CN114002818A

CN114002818A - Optical system, camera module and electronic equipment

Info

Publication number: CN114002818A
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: 2022-02-01
Anticipated expiration: 2041-11-15
Also published as: CN114002818B

Abstract

The invention relates to an optical system, a camera module and an electronic device. An optical system includes, 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 and a concave image-side surface; a second lens element with negative refractive power having a convex object-side surface and a concave image-side surface; a third lens element with negative refractive power having a concave object-side surface and a concave image-side surface; a fourth lens element with positive refractive power having 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 sixth lens element with negative refractive power has a concave object-side surface and a concave image-side surface; a seventh lens element with positive refractive power having a convex object-side surface and a convex image-side surface; and satisfies the following conditions: TTL/FNO is more than 8.50mm and less than 10.50mm, TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis, and 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 technologies, and in particular, to an optical system, a camera module, and an electronic device.

Background

With the increasing requirements of the country on road traffic safety and automobile safety, the function of the panoramic camera in the vehicle is more and more obvious, and the panoramic camera is continuously applied to an automobile auxiliary driving system. Look around the camera, through with a plurality of optical system in the rational distribution of automobile body, splice the birds-eye view picture of car top all directions together, make the driver see the car image all around clearly, can effectively avoid backing a car and roll, scrape the emergence of accidents such as bumper and wheel hub, look around the camera simultaneously and can also discern parking passageway sign, curb and near vehicle, guaranteed the security of traveling of car greatly.

However, the conventional vehicle-mounted all-round lens has the defects that the diaphragm number is large, the aperture of the diaphragm of the lens is easy to be small, the light incoming amount of the lens is insufficient, the illumination is too low and the like, and meanwhile, the conventional vehicle-mounted all-round lens has the problem that the field angle is not enough and the like.

Disclosure of Invention

Accordingly, it is necessary to provide an optical system, an image pickup module, and an electronic apparatus, which address the problems of a small aperture of a diaphragm to be photographed and an insufficient angle of view.

An optical system includes, 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 and a concave image-side surface;

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

a fourth lens element with positive refractive power having a convex object-side surface and a convex image-side surface at 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 optical design, the object-side surface of the first lens element with negative refractive power is a convex surface, and the image-side surface of the first lens element with negative refractive power is a concave surface, so that light rays can be incident into the first lens element at a larger angle, thereby increasing the field angle of the optical system, effectively enlarging the shooting range of the optical system, and meeting the design requirement of widening the angle of the optical system; 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 reasonably receive the light rays, and the light rays are in gentle transition in the second lens, thereby being beneficial to reducing the edge aberration and reducing the ghost risk; the object-side surface and the image-side surface of the third lens element with negative refractive power are both concave, so that the third lens element can effectively receive light rays transmitted from the first lens element and the second lens element in sequence, and the field curvature astigmatism of the optical system can be reduced; the object side surface and the image side surface of the fourth lens element with positive refractive power are both convex surfaces, so that the positive refractive power of the fourth lens element can be reasonably matched with the negative refractive power of the first lens element to the third lens element, thereby being beneficial to reasonably configuring the negative refractive power of the first lens element to the third lens element, increasing the incident angle of light rays incident to the optical system and increasing the field angle; the object side surface and the image object side surface of the fifth lens element with positive refractive power are both convex surfaces, so that the light incident quantity of light rays of a rear lens group (i.e. a lens group formed by the fifth lens element to the seventh lens element) positioned at the image side of the diaphragm can be controlled to a certain degree, the relative illumination of an imaging surface is increased, and the brightness is improved; the object-side surface and the image-side surface of the sixth lens element with negative refractive power are concave, so that the negative refractive power of the sixth lens element can be reasonably matched with the positive refractive power of the fifth lens element, thereby reducing chromatic aberration and tolerance sensitivity of the optical system and improving imaging quality; the object-side surface and the image-side surface of the seventh lens element with positive refractive power are both convex surfaces, which is favorable for correcting the off-axis aberration generated by the optical system, and simultaneously is favorable for enabling the optical system to have enough back focal length, thereby improving the relative illumination of an imaging surface and further optimizing the imaging quality.

And the optical system satisfies the conditional expression:

8.50mm＜TTL/FNO＜10.50mm；

wherein, TTL is a distance (i.e., a total optical length) from an object-side surface of the first lens element to an image plane of the optical system on an optical axis, and FNO is an f-number of the optical system.

When the conditional expression is satisfied, the ratio relation between the total optical length of the optical system and the diaphragm number of the optical system is reasonably controlled, so that the aperture of the diaphragm of the optical system is favorably increased, and the effect of large diaphragm is realized; TTL/FNO is larger than or equal to 10.50mm, so that the total optical length of the optical system is increased, the miniaturization design of the optical system is not facilitated, and the production is not facilitated; TTL/FNO is less than or equal to 8.50mm, the diaphragm number of the optical system is easy to be overlarge, the aperture of the diaphragm of the optical system is reduced, the light incoming quantity is insufficient, the relative illumination is reduced, the imaging quality is influenced, and large-diaphragm imaging is not facilitated.

In one embodiment, the image side surface of the fifth lens is abutted to the object side surface of the sixth lens, so that chromatic aberration of the optical system is reduced, and spherical aberration of the optical system is corrected, thereby improving the resolution of shooting and imaging of the optical system and better improving the imaging quality.

