CN212321964U

CN212321964U - Optical system, image capturing module, electronic equipment and automobile

Info

Publication number: CN212321964U
Application number: CN202021455863.5U
Authority: CN
Inventors: 蔡雄宇; 兰宾利; 周芮
Original assignee: Tianjin OFilm Opto Electronics Co Ltd
Current assignee: Jiangxi Oufei Optics Co ltd
Priority date: 2020-07-22
Filing date: 2020-07-22
Publication date: 2021-01-08
Anticipated expiration: 2030-07-22

Abstract

The utility model relates to an optical system, get for instance module, electronic equipment and car. The optical system includes in order from an object side to an image side: 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 concave object-side surface and a concave image-side surface; a third lens element with positive refractive power; a diaphragm; a fourth lens element with positive refractive power; a fifth lens element with positive refractive power; a sixth lens element with negative refractive power; the optical system satisfies the conditional expression: -20 ≤ f5 ≤ f6/f ≤ 10; wherein f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, and f is the effective focal length of the optical system. The optical system has excellent imaging quality.

Description

Optical system, image capturing module, electronic equipment and automobile

Technical Field

The utility model relates to a field of making a video recording especially relates to an optical system, gets for instance module, electronic equipment and car.

Background

Along with the continuous improvement of people to the security requirement of traveling of car, be provided with on-vehicle camera lens on more and more cars for shoot car scenery image all around, make the driver can know the car road conditions information all around more clearly, avoid rolling, the emergence of accidents such as scraping, improve the security of traveling of car. However, the imaging quality of the current vehicle-mounted camera lens is insufficient, the images of the scenery around the automobile are not clear enough, and the requirement on driving safety is difficult to meet.

SUMMERY OF THE UTILITY MODEL

Therefore, it is necessary to provide an optical system, an image capturing module, an electronic device, and an automobile for solving the problem that the imaging quality of the vehicle-mounted camera lens is reduced due to the insufficient aberration correction capability of the vehicle-mounted camera lens.

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

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 concave object-side surface and a concave image-side surface;

a third lens element with positive refractive power;

a fourth lens element with positive refractive power;

a fifth lens element with positive refractive power;

a sixth lens element with negative refractive power;

and the optical system satisfies the following conditional expression:

-20mm≤f5*f6/f≤-10mm；

wherein f5 is an effective focal length of the fifth lens, f6 is an effective focal length of the sixth lens, and f is an effective focal length of the optical system.

In the optical system, the rear lens group composed of the fifth lens element with positive refractive power and the sixth lens element with negative refractive power can correct aberration generated by the deflected light rays of each lens element at the object side of the rear lens group, so as to improve the imaging quality of the optical system. When the condition formula is met, the phenomenon that the deflection angle of light rays is too large due to the fact that the whole refractive power of the rear lens group is too strong can be avoided, the effect that the emergent angle of the light rays after deflection of the rear lens group is reduced is achieved, the incident angle of the light rays on the imaging surface of the optical system is further reduced, the optical system can be better matched with the photosensitive performance of the photosensitive element, and the imaging quality of the optical system is improved. When f5 f6/f > -10, it is not favorable to suppress the high-order aberration generated by the peripheral field rays on the image plane of the optical system. When f5 is f6/f < -20, it is not favorable to suppress the occurrence of chromatic aberration of the optical system, resulting in a decrease in the imaging quality of the optical system.

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

4≤(R1-R2)/f≤7；

wherein R1 is a curvature radius of an object side surface of the first lens at an optical axis, R2 is a curvature radius of an image side surface of the first lens at the optical axis, and f is an effective focal length of the optical system. By setting the surface types of the object side surface and the image side surface of the first lens element, the first lens element near the object side of the optical system provides negative refractive power for the optical system. When the conditional expressions are satisfied, it is possible to prevent an increase in difficulty in processing the first lens element due to an excessively large difference in the degree of surface curvature between the object-side surface and the image-side surface of the first lens element, and to suppress occurrence of astigmatism in a wide-angle field of view of the optical system. When (R1-R2)/f < 4), the refractive power of the optical system is insufficient, so that light rays with a large angle of view are difficult to enter the optical system, and the maximum angle of view of the optical system is not enlarged. When (R1-R2)/f > 7, the difference between the surface curvatures of the object-side surface and the image-side surface of the first lens is too large, which makes the first lens difficult to process and is liable to generate strong astigmatism and chromatic aberration, which is not favorable for improving the imaging quality of the optical system.

1.5≤R1/ED1≤2.1；

wherein R1 is the radius of curvature of the object-side surface of the first lens at the optical axis, and ED1 is half the maximum effective aperture of the object-side surface of the first lens. The object side surface of the first lens is set to be a convex surface, when the conditional expression is satisfied, the curvature radius and the maximum effective aperture of the object side surface of the first lens at the optical axis can be reasonably configured, so that large-angle light rays can be emitted into the optical system and converged on an imaging surface, and the maximum field angle of the optical system is enlarged. Meanwhile, the maximum effective aperture of the first lens can be shortened, so that the requirement of small head design of the camera lens is met. When R1/ED1 is more than 2.1, the object-side surface of the first lens is too gentle to allow high-angle light rays to enter the optical system, so that the optical system is difficult to realize a wide-angle design. When R1/ED1 is less than 1.5, if the curvature radius of the object-side surface of the first lens element at the optical axis is too small, the surface shape of the object-side surface of the first lens element is too curved, which is not favorable for aberration correction of the system and lens processing, or the maximum effective aperture of the first lens element is too large, which is not favorable for small head design of the camera lens.

R3/f2≥50；

wherein R3 is a radius of curvature of an object-side surface of the second lens at an optical axis, and f2 is an effective focal length of the second lens. If the negative refractive power of the second lens element is too strong, the tolerance sensitivity of the second lens element is easily increased, and the eccentricity sensitivity of the optical system during the assembling process is easily increased, which affects the assembling yield of the optical system. When the conditional expressions are satisfied, the curvature radius of the object side surface of the second lens at the optical axis can be increased, and further the eccentric sensitivity of the optical system to the second lens in the assembling process is reduced, so that the assembling yield of the optical system is improved. When R3/f2 < 50, the object-side surface of the second lens is too curved, which increases the eccentricity sensitivity of the optical system during the assembly process, resulting in a decrease in the assembly yield of the optical system and an increase in the production cost of the optical system.

