WO2022032433A1

WO2022032433A1 - Optical imaging system, image capture module, electronic device and carrier

Info

Publication number: WO2022032433A1
Application number: PCT/CN2020/108203
Authority: WO
Inventors: 蔡雄宇; 赵迪; 兰宾利; 周芮
Original assignee: 欧菲光集团股份有限公司; 天津欧菲光电有限公司
Priority date: 2020-08-10
Filing date: 2020-08-10
Publication date: 2022-02-17

Abstract

An optical imaging system (10), sequentially comprising, from an object side to an image side, a first lens group (12) having negative refractive power, the face (S4) of the first lens group (12) that is closest to the image side being concave; a second lens group (14) having positive refractive power, faces (S5, S6) of the second lens group (14) that are closest to the object side and the image side both being convex; and a third lens group (16) having positive refractive power, faces (S7, S12) of the third lens group (16) that are closest to the object side and the image side both being convex. The optical imaging system (10) further includes a diaphragm (STO), the diaphragm (STO) being arranged on the object side of the third lens group (16). The optical imaging system (10) meets the requirement of a system for ultra-wide-angle imaging by means of rational refractive power configurations, and the size of an ultra-wide-angle lens is reduced and the definition of an imaging effect is ensured. Further provided are an image capture module (100) provided with the optical imaging system (10), an electronic device (200) provided with the image capture module (100), and a carrier (300).

Description

Optical imaging systems, imaging modules, electronic devices and carriers

technical field

The present application relates to the technical field of optical imaging, and in particular, to an optical imaging system, an imaging module, an electronic device and a carrier.

Background technique

At present, in the field of 3C electronic products and automotive cameras, consumers have put forward higher requirements for the imaging quality and size of camera modules. On mobile phones, consumers want a larger field of view without taking up a larger volume. In the automotive field, the requirements for road traffic safety and car safety are constantly increasing. Coupled with the rise of surround view cameras, driver assistance systems and unmanned driving markets, vehicle lenses are increasingly used in automotive assisted driving systems. At the same time, people also put forward higher requirements on the imaging quality of the camera module and the comfort of the picture.

In the process of realizing the present application, the inventor found that there are at least the following problems in the prior art: the existing ultra-wide-angle camera lens is difficult to simultaneously satisfy the shooting and clear imaging of a wide angle range, so that it is difficult to accurately capture images in real time. In order to obtain a larger field of view, the wide-angle lens is often assembled with multiple lenses, so that the size of the wide-angle lens is generally larger.

Application content

In view of the above, it is necessary to propose an optical imaging system and an imaging module, an electronic device and a carrier having the optical imaging system to solve the above problems.

The embodiment of the present application proposes an optical imaging system, which includes sequentially from the object side to the image side:

a first lens group with negative bending power, the surface of the first lens group closest to the image side is a concave surface;

a second lens group with positive inflection power, the surfaces of the second lens group closest to the object side and the image side are both convex;

a third lens group with positive inflection power, the surfaces of the third lens group closest to the object side and the image side are both convex;

The optical imaging system further includes a diaphragm, and the diaphragm is placed on the object side of the third lens group.

In the optical imaging system of the embodiment of the present application, the requirements of the optical imaging system for ultra-wide-angle imaging are met through the reasonable configuration of the bending force of the first lens group, the second lens group and the third lens group. By setting the diaphragm to reduce stray light, it helps to improve the image quality. The optical imaging system ensures the clarity of the imaging effect while reducing the size of the ultra-wide-angle lens.

In some embodiments, the first lens group consists of a first lens having a negative refractive power and a second lens having a negative refractive power;

The second lens group is composed of a third lens having a positive refracting power;

The third lens group is composed of a fourth lens with negative refractive power and a fifth lens with positive refractive power, wherein the fourth lens and the fifth lens are in a cemented structure, and the fourth lens and the The cemented surface of the fifth lens is convex toward the object side of the optical imaging system at the optical axis;

The optical imaging system satisfies the following conditional formula:

-6.5<(f1-f2)/f<-4;

Wherein, f1 and f2 are the focal lengths of the first lens and the second lens, respectively, and f is the focal length of the optical imaging system.

The five-piece lens can better achieve the effect of ultra-wide-angle imaging, and can correct aberrations to avoid distortion of the imaging screen; and, by satisfying the conditional formula, the bending force of the first lens and the second lens is in the optical imaging system. Reasonable distribution in the middle is conducive to suppressing high-order aberrations and chromatic aberrations caused by peripheral beams in the imaging area, thereby improving the resolution performance of the optical imaging system.

In some embodiments, the optical imaging system satisfies the following conditional formula:

16<TTL/f<17;

Wherein, TTL is the distance on the optical axis from the object side of the first lens to the imaging plane of the optical imaging system, and f is the focal length of the optical imaging system.

By defining the relationship between the optical total length of the optical imaging system and the focal length of the optical imaging system, the optical total length of the optical imaging system can be controlled while satisfying the field angle range of the optical imaging system, so as to meet the requirements of the small size of the optical imaging system. ization characteristics. Above the upper limit of the conditional expression, the total length of the optical imaging system is too long, which is not conducive to miniaturization; below the lower limit of the conditional expression, the focal length of the optical imaging system is too long, which is not conducive to satisfying the field angle range of the optical imaging system. Sufficient object space information could not be obtained.