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

2.00＜CT4/EPD＜3.50；

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

When the conditional expression is satisfied, the ratio of the thickness of the fourth lens on the optical axis to the entrance pupil diameter of the optical system is reasonably controlled, so that the f-number of the optical system can be improved, the image sense of the optical system is increased, the presentation capability of details is enhanced, and a clear image can be obtained.

5.00＜Rs1/SAGs1＜7.00；

wherein Rs1 is the curvature radius of the object-side surface of the first lens on the optical axis, and sag 1 is the rise 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 aperture of the object-side surface in the optical axis direction).

When the conditional expression is met, by controlling the size relation between the curvature radius of the object side surface of the first lens and the rise thereof, the first lens is ensured to provide proper negative refractive power for the optical system, and meanwhile, the first lens is favorably controlled to have enough maximum effective aperture, so that the first lens is favorably used for catching light rays entering the optical system at a larger angle, the shooting range of the optical system is expanded, and the field angle is increased; when the Rs1/SAGs1 is larger than or equal to 7.00, the rise of the object-side surface of the first lens is too small, or the curvature radius 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 field angle is not facilitated; rs1/SAGs1 is less than or equal to 5.00, the rise of the object side surface of the first lens is too large, the first lens is too bent, production is not facilitated, the curvature radius of the object side surface of the first lens is too small, ghost images are easy to generate, the risk of ghost images is increased, large aberration is generated, and 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 conditional expression is met, the positive refractive power of the fourth lens can be reasonably configured, the deflection angle of light rays in the optical system at the fourth lens is effectively controlled, the sensitivity of the optical system is further reduced, and the resolution of shooting imaging is improved; when CT4/f4 is larger 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 too large, so that the deflection angle of light rays in the optical system at the fourth lens is too large; when the CT4/f4 is less than or equal to 1.00, the thickness of the fourth lens on the optical axis is reduced, so that the deflection angle of the marginal ray at the fourth lens is too small, which is not beneficial to correcting the aberration of the optical system, and further reduces the imaging quality of the optical system.

2.00＜AT1/∑AT＜3.00；

where AT1 is the distance on the optical axis between the image-side surface of the first lens and the object-side surface of the second lens (i.e., the air space between the first lens and the second lens), Σ AT is the sum of the distances on the optical axis between each adjacent two lenses of the first lens to the seventh lens (i.e., the total air space of the seven lenses of the optical system), i.e., Σ AT is the sum of the air space between the first and second lenses, the air space between the second and third lenses, the air space between the third and fourth lenses, the air space between the fourth and fifth lenses, the air space between the fifth and sixth lenses, and the air space between the sixth and seventh lenses.

When the conditional expression is met, the ratio relation between the air interval between the first lens and the second lens and the total air interval in the optical system is controlled, so that the space distribution of the whole optical system is reasonable, the assembly of the optical system is facilitated, and the production cost of the optical system is effectively reduced; when AT 1/SIGMA AT is larger than or equal to 3.00, the air space between the first lens and the second lens is too large, which is not beneficial to distributing the air space between the lenses of the optical system, and the structure compactness of the optical system can not be effectively improved; AT1/Σ AT ≦ 2.00, the total air space of the optical system increases, risking an increase in the decentering sensitivity between the lenses of the optical system.

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 met, by controlling the ratio relation between the maximum field angle of the optical system and the effective focal length of the optical system, a larger field angle is obtained, the optical system can be favorably developed towards a wide-angle direction, the deflection angle of emergent light can be reduced, the sensitivity of the optical system can be favorably reduced, the aberration of the optical system can be effectively corrected, and the imaging quality is improved; when the FOV/f is larger 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, and the deflection angle of emergent rays is not reduced, so that the problem of edge dark angle of the optical system is caused; when FOV/f is equal to or less than 155.00 °/mm, the maximum angle of view of the optical system decreases, and details of the subject cannot be captured at a large angle well, and it is difficult to achieve a wide angle.

1.50＜SD2/SAGs3＜3.50；

wherein SD2 is half of the maximum effective aperture (i.e. maximum effective half aperture) of the object-side surface of the second lens, and SAGs3 is the rise of the object-side surface of the second lens (i.e. the distance from the intersection of the object-side surface of the second lens and the optical axis to the maximum effective aperture of the object-side surface thereof in the optical axis direction).

When the conditional expression is met, the size of the maximum effective semi-aperture of the object-side surface of the second lens can be effectively controlled by controlling the ratio relation between the maximum effective semi-aperture of the object-side surface of the second lens and the rise of the image-side surface of the second lens, and meanwhile, the rise of the image-side surface of the second lens is controlled in a matching manner, so that the volume of the second lens can be compressed to a greater extent, the optical total length of an optical system can be favorably shortened, the ghost risk can be favorably reduced, and the imaging quality is high; when the SD2/SAGs3 is larger than or equal to 3.50, the maximum effective half aperture of the object side surface of the second lens is not favorably reduced, and the risk that ghost images appear when light enters the second lens is increased; when SD2/SAGs3 is less than or equal to 1.50, the rise of the image side surface of the second lens is too large, the volume of the second lens is not favorably compressed, and the image side surface of the second lens is too curved, so that the processing difficulty of the second lens is large, and the processing cost is increased.

14°/mm＜CRA/|SAGs14|＜16°/mm；

wherein, CRA is the chief ray incident angle of the optical system at the maximum visual field, and SAGs14 is the rise of the image side surface of the seventh lens (i.e. the distance from the intersection point of the image side surface of the seventh lens and the optical axis to the maximum effective aperture of the image side surface in the optical axis direction).