1≤R4/SAG4≤4；

wherein R4 is the radius of curvature of the image side of the second lens at the optical axis, and SAG4 is the sagittal height at the maximum effective aperture of the image side of the second lens. The curvature radius of the image side surface of the second lens at the optical axis influences the refractive power of the second lens, and when the surface-type bending degree of the image side surface of the second lens is larger, the stronger the negative refractive power of the second lens is, the more beneficial the light rays passing through the second lens are to be deflected, so that the light rays can be better converged on the imaging surface of the optical system. When the condition expression is satisfied, the negative refractive power of the second lens element is enhanced, and the astigmatism generated by the deflected light of the first lens element can be effectively corrected. In addition, it is possible to avoid an increase in difficulty in processing the second lens due to an excessive curvature of the surface shape of the image-side surface of the second lens. When R4/SAG4 > 4, the negative refractive power of the second lens is insufficient, which is not favorable for correcting the aberration of the optical system. When R4/SAG4 < 1, the surface shape of the image side surface of the second lens is too curved, which increases the processing difficulty of the second lens, and further causes the second lens to be easy to crack and the like in the aspheric surface process forming process.

-16mm≤f2*f3/f≤3mm；

wherein f2 is an effective focal length of the second lens, f3 is an effective focal length of the third lens, and f is an effective focal length of the optical system. The second lens provides negative refractive power for the optical system, which is beneficial to expanding the width of the light beam in the optical system so as to expand the width of the light beam of the light with a large-angle view field after being deflected by the first lens. And the third lens with positive refractive power can reduce the deflection angle of the light rays passing through the second lens, so that the light beams fill the pupil of the optical system. When the condition is satisfied, the aberration generated by the deflected light rays of the second lens and the third lens is favorably corrected, and the imaging quality of the optical system is improved. When f2 × f3/f is out of the range of the above conditional expressions, it is not favorable to correct the aberration of the optical system, thereby resulting in a decrease in the imaging quality of the optical system.

2≤CT3/SAG5≤15；

wherein CT3 is the thickness of the third lens on the optical axis, i.e. the central thickness of the third lens, SAG5 is the rise of the vector at the maximum effective aperture of the object side surface of the third lens, i.e. the distance from the intersection of the object side surface of the third lens with the optical axis to the maximum effective aperture of the object side surface of the third lens, SAG5 is positive when the maximum effective aperture of the object side surface of the third lens is on the image side of the center of the object side surface of the third lens, and SAG5 is negative when the maximum effective aperture of the object side surface of the third lens is on the object side of the center of the object side surface of the third lens. When the conditional expressions are satisfied, the central thickness of the third lens element and the rise of the object-side surface of the third lens element can be reasonably configured, so that the third lens element has strong positive refractive power, the central thickness of the third lens element is not too large, the surface shape of the object-side surface of the third lens element is not excessively curved, and the increase of the processing difficulty of the third lens element and the increase of the production cost of the optical system are avoided. When CT3/SAG5 < 2, the object-side surface of the third lens is too curved, which increases the processing difficulty of the third lens, and further increases the production cost of the optical system, and also causes the peripheral field of view of the optical system to be prone to aberration, which is not favorable for improving the imaging quality of the optical system. When CT3/SAG5 > 15, the central thickness of the third lens is too large, resulting in too large a density of lenses in the optical system, which in turn results in an increase in the weight of the optical system, which is disadvantageous for reducing the weight of the optical system, and which is also disadvantageous for the compact design of the optical system.

Vdi≤25；

wherein Vdi is the abbe number of the ith lens in the optical system under the d-line, and i is at least one of 1, 2, 3, 4, 5 and 6. When the condition is met, the material of the lens in the optical system can be reasonably configured, the chromatic aberration of the optical system can be corrected, and the imaging quality of the optical system can be improved.

6.0≤TTL/CT4≤9.2；

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 system length of the optical system, and CT4 is a thickness of the fourth lens element on the optical axis. When the conditional expressions are satisfied, the total system length of the optical system and the center thickness of the fourth lens can be reasonably configured, which is beneficial to shortening the total system length of the optical system, so as to satisfy the requirement of miniaturization design and simultaneously be beneficial to reducing the weight of the optical system. When TTL/CT4 is less than 6.0, the central thickness of the fourth lens in the optical system is too large, which results in too large weight ratio of the fourth lens in the optical system, and is not favorable for reducing the weight of the optical system. When TTL/CT4 is more than 9.2, the total length of the optical system is too long, which is not beneficial to the miniaturization design of the optical system.

4.5mm≤2f*tan(VFOV/2)≤5.5mm；

wherein f is the effective focal length of the optical system, and VFOV is the maximum field angle of the optical system in the vertical direction of the effective pixel area on the imaging plane. When the condition formula is satisfied, the maximum field angle of the optical system in the vertical direction of the effective pixel area of the imaging surface can be enlarged to satisfy the requirement of large-view-angle shooting.

HFOV≥180°；

the HFOV is a maximum angle of view of the optical system in a horizontal direction of an effective pixel region on an imaging plane. When the condition formula is satisfied, the maximum field angle of the optical system in the horizontal direction of the effective pixel area of the imaging surface can be enlarged to satisfy the requirement of large-view-angle shooting.

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. By adopting the optical system in the image capturing module, the aberration of the optical system can be better corrected, and the image capturing module has excellent imaging quality, so that the image capturing module also has excellent imaging quality.

An electronic device comprises a shell and the image capturing module, wherein the image capturing module is arranged on the shell. The image capturing module is adopted in the electronic equipment, the aberration of the optical system can be better corrected, and the electronic equipment has excellent imaging quality. When the electronic equipment is applied to the field of vehicle-mounted camera shooting, the electronic equipment can form clear images of scenery around the automobile so as to meet the requirement of driving safety.

An automobile comprises a mounting piece and the electronic equipment, wherein the electronic equipment is arranged on the mounting piece. The electronic equipment is adopted in the automobile, so that the automobile can form clear images for surrounding scenes, and the requirement on driving safety is met.

Drawings

FIG. 1 is a schematic view of an optical system in a first embodiment of the present application;

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

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

FIG. 4 is a 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 view of an optical system according to a third embodiment of the present application;

FIG. 6 is a 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 view of an optical system according to a fourth embodiment of the present application;

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

FIG. 9 is a schematic view of an optical system in a fifth embodiment of the present application;

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

FIG. 11 is a schematic view of an optical system in a sixth embodiment of the present application;

FIG. 12 is a 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 diagram of an electronic device in an embodiment of the present application;

fig. 15 is a schematic view of an automobile according to an embodiment of the present application.

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will be able to make similar modifications without departing from the spirit and scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "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, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present 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," and "fixed" are to be construed broadly and may, 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 meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. 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, referring to fig. 1, the optical system 100 includes, in order from an object side to an image side, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6. 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, the fifth lens element L5 includes an object-side surface S9 and an image-side surface S10, and the sixth lens element L6 includes an object-side surface S11 and an image-side surface S12. And the optical system 100 can be assembled with a lens barrel to form an image pickup lens.

The first lens element L1 with negative refractive power has a convex object-side surface S1 and a concave image-side surface S2 at paraxial regions of the first lens element L1. The second lens element L2 with negative refractive power has a concave object-side surface S3 and a concave image-side surface S4 of the second lens element L2 at the paraxial region. The third lens element L3 has positive 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.

