CN114114619A

CN114114619A - Optical system, image capturing module and electronic equipment

Info

Publication number: CN114114619A
Application number: CN202111360378.9A
Authority: CN
Inventors: 党绪文; 杨健; 李明
Original assignee: Jiangxi Jingchao Optical Co Ltd
Current assignee: Jiangxi Jingchao Optical Co Ltd
Priority date: 2021-11-17
Filing date: 2021-11-17
Publication date: 2022-03-01

Abstract

The invention relates to an optical system, an image capturing module and an electronic device. An optical system includes: a diaphragm; a first lens element with positive refractive power having a convex object-side surface and a concave image-side surface; a second lens element with negative refractive power having a concave image-side surface at its circumference; a third lens element with refractive power; a fourth lens element with positive refractive power having a concave object-side surface and a convex image-side surface at paraxial region; a fifth lens element with negative refractive power having a concave image-side surface at paraxial region and a convex image-side surface at peripheral region; the optical system satisfies: 0.62mm < EPD/2 star TaHFOV-TT < 1.0 mm. The optical system can realize small-head design and miniaturization design, and has good imaging quality.

Description

Optical system, image capturing module and electronic equipment

Technical Field

The present invention relates to the field of camera shooting, and in particular, to an optical system, an image capturing module and an electronic device.

Background

In recent years, with the rapid development of camera technology, camera lenses are increasingly used in portable electronic devices such as smart phones, tablet computers, notebook computers, electronic readers, and the like, wherein the portable design of the electronic devices puts higher demands on the size of the heads of the camera lenses. The camera lens with the small head design has the advantages that the size of the head in the axial direction is small enough, the small head design can be realized, when the camera lens is applied to electronic equipment, the open hole of the lens cone can be reduced, and the portable design of the electronic equipment is facilitated. However, the size of the current camera lens head is difficult to meet the requirement of portable design of electronic equipment.

Disclosure of Invention

Accordingly, there is a need for an optical system, an image capturing module and an electronic apparatus to shorten the size of the head of the camera lens.

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

a diaphragm;

a first lens element with positive 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 concave image-side surface at its circumference;

a third lens element with refractive power;

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

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

and the optical system satisfies the following conditional expression:

0.62mm≤EPD/(2*tanHFOV)-TT≤1.0mm；

and EPD is the diameter of an entrance pupil of the optical system, HFOV is half of the maximum field angle of the optical system, and TT is the distance from the diaphragm to the intersection point of the object side surface of the first lens and the optical axis in the optical axis direction.

In the optical system, the first lens has positive refractive power, so that the total optical length of the optical system can be shortened, the requirement on miniaturization design can be met, and meanwhile, the trend of light rays of each field of view can be compressed, the spherical aberration of the optical system can be reduced, and the requirement on high-image-quality miniaturization of the optical system can be met. The image side surface of the first lens is concave at the paraxial region, so that a reasonable light ray incidence angle is favorably provided for the introduction of marginal light rays, and the imaging quality is favorably improved. The second lens element with negative refractive power has a concave image-side surface at its circumference, which is helpful for increasing the negative focal power effect, gradually diffusing the light rays contracted by the first lens element, reducing the deflection angle of the light rays, and facilitating the correction of the aberration generated by the first lens element. The fourth lens has positive refractive power, so that light rays in an inner view field can be converged, the aperture of light beams in an outer view field can be shrunk, and the compactness of the structure of the optical system can be improved. The object side surface of the fourth lens is a concave surface at the circumference, so that the curvature radius of the image side surface is favorably and reasonably restrained, and the tolerance sensitivity and the risk of stray light generation of the fourth lens are favorably reduced. The image side surface of the fifth lens is a concave surface at a paraxial region, which is beneficial to correcting distortion, astigmatism and field curvature, and further meets the requirements of low aberration and high image quality. The image side surface of the fifth lens is a convex surface at the circumference, so that the incident angle of light on an imaging surface can be kept in a reasonable range, an optical system can obtain large image surface characteristics, and the requirements of high relative brightness and small photosensitive element matching angle are met.

The above conditional expression totally reflects the axial size of the head of the optical system, and determines the minimum opening size of the optical system under the lens barrel. When the condition formula is met, the size of the head of the optical system is favorably shortened by matching with the design of the front diaphragm of the optical system, so that the size of the opening of the lens cone when the lens cone is configured by the optical system is shortened, the appearance of the head of the optical system is favorably improved, and the miniaturization design of the optical system is favorably realized. When the axial size of the head of the optical system exceeds the above conditional expression, the opening of the lens barrel cannot be reduced, and the appearance requirement of the lens is not satisfied; being lower than the lower limit of the conditional expression, the axial size of the head of the optical system is too small, and the diaphragm moves forwards excessively, so that the relative brightness of the edge view field is difficult to improve, and the brightness distribution and the image quality requirements of an imaging picture are influenced.

The optical system has the refractive power and the surface shape characteristics and satisfies the conditional expressions, can realize miniaturization design and small head design, and has large image surface characteristics, thereby having good imaging quality.

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

21≤|R22/SAG22|≤260；

wherein, R22 is a curvature radius of the image side surface of the second lens at the optical axis, and SAG22 is a rise of the image side surface of the second lens at the maximum effective aperture, that is, a distance from an intersection point of the image side surface of the second lens and the optical axis to the maximum effective aperture of the image side surface of the second lens in the optical axis direction. When the conditional expression is met, the ratio of the curvature radius of the image side surface of the second lens to the rise of the image side surface of the second lens can be reasonably configured, so that the second lens can bear lower focal power, and the combination of the first lens and the second lens can quickly converge light rays by utilizing reasonable focal power change, so that paraxial light rays can be refracted at a low deflection angle, and introduction of spherical aberration is reduced; meanwhile, the reasonable configuration of the surface shape of the image side surface of the second lens is also beneficial to enabling marginal rays to enter an optical system as much as possible, so that the marginal field of view has enough diffraction limit and performance; it is also advantageous that the profile of the second lens is not excessively curved, thereby contributing to a reduction in tolerance sensitivity of the second lens.

0.15≤(CT2+CT3)/f≤0.22；

wherein CT2 is the thickness of the second lens element on the optical axis, i.e. the center thickness of the second lens element, CT3 is the thickness of the third lens element on the optical axis, i.e. the center thickness of the third lens element, and f is the effective focal length of the optical system. When the condition formula is met, the ratio of the sum of the central thicknesses of the second lens and the third lens to the effective focal length of the optical system can be reasonably configured, the total length of the optical system is favorably shortened, the miniaturization design is realized, and meanwhile, the structure and the forming rationality of the non-effective diameter of the lens are favorably provided with enough space, so that the second lens and the third lens are favorably formed and assembled. Exceeding the upper limit of the above conditional expression, the center thicknesses of the second lens and the third lens are too large, which is disadvantageous for shortening the total length of the optical system, and is disadvantageous for the miniaturization design of the optical system. Being lower than the lower limit of the conditional expression, the central thicknesses of the second lens and the third lens are insufficient, which brings great obstacles to the assembly process and the molding process and influences the product yield.

CT2 is not less than 0.2mm and not more than 0.32 mm. When the conditional expression is satisfied, the second lens has a sufficiently large central thickness, so that the processing and the forming of the second lens are facilitated, and the tolerance sensitivity of the second lens is reduced; meanwhile, the central thickness of the second lens is not too large, so that the miniaturization design of the optical system is facilitated.