2<d12/f<4;

Wherein, d12 is the air space between the image side of the first lens and the object side of the second lens on the optical axis, and f is the focal length of the optical imaging system.

By satisfying the upper limit of the conditional expression, the first lens can reasonably diverge the incident light beam, so as to better cooperate with the subsequent lens and complete the correction of aberrations well. By satisfying the lower limit of the conditional expression, the light beam is sufficiently divergent to be incident on the second lens, so it is easy to achieve an optical imaging system with strong bending force, thereby further correcting the off-axis aberration of the system. In addition, through the limitation of the air space between the first lens and the second lens, it is beneficial to realize the characteristics of compact structure and miniaturization of the optical imaging system.

-62<R3/R4<-20;

Wherein, R3 is the radius of curvature at the near-optical axis of the object side of the second lens, and R4 is the radius of curvature at the near-optical axis of the image side of the second lens.

Through the reasonable matching of the relationship between the curvature radius of the object side and the image side of the second lens, the side close to the object is set as a negative lens to provide a negative bending force for the system; the light entering the system at a large angle can be controlled to expand the field of view of the optical imaging system Angle range; control the curvature radius of the object side surface of the second lens through the conditional formula, which is beneficial to reduce the probability of ghost images and weaken the intensity of ghost images; the size of R3 will affect the degree of curvature of the lens and the processing difficulty of the lens, R3 is too Small, the degree of curvature of the lens affects the processing of the lens, the larger the R3, the flatter the surface of the lens, and it is easy for other similar plane components to produce ghost images.

3<f3/f<4;

Wherein, f3 is the focal length of the third lens, and f is the focal length of the optical imaging system.

Satisfying the conditional expression can ensure a positive inflection force, and converge the light rays diverged by the first lens and the second lens under the strong negative inflection force; in addition, it can reduce the burden of the converging effect of the fourth lens and the fifth lens, It is not necessary to achieve a strong bending force, so the freedom of design can be ensured. By satisfying the lower limit of the conditional expression, the positive bending force will not become too strong, so the angle between the normals of the surfaces on the object side and the image side of the third lens and the incident light will not become too large, and it is easy to suppress the high order the occurrence of aberrations.

3<(R5-R6)/(R5+R6)<8;

Wherein, R5 is the radius of curvature at the near-optical axis of the object side of the third lens, and R6 is the radius of curvature at the near-optical axis of the image side of the third lens.

By satisfying the lower limit of the conditional expression, the angle at which the chief ray incident image plane of the peripheral viewing angle is easily reduced. Through the conditional upper limit, it is easy to suppress the generation of astigmatism, reduce the risk of ghosting, and improve the resolution capability of the system.

0.5<R5/CT3<2;

Wherein, R5 is the radius of curvature of the object side surface of the third lens near the optical axis, and CT3 is the central thickness of the third lens on the optical axis.

The third lens has a biconvex structure, which can converge light in one step, with a smooth surface, which can reduce the deviation of the incident angle and exit angle of light in different fields of view, thereby reducing the sensitivity; by setting a thicker third lens, the processing difficulty can be reduced And reduce the sensitivity of thickness tolerance, improve yield.

0.5<f45/f123<2;

Wherein, f45 is the combined focal length of the fourth lens and the fifth lens, and f123 is the combined focal length of the first lens, the second lens and the third lens.

If it exceeds the range of the relational expression, the positive bending force of f123 and f45 will be too large or too small, so that the entire optical imaging system will reflect the situation that the local bending force is too large, resulting in the effect of "thermal expansion and cold contraction" of the back focal length of the optical imaging system (ie Under high temperature conditions, the back focal length of the lens will become shorter, and under low temperature conditions, the back focal length of the lens will become unsuitable for the use of the optical imaging system. imaging clarity in the temperature range.

(CT4-CT5)/(α4-α5)<0;

Wherein, CT4 and CT5 are the central thicknesses of the fourth lens and the fifth lens on the optical axis, respectively, α4 and α5 are the thermal expansion coefficients of the fourth lens and the fifth lens, respectively, and the unit of thermal expansion coefficient is 10 ^-5 /°C.

The fourth lens is cemented with the fifth lens, and by setting the parameters satisfying the relational expression, the thermal expansion difference between the fourth lens and the fifth lens is too large to avoid degumming and cracking; it is beneficial to improve the temperature sensitivity of the optical imaging system and ensure the optical imaging. The system can show excellent imaging quality and high resolution under high and low temperature environment.

4<(CT3+d34)/f<5;

Wherein, CT3 is the central thickness of the third lens on the optical axis, d34 is the air space between the image side of the third lens and the object side of the fourth lens on the optical axis, and f is the optical imaging The focal length of the system.

By satisfying the upper limit of the conditional expression, the thickness of the third lens and/or the air space between the third lens and the fourth lens on the optical axis can be prevented from being too large, thereby facilitating the miniaturization of the system; On the premise of performance, increase the central thickness of the third lens and/or the distance between the third lens and the fourth lens on the optical axis of the air, thereby facilitating correction of system aberrations and improving system imaging quality.

The embodiments of the present application provide an image capturing module, including the optical imaging system described in any one of the embodiments; and a photosensitive element, and the photosensitive element is disposed on the image side of the optical imaging system.