When the conditional expression is met, the plane shape of the image side surface of the seventh lens can be effectively controlled by controlling the rise of the image side surface of the seventh lens, so that the image side surface of the seventh lens positioned in front of the imaging surface is not too curved, the seventh lens is favorably formed, and the incident angle of the chief ray of the optical system at the maximum view field is ensured to be large enough, so that more rays are incident on the imaging surface, and the relative illumination of the imaging surface is increased; when CRA/| SAGs14| ≦ 14.00 °/mm, the absolute value of the rise of the image-side surface of the seventh lens is made too large, which causes the seventh lens to be too curved, which is not beneficial to processing, and also easily causes the chief ray incident angle of the optical system at the maximum field of view to be too small, and the relative illumination of the imaging surface to be small; when CRA/| SAGs14| ≧ 16.00 °/mm, then the chief ray angle of the optical system at the maximum field of view is too large to match with the image sensor.

A camera 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. Through adopting above-mentioned optical system for the module of making a video recording can realize the shooting demand of big light ring, wide-angle.

An electronic device comprises a fixing piece and the camera module, wherein the camera module is arranged on the fixing piece. When the scene is shot by the electronic equipment, 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 diagram, an astigmatism diagram, and a distortion diagram of the optical system in the first embodiment;

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

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

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

FIG. 6 includes a longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram of the optical system in the 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 diagram, an astigmatism diagram, and a distortion diagram of the optical system in the fourth embodiment;

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

fig. 10 includes a longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram of the optical system in the fifth embodiment;

fig. 11 is a schematic structural diagram of a camera 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 to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "transverse," "length," "thickness," "upper," "front," "rear," "axial," "radial," and the like are used in the orientations and positional relationships indicated in the drawings for the purpose of convenience and simplicity of description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting.

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

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

It will be understood that when an element is referred to as being "secured to" 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 the 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, that is, the optical axes of the lenses are all located on the same straight line, which can be taken as the optical axis 101 of the optical system 10. Each lens in the optical system 10 is mounted in a lens barrel to assemble an imaging lens.

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

The first lens L1 has an object side surface S1 and an image side surface S2, the second lens L2 has an object side surface S3 and an image side surface S4, the third lens L3 has an object side surface S5 and an image side surface S6, the fourth lens L4 has an object side surface S7 and an image side surface S8, the fifth lens L5 has an object side surface S9 and an image side surface S10, the sixth lens L6 has an object side surface S11 and an image side surface S12, and the seventh lens L539 7 has an object side surface S13 and an image side surface S14. The optical system 10 further has an image plane Si located on the image side of the seventh lens L7, and light rays of the object from the object plane of the optical system 10 can be converged on the image plane Si after being adjusted by the lenses of the optical system 10. Generally, the imaging plane Si of the optical system 10 coincides with the photosensitive surface of the image sensor.

In the embodiment of the present 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 both 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 both 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 it is described that a lens surface has a certain face shape at a paraxial region, that is, the lens surface has such a face shape in the vicinity of the optical axis 101, the region of the lens surface near the maximum effective aperture may have the same face shape or an opposite face shape.

The stop STO is an aperture stop, which is disposed between the fourth lens L4 and the fifth lens L5, and is used to limit the light incident amount of the system and also to suppress aberration and stray light to some extent. The diaphragm may be a separate light barrier fitted between the lenses or may be formed by some holder holding 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.

Through the above lens design, the object-side surface S1 and the image-side surface S2 of the first lens element L1 with negative refractive power are convex and concave, so that light rays can be incident into the first lens element L1 at a larger angle, thereby increasing the field angle of the optical system 10, effectively expanding the shooting range of the optical system 10, and meeting the design requirement of widening the angle of the optical system 10; the object-side surface S3 and the image-side surface S4 of the second lens element L2 with negative refractive power are convex and concave, so that light rays transmitted through the first lens element L1 can enter the second lens element L2 at a large angle, and the second lens element L2 can reasonably receive the light rays; the object-side surface S5 and the image-side surface S6 of the third lens element L3 with negative refractive power are both concave, so that the third lens element L3 can effectively receive light rays transmitted from the first lens element L1 and the second lens element L2 in sequence, which is 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 surfaces, so that the positive refractive power of the fourth lens element L4 can reasonably cooperate with the negative refractive power of the first lens element L1 to the third lens element L3, thereby facilitating reasonable arrangement of the negative refractive power of the first lens element L1 to the third lens element L3, increasing the incident angle of light entering the optical system 10, and increasing the field angle, and in addition, the light can better converge at the stop STO through the fourth lens element L4, so as to ensure that the optical system 10 has a proper aperture, avoid the phenomenon that the aperture of the aperture is too small, and facilitate increasing the light entering amount of the optical system 10, thereby increasing the relative illuminance of the imaging plane 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 surfaces, so that the amount of light entering the rear lens group (i.e., the lens group formed by the fifth lens element L5 through the seventh lens element L7) on the image side of the stop STO can be controlled to some extent, the relative illumination of the image plane 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 both concave, which is favorable for the negative refractive power of the sixth lens element L6 and the positive refractive power of the fifth lens element L5 to reasonably cooperate with each other, so that the chromatic aberration and the tolerance sensitivity of the optical system 10 are favorably reduced, and the imaging quality is improved; the object-side surface S13 and the image-side surface S14 of the seventh lens element L7 with positive refractive power are both convex surfaces, which is favorable for correcting off-axis aberration generated by the optical system 10 and simultaneously is favorable for enabling the optical system 10 to have sufficient back focus, thereby improving the relative illumination of the image plane Si and further optimizing the imaging quality.