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 fourth lens L1. In some embodiments, the optical system 100 further includes an infrared filter L7 disposed on the image side of the sixth lens L6, and the infrared filter L7 includes an object-side surface S13 and an image-side surface S14. Furthermore, the optical system 100 further includes an image plane S17 located on the image side of the sixth lens L6, the image plane S17 is an imaging plane of the optical system 100, and incident light is adjusted by the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 and can be imaged on the image plane S19. It should be noted that the infrared filter L7 may be an infrared cut filter, and is used for filtering the interference light and preventing the interference light from reaching the image plane S17 of the optical system 100 to affect the normal imaging. Also, in some embodiments, the optical system 100 further includes a protective glass L8 disposed on the image side of the infrared filter L7 for protecting the photosensitive elements disposed on the optical system 100.

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. For example, in some embodiments, the object-side surface and the image-side surface of the second lens element L2, the third lens element L3 and the fourth lens element L4 are aspheric, and the object-side surface and the image-side surface of the first lens element L1, the fifth lens element L5 and the sixth lens element L6 are spherical.

In some embodiments, each lens in the optical system 100 may be made of glass or plastic. The use of plastic lenses can reduce the weight and cost 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, the fifth lens L5, or the sixth lens L6 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: -20mm < f5 x f6/f < 10 mm; where f5 is the effective focal length of the fifth lens L5, f6 is the effective focal length of the sixth lens L6, and f is the effective focal length of the optical system 100. Specifically, f5 × f6/f may be: -17.22, -16.89, -16.52, -15.34, -15.01, -14.99, -14.63, -14.28, -13.87 or-13.65, data units are mm. The rear lens group consisting of the fifth lens element L5 with positive refractive power and the sixth lens element L6 with negative refractive power can correct aberrations generated by the deflected light rays of the lens elements at the object side of the rear lens group, so as to improve the imaging quality of the optical system 100. When the above conditional expressions are satisfied, the excessive large deflection angle of light caused by the excessive bending force of the rear lens group can be avoided, the effect of reducing the exit angle of light deflected by the rear lens group is realized, and then the entrance angle of light on the imaging surface of the optical system 100 is reduced, so that the optical system 100 can better match the photosensitive performance of the photosensitive element, and the imaging quality of the optical system 100 is improved. When f5 is f6/f > -10, it is not favorable to suppress the high-order aberration generated by the peripheral field rays on the image plane of the optical system 100. When f5 is f6/f < -20, it is not favorable to suppress the occurrence of chromatic aberration of the optical system 100, resulting in a decrease in the imaging quality of the optical system 100.

In some embodiments, the optical system 100 satisfies the conditional expression: (R1-R2)/f is not more than 4 and not more than 7; where R1 is a radius of curvature of the object-side surface S1 of the first lens element L1 on the optical axis, R2 is a radius of curvature of the image-side surface S2 of the first lens element L1 on the optical axis, and f is an effective focal length of the optical system 100. Specifically, (R1-R2)/f may be: 5.32, 5.39, 5.41, 5.48, 5.56, 5.63, 5.74, 5.82, 5.96, or 6.00. By configuring the surface types of the object-side surface S1 and the image-side surface S2 of the first lens element L1, the first lens element L1 closer to the object side of the optical system 100 provides negative refractive power to the optical system 100. When the above conditional expressions are satisfied, it is possible to prevent an increase in difficulty in processing the first lens element L1 due to an excessively large difference in the degree of surface curvature between the object-side surface S1 and the image-side surface S2 of the first lens element L1, and to suppress occurrence of astigmatism in the optical system 100 in a wide angular field. When (R1-R2)/f < 4), the refractive power of the optical system 100 is insufficient, so that the light rays with a large angle of view are difficult to enter the optical system 100, which is not favorable for expanding the maximum angle of view of the optical system 100. If (R1-R2)/f > 7, the difference between the surface curvatures of the object-side surface S1 and the image-side surface S2 of the first lens L1 is too large, which makes the processing of the first lens L1 difficult, and at the same time, generates strong astigmatism and chromatic aberration easily, which is not favorable for improving the imaging quality of the optical system 100.

In some embodiments, the optical system 100 satisfies the conditional expression: R1/ED1 is more than or equal to 1.5 and less than or equal to 2.1; where R1 is the radius of curvature of the object-side surface S1 of the first lens L1 at the optical axis, and ED1 is half the maximum effective aperture of the object-side surface S1 of the first lens L1. Specifically, R1/ED1 may be: 1.62, 1.64, 1.66, 1.67, 1.69, 1.71, 1.73, 1.74, 1.76 or 1.79. When the object-side surface S1 of the first lens element L1 is convex, the radius of curvature and the maximum effective aperture of the object-side surface S1 of the first lens element L1 along the optical axis can be appropriately configured to allow light rays with a large angle to enter the optical system 100 and converge on the image plane, so as to increase the maximum field angle of the optical system 100. Meanwhile, the maximum effective aperture of the first lens L1 can be shortened to meet the requirement of small head design of the camera lens. When R1/ED1 > 2.1, the shape of the object-side surface S1 of the first lens L1 is too gentle to allow high-angle light rays to enter the optical system 100, which makes it difficult to design the optical system 100 to have a wide angle. When R1/ED1 < 1.5, if the radius of curvature of the object-side surface S1 of the first lens L1 at the optical axis is too small, the object-side surface S1 of the first lens L1 is too curved, which is not favorable for the aberration correction of the system and the lens processing, or the maximum effective aperture of the first lens L1 is too large, which is not favorable for the small head design of the imaging lens.

In some embodiments, the optical system 100 satisfies the conditional expression: r3/f2 is more than or equal to 50; wherein R3 is the radius of curvature of the object-side surface S3 of the second lens L2 at the optical axis, and f2 is the effective focal length of the second lens L2. Specifically, R3/f2 may be: 59.36, 62.34, 64.25, 68.75, 72.16, 75.99, 77.01, 79.23, 80.66, or 82.10. If the negative refractive power of the second lens element L2 is too strong, the tolerance sensitivity of the second lens element L2 is easily increased, and the decentering sensitivity of the optical system 100 during the assembling process is easily increased, which affects the assembling yield of the optical system 100. When the above conditional expressions are satisfied, the curvature radius of the object-side surface S3 of the second lens L2 at the optical axis can be increased, and the decentering sensitivity of the optical system 100 to the second lens L2 during the assembly process is reduced, so as to improve the assembly yield of the optical system 100. When R3/f2 < 50, the object-side surface S3 of the second lens L2 is too curved, which increases the eccentricity sensitivity of the optical system 100 during the assembly process, resulting in a decrease in the assembly yield of the optical system 100 and an increase in the production cost of the optical system 100.