The imaging module of the embodiment of the present application includes an optical imaging system, and the optical imaging system meets the requirements of the imaging module for ultra-wide-angle imaging by reasonably configuring the bending force of the internal lens. The imaging module reduces the size of the ultra-wide-angle lens while ensuring the clarity of the imaging effect.

An embodiment of the present application provides an electronic device, which includes: a casing and the imaging module of the above-mentioned embodiment, where the imaging module is mounted on the casing.

The electronic device of the embodiment of the present application includes an imaging module, and through a reasonable configuration of bending force, the imaging quality of the optical imaging system can be improved, aberrations can be corrected, and the overall volume of the optical imaging system can be reduced.

An embodiment of the present application proposes a carrier, which includes: a body and the imaging module of the above-mentioned embodiment, wherein the imaging module is mounted on the body.

The carrier of the embodiment of the present application includes an imaging module, and through a reasonable configuration of bending force, the imaging quality of the optical imaging system can be improved, aberrations can be corrected, and the overall volume of the optical imaging system can be reduced.

Description of drawings

The above and/or additional aspects and advantages of the present application may be apparent and readily understood from the following description of embodiments in conjunction with the accompanying drawings, wherein:

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

FIG. 2 is a schematic diagram of spherical aberration (mm), astigmatism (mm) and distortion (%) of the optical imaging system in the first embodiment of the present application.

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

FIG. 4 is a schematic diagram of spherical aberration (mm), astigmatism (mm) and distortion (%) of the optical imaging system in the second embodiment of the present application.

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

FIG. 6 is a schematic diagram of spherical aberration (mm), astigmatism (mm) and distortion (%) of the optical imaging system in the third embodiment of the present application.

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

8 is a schematic diagram of spherical aberration (mm), astigmatism (mm) and distortion (%) of the optical imaging system in the fourth embodiment of the present application.

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

10 is a schematic diagram of spherical aberration (mm), astigmatism (mm) and distortion (%) of the optical imaging system in the fifth embodiment of the present application.

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

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

FIG. 13 is a schematic structural diagram of a carrier according to an embodiment of the present application.

Description of main component symbols

Image acquisition module 100

Optical imaging system 10

The first lens group 12

The first lens L1

Second lens L2

The second lens group 14

The third lens L3

The third lens group 16

Fourth lens L4

Fifth lens L5

Filter L6

Protective glass L7

Aperture STO

Object side S1, S3, S5, S7, S9, S11, S13

Like the side S2, S4, S6, S8, S10, S12, S14

Like face S15

Photosensitive element 20

Electronic device 200

Shell 210

Vehicle 300

Ontology 310

detailed description

In order to make the objectives, technical solutions and advantages of the present application more clear, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " Orientation or position indicated by "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", clockwise, "counterclockwise", etc. The relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does 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 Can not be construed as a limitation to the application. In addition, the terms "first" and "second" are only used for description purposes, and cannot be interpreted as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus , the features defined with "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more , unless otherwise specifically defined.

In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; it can be a mechanical connection, an electrical connection or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction of two elements relation. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

In this application, unless otherwise expressly specified and defined, a first feature "on" or "under" a second feature may include direct contact between the first and second features, or may include the first and second features Not directly but through additional features between them. Also, the first feature being "above", "over" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature is "below", "below" and "beneath" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is level less than the second feature.

The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, the components and arrangements of specific examples are described below. Of course, they are only examples and are not intended to limit the application. Furthermore, this application may repeat reference numerals and/or reference letters in different instances for the purpose of simplicity and clarity, and does not in itself indicate a relationship between the various embodiments and/or arrangements discussed. In addition, this application provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

Referring to FIG. 1 , the optical imaging system 10 provided by the embodiment of the present application includes sequentially from the object side to the image side: a first lens group 12 with negative bending force, and the surface of the first lens group 12 closest to the image side is a concave surface; The second lens group 14 with positive refractive power, the surfaces of the second lens group 14 closest to the object side and the image side are convex; the third lens group 16 with positive refractive power, the third lens group 16 is closest to the object side and the image side. The side faces are all convex.

Further, the optical imaging system 10 further includes a diaphragm STO, and the diaphragm STO is placed on the object side of the third lens group 16, specifically, the diaphragm STO is placed on the object side of the first lens group 12, or the first lens group 12 and the second lens group 14 , or between the second lens group 14 and the third lens group 16 .

In the optical imaging system 10 of the embodiment of the present application, the first lens group 12 , the second lens group 14 , and the third lens group 16 are reasonably configured with bending force to meet the requirements of the optical imaging system 10 for ultra-wide-angle imaging. By setting the diaphragm STO to reduce stray light, it helps to improve the image quality. The optical imaging system 10 ensures the sharpness of the imaging effect while reducing the size of the ultra-wide-angle lens.

In some embodiments, the first lens group 12 is composed of a first lens L1 with a negative inflection power and a second lens L2 with a negative inflection power; the second lens group 14 is composed of a third lens L3 with a positive refractive power; The third lens group 16 is composed of a fourth lens L4 having a negative refractive power and a fifth lens L5 having a positive refractive power, wherein the fourth lens L4 and the fifth lens L5 are in a cemented structure, and the fourth lens L4 and the fifth lens L5 The glued surface is convex toward the object side of the optical imaging system 10 at the optical axis.