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

8.50mm＜TTL/FNO＜10.50mm；

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

When the above conditional expressions are satisfied, the aperture of the optical system 10 is favorably enlarged by reasonably controlling the ratio of the total optical length of the optical system 10 to the f-number of the optical system 10, so that a large aperture effect is realized; TTL/FNO is larger than or equal to 10.50mm, so that the total optical length of the optical system 10 is increased, the miniaturization design of the optical system 10 is not facilitated, and the production is not facilitated; TTL/FNO is less than or equal to 8.50mm, which may easily result in an excessively large f-number of the optical system 10, and thus the aperture of the optical system 10 is reduced, resulting in insufficient light incident amount, reduced relative illumination, and influence on the imaging quality, and is not favorable for large aperture imaging.

Preferably, in some embodiments, the image-side surface of the fifth lens L5 abuts against the object-side surface S11 of the sixth lens L6, which is beneficial to reduce chromatic aberration of the optical system 10 and correct spherical aberration of the optical system 10, so that the resolution of the shooting image of the optical system 10 is improved, and the imaging quality is better improved.

It is noted that in some embodiments, at least one lens in the optical system 10 has an aspheric surface, and when at least one side surface (object side surface or image side surface) of the lens is aspheric, the lens is said to have an aspheric surface. Specifically, both the object-side surface and the image-side surface of each lens may be designed to be aspherical. The aspheric surface configuration can further help the optical system 10 to effectively eliminate aberration, ghost image, astigmatism, chromatic aberration, spherical aberration, etc., and improve the imaging quality. Of course, in other embodiments, at least one lens in the optical system 10 may have a spherical surface shape, and the design of the spherical surface shape may reduce the difficulty and cost of manufacturing the lens. It should be noted that there may be some deviation in the ratios of the dimensions of the thickness, surface curvature, etc. of the respective lenses in the drawings. It should also be noted that when the object side surface or the image side surface of a lens is aspheric, the surface may have a reverse curvature, and the surface shape of the surface from the center to the 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 high-angle light rays of the first lens element L1 can be reasonably incident on the second lens element L2, and the risk of ghost images is reduced while the edge aberration is reduced.

Preferably, in one embodiment, both the object-side surface and the image-side surface of the third lens element L3 are aspheric, so that astigmatism of the optical system 10 is more effectively corrected.

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

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

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

Preferably, in one embodiment, the fifth lens L5 and the sixth lens L6 are arranged as cemented lenses.

Through the arrangement of the cemented lens, the chromatic aberration and the corrected spherical aberration of the optical system 10 are favorably reduced, the shooting resolution of the optical system 10 is favorably improved, and the function of high-pixel shooting is realized, so that the imaging quality is improved, in addition, the optical total length of the optical system 10 is favorably shortened, meanwhile, the process of installing the fifth lens L5 and the sixth lens L6 in the optical system 10 is simpler, the installation difficulty is reduced, and the tolerance sensitivity between the fifth lens L5 and the sixth lens L6 is favorably reduced. Of course, in other embodiments, the fifth lens L5 and the sixth lens L6 may be disposed at an interval from each other.

Furthermore, in some embodiments, the optical system 10 further satisfies at least one of the following relationships, and when any one of the conditional expressions is satisfied, the corresponding technical effect is brought about:

2.00 < CT4/EPD < 3.50; 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 conditional expressions 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 expressions are 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 picture feeling of the optical system 10, enhancing the presenting capability of details, and obtaining a clear image.

5.00＜Rs1/SAGs1＜7.00；

Wherein Rs1 is the curvature radius of the object-side surface S1 of the first lens element L1 on the optical axis 101, and sag 1 is the rise 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 in the direction of the optical axis 101). For example, in some embodiments, the numerical values of the conditional expressions 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 expressions are satisfied, by controlling the relationship between the curvature radius and the rise of the object-side surface S1 of the first lens element L1, while ensuring that the first lens element L1 provides the optical system 10 with a suitable negative refractive power, it is also beneficial to control the first lens element L1 to have a sufficient maximum effective aperture, so that the first lens element L1 can grasp the light rays entering the optical system 10 at a large angle, so as to expand the shooting range of the optical system 10 and increase the field angle; when Rs1/SAGs1 is equal to or greater than 7.00, the rise of the object-side surface S1 of the first lens element L1 is too small, or the curvature radius 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 favorable for increasing the field angle; rs1/SAGs1 is less than or equal to 5.00, the rise 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, large 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 conditional expressions 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 conditional expression is satisfied, the positive refractive power of the fourth lens element L4 can be reasonably configured, and the deflection angle of the light in the optical system 10 at the position of the fourth lens element L4 is effectively controlled, so that the sensitivity of the optical system 10 is reduced, and the resolution of the shot image is improved; when the CT4/f4 is greater than or equal to 2.00, the focal length of the fourth lens element L4 decreases, and the positive refractive power provided to the optical system 10 is too large, which results in too large a deflection angle of light rays in the optical system 10 at the fourth lens element L4; 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, so that the deflection angle of the marginal ray at the fourth lens L4 is too small, which is not favorable for correcting the aberration of the optical system 10, and further reduces the imaging quality of the optical system 10.