In some embodiments, the optical system 100 satisfies the conditional expression: R4/SAG4 is more than or equal to 1 and less than or equal to 4; where R4 is the radius of curvature of the image-side surface S4 of the second lens L2 at the optical axis, and SAG4 is the sagittal height of the image-side surface S4 of the second lens L2 at the maximum effective aperture. Specifically, R4/SAG4 may be: 1.17, 1.32, 1.75, 1.96, 2.23, 2.54, 2.76, 2.95, 3.14 or 3.27. The curvature radius of the image-side surface S4 of the second lens element L2 at the optical axis affects the refractive power of the second lens element L2, and when the surface curvature degree of the image-side surface S4 of the second lens element L2 is larger, the negative refractive power of the second lens element L2 is stronger, which is more beneficial to deflecting the light beam passing through the second lens element L2, so that the light beam can better converge on the image plane of the optical system 100. When the above conditional expressions are satisfied, the negative refractive power of the second lens element L2 is enhanced, and the astigmatism generated by the deflected light of the first lens element L1 can be effectively corrected. In addition, it is possible to avoid an increase in the difficulty of processing the second lens L2 due to excessive curvature of the surface of the image-side surface S4 of the second lens L2. When R4/SAG4 > 4, the negative refractive power of the second lens element L2 is insufficient, which is not favorable for correcting the aberration of the optical system 100. When R4/SAG4 is less than 1, the surface of the image-side surface S4 of the second lens L2 is too curved, which increases the processing difficulty of the second lens L2, and further causes the problem that the second lens L2 is easy to crack during the aspheric surface process.

In some embodiments, the optical system 100 satisfies the conditional expression: -16mm ≤ f2 × f3/f ≤ 3 mm; where f2 is the effective focal length of the second lens L2, f3 is the effective focal length of the third lens L3, and f is the effective focal length of the optical system 100. Specifically, f2 × f3/f may be: -14.99, -13.25, -12.63, -11.27, -10.67, -9.38, -7.26, -6.55, -5.32, or-4.15, data units in mm. The second lens element L2 provides negative refractive power for the optical system 100, which is beneficial to expanding the width of the light beam in the optical system 100, so as to expand the width of the light beam after the light beam with a large angular field of view is deflected by the first lens element L1. By providing the third lens element L3 with positive refractive power, the deflection angle of the light beam passing through the second lens element L2 can be reduced, and the light beam fills the pupil of the optical system 100. When the above conditional expressions are satisfied, it is beneficial to correct the aberration generated by the deflected light rays of the second lens element L2 and the third lens element L3, and the imaging quality of the optical system 100 is improved. When f2 × f3/f is out of the range of the above conditional expressions, it is not favorable for correcting the aberration of the optical system 100, and the imaging quality of the optical system 100 is reduced.

In some embodiments, the optical system 100 satisfies the conditional expression: 2 is less than or equal to CT3/SAG5 is less than or equal to 15; here, CT3 is the thickness of the third lens L3 on the optical axis, i.e., the center thickness of the third lens L3, and SAG5 is the sagittal height of the third lens L3 at the maximum effective aperture of the object-side surface S5. Specifically, CT3/SAG5 may be: 2.57, 3.84, 4.63, 6.89, 8.34, 9.25, 10.50, 11.67, 12.33, or 13.62. When the above conditional expressions are satisfied, the center thickness of the third lens element L3 and the rise of the object-side surface S5 of the third lens element L3 can be reasonably arranged, so that the center thickness of the third lens element L3 is not excessively large while the third lens element L3 has strong positive refractive power, and the surface shape of the object-side surface S5 of the third lens element L3 is not excessively curved, thereby preventing the increase in the manufacturing cost of the optical system 100 due to the increase in the difficulty in processing the third lens element L3. When CT3/SAG5 < 2, the surface shape of the object-side surface S5 of the third lens L3 is too curved, which increases the difficulty of processing the third lens L3 and thus increases the production cost of the optical system 100; meanwhile, aberration is easily generated in the peripheral field of view of the optical system 100, which is not favorable for improving the imaging quality of the optical system 100. When CT3/SAG5 > 15, the center thickness of the third lens L3 is too large, resulting in an excessively large density of lenses in the optical system 100, which in turn results in an increase in the weight of the optical system 100, which is disadvantageous for reducing the weight of the optical system 100, and which is also disadvantageous for the compact design of the optical system 100.

In some embodiments, the optical system 100 satisfies the conditional expression: vdi is less than or equal to 25; where Vdi is the abbe number of the i-th lens of the optical system 100 under the d-line, and i is one of 1, 2, 3, 4, 5, and 6. Specifically, Vd3 may be: 20.10, 20.16, 20.56, 20.97, 21.18, 21.32, 21.86, 22.43 or 23.13; vd6 may be: 16.48. when the above conditional expressions are satisfied, the materials of the lenses in the optical system 100 can be reasonably configured, which is beneficial to correcting chromatic aberration of the optical system 100, and further improves the imaging quality of the optical system 100.

In some embodiments, the optical system 100 satisfies the conditional expression: TTL/CT4 is more than or equal to 6.0 and less than or equal to 9.2; wherein, TTL is an axial distance from the object-side surface S1 of the first lens element L1 to the image plane of the optical system 100, i.e., a total system length of the optical system 100, and CT4 is an axial thickness of the fourth lens element L4. Specifically, TTL/CT4 may be: 7.88, 7.90, 7.95, 7.96, 7.99, 8.01, 8.03, 8.06, 8.11 or 8.18. When the above conditional expressions are satisfied, the total system length of the optical system 100 and the center thickness of the fourth lens L4 can be reasonably arranged, which is advantageous for shortening the total system length of the optical system 100 to satisfy the requirement of the compact design and also advantageous for reducing the weight of the optical system 100. When TTL/CT4 is less than 6.0, the central thickness of the fourth lens L4 in the optical system 100 is too large, which results in too large weight ratio of the fourth lens L4 in the optical system 100, and is not favorable for reducing the weight of the optical system 100. When TTL/CT4 is greater than 9.2, the total length of the optical system 100 is too long, which is not favorable for the compact design of the optical system 100.

In some embodiments, the optical system 100 satisfies the conditional expression: 2f tan (VFOV/2) is less than or equal to 4.5mm and less than or equal to 5.5 mm; where f is the effective focal length of the optical system 100, and VFOV is the maximum field angle of the optical system 100 in the vertical direction of the effective pixel area on the image plane. In particular, 2f tan (VFOV/2) may be: 5.05, 5.07, 5.09, 5.13, 5.15, 5.16, 5.18, 5.19, 5.20, or 5.21, in mm. When the above conditional expressions are satisfied, the maximum field angle of the optical system 100 in the vertical direction of the effective pixel area of the imaging plane can be enlarged to satisfy the requirement of large-angle shooting.