It can be understood that the five-piece lens can better achieve the effect of ultra-wide-angle imaging, and can correct aberrations to avoid distortion of the imaging screen.

Further, the first lens L1 has an object side S1 and an image side S2, the second lens L2 has an object side S3 and an image side S4, the third lens L3 has an object side S5 and an image side S6, and the fourth lens L4 has an object side S7. In addition to the image side S8, the fifth lens L5 has an object side S9 and an image side S10. The image side S8 of the fourth lens L4 and the object side S9 of the fifth lens L5 are cemented surfaces.

In some embodiments, the object side S1 of the first lens L1 is convex at the optical axis, and the image side S2 is concave at the optical axis; the object side S3 of the second lens L2 is concave at the optical axis, and the image side S4 is concave at the optical axis. The optical axis is concave; the object side S5 of the third lens L3 is convex at the optical axis, and the image side S6 is convex at the optical axis; the object side S7 of the fourth lens L4 is convex at the optical axis, and the image side S8 is at the optical axis. The optical axis is concave; the object side S9 of the fifth lens L5 and the optical axis are convex, and the image side S10 and the optical axis are convex.

Through reasonable lens configuration, the optical imaging system 10 has a wide field of view, and while maintaining good optical performance, the size of the optical imaging system 10 is reduced, and the miniaturization of the optical imaging system 10 is realized.

In some embodiments, the diaphragm STO is disposed between the third lens L3 and the fourth lens L4, thereby providing a possibility to realize a large viewing angle. In addition, the central diaphragm STO makes the structure of the optical imaging system 10 have a certain symmetry, so that the optical distortion can be better controlled.

In some embodiments, the optical imaging system 10 further includes a filter L6, and the filter L6 has an object side S11 and an image side S12. The filter L6 is arranged on the image side of the fifth lens L5 to filter out non-visible light and other light in other wavelength bands, such as infrared light, and only allow visible light to pass through, so that the optical imaging system 10 can image more clearly and avoid interference.

In some embodiments, the optical imaging system 10 further includes a protective glass L7 having an object side S13 and an image side S14. The protective glass L7 is provided between the image surface S12 and the image surface S15 of the optical filter L6. The protective glass L7 is completely transparent, and light can directly pass through, and the protective glass L7 is used to protect the photosensitive elements and the like outside the optical imaging system 10 .

When the optical imaging system 10 is used for imaging, the light emitted or reflected by the object enters the optical imaging system 10 from the object side direction, and passes through the first lens L1, the second lens L2, the third lens L3, and the fourth lens in sequence L4, the fifth lens L5, the filter L6 and the protective glass L7 are finally converged on the image plane S15.

In some embodiments, the first lens L1 and the filter L6 are made of glass, and the second lens L2 , the third lens L3 , the fourth lens L4 and the fifth lens L5 are made of plastic.

In some embodiments, the first lens L1 is a spherical mirror, and the second lens L2 , the third lens L3 , the fourth lens L4 and the fifth lens L5 are all aspherical mirrors.

In some embodiments, the optical imaging system 10 satisfies the following conditional formula:

16<TTL/f<17;

Among them, TTL is the distance from the object side S1 of the first lens L1 to the image plane S15 of the optical imaging system 10 on the optical axis, and f is the focal length of the optical imaging system 10, that is, TTL/f can be any in (16, 17) Value, for example: 16.1, 16.25, 16.5, 16.7, 16.9, etc.

By satisfying the limitation of the conditional expression, the relationship between the total optical length of the optical imaging system 10 along the optical axis and the focal length of the optical imaging system 10 is determined. The feature of miniaturization of the optical imaging system 10 is achieved. When TTL/f is higher than the upper limit of the conditional expression, the overall length of the optical imaging system 10 is too long, which is not conducive to realizing miniaturization; when TTL/f is lower than the lower limit of the conditional expression, the focal length of the optical imaging system 10 is too long, which is not conducive to satisfying the requirements of the optical imaging system. With a field of view range of 10, sufficient object space information cannot be obtained.

-6.5<(f1-f2)/f<-4;

Among them, f1 and f2 are the focal lengths of the first lens L1 and the second lens L2 respectively, and f is the focal length of the optical imaging system 10, that is, (f1-f2)/f can be any value within (-6.5, -4) , for example, the values are: -6.4, -6, -5, -4.5, -4.1, etc.

By satisfying the limitation of the conditional expression, the bending forces of the first lens L1 and the second lens L2 are reasonably distributed in the optical imaging system, which is beneficial to suppress the high-order aberration and chromatic aberration caused by the peripheral beams in the imaging area, thereby improving the optical imaging. The resolution performance of the system. When (f1-f2)/f exceeds the limit of the conditional expression, the light beams around the imaging area are likely to cause high-order aberrations, which in turn lead to chromatic aberration during imaging, affecting the clarity and color accuracy of the imaging effect.

2<d12/f<4;

Wherein, d12 is the air space between the image side S2 of the first lens L1 and the object side S3 of the second lens L2 on the optical axis, and f is the focal length of the optical imaging system 10, that is, d12/f can be in the range of (2, 4) Any value within the value, for example, the value is: 2.1, 2.5, 3, 3.5, 3.9, etc.