0.34mm^-1≤TTL/(IMGH*f)≤0.4mm^-1；

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, i.e., a total optical length of the optical system, IMGH is a half of an image height corresponding to a maximum field angle of the optical system, and f is an effective focal length of the optical system. When the condition is satisfied, the total length of the optical system is favorably compressed, so that the requirement of miniaturization design is satisfied; meanwhile, the optical system can obtain large image surface characteristics, so that the imaging quality is good. When the total length of the optical system exceeds the upper limit of the conditional expression, the total length of the optical system is too large, and the image plane is too small, so that the requirements of large image plane and small image plane are not met; the total length of the optical system is too short and the structure is too compact below the lower limit of the conditional expression, so that the refractive power born by each lens for completing light convergence is too large, and the deflection angle of the light in each lens is too large, so that the design difficulty of the lenses is large, the surface shape is easy to be distorted for many times, the tolerance sensitivity of each lens is increased, and the manufacturability of the optical system is reduced; meanwhile, the light rays of the edge field are restricted by large-range vignetting, so that good relative illumination is difficult to obtain, and the brightness distribution of an imaging picture is influenced.

TTL is not less than 3.7mm and not more than 4.6 mm. When the conditional expressions are met, the total length of the optical system is not too short, so that sufficient space is available for deflecting light rays, the refractive power borne by each lens is not too strong, the excellent optical imaging quality is favorably ensured, and the tolerance sensitivity of each lens is reduced; meanwhile, the total length of the optical system is favorably shortened, so that gaps among the lenses are reduced, the structure of the optical system is more compact, and the miniaturization design of the optical system is favorably realized.

2.5≤|R42/(R42+EPD)|≤4.5；

wherein R42 is a radius of curvature of an image-side surface of the fourth lens element at a paraxial region. When the conditional expressions are met, the curvature radius of the image side surface of the fourth lens and the entrance pupil diameter of the optical system can be reasonably configured, so that the focal power of the fourth lens can be favorably adjusted, the influence of the focal power on the process performance of the fourth lens caused by over concentration on the fourth lens is avoided, the surface types of the object side surface and the image side surface of the fourth lens are favorably restrained, and the influence of the excessive bending of the surface type of the fourth lens on the manufacturability is avoided; in addition, the correction of high-order aberration is further enhanced on the basis of reducing three-level aberrations such as spherical aberration, coma aberration, field curvature and the like, and the tolerance sensitivity of the optical system is reduced; in addition, the optical system is beneficial to increasing the diameter of the entrance pupil of the optical system, and better light entering quantity is obtained.

the absolute R42 absolute is more than or equal to 0.9mm and less than or equal to 3 mm. When the conditional expression is met, the curvature radius of the image side surface of the fourth lens can be reasonably configured, excessive bending of the image side surface of the fourth lens is avoided, and particularly the projection of the central area is avoided, so that the low-angle stray light reflection of the fourth lens is reduced, and the influence of ghost on imaging is reduced; meanwhile, the image side surface of the fourth lens is prevented from being too gentle, so that the fourth lens can effectively deflect light.

0.5≤|R32/f|≤3.5；

wherein R32 is a radius of curvature of an image-side surface of the third lens at an optical axis, and f is an effective focal length of the optical system. When the conditional expression is met, the ratio of the curvature radius of the image side surface of the third lens to the effective focal length of the optical system can be reasonably configured, so that the high-grade spherical aberration generated by the third lens can be favorably inhibited, and the optical system has good imaging quality; meanwhile, the excessive distortion of the surface shape of the third lens can be avoided, so that the tolerance sensitivity of the third lens is reduced. Below the lower limit of the conditional expression, the image side surface of the third lens is too curved, so that tolerance sensitivity is increased; exceeding the upper limit of the above conditional expression, the image-side surface profile of the third lens is too gentle, which is not favorable for correcting spherical aberration.

8≤R12/CT1≤40；

wherein R12 is a curvature radius of an image-side surface of the first lens element at an optical axis, and CT1 is a thickness of the first lens element at the optical axis, i.e., a center thickness of the first lens element. When the conditional expression is met, the ratio of the curvature radius of the image side surface of the first lens to the central thickness of the first lens can be reasonably configured, so that the focal power of the first lens can be enhanced, the first lens can rapidly converge marginal rays, and the introduction of spherical aberration is inhibited; meanwhile, the diameter of the entrance pupil of the optical system is increased, so that the diaphragm is moved forwards, the thickness uniformity of the first lens is improved, and the first lens has good manufacturability and low sensitivity.

2.3≤SP5/CT5≤3.2；

wherein SP5 is the farthest distance from the object-side surface of the fifth lens element to the image-side surface of the fifth lens element in the optical axis direction, and CT5 is the thickness of the fifth lens element in the optical axis direction, i.e., the center thickness of the fifth lens element. When the condition is satisfied, the thickness of the fifth lens is more uniform, the forming difficulty and the processing surface type error of the fifth lens are reduced, and the regulation of optical distortion and the improvement of optical performance in actual production are facilitated; meanwhile, the molding and reliability of the fifth lens are prevented from being influenced by the excessively thin thickness of the center of the fifth lens. Exceeding the upper limit of the above conditional expressions, the thickness uniformity of the fifth lens is poor, and the center thickness of the fifth lens is excessively small, which is disadvantageous to the molding and processing of the fifth lens.

An image capturing module includes a photosensitive element and the optical system of any of the above embodiments, wherein the photosensitive element is disposed at an image side of the optical system. The optical system is adopted in the image capturing module, so that the image capturing module is favorable for realizing miniaturization design and small head design, and has large image surface characteristics, thereby having good imaging quality.

An electronic device comprises a shell and the image capturing module, wherein the image capturing module is arranged on the shell. Adopt above-mentioned getting for instance the module among the electronic equipment, getting for instance the module can satisfy the demand of miniaturized design and little head design, is favorable to the portable design of electronic equipment, gets for instance the module still possesses big image plane characteristic simultaneously, can make electronic equipment possess good image quality.

Drawings

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

FIG. 2 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of an optical system in a first embodiment of the present application;

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

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

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

FIG. 6 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of an optical system in a third embodiment of the present application;

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

FIG. 8 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of an optical system in a fourth embodiment of the present application;

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

FIG. 10 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of an optical system in a fifth embodiment of the present application;

FIG. 11 is a schematic structural diagram of an optical system according to a sixth embodiment of the present application;

FIG. 12 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of an optical system in a sixth embodiment of the present application;

fig. 13 is a schematic view of an image capturing module according to an embodiment of the present application;

fig. 14 is a schematic diagram of an electronic device in 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," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the 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 not to be considered limiting of the invention.

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.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

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. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

In some embodiments of the present disclosure, the optical system 100 includes, in order from an object side to an image side along an optical axis 110, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5, referring to fig. 1. Specifically, the first lens element L1 includes an object-side surface S1 and an image-side surface S2, the second lens element L2 includes an object-side surface S3 and an image-side surface S4, the third lens element L3 includes an object-side surface S5 and an image-side surface S6, the fourth lens element L4 includes an object-side surface S7 and an image-side surface S8, and the fifth lens element L5 includes an object-side surface S9 and an image-side surface S10. The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 are coaxially disposed, and an axis common to the lenses in the optical system 100 is an optical axis 110 of the optical system 100. In some embodiments, the optical system 100 further includes an image plane S13 located on the image side of the fifth lens L5, and the incident light can be imaged on the image plane S13 after being adjusted by the first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5.