In some embodiments, the optical system 100 satisfies the conditional expression: HFOV is more than or equal to 180 degrees; the HFOV is a maximum angle of view of the optical system 100 in the horizontal direction of the effective pixel area on the imaging plane. Specifically, the HFOV may be: 200.7, 200.8, 200.9 or 201.0. When the above conditional expressions are satisfied, the maximum field angle of the optical system 100 in the horizontal direction of the effective pixel area on the imaging plane can be enlarged to satisfy the requirement of large-field-angle shooting.

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 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 first lens element L1 with negative 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, a fifth lens element L5 with positive refractive power, and a sixth lens element L6 with negative refractive power. Fig. 2 is a graph of spherical aberration, astigmatism and distortion of the optical system 100 in the first embodiment, in which the reference wavelengths of the astigmatism and distortion maps are 587.5618nm, and in the second, third and fourth embodiments of the present application, the reference wavelengths of the astigmatism and distortion maps are both 587.5618nm, while in the fifth and sixth embodiments, the reference wavelengths of the astigmatism and distortion maps are 546.0740 nm.

The object-side surface S1 of the first lens element L1 is convex paraxially, and the image-side surface S2 is concave paraxially;

the object-side surface S3 of the second lens element L2 is concave 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 convex paraxially, and the image-side surface S6 is concave paraxially;

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

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

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

The object-side and image-side surfaces of the second lens L2, the third lens L3, and the fourth lens L4 are aspheric, and the object-side and image-side surfaces of the first lens L1, the fifth lens L5, and the sixth lens L6 are spherical.

The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are all made of glass.

Further, the optical system 100 satisfies the conditional expression: f5 × f 6/f-17.22 mm; where f5 is the effective focal length of the fifth lens L5, f6 is the effective focal length of the sixth lens L6, and f is the effective focal length of the optical system 100. The rear lens group consisting of the fifth lens element L5 with positive refractive power and the sixth lens element L6 with negative refractive power can correct aberrations generated by the deflected light rays of the lens elements at the object side of the rear lens group, so as to improve the imaging quality of the optical system 100. When the above conditional expressions are satisfied, the excessive large deflection angle of light caused by the excessive bending force of the rear lens group can be avoided, the effect of reducing the exit angle of light deflected by the rear lens group is realized, and then the entrance angle of light on the imaging surface of the optical system 100 is reduced, so that the optical system 100 can better match the photosensitive performance of the photosensitive element, and the imaging quality of the optical system 100 is improved. When f5 is f6/f > -10, it is not favorable to suppress the high-order aberration generated by the peripheral field rays on the image plane of the optical system 100. When f5 is f6/f < -20, it is not favorable to suppress the occurrence of chromatic aberration of the optical system 100, resulting in a decrease in the imaging quality of the optical system 100.

The optical system 100 satisfies the conditional expression: (R1-R2)/f ═ 5.85; where R1 is a radius of curvature of the object-side surface S1 of the first lens element L1 on the optical axis, R2 is a radius of curvature of the image-side surface S2 of the first lens element L1 on the optical axis, and f is an effective focal length of the optical system 100. By configuring the surface types of the object-side surface S1 and the image-side surface S2 of the first lens element L1, the first lens element L1 closer to the object side of the optical system 100 provides negative refractive power to the optical system 100. When the above conditional expressions are satisfied, it is possible to prevent an increase in difficulty in processing the first lens element L1 due to an excessively large difference in the degree of surface curvature between the object-side surface S1 and the image-side surface S2 of the first lens element L1, and to suppress occurrence of astigmatism in the optical system 100 in a wide angular field. When (R1-R2)/f < 4), the refractive power of the optical system 100 is insufficient, so that the light rays with a large angle of view are difficult to enter the optical system 100, which is not favorable for expanding the maximum angle of view of the optical system 100. If (R1-R2)/f > 7, the difference between the surface curvatures of the object-side surface S1 and the image-side surface S2 of the first lens L1 is too large, which makes the processing of the first lens L1 difficult, and at the same time, generates strong astigmatism and chromatic aberration easily, which is not favorable for improving the imaging quality of the optical system 100.

The optical system 100 satisfies the conditional expression: R1/ED1 is 1.66; where R1 is the radius of curvature of the object-side surface S1 of the first lens L1 at the optical axis, and ED1 is half the maximum effective aperture of the object-side surface S1 of the first lens L1. When the object-side surface S1 of the first lens element L1 is convex, the radius of curvature and the maximum effective aperture of the object-side surface S1 of the first lens element L1 along the optical axis can be appropriately configured to allow light rays with a large angle to enter the optical system 100 and converge on the image plane, so as to increase the maximum field angle of the optical system 100. Meanwhile, the maximum effective aperture of the first lens L1 can be shortened to meet the requirement of small head design of the camera lens. When R1/ED1 > 2.1, the shape of the object-side surface S1 of the first lens L1 is too gentle to allow high-angle light rays to enter the optical system 100, which makes it difficult to design the optical system 100 to have a wide angle. When R1/ED1 < 1.5, if the radius of curvature of the object-side surface S1 of the first lens L1 at the optical axis is too small, the object-side surface S1 of the first lens L1 is too curved, which is not favorable for the aberration correction of the system and the lens processing, or the maximum effective aperture of the first lens L1 is too large, which is not favorable for the small head design of the imaging lens.

The optical system 100 satisfies the conditional expression: r3/f2 ═ 75.45; wherein R3 is the radius of curvature of the object-side surface S3 of the second lens L2 at the optical axis, and f2 is the effective focal length of the second lens L2. If the negative refractive power of the second lens element L2 is too strong, the tolerance sensitivity of the second lens element L2 is easily increased, and the decentering sensitivity of the optical system 100 during the assembling process is easily increased, which affects the assembling yield of the optical system 100. When the above conditional expressions are satisfied, the curvature radius of the object-side surface S3 of the second lens L2 at the optical axis can be increased, and the decentering sensitivity of the optical system 100 to the second lens L2 during the assembly process is reduced, so as to improve the assembly yield of the optical system 100. When R3/f2 < 50, the object-side surface S3 of the second lens L2 is too curved, which increases the eccentricity sensitivity of the optical system 100 during the assembly process, resulting in a decrease in the assembly yield of the optical system 100 and an increase in the production cost of the optical system 100.