By satisfying the limitation of the conditional expression, the first lens L1 can reasonably diverge the incident light beam, so as to better cooperate with the subsequent lenses, complete the correction of aberrations well, and make the light beam sufficiently divergent to be incident on the second lens L2, Therefore, it is easy to achieve the optical imaging system 10 with strong bending force, so as to further correct the off-axis aberration of the system. In addition, through the limitation of the air space between the first lens L1 and the second lens L2, it is beneficial to realize the characteristics of compact structure and miniaturization of the optical imaging system. When d12/f is higher than the upper limit of the conditional expression, the air space between the first lens L1 and the second lens L2 on the optical axis is too large, which is not conducive to the improvement of the assembly yield and is prone to stray light; The interval setting will increase the overall length of the optical imaging system 10, which is not conducive to the miniaturization of the system. When d12/f is lower than the lower limit of the conditional expression, the air space between the first lens L1 and the second lens L2 on the optical axis is too small, which is not conducive to the light beam being refracted by the first lens L1 and fully diverging to enter the second lens L2, And it is not conducive to correct the aberration of the optical imaging system 10, thereby affecting the imaging quality.

-62<R3/R4<-20;

Wherein, R3 is the radius of curvature at the near-optical axis of the object side S3 of the second lens L2, and R4 is the radius of curvature at the near-optical axis of the image side S4 of the second lens L2, that is, R3/R4 can be (-62, -20 ), for example, the values are: -60, -50, -40, -30, -21, etc.

Through the reasonable matching of the relationship between the curvature radius of the object side S3 of the second lens L2 and the image side S4, the second lens L2 is set as a negative lens near the object side to provide a negative bending force for the system; it can control the light entering the system at a large angle, Expand the field of view of the optical imaging system 10 . By satisfying the limitation of the conditional expression, controlling the curvature radius of the object side S3 of the second lens L2 is beneficial to reduce the probability of ghost images and weaken the intensity of ghost images; the size of R3 will affect the degree of curvature of the lens and the processing difficulty of the lens, R3 If it is too small, the curvature of the lens will affect the processing of the lens. The larger the R3, the flatter the surface of the lens, and it is easy for other similar plane parts to produce ghost images.

3<f3/f<4;

Wherein, f3 is the focal length of the third lens L3, and f is the focal length of the optical imaging system 10, that is, f3/f can be any value within the range of (3, 4), for example, the values are: 3.1, 3.3, 3.6, 3.8 , 3.9, etc.

By satisfying the definition of the conditional expression, it is possible to ensure a positive inflection force, and to converge the light rays used for diffusing the first lens L1 and the second lens L2 under the strong negative inflection force; The burden of the converging action of the five-lens L5 does not need to achieve a strong bending force, so the degree of freedom of design can be ensured. It can also ensure that the angle between the normal of the object side surface S5 and the image side surface S6 of the third lens L3 and the incident light does not become too large, and it is easy to suppress the occurrence of high-order aberrations. When f3/f exceeds the limit of the conditional expression, the positive bending force will become too strong, which is not conducive to suppressing high-order aberrations.

3<(R5-R6)/(R5+R6)<8;

Wherein, R5 is the radius of curvature at the near-optical axis of the object side S5 of the third lens L3, and R6 is the radius of curvature at the near-optical axis of the image side S6 of the third lens L3, namely (R5-R6)/(R5+R6) It can be any value within the range of (3, 8), for example, the value is: 3.1, 3.3, 3.6, 3.8, 7.9.

By satisfying the limitation of the conditional expression, it is possible to reduce the angle at which the chief ray enters the image plane S15 of the peripheral viewing angle. It can also suppress the generation of astigmatism, reduce the risk of ghosting, and improve the resolution capability of the system. When (R5-R6)/(R5+R6) exceeds the range of the conditional expression, astigmatism is likely to occur, which reduces the imaging quality.

0.5<R5/CT3<2;

Among them, R5 is the curvature radius of the object side S5 of the third lens L3 near the optical axis, CT3 is the thickness of the third lens L3 on the optical axis, that is, R5/CT3 can be any value within the range of (0.5, 2) , for example, the values are: 0.6, 1, 1.3, 1.6, 1.9, etc.

Since the third lens L3 has a biconvex structure, by satisfying the conditional expression, the light can be further converged to make the surface of the third lens L3 smooth, which can reduce the deviation of the incident angle and the exit angle of the light in different fields of view, thereby reducing the sensitivity ; And by setting the thicker third lens L3, the processing difficulty can be reduced, the sensitivity of the thickness tolerance can be reduced, and the yield can be improved.

0.5<f45/f123<2;

Wherein, f45 is the combined focal length of the fourth lens L4 and the fifth lens L5, and f123 is the combined focal length of the first lens L1, the second lens L2 and the third lens L3, that is, f45/f123 can be in the range of (0.5, 2) Any value of , for example: 0.6, 1, 1.3, 1.6, 1.9.

By satisfying the constraints of the conditional expression, the positive bending force can be limited within a reasonable range. When f45/f123 exceeds the range of the conditional expression, the positive bending force of f123 and f45 is too large or too small, so that the entire optical imaging system 10 is in a situation where the local bending force is too large, resulting in the back focal length of the optical imaging system (BFL, Back Focal Length) The effect of "thermal expansion and cold contraction" (that is, under high temperature conditions, the back focal length of the lens will become shorter, and under low temperature conditions, the back focal length of the lens will become unsuitable for the use of the optical imaging system) is too obvious, Thus, the imaging clarity of the optical imaging system 10 in the temperature range of -40°C to +85°C is affected.