The first lens element L1 with positive refractive power is helpful for shortening the total optical length of the optical system 100 to meet the requirement of miniaturization design, and is also beneficial for compressing the light direction of each field of view, thereby being beneficial for reducing the spherical aberration of the optical system 100 and meeting the requirement of miniaturization of the optical system 100 with high image quality. The object-side surface S1 of the first lens element L1 is convex at the paraxial region 110. The image-side surface S2 of the first lens element L1 is concave at the paraxial region 110, which is favorable for providing a reasonable incident angle of light rays for introducing marginal light rays, thereby improving the image quality. The second lens element L2 with negative refractive power has a concave image-side surface S2 at the periphery, which helps to increase the negative power effect, gradually diffuse the light rays converging from the first lens element L1, reduce the deflection angle of the light rays, and help to correct the aberration generated by the first lens element L1. The third lens element L3 has refractive power. The fourth lens element L4 with positive refractive power is beneficial to converging light rays in the inner field of view, shrinking the aperture of light beams in the outer field of view, and improving the compactness of the optical system 100. The object-side surface S7 of the fourth lens L4 is concave at the circumference, which is beneficial to reasonably restrict the curvature radius of the image-side surface S8, thereby being beneficial to reducing tolerance sensitivity of the fourth lens L4 and risk of stray light generation. The image-side surface S8 of the fourth lens element L4 is convex at the paraxial region 110. The fifth lens element L5 has negative refractive power. The image-side surface S10 of the fifth lens element L5 is concave at the paraxial region 110, which is favorable for correcting distortion, astigmatism and field curvature, thereby meeting the requirements of low aberration and high image quality. The image-side surface S10 of the fifth lens element L5 is convex at the circumference, so that the incident angle of light on the image plane S13 can be kept in a reasonable range, which is beneficial for the optical system 100 to obtain large image plane characteristics, and meets the requirements of high relative brightness and small matching angle of the photosensitive elements.

In addition, in some embodiments, the optical system 100 is provided with a stop STO, which may be disposed on the object side of the first lens L1. In some embodiments, the optical system 100 further includes an infrared filter L6 disposed on the image side of the fifth lens L5. The ir filter L6 may be an ir cut filter, and is used to filter out interference light, so as to prevent the interference light from reaching the imaging surface S13 of the optical system 100 and affecting normal imaging.

In some embodiments, the object-side surface and the image-side surface of each lens of optical system 100 are both aspheric. The adoption of the aspheric surface structure can improve the flexibility of lens design, effectively correct spherical aberration and improve imaging quality. In other embodiments, the object-side surface and the image-side surface of each lens of the optical system 100 may be spherical. It should be noted that the above embodiments are only examples of some embodiments of the present application, and in some embodiments, the surface of each lens in the optical system 100 may be an aspheric surface or any combination of spherical surfaces.

In some embodiments, each lens in the optical system 100 may be made of glass or plastic. The lens made of plastic material can reduce the weight of the optical system 100 and the production cost, and the light and thin design of the optical system 100 can be realized by matching with the small size of the optical system 100. The glass lens provides the optical system 100 with excellent optical performance and high temperature resistance. It should be noted that the material of each lens in the optical system 100 may be any combination of glass and plastic, and is not necessarily both glass and plastic.

It is to be noted that the first lens L1 does not mean that there is only one lens, and in some embodiments, there may be two or more lenses in the first lens L1, and the two or more lenses can form a cemented lens, and a surface of the cemented lens closest to the object side can be regarded as the object side surface S1, and a surface of the cemented lens closest to the image side can be regarded as the image side surface S2. Alternatively, although no cemented lens is formed between the lenses of the first lens L1, the distance between the lenses is relatively fixed, and in this case, the object-side surface of the lens closest to the object side is the object-side surface S1, and the image-side surface of the lens closest to the image side is the image-side surface S2. In addition, the number of lenses in the second lens L2, the third lens L3, the fourth lens L4, or the fifth lens L5 in some embodiments may also be greater than or equal to two, and a cemented lens may be formed between any two adjacent lenses, or may also be a non-cemented lens.

Further, in some embodiments, the optical system 100 satisfies the conditional expression: EPD/(2. multidot tanHFOVV) -TT is less than or equal to 1.0mm and less than or equal to 0.62 mm; where EPD is the entrance pupil diameter of the optical system 100, HFOV is half of the maximum field angle of the optical system 100, and TT is the distance from the stop STO to the intersection of the object-side surface S1 of the first lens L1 and the optical axis 110 in the direction of the optical axis 110. Specifically, EPD/2/tan (FOV/2) -TT may be: 0.649, 0.673, 0.697, 0.725, 0.748, 0.826, 0.853, 0.921, 0.947 or 0.977, the numerical units being mm. The above conditional expressions collectively reflect the size of the head of the optical system 100 in the direction of the optical axis 110, and determine the minimum opening size of the optical system 100 in cooperation with the lens barrel. When the above conditional expressions are satisfied, the design of the front stop STO of the optical system 100 is used to facilitate shortening the head size of the optical system 100, thereby shortening the opening size of the lens barrel when the optical system 100 is configured with the lens barrel, facilitating the improvement of the head appearance of the optical system 100, and facilitating the miniaturization design of the optical system 100. Above the above conditional expression, the axial size of the head of the optical system 100 is too large, and the opening of the lens barrel cannot be reduced, which is insufficient to meet the requirement of the lens appearance; being lower than the lower limit of the above conditional expression, the axial dimension of the head of the optical system 100 is too small, and the stop STO moves forward excessively, so that the relative brightness of the edge field is difficult to be improved, and the brightness distribution and the image quality requirement of the imaging picture are affected.

Having the above-described refractive power and surface shape characteristics and satisfying the above-described conditional expressions, the optical system 100 can realize a miniaturized design and a small head design, and has a large image plane characteristic, thereby having good imaging quality.

In some embodiments, the optical system 100 satisfies the conditional expression: R22/SAG22 is more than or equal to 21 and less than or equal to 260; wherein, R22 is the radius of curvature of the image-side surface S4 of the second lens L2 at the optical axis 110, and SAG22 is the rise of the image-side surface S4 of the second lens L2 at the maximum effective aperture. Specifically, | R22/SAG22| may be: 23.645, 25.341, 26.874, 28.666, 30.105, 30.551, 50.631, 80.745, 150.258, or 252.336. When the conditional expressions are met, the ratio of the curvature radius to the rise of the image side surface S4 of the second lens L2 can be reasonably configured, so that the second lens L2 can bear lower focal power, and the combination of the first lens L1 and the second lens L2 can quickly converge light rays by utilizing reasonable focal power change, so that paraxial light rays can be refracted at a low deflection angle, and introduction of spherical aberration is reduced; meanwhile, the reasonable configuration of the surface shape of the image-side surface S4 of the second lens L2 is also beneficial to enable marginal rays to enter the optical system 100 as much as possible, so that the marginal field of view has sufficient diffraction limit and performance; it is also advantageous that the profile of the second lens L2 is not excessively curved, thereby contributing to a reduction in tolerance sensitivity of the second lens L2.