The optical system 100 satisfies the conditional expression: R4/SAG4 ═ 1.26; where R4 is the radius of curvature of the image-side surface S4 of the second lens L2 at the optical axis, and SAG4 is the sagittal height of the image-side surface S4 of the second lens L2 at the maximum effective aperture. The curvature radius of the image-side surface S4 of the second lens element L2 at the optical axis affects the refractive power of the second lens element L2, and when the surface curvature degree of the image-side surface S4 of the second lens element L2 is larger, the negative refractive power of the second lens element L2 is stronger, which is more beneficial to deflecting the light beam passing through the second lens element L2, so that the light beam can better converge on the image plane of the optical system 100. When the above conditional expressions are satisfied, the negative refractive power of the second lens element L2 is enhanced, and the astigmatism generated by the deflected light of the first lens element L1 can be effectively corrected. In addition, it is possible to avoid an increase in the difficulty of processing the second lens L2 due to excessive curvature of the surface of the image-side surface S4 of the second lens L2. When R4/SAG4 > 4, the negative refractive power of the second lens element L2 is insufficient, which is not favorable for correcting the aberration of the optical system 100. When R4/SAG4 is less than 1, the surface of the image-side surface S4 of the second lens L2 is too curved, which increases the processing difficulty of the second lens L2, and further causes the problem that the second lens L2 is easy to crack during the aspheric surface process.

The optical system 100 satisfies the conditional expression: f 2f 3/f-5.82; where f2 is the effective focal length of the second lens L2, f3 is the effective focal length of the third lens L3, and f is the effective focal length of the optical system 100. The second lens element L2 provides negative refractive power for the optical system 100, which is beneficial to expanding the width of the light beam in the optical system 100, so as to expand the width of the light beam after the light beam with a large angular field of view is deflected by the first lens element L1. By providing the third lens element L3 with positive refractive power, the deflection angle of the light beam passing through the second lens element L2 can be reduced, and the light beam fills the pupil of the optical system 100. When the above conditional expressions are satisfied, it is beneficial to correct the aberration generated by the deflected light rays of the second lens element L2 and the third lens element L3, and the imaging quality of the optical system 100 is improved. When f2 × f3/f is out of the range of the above conditional expressions, it is not favorable for correcting the aberration of the optical system 100, and the imaging quality of the optical system 100 is reduced.

The optical system 100 satisfies the conditional expression: CT3/SAG5 ═ 2.57; here, CT3 is the thickness of the third lens L3 on the optical axis, i.e., the center thickness of the third lens L3, and SAG5 is the sagittal height of the third lens L3 at the maximum effective aperture of the object-side surface S5. When the above conditional expressions are satisfied, the center thickness of the third lens element L3 and the rise of the object-side surface S5 of the third lens element L3 can be reasonably arranged, so that the center thickness of the third lens element L3 is not excessively large while the third lens element L3 has strong positive refractive power, and the surface shape of the object-side surface S5 of the third lens element L3 is not excessively curved, thereby preventing the increase in the manufacturing cost of the optical system 100 due to the increase in the difficulty in processing the third lens element L3. When CT3/SAG5 < 2, the surface shape of the object-side surface S5 of the third lens L3 is too curved, which increases the difficulty of processing the third lens L3 and thus increases the production cost of the optical system 100; meanwhile, aberration is easily generated in the peripheral field of view of the optical system 100, which is not favorable for improving the imaging quality of the optical system 100. When CT3/SAG5 > 15, the center thickness of the third lens L3 is too large, resulting in an excessively large density of lenses in the optical system 100, which in turn results in an increase in the weight of the optical system 100, which is disadvantageous for reducing the weight of the optical system 100, and which is also disadvantageous for the compact design of the optical system 100.

The optical system 100 satisfies the conditional expression: vd3 ═ 23.13; vd 6-16.48; vd3 is the abbe number of the third lens L3 under d-line, and Vd6 is the abbe number of the sixth lens L6 under d-line. When the above conditional expressions are satisfied, the materials of the third lens L3 and the sixth lens L6 in the optical system 100 can be reasonably configured, which is beneficial to correcting chromatic aberration of the optical system 100, and further improves the imaging quality of the optical system 100.

The optical system 100 satisfies the conditional expression: TTL/CT4 ═ 8.18; wherein, TTL is an axial distance from the object-side surface S1 of the first lens element L1 to the image plane of the optical system 100, and CT4 is an axial thickness of the fourth lens element L4. When the above conditional expressions are satisfied, the total system length of the optical system 100 and the center thickness of the fourth lens L4 can be reasonably arranged, which is advantageous for shortening the total system length of the optical system 100 to satisfy the requirement of the compact design and also advantageous for reducing the weight of the optical system 100. When TTL/CT4 is less than 6.0, the central thickness of the fourth lens L4 in the optical system 100 is too large, which results in too large weight ratio of the fourth lens L4 in the optical system 100, and is not favorable for reducing the weight of the optical system 100. When TTL/CT4 is greater than 9.2, the total length of the optical system 100 is too long, which is not favorable for the compact design of the optical system 100.

The optical system 100 satisfies the conditional expression: 2f tan (VFOV/2) ═ 5.05; where f is the effective focal length of the optical system 100, and VFOV is the maximum field angle of the optical system 100 in the vertical direction of the effective pixel area on the image plane. When the above conditional expressions are satisfied, the maximum field angle of the optical system 100 in the vertical direction of the effective pixel area of the imaging plane can be enlarged to satisfy the requirement of large-angle shooting.

The optical system 100 satisfies the conditional expression: HFOV is 200.8 °; the HFOV is a maximum angle of view in the horizontal direction corresponding to the optical system 100 when a half of the horizontal direction length of the effective pixel region on the imaging plane is 2.88mm, and the other embodiments are also the same. When the above conditional expressions are satisfied, the maximum field angle of the optical system 100 in the horizontal direction of the effective pixel area on the imaging plane can be enlarged to satisfy the requirement of large-field-angle shooting.

In addition, the parameters of the optical system 100 are given in table 1. Among them, the image plane S17 in table 1 may be understood as an imaging plane of the optical system 100. The elements from the object plane (not shown) to the image plane S17 are sequentially arranged in the order of the elements from top to bottom in table 1. The Y radius in table 1 is the radius of curvature of the object-side surface or the image-side surface of the corresponding surface number at the optical axis. Surface number 1 and surface number 2 are the object-side surface S1 and the image-side surface S2 of the first lens L1, respectively, that is, in the same lens, the surface with the smaller surface number is the object-side surface, and the surface with the larger surface number is the image-side surface. The first numerical value in the "thickness" parameter column of the first lens element L1 is the axial thickness of the lens element, and the second numerical value is the axial distance from the image-side surface of the lens element to the object-side surface of the following lens element in the image-side direction.

Note that, in this embodiment and the following embodiments, the optical system 100 may not be provided with the infrared filter L7 and the protective glass L8, but the distance from the image side surface S12 to the image surface S17 of the sixth lens L6 is kept constant at this time.

In the first embodiment, the total effective focal length f of the optical system 100 is 1.25mm, the f-number FNO is 2.1, and when the half of the horizontal length of the effective pixel region on the imaging plane of the optical system 100 is 2.88mm, the maximum field angle HFOV of the optical system in the horizontal direction of the effective pixel region on the imaging plane is 200.8 °.