(CT4-CT5)/(α4-α5)<0;

Among them, CT4 and CT5 are the central thicknesses of the fourth lens L4 and the fifth lens L5 on the optical axis, respectively, α4 and α5 are the thermal expansion coefficients of the fourth lens L4 and the fifth lens L5, respectively, and the thermal expansion coefficient unit is 10 ^-5 / °C. That is, the values of (CT4-CT5) and (α4-α5) are one positive and one negative.

Since the fourth lens L4 and the fifth lens L5 are cemented, by setting the parameters satisfying the conditional expression, the fourth lens L4 and the fifth lens L5 can be prevented from degumming and cracking due to the excessive thermal expansion difference, which is also conducive to improving the optical imaging. The temperature sensitivity of the system 10 ensures that the optical imaging system 10 can perform excellent imaging quality and high resolution in both high and low temperature environments.

4<(CT3+d34)/f<5;

Wherein, CT3 is the central thickness of the third lens L3 on the optical axis, d34 is the air space between the image side of the third lens L3 and the object side of the fourth lens L4 on the optical axis, f is the focal length of the optical imaging system 10, That is, (CT3+d34)/f can be any value within the range of (4, 5), for example, the values are: 4.1, 4.3, 4.6, 4.9, and so on.

By satisfying the limitation of the conditional expression, the thickness of the third lens L3 and/or the air interval between the third lens L3 and the fourth lens L4 on the optical axis can be avoided from being too large, thereby facilitating the realization of system miniaturization; On the premise of performance, the central thickness of the third lens L3 and/or the air distance between the third lens L3 and the fourth lens L4 on the optical axis are appropriately increased, so as to facilitate the correction of system aberrations and improve the imaging quality of the system. When (CT3+d34)/f exceeds the upper limit of the conditional expression, the thickness of the third lens L3 and/or the air interval between the third lens L3 and the fourth lens L4 on the optical axis is too large, which is not conducive to realizing the miniaturization of the optical imaging system 10 change. When (CT3+d34)/f exceeds the lower limit of the conditional expression, it is not conducive to the correction of aberrations of the optical imaging system 10, thereby reducing the imaging quality of the optical imaging system 10.

In some embodiments, at least one surface of at least one lens in optical imaging system 10 is aspherical. For example, in the first embodiment, the second lens L2 , the third lens L3 , the fourth lens L4 and the fifth lens L5 in the optical imaging system 10 are all aspherical surfaces.

The shape of the aspheric surface is determined by the following formula:

where Z is the longitudinal distance between any point on the aspheric surface and the vertex of the surface, r is the distance from any point on the aspheric surface to the optical axis, c is the vertex curvature (the reciprocal of the radius of curvature), k is the conic constant, and Ai is the i-th order of the aspheric surface Correction factor.

In this way, the optical imaging system 10 can effectively reduce the overall size of the optical imaging system 10 by adjusting the curvature radius and aspheric coefficient of each lens surface, occupy a small space, and can effectively correct aberrations and improve imaging quality.

first embodiment

Please refer to FIG. 1 and FIG. 2 at the same time, the optical imaging system 10 of the first embodiment sequentially includes a first lens L1 having a negative inflection force, a second lens L2 having a negative inflection force, and a positive inflection force from the object side to the image side. The third lens L3, the fourth lens L4 with negative refractive power, and the fifth lens L5 with positive refractive power.

The object side S1 of the first lens L1 is convex at the optical axis, and the image side S2 is concave at the optical axis; the object side S3 of the second lens L2 is concave at the optical axis, and the image side S4 is concave at the optical axis; The object side S5 of the third lens L3 is convex at the optical axis, and the image side S6 is convex at the optical axis; the object side S7 of the fourth lens L4 is convex at the optical axis, and the image side S8 is concave at the optical axis; The object side S9 of the fifth lens L5 is convex at the optical axis, and the image side S10 is convex at the optical axis.

Further, the stop STO is provided between the third lens L3 and the fourth lens L4.

Further, the optical imaging system 10 further includes a filter L6 arranged on the image side S10 of the fifth lens L5 and a protective glass L7 arranged between the image side S12 and the image surface S15 of the filter L6.

The reference wavelength in the first embodiment is 546.074 nm, and the optical imaging system 10 in the first embodiment satisfies the conditions of the following table.

Table 1

It should be noted that f is the focal length of the optical imaging system 10 , FNO is the aperture number of the optical imaging system 10 , and FOV is the field angle of the optical imaging system 10 .

Table 2

Second Embodiment

Please refer to FIG. 3 and FIG. 4 at the same time, the optical imaging system 10 of the second embodiment sequentially includes a first lens L1 with negative inflection force, a second lens L2 with negative inflection force, and a positive inflection force in sequence from the object side to the image side The third lens L3, the fourth lens L4 with negative refractive power, and the fifth lens L5 with positive refractive power.