In some embodiments, the optical system 100 satisfies the conditional expression: 0.15 to (CT2+ CT3)/f to 0.22; wherein CT2 is the thickness of the second lens element L2 on the optical axis 110, CT3 is the thickness of the third lens element L3 on the optical axis 110, and f is the effective focal length of the optical system 100. Specifically, (CT2+ CT3)/f may be: 0.155, 0.162, 0.170, 0.178, 0.185, 0.193, 0.199, 0.202, 0.209, or 0.213. When the above conditional expressions are satisfied, the ratio of the sum of the central thicknesses of the second lens L2 and the third lens L3 to the effective focal length of the optical system 100 can be configured reasonably, which is beneficial to shortening the total length of the optical system 100, realizing miniaturization design, and providing enough space for the structure and the forming rationality of the non-effective diameter of the lens, thereby being beneficial to forming and assembling the second lens L2 and the third lens L3. Exceeding the upper limit of the above conditional expressions, the center thicknesses of the second lens L2 and the third lens L3 are too large, which is disadvantageous for shortening the total length of the optical system 100 and is disadvantageous for downsizing the design of the optical system 100. Below the lower limit of the above conditional expression, the center thicknesses of the second lens L2 and the third lens L3 are not sufficient, which brings great obstacles to the assembly process and the molding process and affects the product yield.

In some embodiments, the optical system 100 satisfies the conditional expression: CT2 is not less than 0.2mm and not more than 0.32 mm. When the above conditional expressions are satisfied, the second lens L2 has a sufficiently large center thickness, which is beneficial to processing and molding the second lens L2, and is beneficial to reducing tolerance sensitivity of the second lens L2; it is also advantageous to prevent the center thickness of the second lens L2 from being excessively large, thereby facilitating the compact design of the optical system 100.

In some embodiments, the optical system 100 satisfies the conditional expression: 0.34mm^-1≤TTL/(IMGH*f)≤0.4mm^-1(ii) a Wherein, TTL is a distance from the object-side surface S1 of the first lens element L1 to the image plane S13 of the optical system 100 on the optical axis 110, i.e., the total optical length of the optical system 100, IMGH is a half of the image height corresponding to the maximum field angle of the optical system 100, and f is the effective focal length of the optical system 100. Specifically, TTL/(IMGH × f) may be: 0.337, 0.342, 0.345, 0.350, 0.355, 0.367, 0.371, 0.379, 0.382 or 0.391, the numerical units are mm^-1. When the condition is satisfied, the total length of the optical system is favorably compressed, so that the requirement of miniaturization design is satisfied; meanwhile, the optical system 100 is facilitated to obtain large image plane characteristics, so that the imaging quality is good. When the total length of the optical system 100 exceeds the upper limit of the conditional expression, the total length is too large, and the image plane is too small, so that the requirements of large image plane and small image plane are not met; below the lower limit of the conditional expression, the total length of the optical system 100 is too short, the structure is too compact, so that the refractive power borne by each lens for completing light convergence is too large, and the deflection angle of light in each lens is too large, so that the design difficulty of the lens is large, the surface shape is easy to be distorted for many times, the tolerance sensitivity of each lens is increased, and the manufacturability of the optical system 100 is reduced; meanwhile, the light rays of the edge field are restricted by large-range vignetting, so that good relative illumination is difficult to obtain, and the brightness distribution of an imaging picture is influenced.

It should be noted that in some embodiments, the optical system 100 may match a photosensitive element having a rectangular photosensitive surface, and the imaging surface S13 of the optical system 100 coincides with the photosensitive surface of the photosensitive element. At this time, the effective pixel region on the imaging plane S13 of the optical system 100 has a horizontal direction and a diagonal direction, the maximum field angle FOV can be understood as the maximum field angle in the diagonal direction of the optical system 100, and ImgH can be understood as a half of the length in the diagonal direction of the effective pixel region on the imaging plane S13 of the optical system 100.

In some embodiments, the optical system 100 satisfies the conditional expression: TTL is not less than 3.7mm and not more than 4.6 mm. When the conditional expressions are satisfied, the total length of the optical system 100 is not too short, so that sufficient space is available for deflecting light rays, the refractive power borne by each lens is not too strong, the excellent optical imaging quality is favorably ensured, and the tolerance sensitivity of each lens is reduced; meanwhile, the total length of the optical system 100 is shortened, so that the gap between the lenses is reduced, the structure of the optical system 100 is more compact, and the miniaturization design of the optical system 100 is facilitated.

In some embodiments, the optical system 100 satisfies the conditional expression: the absolute value of R42/(R42+ EPD) is more than or equal to 2.5 and less than or equal to 4.5; wherein R42 is the radius of curvature of the image-side surface S8 of the fourth lens element L4 at the paraxial region 110. Specifically, | R42/(R42+ EPD) | may be: 2.515, 2.751, 2.938, 3.054, 3.587, 3.631, 3.774, 3.998, 4.115, or 4.311. When the conditional expressions are satisfied, the curvature radius of the image-side surface S8 of the fourth lens L4 and the entrance pupil diameter of the optical system 100 can be reasonably configured, which is beneficial to adjusting the focal power of the fourth lens L4, so as to avoid the influence of the focal power on the process performance of the fourth lens L4 caused by over-concentration on the fourth lens L4, and simultaneously, the surface shapes of the object-side surface S7 and the image-side surface S8 of the fourth lens L4 are restrained, and the influence of the excessive bending of the surface shape of the fourth lens L4 on the manufacturability is avoided; in addition, the correction of high-order aberration is further enhanced on the basis of reducing three-level aberrations such as spherical aberration, coma aberration, field curvature and the like, and the tolerance sensitivity of the optical system 100 is reduced; in addition, it is also helpful to increase the diameter of the entrance pupil of the optical system 100, so as to obtain better light-entering amount.

In some embodiments, the optical system 100 satisfies the conditional expression: the absolute R42 absolute is more than or equal to 0.9mm and less than or equal to 3 mm. When the conditional expression is satisfied, the curvature radius of the image-side surface S8 of the fourth lens L4 can be reasonably configured, and excessive surface curvature of the image-side surface S8 of the fourth lens L4, especially the protrusion of the central region, is avoided, so that the low-angle stray light reflection of the fourth lens L4 is favorably reduced, and the influence of ghost on imaging is reduced; meanwhile, the image-side surface S8 of the fourth lens L4 is prevented from being too gentle, so that the fourth lens L4 can effectively deflect light.

In some embodiments, the optical system 100 satisfies the conditional expression: r32/f is more than or equal to 0.5 and less than or equal to 3.5; where R32 is a curvature radius of the image-side surface S6 of the third lens element L3 on the optical axis 110, and f is an effective focal length of the optical system 100. Specifically, | R32/f | may be: 0.670, 0.971, 1.255, 1.789, 2.205, 2.654, 2.784, 3.028, 3.214, or 3.445. When the above conditional expressions are satisfied, the ratio of the curvature radius of the image-side surface S6 of the third lens L3 to the effective focal length of the optical system 100 can be configured reasonably, which is beneficial to suppressing the high-order spherical aberration generated by the third lens L3, so that the optical system 100 has good imaging quality; meanwhile, excessive distortion of the surface shape of the third lens L3 can be avoided, thereby reducing the tolerance sensitivity of the third lens L3. Below the lower limit of the above conditional expression, the image-side surface S6 of the third lens L3 is excessively curved, increasing the tolerance sensitivity; exceeding the upper limit of the above conditional expression makes the image-side surface S6 of the third lens L3 have a gentle surface shape, which is not favorable for correcting spherical aberration.