2.00＜AT1/∑AT＜3.00；

Here, AT1 is a distance on the optical axis 101 between the image-side surface of the first lens L1 and the object-side surface S3 of the second lens L2 (i.e., an air space between the first lens L1 and the second lens L2), Σ AT is a sum of distances on the optical axis 101 between two adjacent lenses of the first lens L1 to the seventh lens L7 (i.e., a total air space of seven lenses of the optical system 10), i.e., Σ AT is a sum of an air space between the first and second lenses L2, an air space between the second and third lenses L3, an air space between the third and fourth lenses L4, an air space between the fourth and fifth lenses L5, an air space between the fifth and sixth lenses L6, and an air space between the sixth and seventh lenses L7. For example, in some embodiments, the numerical values of the conditional expressions are specifically: 2.055, 2.139, 2.240, 2.345, 2.462, 2.584, 2.688, 3.793, 2.841, or 2.973.

When the above conditional expressions are satisfied, by controlling the ratio relationship between the air space between the first lens L1 and the second lens L2 and the total air space in the optical system 10, the spatial distribution of the whole optical system 10 is reasonable, which is beneficial to the assembly of the optical system 10 and effectively reduces the production cost of the optical system 10; when AT1/Σ AT is equal to or greater than 3.00, the air space between the first lens L1 and the second lens L2 is too large, which is not favorable for distributing the air space between the lenses of the optical system 10, and the structural compactness of the optical system 10 cannot be effectively improved; AT1/Σ AT ≦ 2.00, the total air space of the optical system 10 is increased, risking increased eccentricity sensitivity between the lenses 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 conditional expressions are specifically: 137.331 °/mm, 138.412 °/mm, 140.894 °/mm, 143.262 °/mm, 144.286 °/mm, 146.377 °/mm, 147.445 °/mm, 149.841 °/mm, 150.557 °/mm or 152.446 °/mm.

When the 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 towards a wide-angle direction, and simultaneously, the deflection angle of the emergent light can be reduced, which is beneficial to reducing the sensitivity of the optical system 10, and effectively correcting the aberration of the optical system 10, thereby achieving the imaging quality; when the FOV/f is larger 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, and the deflection angle of emergent rays is not reduced, so that the problem of edge dark angle of the optical system 10 is caused; when FOV/f is equal to or less than 155.00 °/mm, the maximum angle of view of the optical system 10 is reduced, and details of the subject cannot be captured at a large angle well, and it is difficult to achieve a wide angle.

1.50＜SD2/SAGs3＜3.50；

Where SD2 is half of the maximum effective aperture of the object-side surface S3 of the second lens L2 (i.e., the maximum effective half aperture), and SAGs3 is the rise of the object-side surface S3 of the second lens L2 (i.e., the distance from the intersection of the object-side surface S3 of the second lens L2 and the optical axis 101 to the maximum effective aperture of the object-side surface thereof in the optical axis 101 direction). For example, in some embodiments, the numerical values of the conditional expressions 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 conditional expressions are satisfied, by controlling the ratio of the maximum effective half aperture of the object-side surface S3 of the second lens L2 to the rise of the image-side surface thereof, the size of the maximum effective half aperture of the object-side surface S3 of the second lens L2 can be effectively controlled, and simultaneously, by controlling the rise of the image-side surface of the second lens L2 in a matching manner, the volume of the second lens L2 can be compressed to a greater extent, which is beneficial to shortening the optical overall length of the optical system 10, and is beneficial to reducing ghost risks, so that the imaging quality is high; when SD2/SAGs3 is larger than or equal to 3.50, the maximum effective half caliber of the object side surface S3 of the second lens L2 is not favorably reduced, and the risk that ghost images appear when light enters the second lens L2 is increased; when SD2/SAGs3 is less than or equal to 1.50, the rise of the image side surface of the second lens L2 is too large, which is not favorable for compressing the volume of the second lens L2, and the image side surface of the second lens L2 is too curved, so that the processing difficulty of the second lens L2 is large, 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 SAGs14 is the rise of the image-side surface of the seventh lens L7 (i.e., the distance from the intersection of the image-side surface of the seventh lens L7 and the optical axis 101 to the maximum effective aperture of the image-side surface thereof in the direction of the optical axis 101). For example, in some embodiments, the numerical values of the conditional expressions are specifically: 15.932 °/mm, 15.474 °/mm, 15.169 °/mm, 15.087 °/mm, 14.930 °/mm, 14.790 °/mm, 14.533 °/mm, 14.324 °/mm, 14.227 °/mm or 14.066 °/mm.

When the above conditional expression is satisfied, by controlling the rise 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 plane Si is not too curved, which is beneficial to molding 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, so that more rays are incident on the imaging plane Si, thereby increasing the relative illuminance of the imaging plane Si; when CRA/| SAGs14| ≦ 14.00 °/mm, the absolute value of the rise of the image-side surface of the seventh lens is made too large, which causes the seventh lens to be too curved, which is not beneficial to processing, and also easily causes the chief ray incident angle of the optical system at the maximum field of view to be too small, and the relative illumination of the imaging surface to be small; when CRA/| SAGs14| ≧ 16.00 °/mm, then the chief ray angle of the optical system at the maximum field of view is too large to match with the image sensor.