The reference wavelength in the second embodiment is 546.074 nm, and the optical imaging system 10 in the second embodiment satisfies the conditions of the following table.

table 3

Table 4

Third Embodiment

Please refer to FIG. 5 and FIG. 6 at the same time, the optical imaging system 10 of the third embodiment sequentially includes a first lens L1 having a negative inflection force, a second lens L2 having a negative inflection force, and a positive inflection force from the object side to the image side. The third lens L3, the fourth lens L4 with negative refractive power, and the fifth lens L5 with positive refractive power.

The reference wavelength in the third embodiment is 546.074 nm, and the optical imaging system 10 in the third embodiment satisfies the conditions of the following table.

table 5

Table 6

Fourth Embodiment

Please refer to FIG. 7 and FIG. 8 at the same time, the optical imaging system 10 of the fourth embodiment sequentially includes a first lens L1 with negative inflection force, a second lens L2 with negative inflection force, and a positive inflection force in sequence from the object side to the image side The third lens L3, the fourth lens L4 with negative refractive power, and the fifth lens L5 with positive refractive power.

The reference wavelength in the fourth embodiment is 546.074 nm, and the optical imaging system 10 in the fourth embodiment satisfies the conditions of the following table.

Table 7

Table 8

Fifth Embodiment

Please refer to FIG. 9 and FIG. 10 at the same time, the optical imaging system 10 of the fifth embodiment sequentially includes a first lens L1 having a negative inflection force, a second lens L2 having a negative inflection force, and a positive inflection force from the object side to the image side. The third lens L3, the fourth lens L4 with negative refractive power, and the fifth lens L5 with positive refractive power.

The reference wavelength in the fifth embodiment is 546.074 nm, and the optical imaging system 10 in the fifth embodiment satisfies the conditions of the following table.

Table 9

Table 10

Table 11 shows (f1-f2)/f, TTL/f, d12/f, R3/R4, f3/f, (R5-R6)/(R5+R6 in the optical imaging systems of the first to fifth embodiments ), R5/CT3, f45/f123, (CT4-CT5)/(α4-α5) and (CT3+d34)/f values.

Form 11

实施例Example	(f1-f2)/f(f1-f2)/f	TTL/fTTL/f	d12/fd12/f	R3/R4R3/R4	f3/ff3/f
一one	-4.809-4.809	16.54216.542	2.8122.812	-59.892-59.892	3.5453.545
二two	-4.806-4.806	16.51216.512	2.8142.814	-60.532-60.532	3.5513.551
三three	-4.846-4.846	16.61116.611	2.8562.856	-61.777-61.777	3.5823.582
四Four	-4.912-4.912	16.65616.656	2.8942.894	-46.230-46.230	3.6063.606
五Fives	-5.108-5.108	16.78716.787	3.0493.049	-20.925-20.925	3.6213.621
实施例Example	(R5-R6)/(R5+R6)(R5-R6)/(R5+R6)	R5/CT3R5/CT3	f45/f123f45/f123	(CT4-CT5)/(α4-α5)(CT4-CT5)/(α4-α5)	(CT3+d34)/f(CT3+d34)/f
一one	3.0723.072	1.5781.578	1.6181.618	-1.208-1.208	4.4584.458
二two	3.1903.190	1.5511.551	1.5141.514	-1.232-1.232	4.4624.462
三three	3.7053.705	1.4411.441	1.3241.324	-1.242-1.242	4.5294.529
四Four	3.5803.580	1.4741.474	1.2801.280	-1.210-1.210	4.5294.529
五Fives	7.4187.418	1.1431.143	1.0381.038	-1.104-1.104	4.6914.691

Referring to FIG. 11 , the image capturing module 100 according to the embodiment of the present application includes an optical imaging system 10 and a photosensitive element 20 , and the photosensitive element 20 is disposed on the image side of the optical imaging system 10 .

Specifically, the photosensitive element 20 may be a complementary metal oxide semiconductor (CMOS, Complementary Metal Oxide Semiconductor) image sensor or a charge-coupled device (CCD, Charge-coupled Device).

The imaging module 100 according to the embodiment of the present application uses an aspherical lens in the optical imaging system 10 to correct aberrations through a reasonable configuration of the bending force and surface shape of each lens, so as to directly maintain a small size without increasing the number of lenses. And while being lightweight, it can maintain good optical performance and a large field of view, and can capture the details of the subject well.

Referring to FIG. 12 , the electronic device 200 according to the embodiment of the present application includes a casing 210 and an imaging module 100 , and the imaging module 100 is installed on the casing 210 .

The electronic device 200 in the embodiment of the present application includes, but is not limited to, a smart phone, a tablet computer, a notebook computer, an electronic book reader, a portable multimedia player (PMP), a portable phone, a video phone, a digital still camera, and a mobile medical device , wearable devices and other electronic devices that support imaging.

The optical imaging system 10 in the electronic device 200 of the above-mentioned embodiment corrects the aberration by using the aspherical lens in the optical imaging system 10 through the reasonable configuration of the tortuosity and surface shape of each lens, so as to realize the improvement without increasing the number of lenses. While directly maintaining the small and light weight, it can also maintain good optical performance and a large field of view, which can capture the details of the subject well.

Referring to FIG. 13 , the carrier 300 in the embodiment of the present application includes a main body 310 and an imaging module 100 , and the imaging module 100 is installed on the main body 310 .