In some embodiments, the optical system 100 satisfies the conditional expression: R12/CT1 is more than or equal to 8 and less than or equal to 40; wherein R12 is a curvature radius of the image-side surface S2 of the first lens element L1 along the optical axis 110, and CT1 is a thickness of the first lens element L1 along the optical axis 110. Specifically, R12/CT1 may be: 8.227, 10.517, 13.547, 16.320, 18.563, 24.501, 28.664, 35.102, 36.557, or 38.322. When the conditional expressions are satisfied, the ratio of the curvature radius of the image side surface S2 of the first lens L1 to the central thickness of the first lens L1 can be reasonably configured, which is beneficial to enhancing the focal power of the first lens L1, so that the first lens L1 can quickly converge marginal rays and inhibit the introduction of spherical aberration; meanwhile, the diameter of the entrance pupil of the optical system 100 is increased, so that the diaphragm STO is moved forward, the thickness uniformity of the first lens L1 is improved, and the first lens L1 has good manufacturability and low sensitivity.

In some embodiments, the optical system 100 satisfies the conditional expression: SP5/CT5 is more than or equal to 2.3 and less than or equal to 3.2; SP5 is the farthest distance from the object-side surface S9 of the fifth lens element L5 to the image-side surface S10 of the fifth lens element L5 along the optical axis 110, and CT5 is the thickness of the fifth lens element L5 along the optical axis 110. Specifically, SP5/CT5 may be: 2.407, 2.455, 2.468, 2.533, 2.677, 2.812, 2.854, 2.903, 2.967, or 3.016. When the conditional expressions are met, the thickness of the fifth lens L5 is more uniform, and the forming difficulty and the processing surface type error of the fifth lens L5 are reduced, so that the regulation and control of optical distortion and the improvement of optical performance in actual production are facilitated; meanwhile, the center thickness of the fifth lens L5 is prevented from being too thin, which affects the molding and reliability of the fifth lens L5. Exceeding the upper limit of the above conditional expression, the thickness uniformity of the fifth lens L5 is poor, and the center thickness of the fifth lens L5 is excessively small, which is disadvantageous to the molding and processing of the fifth lens L5.

The reference wavelengths of the above effective focal length values are all 587 nm.

Based on the above description of the embodiments, more specific embodiments and drawings are set forth below for detailed description.

First embodiment

Referring to fig. 1 and fig. 2, fig. 1 is a schematic structural diagram of the optical system 100 in the first embodiment, and the optical system 100 includes, in order from an object side to an image side, a stop STO, a first lens element L1 with positive refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with positive refractive power, a fourth lens element L4 with positive refractive power, and a fifth lens element L5 with negative refractive power. Fig. 2 is a graph of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the first embodiment, which is sequentially from left to right, wherein the reference wavelength of the astigmatism graph and the distortion graph is 587nm, and the other embodiments are the same.

The object-side surface S1 of the first lens element L1 is convex at a paraxial region 110 and convex at a peripheral region;

the image-side surface S2 of the first lens element L1 is concave at the paraxial region 110 and convex at the periphery;

the object-side surface S3 of the second lens element L2 is convex at a paraxial region 110 and convex at a peripheral region;

the image-side surface S4 of the second lens element L2 is concave at a paraxial region 110 and concave at a peripheral region;

the object-side surface S5 of the third lens element L3 is convex at a paraxial region 110 and concave at a peripheral region;

the image-side surface S6 of the third lens element L3 is concave at a paraxial region 110 and convex at a peripheral region;

the object-side surface S7 of the fourth lens element L4 is convex at a paraxial region 110 and concave at a peripheral region;

the image-side surface S8 of the fourth lens element L4 is convex at a paraxial region 110 and convex at a peripheral region;

the object-side surface S9 of the fifth lens element L5 is convex at a paraxial region 110 and convex at a peripheral region;

the image-side surface S10 of the fifth lens element L5 is concave at a paraxial region 110 and convex at a peripheral region.

The object-side and image-side surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 are aspheric.

It should be noted that, in the present application, when a surface of the lens is described as being convex at a position near the optical axis 110 (the central region of the surface), it is understood that the region of the surface of the lens near the optical axis 110 is convex. When a surface of a lens is described as concave at the circumference, it is understood that the surface is concave near the region of maximum effective radius. For example, when the surface is convex at a paraxial region 110 and also convex at a peripheral region, the shape of the surface from the center (the intersection of the surface with the optical axis 110) to the edge direction may be purely convex; or a convex shape at the center is firstly transited to a concave shape, and then becomes a convex shape near the maximum effective radius. Here, only examples are made to illustrate the relationship at the optical axis 110 and the circumference, and various shape structures (concave-convex relationship) of the surface are not fully embodied, but other cases can be derived from the above examples.

The first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 are all made of plastic.

Further, the optical system 100 satisfies the conditional expression: EPD/(2. tanHFOV) -TT is 0.845 mm; where EPD is the entrance pupil diameter of the optical system 100, HFOV is half of the maximum field angle of the optical system 100, and TT is the distance from the stop STO to the intersection of the object-side surface S1 of the first lens L1 and the optical axis 110 in the direction of the optical axis 110. The above conditional expressions collectively reflect the size of the head of the optical system 100 in the direction of the optical axis 110, and determine the minimum opening size of the optical system 100 in cooperation with the lens barrel. When the above conditional expressions are satisfied, the design of the front stop STO of the optical system 100 is used to facilitate shortening the head size of the optical system 100, thereby shortening the opening size of the lens barrel when the optical system 100 is configured with the lens barrel, facilitating the improvement of the head appearance of the optical system 100, and facilitating the miniaturization design of the optical system 100.

The optical system 100 satisfies the conditional expression: R22/SAG22| ═ 23.645; wherein, R22 is the radius of curvature of the image-side surface S4 of the second lens L2 at the optical axis 110, and SAG22 is the rise of the image-side surface S4 of the second lens L2 at the maximum effective aperture. When the conditional expressions are met, the ratio of the curvature radius to the rise of the image side surface S4 of the second lens L2 can be reasonably configured, so that the second lens L2 can bear lower focal power, and the combination of the first lens L1 and the second lens L2 can quickly converge light rays by utilizing reasonable focal power change, so that paraxial light rays can be refracted at a low deflection angle, and introduction of spherical aberration is reduced; meanwhile, the reasonable configuration of the surface shape of the image-side surface S4 of the second lens L2 is also beneficial to enable marginal rays to enter the optical system 100 as much as possible, so that the marginal field of view has sufficient diffraction limit and performance; it is also advantageous that the profile of the second lens L2 is not excessively curved, thereby contributing to a reduction in tolerance sensitivity of the second lens L2.

The optical system 100 satisfies the conditional expression: (CT2+ CT3)/f is 0.181; wherein CT2 is the thickness of the second lens element L2 on the optical axis 110, CT3 is the thickness of the third lens element L3 on the optical axis 110, and f is the effective focal length of the optical system 100. When the above conditional expressions are satisfied, the ratio of the sum of the central thicknesses of the second lens L2 and the third lens L3 to the effective focal length of the optical system 100 can be configured reasonably, which is beneficial to shortening the total length of the optical system 100, realizing miniaturization design, and providing enough space for the structure and the forming rationality of the non-effective diameter of the lens, thereby being beneficial to forming and assembling the second lens L2 and the third lens L3.

The optical system 100 satisfies the conditional expression: TTL/(IMGH f) ═ 0.375mm^-1(ii) a Wherein, TTL is a distance on the optical axis 110 from the object-side surface S1 of the first lens element L1 to the image plane S13 of the optical system 100, IMGH is a half of the image height corresponding to the maximum field angle of the optical system 100, and f is the effective focal length of the optical system 100. When the condition is satisfied, the total length of the optical system is favorably compressed, so that the requirement of miniaturization design is satisfied; meanwhile, the optical system 100 is facilitated to obtain large image plane characteristics, so that the imaging quality is good.