It should be noted that the effective focal length in each of the above relation conditions refers to the wavelength of 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 relation conditions and the technical effects thereof are directed to the six-piece optical system 10 having the above lens design. When the lens design (the number of lenses, the refractive power arrangement, the surface type arrangement, etc.) of the optical system 10 cannot be ensured, it is difficult to ensure that the optical system 10 can still have the corresponding technical effect while satisfying the relationships, and even the imaging performance may be significantly reduced.

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, at least one lens of the optical system 10 is made of Glass (GL). The lens made of plastic can reduce the production cost of the optical system 10, and the lens made of glass can endure higher or lower temperature and has excellent optical effect and better stability. In some embodiments, at least two lenses made of different materials may be disposed in the optical system 10, for example, a combination of a glass lens and a plastic lens may be adopted, but the specific configuration relationship may be determined according to practical requirements, and is not exhaustive here.

In some embodiments, the optical system 10 includes a filter 110, and the filter 110 is disposed on the fifth lens element L5 and on the image side of the image plane Si of the system. Specifically, the optical filter 110 is an infrared cut filter, and is used for filtering infrared light and preventing the infrared light from reaching the imaging plane Si of the system, so as to prevent 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 filter 110 is not a component of the optical system 10, and the 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 a camera module. In other embodiments, the function of filtering infrared light can also be achieved by disposing a filter 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 types of the respective lens surfaces in the optical system 10 are as follows:

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

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

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

the object-side surface S7 of the fourth lens element L4 is convex at the paraxial region, and the image-side surface S8 is convex at the paraxial region;

the object-side surface S9 of the fifth lens element L5 is convex at the paraxial region, and the image-side surface S10 is convex at the paraxial region;

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

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

In the embodiments of the present application, when it is described that a lens surface has a certain surface shape at a paraxial region, it means that the lens surface has the surface shape in the vicinity of the optical axis 101.

Specifically, 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 surfaces, and are made of glass; the object-side surface and the image-side surface of each of the second lens element L2, the third lens element L3, the fifth lens element L5, the sixth lens element L6, and the seventh lens element L7 are aspheric, and the material of each lens element is plastic.

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

The lens parameters of the optical system 10 in this embodiment are presented in table 1 below. The elements of the optical system 10 from the object side to the image side are arranged in the order from top to bottom according to table 1, wherein the stop STO represents an aperture stop. The filter 110 may be part of the optical system 10 or may be removed from the optical system 10, but the total optical length of the optical system 110 remains unchanged after the filter 110 is removed. The infrared filter 110 is used to filter infrared light. The Y radius 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 list 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 next optical element (lens or stop) on the optical axis 101, wherein the thickness parameter of the stop represents the distance from the stop surface to the object side of the adjacent lens on the image side on the optical axis 101. The reference wavelength of refractive index and abbe number of each lens in the table was 587.6nm, the reference wavelength of focal length (effective focal length) was 538nm, and the numerical units of Y radius, thickness, and focal length (effective focal length) were all millimeters (mm). In addition, the parameter data and the lens surface shape structure used for the relational expression calculation in the following embodiments are subject to the data in the lens parameter table in the corresponding embodiment.

TABLE 1

As can be seen from table 1, the effective focal length f of the optical system 10 in the first embodiment is 1.41mm, the f-number FNO is 1.80, the maximum field angle FOV is 202 °, the total optical length TTL is 16.90mm, the field angle of the image taken by the optical system 10 is large, the aperture is large, and the imaging effect is good. 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 corresponding to the rectangular effective pixel area of the 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

Number of noodles	S3	S4	S5	S6	S9
						k	-8.083E-01	-9.626E-01	4.661E-01	-1.206E+01	-5.670E+00
A4	-1.707E-03	-2.141E-02	-1.538E-04	5.567E-03	-1.421E-02
						A6	4.898E-04	4.933E-02	8.435E-03	1.009E-02	6.472E-02
A8	-7.788E-04	-5.419E-02	-1.441E-04	-3.484E-03	-2.068E-01
						A10	3.494E-04	3.257E-02	-3.324E-03	6.003E-06	3.846E-01
A12	-8.014E-05	-1.088E-02	2.589E-03	-2.092E-04	-4.403E-01
						A14	1.078E-05	5.782E-03	-9.760E-04	4.344E-04	3.136E-01
A16	-8.600E-07	-2.714E-05	2.040E-04	-5.184E-04	-1.357E-01
						A18	3.779E-08	-3.247E-05	-2.251E-05	1.292E-04	3.268E-02
A20	-7.047E-10	3.261E-06	1.031E-06	-1.172E-05	-3.366E-03

Number of noodles	S11	S12	S13	S14
						k	-1.276E-01	-4.617E+01	-5.459E+01	-4.033E+00
A4	-1.945E-01	6.961E-03	1.507E-03	-8.157E-03
						A6	2.209E-01	-1.529E-02	-1.427E-03	-6.920E-03
A8	-3.446E-01	2.308E-02	-5.191E-04	7.863E-03
						A10	7.179E-01	-1.871E-02	1.146E-03	-4.369E-03
A12	-5.898E-01	9.358E-03	-7.171E-04	1.471E-03
						A14	4.429E-01	-2.932E-03	2.398E-04	-3.108E-04
A16	-2.017E-01	5.593E-04	-4.512E-05	7.020E-05
						A18	5.030E-02	-5.944E-05	4.509E-06	-2.903E-06
A20	-5.275E-03	2.695E-06	-1.868E-07	8.979E-08

The surface shape of the aspheric surface can be calculated by referring to an aspheric surface formula:

where Z is the rise 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 a conic coefficient, and Ai is a coefficient corresponding to the ith order high term. It should be noted that the actual face shape of the lens is not limited to that shown in the drawings, which are not drawn to scale and may differ from the actual face configuration of the lens.

