image side of the optical system 10. The image sensor 210 may be a CCD (Charge Coupled Device ) or CMOS (Complementary Metal Oxide Semiconductor, complementary metal oxide semiconductor). Generally, the imaging surface Si of the optical system 10 overlaps the photosensitive surface of the image sensor 210 at the time of assembly. By adopting the optical system 10, the camera module 20 can realize the shooting requirements of large aperture and wide angle, and has good imaging effect.

Referring to fig. 12, some embodiments of the application also provide an electronic device 30. The electronic device 30 includes a fixing member 310, and the camera module 20 is mounted on the fixing member 310, where the fixing member 310 may be a display screen, a touch display screen, a circuit board, a middle frame, a rear cover, and the like. The electronic device 30 may be, but is not limited to, a smart phone, a smart watch, smart glasses, an electronic book reader, a vehicle-mounted camera device, a monitoring device, a drone, a medical device (e.g., an endoscope), a tablet computer, a biometric device (e.g., a fingerprint recognition device or a pupil recognition device, etc.), a PDA (Personal Digital Assistant, a personal digital assistant), a drone, etc. In some embodiments, when the electronic device 30 is an in-vehicle image capturing device, the image capturing module 20 may be used as an in-vehicle lens for the device, and the fixture 310 is used to mount the electronic device 30 on a vehicle. Because the size of the camera module 20 is smaller, the limitation of the size setting of the electronic equipment 30 is released, conditions are provided for the electronic equipment to develop in a miniaturized manner, when the electronic equipment 30 is utilized to shoot scenes, the shooting requirements of large aperture and wide angle can be realized, the shooting range is wide, the shooting aperture is large, the imaging effect is good, and the shooting quality can be better improved.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the 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 protection of the present invention is to be determined by the appended claims.

Claims

1. An optical system, characterized in that the number of lenses with refractive power in the optical system is seven, and the optical system sequentially comprises, from an object side to an image side along an optical axis:

a diaphragm is arranged between the fourth lens and the fifth lens;

and the optical system satisfies the following conditional expression:

9.384mm≤TTL/FNO≤9.426mm；

1.00＜CT4/f4＜2.00；

wherein TTL is the distance between the object side surface of the first lens element and the imaging surface of the optical system on the optical axis, FNO is the f-number of the optical system, CT4 is the thickness of the fourth lens element on the optical axis, and f4 is the effective focal length of the fourth lens element.

2. The optical system of claim 1, wherein the optical system further satisfies the conditional expression:

2.00＜CT4/EPD＜3.50；

wherein EPD is the entrance pupil diameter of the optical system.

3. The optical system of claim 1, wherein the optical system further satisfies the conditional expression:

5.00＜Rs1/SAGs1＜7.00；

wherein Rs1 is the radius of curvature of the object side surface of the first lens on the optical axis, SAGs1 is the sagittal height of the object side surface of the first lens at the maximum effective caliber.

4. The optical system of claim 1, wherein the object side and the image side of the first lens and the fourth lens are spherical, and the object side and the image side of the second lens, the third lens, the fifth lens, the sixth lens, and the seventh lens are aspherical.

5. The optical system of claim 1, wherein the first lens and the fourth lens are made of glass, and the second lens, the third lens, the fifth lens, the sixth lens and the seventh lens are made of plastic.

6. The optical system of claim 1, wherein the optical system further satisfies the conditional expression:

135.00°/mm＜FOV/f＜155.00°/mm；

7. The optical system of claim 1, wherein the optical system further satisfies the conditional expression:

1.50＜SD2/SAGs3＜3.50；

Wherein SD2 is half of the maximum effective caliber of the object side surface of the second lens, and sag 3 is the sagittal height of the object side surface of the second lens at the maximum effective caliber.

8. The optical system of claim 1, wherein the optical system further satisfies the conditional expression:

14.00°/mm＜CRA/|SAGs14|＜16.00°/mm；

wherein CRA is the chief ray incidence angle of the optical system at the maximum field of view, and sag 14 is the sagittal height of the image side surface of the seventh lens at the maximum effective aperture.

9. An imaging module comprising an image sensor and the optical system of any one of claims 1 to 8, wherein the image sensor is disposed on an image side of the optical system.

10. An electronic device, comprising a fixing member and the camera module set according to claim 9, wherein the camera module set is disposed on the fixing member.