The optical system 100 satisfies the conditional expression: R42/(R42+ EPD) | 2.639; wherein R42 is the radius of curvature of the image-side surface S8 of the fourth lens element L4 at the paraxial region 110. When the conditional expressions are satisfied, the curvature radius of the image-side surface S8 of the fourth lens L4 and the entrance pupil diameter of the optical system 100 can be reasonably configured, which is beneficial to adjusting the focal power of the fourth lens L4, so as to avoid the influence of the focal power on the process performance of the fourth lens L4 caused by over-concentration on the fourth lens L4, and simultaneously, the surface shapes of the object-side surface S7 and the image-side surface S8 of the fourth lens L4 are restrained, and the influence of the excessive bending of the surface shape of the fourth lens L4 on the manufacturability is avoided; in addition, the correction of high-order aberration is further enhanced on the basis of reducing three-level aberrations such as spherical aberration, coma aberration, field curvature and the like, and the tolerance sensitivity of the optical system 100 is reduced; in addition, it is also helpful to increase the diameter of the entrance pupil of the optical system 100, so as to obtain better light-entering amount.

The optical system 100 satisfies the conditional expression: r32/f 2.899; where R32 is a curvature radius of the image-side surface S6 of the third lens element L3 on the optical axis 110, and f is an effective focal length of the optical system 100. When the above conditional expressions are satisfied, the ratio of the curvature radius of the image-side surface S6 of the third lens L3 to the effective focal length of the optical system 100 can be configured reasonably, which is beneficial to suppressing the high-order spherical aberration generated by the third lens L3, so that the optical system 100 has good imaging quality; meanwhile, excessive distortion of the surface shape of the third lens L3 can be avoided, thereby reducing the tolerance sensitivity of the third lens L3.

The optical system 100 satisfies the conditional expression: R12/CT1 ═ 19.260; wherein R12 is a curvature radius of the image-side surface S2 of the first lens element L1 along the optical axis 110, and CT1 is a thickness of the first lens element L1 along the optical axis 110. When the conditional expressions are satisfied, the ratio of the curvature radius of the image side surface S2 of the first lens L1 to the central thickness of the first lens L1 can be reasonably configured, which is beneficial to enhancing the focal power of the first lens L1, so that the first lens L1 can quickly converge marginal rays and inhibit the introduction of spherical aberration; meanwhile, the diameter of the entrance pupil of the optical system 100 is increased, so that the diaphragm STO is moved forward, the thickness uniformity of the first lens L1 is improved, and the first lens L1 has good manufacturability and low sensitivity.

The optical system 100 satisfies the conditional expression: SP5/CT5 ═ 2.547; SP5 is the farthest distance from the object-side surface S9 of the fifth lens element L5 to the image-side surface S10 of the fifth lens element L5 along the optical axis 110, and CT5 is the thickness of the fifth lens element L5 along the optical axis 110. When the conditional expressions are met, the thickness of the fifth lens L5 is more uniform, and the forming difficulty and the processing surface type error of the fifth lens L5 are reduced, so that the regulation and control of optical distortion and the improvement of optical performance in actual production are facilitated; meanwhile, the center thickness of the fifth lens L5 is prevented from being too thin, which affects the molding and reliability of the fifth lens L5.

In addition, the parameters of the optical system 100 are given in table 1. In which elements from the object plane (not shown) to the image plane S13 are sequentially arranged in the order of elements from top to bottom of table 1. The Y radius in table 1 is the radius of curvature of the object-side or image-side surface at the optical axis 110 for the corresponding surface number. Surface numbers S1 and S2 denote an object-side surface S1 and an image-side surface S2 of the first lens L1, respectively, that is, in the same lens, a surface with a smaller surface number is an object-side surface, and a surface with a larger surface number is an image-side surface. The first numerical value in the "thickness" parameter column of the first lens element L1 is the thickness of the lens element along the optical axis 110, and the second numerical value is the distance between the image-side surface and the rear surface of the lens element along the image-side direction along the optical axis 110.

It should be noted that, in this embodiment and the following embodiments, the optical system 100 may not be provided with the infrared filter L6, but the distance from the image side surface S10 of the fifth lens L5 to the image plane S13 is kept unchanged.

In the first embodiment, the effective focal length f of the optical system 100 is 3.5mm, the total optical length TTL is 4.37mm, the maximum field angle FOV is 85.87deg, and the f-number FNO is 2.26. The optical system 100 can realize a compact design and a small head design, and has a large image plane characteristic and good imaging quality.

And the reference wavelengths of the focal length, refractive index and abbe number of each lens are 587nm, and the same is true for other embodiments.

TABLE 1

Further, aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are given by table 2. Wherein, the surface numbers from S1 to S10 represent the image side or the object side S1 to S10, respectively. And K-a20 from top to bottom respectively indicate the types of aspheric coefficients, where K indicates a conic coefficient, a4 indicates a quartic aspheric coefficient, a6 indicates a sextic aspheric coefficient, A8 indicates an octal aspheric coefficient, and so on. In addition, the aspherical surface coefficient formula is as follows:

wherein Z is the distance from the corresponding point on the aspheric surface to the plane tangent to the surface vertex, r is the distance from the corresponding point on the aspheric surface to the optical axis 110, c is the curvature of the aspheric surface vertex, K is the conic coefficient, and Ai is the coefficient corresponding to the i-th high-order term in the aspheric surface type formula.

TABLE 2

In addition, fig. 2 includes a Longitudinal Spherical Aberration diagram (Longitudinal Spherical Aberration) of the optical system 100, in which the Longitudinal Spherical Aberration curve represents the convergent focus deviation of light rays of different wavelengths after passing through the lens, wherein the ordinate represents Normalized Pupil coordinates (Normalized Pupil Coordinator) from the Pupil center to the Pupil edge, and the abscissa represents the focus deviation, i.e., the distance (in mm) from the image plane S17 to the intersection of the light rays and the optical axis 110. It can be known from the longitudinal spherical aberration diagram 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. Fig. 2 also includes an astigmatism graph (ASTIGMATIC FIELD CURVES) of the optical system 100 in which the abscissa represents the focus offset and the ordinate represents the image height in mm, and the S-curve in the astigmatism graph represents sagittal curvature at 587nm and the T-curve represents meridional curvature at 587 nm. As can be seen from the figure, the curvature of field of the optical system 100 is small, the curvature of field and astigmatism of each field are well corrected, and the center and the edge of the field have clear images. Fig. 2 further includes a DISTORTION plot (distorrion) of the optical system 100, where the DISTORTION plot represents DISTORTION magnitude values corresponding to different angles of view, where the abscissa represents DISTORTION value in mm and the ordinate represents image height in mm. As can be seen from the figure, the image distortion caused by the main beam is small, and the imaging quality of the system is excellent.

Second embodiment

Referring to fig. 3 and 4, fig. 3 is a schematic structural diagram of the optical system 100 in the second embodiment, in which the optical system 100 includes, in order from an object side to an image side, a stop STO, a first lens element L1 with positive refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with positive refractive power, a fourth lens element L4 with positive refractive power, and a fifth lens element L5 with negative refractive power. Fig. 4 is a graph of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the second embodiment, which is shown from left to right.

the object-side surface S9 of the fifth lens element L5 is convex at a paraxial region 110 and concave at a peripheral region;

In addition, the parameters of the optical system 100 are given in table 3, and the definitions of the parameters can be obtained from the first embodiment, which is not described herein.