And the focal length, refractive index and Abbe number of each lens are values at d-line (587.56nm), and the same applies to other embodiments.

TABLE 1

Further, aspheric coefficients of the image-side or object-side surface of the second lens L2, the third lens L3, and the fourth lens L4 in the optical system 100 are given in table 2. Wherein, the surface numbers represent the image side or the object side S3-S8 from 3-8, 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:

z is the distance from a corresponding point on the aspheric surface to a plane tangent to the surface vertex, r is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the aspheric surface vertex, k is a conical coefficient, and Ai is a coefficient corresponding to the ith high-order term in the aspheric surface type formula.

TABLE 2

Number of noodles

3

4

5

6

7

8

K

0.00E+00

-3.23E+00

-4.73E+00

6.10E+01

-8.33E+01

-1.84E-01

A4

6.03E-04

1.30E-02

1.07E-02

1.80E-02

-3.07E-02

8.92E-03

A6

0.00E+00

-2.04E-03

3.91E-04

4.83E-03

-4.92E-03

1.44E-03

A8

0.00E+00

6.76E-04

3.01E-04

-2.94E-03

1.83E-02

-3.62E-04

A10

0.00E+00

-5.24E-05

-2.59E-05

7.39E-04

-3.53E-02

1.49E-04

A12

0.00E+00

2.33E-23

-2.72E-23

1.74E-25

2.50E-02

-3.78E-04

A14

0.00E+00

-7.26E-03

0.00E+00

A16

0.00E+00

A18

0.00E+00

A20

0.00E+00

Second embodiment

Referring to fig. 3 and 4, fig. 3 is a schematic 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 first lens element L1 with negative 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, a fifth lens element L5 with positive refractive power, and a sixth lens element L6 with negative refractive power. Fig. 4 is a graph of spherical aberration, astigmatism and distortion of the optical system 100 in the second embodiment, from left to right.

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

3

4

5

6

7

8

K

0.00E+00

-1.14E+00

-5.59E+00

4.27E-01

-3.78E+01

-8.49E-01

A4

1.05E-03

-1.74E-02

1.90E-02

3.10E-02

-2.35E-02

-7.81E-03

A6

0.00E+00

4.99E-03

-1.68E-03

9.60E-03

1.26E-02

-3.04E-03

A8

0.00E+00

-7.17E-04

4.25E-04

1.50E-02

4.62E-03

4.13E-04

A10

0.00E+00

7.19E-05

5.16E-06

-1.10E-02

-2.65E-02

-2.40E-04

A12

0.00E+00

3.51E-21

-2.64E-21

1.74E-25

2.50E-02

-1.45E-03

A14

0.00E+00

-7.26E-03

0.00E+00

A16

0.00E+00

A18

0.00E+00

A20

0.00E+00

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

f5*f6/f	-14.69	f2*f3/f	-9.35
				(R1-R2)/f	5.77	CT3/SAG5	3.20
R1/ED1	1.65	TTL/CT4	7.88
				R3/f2	62.56	2f*tan(VFOV/2)	5.08
R4/SAG4	1.71	HFOV	201.0

third embodiment

Referring to fig. 5 and 6, fig. 5 is a schematic 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 first lens element L1 with negative 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, a fifth lens element L5 with positive refractive power, and a sixth lens element L6 with negative refractive power. Fig. 6 is a graph of spherical aberration, astigmatism and distortion of the optical system 100 in the third embodiment, from left to right.

the object-side surface S5 of the third lens element L3 is convex paraxially, and the image-side surface S6 is convex paraxially;

The object-side surface S3 of the second lens element L2 is spherical, the image-side surface S4 is aspherical, the object-side surfaces and the image-side surfaces of the third lens element L3 and the fourth lens element L4 are aspherical, and the object-side surfaces and the image-side surfaces of the first lens element L1, the fifth lens element L5, and the sixth lens element L6 are spherical.

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

f5*f6/f	-15.71	f2*f3/f	-5.00
				(R1-R2)/f	6.00	CT3/SAG5	2.89
R1/ED1	1.72	TTL/CT4	7.93
				R3/f2	77.38	2f*tan(VFOV/2)	5.21
R4/SAG4	1.24	HFOV	200.8

fourth embodiment

Referring to fig. 7 and 8, fig. 7 is a schematic 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 first lens element L1 with negative 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, a fifth lens element L5 with positive refractive power, and a sixth lens element L6 with negative refractive power. Fig. 8 is a graph showing the spherical aberration, astigmatism and distortion of the optical system 100 in the fourth embodiment in order from left to right.

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

Number of noodles	4	5	6	7	8
						K	-2.43E+00	-2.58E+00	-2.68E+01	-3.39E+00	-2.43E-02
A4	1.19E-03	-7.67E-03	6.56E-03	-2.51E-02	4.63E-03
						A6	6.07E-04	3.15E-03	4.38E-04	-8.83E-03	7.20E-04
A8	-4.03E-05	-3.30E-04	-1.63E-04	1.94E-02	-1.81E-04
						A10	0.00E+00	1.91E-05	6.41E-05	-3.53E-02	5.42E-05
A12	0.00E+00	6.30E-25	-3.76E-27	2.50E-02	-2.04E-06
						A14	0.00E+00	0.00E+00	0.00E+00	-7.26E-03	0.00E+00
A16	0.00E+00	0.00E+00	0.00E+00	0.00E+00	0.00E+00
						A18	0.00E+00	0.00E+00	0.00E+00	0.00E+00	0.00E+00
A20	0.00E+00	0.00E+00	0.00E+00	0.00E+00	0.00E+00

f5*f6/f	-13.65	f2*f3/f	-4.15
				(R1-R2)/f	5.79	CT3/SAG5	2.61
R1/ED1	1.72	TTL/CT4	8.03
				R3/f2	82.10	2f*tan(VFOV/2)	5.12
R4/SAG4	1.17	HFOV	200.7

fifth embodiment

Referring to fig. 9 and 10, fig. 9 is a schematic 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 first lens element L1 with negative 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, a fifth lens element L5 with positive refractive power, and a sixth lens element L6 with negative refractive power. Fig. 10 is a graph showing the spherical aberration, astigmatism and distortion of the optical system 100 in the fifth embodiment in order from left to right.