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

fig. 2 includes a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph of the optical system 10 in the first embodiment, wherein the reference wavelengths of the astigmatism graph and the distortion graph are 536nm, and the reference wavelengths of the astigmatism graph and the distortion graph in other embodiments are the same.

Longitudinal Spherical Aberration plots (Longitudinal Spherical Aberration) show the deviation of the converging focus of different wavelengths of light through the lens. The ordinate of the vertical spherical aberration diagram represents the Normalized Pupil coordinate (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 point of the ray and the optical axis. It can be known from the longitudinal spherical aberration curve chart that the convergent focus deviation degrees of the light rays with different wavelengths in the first embodiment tend to be consistent, and the diffuse speckles or color halos in the imaging picture are effectively inhibited.

Astigmatism graphs (Astigmatic Field Curves) in which the abscissa in the X-axis direction represents the focus shift (in mm), the ordinate in the Y-axis direction represents the Field angle (in °), the S-curve in the figure represents sagittal Field curvature at 536m, and the T-curve represents meridional Field curvature at 536 nm. As can be seen from the figure, the field curvature of the optical system is small, the degree of field curvature is effectively suppressed, the difference between the sagittal field curvature and the meridional field curvature in each field is small, and the astigmatism in each field is well controlled, so that the center to the edge of the field of view of the optical system 10 can be clearly imaged.

Distortion graphs (Distortion) in which the abscissa in the X-axis direction represents Distortion, the ordinate in the Y-axis direction represents a field angle (in °), and Distortion curves represent Distortion magnitudes 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 an object side to an image side, 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 stop STO, 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.

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 surfaces, and are made of glass; the object-side surface and the image-side surface of each of the second lens element L2, the third lens element L3, the fifth lens element L5, the sixth lens element L6, and the seventh lens element L7 are aspheric, and the material of each lens element is plastic. In addition, the fifth lens L5 and the sixth lens L6 collectively form a cemented lens.

In addition, the lens parameters of the optical system 10 in the second embodiment are shown in tables 3 and 4, wherein the definitions of the structures and parameters can be obtained from the first embodiment, which is not repeated herein.

TABLE 3

TABLE 4

Number of noodles	S3	S4	S5	S6	S9
						k	-4.451E-01	-4.561E-01	4.125E-01	-4.294E+01	-4.678E+00
A4	-9.346E-05	-2.152E-02	8.480E-03	1.294E-02	-9.291E-03
						A6	-5.623E-04	6.389E-02	-1.453E-02	-1.755E-02	2.864E-02
A8	-5.263E-04	-8.860E-02	3.503E-02	5.135E-02	-8.701E-02
						A10	3.637E-04	6.946E-02	-3.582E-02	-6.509E-02	1.638E-01
A12	-1.011E-04	-3.323E-02	2.165E-02	4.822E-02	-1.976E-01
						A14	1.566E-05	9.893E-03	-8.120E-03	-2.191E-02	1.515E-01
A16	-4.413E-06	-4.773E-03	4.857E-03	6.011E-03	-7.109E-02
						A18	6.946E-08	1.729E-04	-2.367E-04	-9.143E-04	1.851E-02
A20	-1.439E-09	-6.915E-06	1.290E-05	5.923E-05	-2.039E-03

Number of noodles	S11	S12	S13	S14
						k	-2.412E-01	-5.148E+01	-2.757E+01	-3.716E+00
A4	-1.905E-01	6.227E-03	3.190E-03	-5.263E-03
						A6	2.084E-01	-1.826E-02	-7.513E-03	-1.322E-02
A8	-3.410E-01	2.600E-02	3.251E-03	1.439E-02
						A10	6.043E-01	-1.758E-02	5.245E-04	-7.659E-03
A12	-4.615E-01	6.592E-03	-1.043E-03	3.216E-03
						A14	5.882E-01	-1.331E-03	4.356E-04	-7.488E-04
A16	-2.663E-01	1.102E-04	-8.862E-05	1.066E-04
						A18	6.508E-02	3.860E-06	9.099E-06	-8.487E-06
A20	-6.635E-03	-9.009E-07	-3.776E-07	2.909E-07

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 shift corresponding to the longitudinal spherical aberration at each wavelength is small, the degree of curvature of field is well suppressed, the astigmatism is reasonably adjusted, and the distortion is 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, 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 stop STO, 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.

In addition, the lens parameters of the optical system 10 in the third embodiment are given in tables 5 and 6, wherein the definitions of the structures and parameters can be obtained from the first embodiment, which are not repeated herein.

TABLE 5

TABLE 6

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 shift corresponding to the longitudinal spherical aberration at each wavelength is small, the degree of curvature of field is well suppressed, the astigmatism is reasonably adjusted, and the distortion is 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, 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 stop STO, 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.

In addition, the lens parameters of the optical system 10 in the fourth embodiment are given in tables 7 and 8, wherein the definitions of the structures and parameters can be obtained from the first embodiment, which is not repeated herein.