TABLE 3

Further, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are shown in table 4, and the definitions of the parameters can be obtained from the first embodiment, which is not repeated herein.

TABLE 4

Number of noodles	S1	S2	S3	S4	S5
						K	-1.444E+00	8.230E+01	-9.900E+01	1.729E-01	-1.461E+01
A4	2.766E-02	-3.289E-01	-2.755E-01	-1.377E-01	-3.142E-01
						A6	-1.094E-01	9.558E-01	9.467E-01	9.339E-01	1.484E+00
A8	9.342E-01	-8.801E-01	-2.457E-01	-3.836E+00	-8.211E+00
						A10	-5.515E+00	-1.202E+01	-1.392E+01	1.211E+01	3.096E+01
A12	1.842E+01	5.866E+01	6.042E+01	-2.730E+01	-7.618E+01
						A14	-3.640E+01	-1.214E+02	-1.189E+02	4.148E+01	1.188E+02
A16	4.179E+01	1.307E+02	1.236E+02	-3.943E+01	-1.133E+02
						A18	-2.589E+01	-7.165E+01	-6.577E+01	2.086E+01	6.023E+01
A20	6.733E+00	1.589E+01	1.412E+01	-4.645E+00	-1.366E+01
						Number of noodles	S6	S7	S8	S9	S10
K	-2.773E+01	-2.142E+00	-8.463E+00	-6.903E+01	-7.239E+00
						A4	-1.186E-01	-5.264E-02	-1.917E-01	-2.341E-01	-5.712E-02
A6	3.176E-01	5.174E-02	4.144E-01	7.403E-02	-2.638E-02
						A8	-1.735E+00	-2.449E-01	-7.506E-01	-1.296E-02	4.291E-02
A10	5.488E+00	5.082E-01	8.472E-01	1.307E-02	-2.467E-02
						A12	-1.066E+01	-5.144E-01	-5.522E-01	-8.410E-03	7.983E-03
A14	1.273E+01	2.771E-01	2.144E-01	2.594E-03	-1.556E-03
						A16	-9.157E+00	-8.013E-02	-4.948E-02	-4.308E-04	1.802E-04
A18	3.653E+00	1.151E-02	6.316E-03	3.767E-05	-1.137E-05
						A20	-6.171E-01	-6.203E-04	-3.449E-04	-1.371E-06	2.998E-07

According to the provided parameter information, the following data can be deduced:

EPD/(2*tanHFOV)-TT(mm)	0.735	\|R42/(R42+EPD)\|	3.111
				\|R22/SAG22\|	31.472	\|R32/f\|	0.670
(CT2+CT3)/f	0.165	R12/CT1	38.322
				TTL/(IMGH*f)(mm^-1)	0.353	SP5/CT5	2.407

in addition, as can be seen from the aberration diagram in fig. 4, the longitudinal spherical aberration, astigmatism and distortion of the optical system 100 are well controlled, so that the optical system 100 of this embodiment has good imaging quality.

Third embodiment

Referring to fig. 5 and 6, fig. 5 is a schematic structural diagram of the optical system 100 in the third embodiment, in which the optical system 100 includes, in order from an object side to an image side, a stop STO, a first lens element L1 with positive refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with positive refractive power, a fourth lens element L4 with positive refractive power, and a fifth lens element L5 with negative refractive power. Fig. 6 is a graph of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the third embodiment, from left to right.

the image-side surface S6 of the third lens element L3 is concave at a paraxial region 110 and concave at a peripheral region;

the object-side surface S7 of the fourth lens element L4 is concave at a paraxial region 110 and concave at a peripheral region;

In addition, the parameters of the optical system 100 are given in table 5, and the definitions of the parameters can be obtained from the first embodiment, which is not described herein again.

TABLE 5

Further, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are shown in table 6, and the definitions of the parameters can be obtained from the first embodiment, which is not repeated herein.

TABLE 6

And, according to the above provided parameter information, the following data can be derived:

EPD/(2*tanHFOV)-TT(mm)	0.754	\|R42/(R42+EPD)\|	3.194
				\|R22/SAG22\|	26.355	\|R32/f\|	1.206
(CT2+CT3)/f	0.161	R12/CT1	17.364
				TTL/(IMGH*f)(mm^-1)	0.391	SP5/CT5	2.722

in addition, as can be seen from the aberration diagram in fig. 6, the longitudinal spherical aberration, astigmatism and distortion of the optical system 100 are well controlled, so that the optical system 100 of this embodiment has good imaging quality.

Fourth embodiment

Referring to fig. 7 and 8, fig. 7 is a schematic structural diagram of the optical system 100 in the fourth embodiment, in which the optical system 100 includes, in order from an object side to an image side, a stop STO, a first lens element L1 with positive 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, and a fifth lens element L5 with negative refractive power. Fig. 8 is a graph of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the fourth embodiment, which is shown from left to right.

the object-side surface S3 of the second lens element L2 is concave at a paraxial region 110 and concave at a peripheral region;

the image-side surface S4 of the second lens element L2 is convex at a paraxial region 110 and concave at a peripheral region;

the object-side surface S9 of the fifth lens element L5 is concave at a paraxial region 110 and convex at a peripheral region;

In addition, the parameters of the optical system 100 are given in table 7, and the definitions of the parameters can be obtained from the first embodiment, which is not described herein.

TABLE 7

Further, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are shown in table 8, and the definitions of the parameters can be obtained from the first embodiment, which is not repeated herein.

TABLE 8

EPD/(2*tanHFOV)-TT(mm)	0.649	\|R42/(R42+EPD)\|	2.515
				\|R22/SAG22\|	252.336	\|R32/f\|	1.909
(CT2+CT3)/f	0.155	R12/CT1	8.617
				TTL/(IMGH*f)(mm^-1)	0.361	SP5/CT5	3.016

in addition, as can be seen from the aberration diagram in fig. 8, the longitudinal spherical aberration, astigmatism, and distortion of the optical system 100 are well controlled, so that the optical system 100 of this embodiment has good imaging quality.

Fifth embodiment

Referring to fig. 9 and 10, fig. 9 is a schematic structural diagram of the optical system 100 in the fifth embodiment, in which the optical system 100 includes, in order from an object side to an image side, a stop STO, a first lens element L1 with positive refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with positive refractive power, a fourth lens element L4 with positive refractive power, and a fifth lens element L5 with negative refractive power. Fig. 10 is a graph showing the longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the fifth embodiment from left to right.

the image-side surface S2 of the first lens element L1 is concave at the paraxial region 110 and concave at the periphery;

the object-side surface S3 of the second lens element L2 is convex at a paraxial region 110 and concave at a peripheral region;

the object-side surface S5 of the third lens element L3 is convex at a paraxial region 110 and convex at a peripheral region;

the image-side surface S6 of the third lens element L3 is convex at a paraxial region 110 and convex at a peripheral region;

In addition, the parameters of the optical system 100 are given in table 9, and the definitions of the parameters can be obtained from the first embodiment, which is not described herein.

TABLE 9

Further, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are shown in table 10, and the definitions of the parameters can be obtained from the first embodiment, which is not repeated herein.