The vehicle 300 in the embodiment of the present application includes, but is not limited to, a small passenger car, a small truck, a large passenger car, a large truck, a forklift, a bulldozer, and other vehicles that can be driven manually or automatically.

The optical imaging system 10 in the carrier 300 of the above-mentioned embodiment uses the aspherical lens in the optical imaging system 10 to correct the aberration through the reasonable configuration of the tortuosity and surface shape of each lens, so as to realize the improvement without increasing the number of lenses. While directly maintaining the small and light weight, it can also maintain good optical performance and a large field of view, which can capture the details of the subject well.

It will be apparent to those skilled in the art that the present application is not limited to the details of the above-described exemplary embodiments, but that the present application may be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Accordingly, the embodiments are to be regarded in all respects as illustrative and not restrictive, and the scope of the application is to be defined by the appended claims rather than the foregoing description, which is therefore intended to fall within the scope of the claims. All changes within the meaning and scope of the equivalents of , are included in this application.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present application can be Modifications or equivalent substitutions can be made without departing from the spirit and scope of the technical solutions of the present application.

Claims

An optical imaging system, characterized in that, from the object side to the image side, it comprises:

a first lens group with negative bending power, the surface of the first lens group closest to the image side is a concave surface;

a second lens group with positive inflection power, the surfaces of the second lens group closest to the object side and the image side are both convex;

a third lens group with positive inflection power, the surfaces of the third lens group closest to the object side and the image side are both convex;

The optical imaging system further includes a diaphragm, and the diaphragm is placed on the object side of the third lens group.
The optical imaging system of claim 1, wherein:

The first lens group is composed of a first lens with negative inflection power and a second lens with negative inflection power;

The second lens group is composed of a third lens having a positive refracting power;

The third lens group is composed of a fourth lens with negative refractive power and a fifth lens with positive refractive power, wherein the fourth lens and the fifth lens are in a cemented structure, and the fourth lens and the The cemented surface of the fifth lens is convex toward the object side of the optical imaging system at the optical axis;

The optical imaging system satisfies the following conditional formula:

-6.5<(f1-f2)/f<-4;

Wherein, f1 and f2 are the focal lengths of the first lens and the second lens, respectively, and f is the focal length of the optical imaging system.
The optical imaging system according to claim 2, wherein the optical imaging system satisfies the following conditional formula:

16<TTL/f<17;

Wherein, TTL is the distance from the object side of the first lens to the imaging surface of the optical imaging system on the optical axis, and f is the focal length of the optical imaging system.
The optical imaging system according to claim 2, wherein the optical imaging system satisfies the following conditional formula:

2<d12/f<4;

Wherein, d12 is the air space between the image side of the first lens and the object side of the second lens on the optical axis, and f is the focal length of the optical imaging system.
The optical imaging system according to claim 2, wherein the optical imaging system satisfies the following conditional formula:

-62<R3/R4<-20;

Wherein, R3 is the radius of curvature at the near-optical axis of the object side of the second lens, and R4 is the radius of curvature at the near-optical axis of the image side of the second lens.
The optical imaging system according to claim 2, wherein the optical imaging system satisfies the following conditional formula:

3<f3/f<4;

Wherein, f3 is the focal length of the third lens, and f is the focal length of the optical imaging system.
The optical imaging system according to claim 2, wherein the optical imaging system satisfies the following conditional formula:

3<(R5-R6)/(R5+R6)<8;

Wherein, R5 is the radius of curvature at the near-optical axis of the object side of the third lens, and R6 is the radius of curvature at the near-optical axis of the image side of the third lens.
The optical imaging system according to claim 2, wherein the optical imaging system satisfies the following conditional formula:

0.5<R5/CT3<2;

Wherein, R5 is the radius of curvature of the object side surface of the third lens near the optical axis, and CT3 is the central thickness of the third lens on the optical axis.
The optical imaging system according to claim 2, wherein the optical imaging system satisfies the following conditional formula:

0.5<f45/f123<2;

Wherein, f45 is the combined focal length of the fourth lens and the fifth lens, and f123 is the combined focal length of the first lens, the second lens and the third lens.
The optical imaging system according to claim 2, wherein the optical imaging system satisfies the following conditional formula:

(CT4-CT5)/(α4-α5)<0;

Wherein, CT4 and CT5 are the central thicknesses of the fourth lens and the fifth lens on the optical axis, respectively, α4 and α5 are the thermal expansion coefficients of the fourth lens and the fifth lens, respectively, and the unit of thermal expansion coefficient is 10 -5 /°C.
The optical imaging system according to claim 2, wherein the optical imaging system satisfies the following conditional formula:

4<(CT3+d34)/f<5;

Wherein, CT3 is the central thickness of the third lens on the optical axis, d34 is the air space between the image side of the third lens and the object side of the fourth lens on the optical axis, and f is the optical imaging The focal length of the system.
An imaging module, comprising:

The optical imaging system of any one of claims 1 to 11; and

A photosensitive element, the photosensitive element is arranged on the image side of the optical imaging system.
An electronic device, comprising:

the shell; and

The imaging module according to claim 12, wherein the imaging module is mounted on the casing.
A vehicle comprising:

ontology; and

The imaging module according to claim 12, wherein the imaging module is mounted on the body.