TABLE 7

TABLE 8

Number of noodles	S3	S4	S5	S6	S9
						k	-6.813E-01	-3.941E-01	9.985E-01	-5.261E+01	-5.607E+00
A4	4.707E-04	-1.694E-02	1.020E-02	1.669E-02	-9.490E-03
						A6	-1.082E-03	5.153E-02	-2.247E-02	-2.813E-02	3.911E-02
A8	-4.647E-04	-7.119E-02	4.414E-02	6.226E-02	-1.387E-01
						A10	3.949E-04	5.371E-02	-4.146E-02	-6.789E-02	2.892E-01
A12	-1.131E-04	-2.445E-02	2.363E-02	4.437E-02	-3.682E-01
						A14	1.756E-05	6.900E-03	-8.462E-03	-1.789E-02	2.883E-01
A16	-4.575E-06	-1.167E-03	1.859E-03	4.346E-03	-1.354E-01
						A18	7.681E-08	1.064E-04	-2.286E-04	-5.804E-04	3.489E-02
A20	-1.579E-09	-3.874E-06	1.204E-05	3.263E-05	-3.780E-03

Number of noodles	S11	S12	S13	S14
						k	-1.273E-01	-2.340E+01	-1.898E+01	-3.663E+00
A4	-1.386E-01	7.827E-03	7.729E-03	-8.037E-03
						A6	-1.414E-01	-3.047E-02	-1.897E-02	-8.173E-03
A8	5.933E-01	4.210E-02	1.326E-02	9.476E-03
						A10	-9.073E-01	-2.751E-02	-4.434E-03	-5.963E-03
A12	8.426E-01	1.004E-02	5.709E-04	2.285E-03
						A14	-5.189E-01	-2.017E-03	7.894E-05	-4.427E-04
A16	2.058E-01	1.795E-04	-3.668E-05	7.858E-05
						A18	-4.693E-02	2.292E-06	4.631E-06	-6.394E-06
A20	4.633E-03	-1.096E-06	-2.078E-07	2.269E-07

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

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 shift corresponding to the longitudinal spherical aberration at each wavelength is small, the degree of curvature of field is well suppressed, the astigmatism is reasonably adjusted, and the distortion is 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, 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 stop STO, 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.

In addition, the lens parameters of the optical system 10 in the fifth embodiment are given in tables 9 and 10, wherein the definitions of the structures and parameters can be obtained from the first embodiment, which are not repeated herein.

TABLE 9

Watch 10

Number of noodles	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

Number of noodles	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 well controlled, wherein the focal shift corresponding to the longitudinal spherical aberration at each wavelength is small, the degree of curvature of field is well suppressed, the astigmatism is reasonably adjusted, and the distortion is effectively suppressed.

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

In addition, referring to fig. 11, some embodiments of the present application further provide a camera module 20, where the camera module 20 may include the optical system 10 and the image sensor 210 according to any of the embodiments, and the image sensor 210 is disposed on an image side of the optical system 10. The image sensor 210 may be a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). Generally, the imaging plane Si of the optical system 10 overlaps the photosensitive surface of the image sensor 210 when assembled. Through adopting above-mentioned optical system 10 for module 20 of making a video recording can realize the shooting demand of big light ring, wide-angle, and it is effectual to form an image simultaneously.

Referring to fig. 12, some embodiments of the present application also provide an electronic device 30. The electronic device 30 includes a fixing member 310, the camera module 20 is mounted on the fixing member 310, and the fixing member 310 may be a display screen, a touch display screen, a circuit board, a middle frame, a rear cover, or 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, a monitoring device, an unmanned aerial vehicle, a medical device (such as an endoscope), a tablet computer, a biometric device (such as a fingerprint recognition device or a pupil recognition device), a PDA (Personal Digital Assistant), an unmanned aerial vehicle, and the like. In some embodiments, when the electronic device 30 is a vehicle-mounted camera device, the camera module 20 can be used as a vehicle-mounted all-round lens of the device, and the fixing member 310 is used for mounting the electronic device 30 on a vehicle. Because the size of the module of making a video recording 20 is less, released the restriction that the size of electronic equipment 30 set up, for electronic equipment to miniaturized development provides the condition, when utilizing electronic equipment 30 to shoot the scene, can realize the shooting demand of big light ring, wide-angle for the wide and shooting light ring of the scope of shooting is big, and it is effectual to form an image simultaneously, and the shooting quality can obtain better promotion.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An optical system comprising, in order 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 conditional expression:

8.50mm＜TTL/FNO＜10.50mm；

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

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

2.00＜CT4/EPD＜3.50；

3. The optical system according to 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, and SAGs1 is the rise of the object-side surface of the first lens at the maximum effective aperture.

4. The optical system according to claim 1, wherein the optical system further satisfies the conditional expression:

1.00＜CT4/f4＜2.00；

5. The optical system according to claim 1, wherein the optical system further satisfies the conditional expression:

2.00＜AT1/∑AT＜3.00；

wherein AT1 is a distance on an optical axis between an image side surface of the first lens element and an object side surface of the second lens element, and Σ AT is a sum of distances on the optical axis between two adjacent ones of the first to seventh lens elements.

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

135.00°/mm＜FOV/f＜155.00°/mm；

7. The optical system according to 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 aperture of the object-side surface of the second lens, SAGs3 is the rise of the object-side surface of the second lens at the maximum effective aperture.

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

14.00°/mm＜CRA/|SAGs14|＜16.00°/mm；

wherein CRA is a chief ray incident angle of the optical system at the maximum visual field, SAGs14 is a rise of an image-side surface of the seventh lens at the maximum effective aperture.

9. A camera 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 of claim 9, wherein the camera module is disposed on the fixing member.