Watch 10

Number of noodles	S1	S2	S3	S4	S5
						K	-3.156E-01	6.593E+00	-9.900E+01	-2.379E+01	2.423E+01
A4	2.330E-02	-5.893E-02	-1.378E-01	-2.212E-02	-9.277E-02
						A6	2.999E-02	1.160E-02	1.025E-01	1.663E-02	8.274E-02
A8	-1.140E-01	-1.995E-01	-1.366E+00	-2.105E-01	5.379E-02
						A10	4.914E-01	4.232E-01	4.848E+00	5.877E-01	-5.759E-01
A12	-1.151E+00	-4.634E-01	-9.124E+00	-5.668E-01	1.345E+00
						A14	1.373E+00	-1.417E-01	8.837E+00	2.314E-01	-1.721E+00
A16	-5.768E-01	6.601E-01	-3.207E+00	1.979E-02	1.268E+00
						A18	0.000E+00	0.000E+00	0.000E+00	0.000E+00	-4.909E-01
A20	0.000E+00	0.000E+00	0.000E+00	0.000E+00	7.782E-02
						Number of noodles	S6	S7	S8	S9	S10
K	7.699E+00	2.188E+01	-3.891E+00	-5.729E+01	-4.232E+00
						A4	-1.179E-01	2.403E-02	-7.431E-03	-3.080E-01	-2.183E-01
A6	8.252E-02	-2.017E-01	-1.417E-01	7.541E-02	1.780E-01
						A8	-4.127E-01	2.841E-01	2.079E-01	1.254E-01	-1.019E-01
A10	1.300E+00	-5.245E-01	-2.742E-01	-1.352E-01	4.051E-02
						A12	-2.468E+00	7.746E-01	2.928E-01	6.545E-02	-1.118E-02
A14	2.791E+00	-6.981E-01	-1.801E-01	-1.816E-02	2.085E-03
						A16	-1.859E+00	3.623E-01	6.082E-02	2.958E-03	-2.493E-04
A18	6.704E-01	-9.945E-02	-1.068E-02	-2.636E-04	1.720E-05
						A20	-9.895E-02	1.118E-02	7.683E-04	9.942E-06	-5.180E-07

EPD/(2*tanHFOV)-TT(mm)	0.704	\|R42/(R42+EPD)\|	4.311
				\|R22/SAG22\|	23.702	\|R32/f\|	3.445
(CT2+CT3)/f	0.213	R12/CT1	9.408
				TTL/(IMGH*f)(mm^-1)	0.378	SP5/CT5	2.890

in addition, as can be seen from the aberration diagram in fig. 10, the longitudinal spherical aberration, astigmatism, and distortion of the optical system 100 are well controlled, so that the optical system 100 of this embodiment has good imaging quality.

Sixth embodiment

Referring to fig. 11 and 12, fig. 11 is a schematic structural diagram of the optical system 100 in the sixth embodiment, in which the optical system 100 includes, in order from an object side to an image side, a stop STO, a first lens element L1 with positive refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with positive refractive power, a fourth lens element L4 with positive refractive power, and a fifth lens element L5 with negative refractive power. Fig. 12 is a graph showing longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the sixth embodiment, in order from left to right.

the object-side surface S5 of the third lens element L3 is concave at a paraxial region 110 and concave at a peripheral region;

In addition, the parameters of the optical system 100 are given in table 11, and the definitions of the parameters can be obtained from the first embodiment, which is not described herein.

TABLE 11

Further, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are given in table 12, and the definitions of the parameters can be obtained from the first embodiment, which is not repeated herein.

TABLE 12

EPD/(2*tanHFOV)-TT(mm)	0.977	\|R42/(R42+EPD)\|	3.944
				\|R22/SAG22\|	30.050	\|R32/f\|	1.576
(CT2+CT3)/f	0.191	R12/CT1	8.227
				TTL/(IMGH*f)(mm^-1)	0.337	SP5/CT5	2.602

in addition, as can be seen from the aberration diagram in fig. 12, the longitudinal spherical aberration, astigmatism, and distortion of the optical system 100 are well controlled, so that the optical system 100 of this embodiment has good imaging quality.

Referring to fig. 13, in some embodiments, the optical system 100 may be assembled with the photosensitive element 210 to form the image capturing module 200. At this time, the light-sensing surface of the light-sensing element 210 can be regarded as the image-forming surface S13 of the optical system 100. The image capturing module 200 may further include an infrared filter L6, and the infrared filter L6 is disposed between the image side surface S10 and the image plane S13 of the fifth lens element L5. Specifically, the photosensitive element 210 may be a Charge Coupled Device (CCD) or a Complementary Metal-Oxide Semiconductor (CMOS) Device. The optical system 100 is adopted in the image capturing module 200, which is beneficial to the image capturing module 200 to realize miniaturization design and small head design, and has large image surface characteristics, thereby having good imaging quality.

Referring to fig. 13 and 14, in some embodiments, the image capturing module 200 may be applied to an electronic device 300, the electronic device 300 includes a housing 310, and the image capturing module 200 is disposed in the housing 310. Specifically, the electronic apparatus 300 may be, but is not limited to, a wearable device such as a mobile phone, a video phone, a smart phone, an electronic book reader, a vehicle-mounted image capturing apparatus such as a car recorder, or a smart watch. When the electronic device 300 is a smartphone, the housing 310 may be a middle frame of the electronic device 300. Adopt above-mentioned module 200 of getting for instance in electronic equipment 300, get for instance module 200 can satisfy the demand of miniaturized design and little head design, is favorable to electronic equipment 300's portable design, gets for instance module 200 still possesses big image plane characteristic simultaneously, can make electronic equipment 300 possess good imaging quality.

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;

a third lens element with refractive power;

and the optical system satisfies the following conditional expression:

0.62mm≤EPD/(2*tanHFOV)-TT≤1.0mm；

2. The optical system according to claim 1, wherein the following conditional expression is satisfied:

21≤|R22/SAG22|≤260；

wherein R22 is the radius of curvature of the image-side surface of the second lens at the optical axis, and SAG22 is the rise of the image-side surface of the second lens at the maximum effective aperture.

3. The optical system according to claim 1, wherein the following conditional expression is satisfied:

0.15≤(CT2+CT3)/f≤0.22；

wherein CT2 is the thickness of the second lens element, CT3 is the thickness of the third lens element, and f is the effective focal length of the optical system.

4. The optical system according to claim 1, wherein the following conditional expression is satisfied:

0.34mm^-1≤TTL/(IMGH*f)≤0.4mm^-1；

wherein, TTL is a distance on an optical axis from an object-side surface of the first lens element to an imaging surface of the optical system, IMGH is a half of an image height corresponding to a maximum field angle of the optical system, and f is an effective focal length of the optical system.

5. The optical system according to claim 1, wherein the following conditional expression is satisfied:

2.5≤|R42/(R42+EPD)|≤4.5；

wherein R42 is a radius of curvature of an image-side surface of the fourth lens element at a paraxial region.

6. The optical system according to claim 1, wherein the following conditional expression is satisfied:

0.5≤|R32/f|≤3.5；

wherein R32 is a radius of curvature of an image-side surface of the third lens at an optical axis, and f is an effective focal length of the optical system.

7. The optical system according to claim 1, wherein the following conditional expression is satisfied:

8≤R12/CT1≤40；

wherein R12 is a curvature radius of an image-side surface of the first lens element on an optical axis, and CT1 is a thickness of the first lens element on the optical axis.

8. The optical system according to claim 1, wherein the following conditional expression is satisfied:

2.3≤SP5/CT5≤3.2；

wherein SP5 is a maximum distance from an object-side surface of the fifth lens element to an image-side surface of the fifth lens element in an optical axis direction, and CT5 is a thickness of the fifth lens element in the optical axis direction.

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

10. An electronic device, comprising a housing and the image capturing module of claim 9, wherein the image capturing module is disposed on the housing.