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

3

4

5

6

7

8

K

0.00E+00

6.16E+00

4.58E+00

8.98E+01

-3.84E-02

A4

8.67E-04

-1.17E-02

3.91E+03

2.57E-03

-1.85E-02

7.29E-03

A6

0.00E+00

2.82E-04

-3.83E+02

9.55E-04

-3.27E-03

-3.16E-03

A8

0.00E+00

-1.68E-05

-1.72E+02

-3.71E-04

1.35E-02

3.06E-03

A10

0.00E+00

-1.98E-06

6.69E+01

4.98E-05

-3.20E-02

-1.17E-03

A12

0.00E+00

-1.48E+01

0.00E+00

2.84E-02

1.86E-04

A14

0.00E+00

5.67E+00

0.00E+00

-7.25E-03

-1.24E-06

A16

0.00E+00

A18

0.00E+00

A20

0.00E+00

sixth embodiment

Referring to fig. 11 and 12, fig. 11 is a schematic 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 first lens element L1 with negative 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, a fifth lens element L5 with positive refractive power, and a sixth lens element L6 with negative refractive power. Fig. 12 is a graph showing the spherical aberration, astigmatism and distortion of the optical system 100 in the sixth embodiment in order from left to right.

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

Number of noodles	4	5	6	7	8
						K	0.00E+00	1.78E+01	2.70E+00	6.28E+01	8.54E-03
A4	-1.17E-02	3.91E+03	4.38E-03	-1.91E-02	7.01E-03
						A6	0.00E+00	-3.83E+02	-1.30E-04	6.56E-03	-3.37E-03
A8	0.00E+00	-1.72E+02	2.29E-05	1.39E-03	3.30E-03
						A10	0.00E+00	6.72E+01	-6.33E-06	-2.59E-02	-1.23E-03
A12	0.00E+00	-1.61E+01	0.00E+00	2.84E-02	1.86E-04
						A14	0.00E+00	6.94E+00	0.00E+00	-7.25E-03	-1.24E-06
A16	0.00E+00	0.00E+00	0.00E+00	0.00E+00	0.00E+00
						A18	0.00E+00	0.00E+00	0.00E+00	0.00E+00	0.00E+00
A20	0.00E+00	0.00E+00	0.00E+00	0.00E+00	0.00E+00

f5*f6/f	-16.32	f2*f3/f	-14.99
				(R1-R2)/f	5.63	CT3/SAG5	13.62
R1/ED1	1.79	TTL/CT4	7.93
				R3/f2	59.36	2f*tan(VFOV/2)	5.18
R4/SAG4	3.27	HFOV	200.9

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 may be regarded as the image surface S17 of the optical system 100. Also, generally, the photosensitive element 210 has a rectangular imaging area, the imaging area of the photosensitive element 210 has a length and a width, and the length direction of the photosensitive element 210 corresponds to the horizontal direction of the effective pixel area of the optical system 100 on the imaging plane, and the width direction of the photosensitive element 210 corresponds to the vertical direction of the effective pixel area of the optical system 100 on the imaging plane. In addition, the image capturing module 200 may further include an infrared filter L7, and the infrared filter L7 is disposed between the image side surface S12 and the image surface S17 of the sixth lens element L6. Specifically, the photosensitive element 210 may be a Charge Coupled Device (CCD) or a Complementary Metal-Oxide Semiconductor (CMOS) Device. The image capturing module 200 may further include a protective glass L8, wherein the protective glass L8 is disposed on the image side of the ir filter L7 for protecting the photosensitive element 210. By adopting the optical system 100 in the image capturing module 200, the aberration of the optical system 100 can be better corrected, and the image capturing module 200 has excellent 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 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. Of course, electronic equipment 300 still can be for on-vehicle camera, vehicle event data recorder etc. be used for on-vehicle device in the field of making a video recording, and electronic equipment 300 installs on the car, can shoot the scenery image all around the car, makes the driver can know the road conditions information all around the car more clearly, avoids rolling, the emergence of accidents such as scraping, improves the driving safety nature of car. By using the image capturing module 200 in the electronic device 300, the aberration of the optical system 100 can be better corrected, so that the electronic device 300 has excellent image quality. When the electronic device 300 is applied to the field of vehicle-mounted camera shooting, scenes around the automobile can be clearly imaged so as to meet the requirement of driving safety.

Referring to fig. 14 and 15, in some embodiments, the electronic device 300 may be used in an automobile 400, and the automobile 400 further includes a mounting member 410, and the electronic device 300 is disposed on the mounting member 410. Specifically, the mounting member 410 may be a body of the automobile 400 or a component such as a rear view mirror. The electronic device 300 is adopted in the automobile 400, which is beneficial for the automobile 400 to form clear images for the scenes around so as to meet the requirement of driving safety.

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 represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. An optical system comprising, in order from an object side to an image side:

a third lens element with positive refractive power;

a fourth lens element with positive refractive power;

a fifth lens element with positive refractive power;

a sixth lens element with negative refractive power;

and the optical system satisfies the following conditional expression:

-20mm≤f5*f6/f≤-10mm；

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

4≤(R1-R2)/f≤7；

wherein R1 is a curvature radius of an object side surface of the first lens at an optical axis, and R2 is a curvature radius of an image side surface of the first lens at the optical axis.

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

1.5≤R1/ED1≤2.1；

wherein R1 is the radius of curvature of the object-side surface of the first lens at the optical axis, and ED1 is half the maximum effective aperture of the object-side surface of the first lens.

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

R3/f2≥50；

wherein R3 is a radius of curvature of an object-side surface of the second lens at an optical axis, and f2 is an effective focal length of the second lens.

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

1≤R4/SAG4≤4；

wherein R4 is the radius of curvature of the image side of the second lens at the optical axis, and SAG4 is the sagittal height at the maximum effective aperture of the image side of the second lens.

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

-16mm≤f2*f3/f≤3mm；

wherein f2 is the effective focal length of the second lens, and f3 is the effective focal length of the third lens.

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

2≤CT3/SAG5≤15；

wherein CT3 is the thickness of the third lens on the optical axis, SAG5 is the sagittal height at the maximum effective aperture of the object side of the third lens.

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

Vdi≤25；

wherein Vdi is the abbe number of the ith lens in the optical system under the d-line, and i is at least one of 1, 2, 3, 4, 5 and 6.

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

6.0≤TTL/CT4≤9.2；

wherein, TTL is an axial distance from an object-side surface of the first lens element to an image plane of the optical system, and CT4 is an axial thickness of the fourth lens element.

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

4.5mm≤2f*tan(VFOV/2)≤5.5mm；

wherein f is the effective focal length of the optical system, and VFOV is the maximum field angle of the optical system in the vertical direction of the effective pixel area on the imaging plane.

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

HFOV≥180°；

the HFOV is a maximum angle of view of the optical system in a horizontal direction of an effective pixel region on an imaging plane.

12. An image capturing module, comprising a photosensitive element and the optical system of any one of claims 1 to 11, wherein the photosensitive element is disposed on an image side of the optical system.

13. An electronic device, comprising a housing and the image capturing module of claim 12, wherein the image capturing module is disposed on the housing.

14. An automobile comprising a mount and the electronic device of claim 13, wherein the electronic device is provided to the mount.