WO2021174489A1

WO2021174489A1 - Optical imaging system and image capturing device having same, and electronic device

Info

Publication number: WO2021174489A1
Application number: PCT/CN2020/078004
Authority: WO
Inventors: 蔡雄宇; 兰宾利; 赵迪; 周芮
Original assignee: 天津欧菲光电有限公司
Priority date: 2020-03-05
Filing date: 2020-03-05
Publication date: 2021-09-10

Abstract

An optical imaging system (100), comprising an optical lens group. The optical lens group comprises a first lens (1), a second lens (2), a third lens (3), a fourth lens (4), a fifth lens (5), a sixth lens (6), a seventh lens (7), and an eighth lens (8) sequentially arranged in the axial direction. The first lens (1), the second lens (2), the fifth lens (5), the sixth lens (6), and the seventh lens (7) all have positive refractive power. The third lens (3), the fourth lens (4), and the eighth lens (8) all have negative refractive power.

Description

Optical imaging system and imaging device and electronic device with same

Technical field

The present disclosure relates to the field of optical imaging technology, and in particular, to an optical imaging system, an imaging device and an electronic device having the optical imaging system.

Background technique

In the related technology, the telephoto lens has a long focal length, a small angle of view, and a large image on the film. Therefore, it can shoot a larger image at the same distance than a standard lens, which is suitable for shooting distant objects. For example, the front-view camera in the vehicle-mounted camera needs to observe longer-distance images. It provides the driver with a reference for the blind spot area outside the observable area of the human eye, so that the driver can grasp the road conditions ahead in real time during driving. Safe driving provides guarantee. Therefore, the front-view camera should use a longer focal length. However, the existing telephoto lens, such as the front-view camera in the vehicle-mounted camera, needs to capture the observation object at a long distance, and the overall pixel is difficult to guarantee.

Summary of the invention

The present disclosure aims to solve at least one of the technical problems existing in the prior art. To this end, an objective of the present disclosure is to provide an optical imaging system that can achieve high-definition shooting while achieving a long focal length.

Another objective of the present disclosure is to provide an imaging device with the above-mentioned optical imaging system.

Another objective of the present disclosure is to provide an electronic device having the above-mentioned image capturing device.

An optical imaging system according to an embodiment of the first aspect of the present disclosure includes: an optical lens group including a first lens, a second lens, a third lens, a fourth lens, and a fifth lens sequentially arranged along an axial direction , The sixth lens, the seventh lens and the eighth lens, the first lens, the second lens, the fifth lens, the sixth lens and the seventh lens all have positive refractive power, the The third lens, the fourth lens and the eighth lens all have negative refractive power.

According to the optical imaging system of the embodiment of the present disclosure, the first lens, the second lens, the fifth lens, the sixth lens, and the seventh lens all have positive refractive power, so that the optical imaging system has sufficient converging ability to make optical imaging The structure of the system is compact, and the total length of the optical lens group is prevented from being too long. By making the third lens, the fourth lens and the eighth lens all have negative refractive power, the light with a large angle of view can enter the optical imaging system. At the same time, through the corresponding optimization settings of the first lens to the eighth lens, the configuration of the optical lens group is more reasonable, so that the optical imaging system can meet the long focal length, and at the same time, it is beneficial to realize the high pixelization of the optical lens group and improve the optical system. The imaging quality of the imaging system.

According to some examples of the present disclosure, the object side of the second lens is convex at the optical axis, the image side of the second lens is concave at the optical axis, and the object side of the third lens is at the optical axis. Convex surface, the image side surface of the third lens is concave at the optical axis, and the second lens and the third lens are cemented with each other. Therefore, by cementing the second lens and the third lens with each other, the optical imaging system has a compact structure, which is conducive to the realization of a miniaturized design, and a balance is achieved in reducing the volume and improving the system resolution. Moreover, by making the object side surfaces of the second lens and the third lens convex on the optical axis and the image side surface on the optical axis concave, it is beneficial to correct the curvature of the image surface, reduce the sensitivity of assembly, and improve the resolution of the system.

According to some examples of the present disclosure, the object side surface and the image side surface of the fourth lens are both concave at the optical axis, the object side surface and the image side surface of the fifth lens are both convex at the optical axis, and the fourth lens And the fifth lens are cemented with each other. Therefore, by cementing the fourth lens and the fifth lens with each other, the structure of the optical imaging system can be made more compact, and a miniaturized design can be realized. Moreover, by making the object side surface of the fourth lens concave at the optical axis, it is advantageous to correct astigmatism.

According to some examples of the present disclosure, the object side of the first lens is convex at the optical axis, the image side of the first lens is concave at the optical axis, and the object side and image side of the sixth lens are at the optical axis. The axis is convex, the object side of the seventh lens is convex at the optical axis, the image side of the seventh lens is flat or concave at the optical axis, and the object side of the eighth lens is at the optical axis It is a concave surface, and the image side surface of the eighth lens is convex or concave at the optical axis. Thus, by making the object side surface of the first lens convex at the optical axis and the first lens has a positive refractive power, this arrangement can expand the angle of view. Moreover, by making the image side surface of the first lens concave at the optical axis, it is advantageous for peripheral light with a larger viewing angle to enter the optical lens group, thereby expanding the imaging range.

According to some examples of the present disclosure, a filter film is provided on the object side or image side of one of the first lens to the eighth lens; or a filter film is provided between the image side and the imaging surface of the eighth lens. There are filters. The filter film is used to transmit visible light and cut off the infrared light band. Separate setting of the filter is beneficial to the assembly process of the lens system; setting the filter film on the lens surface is more conducive to maintaining the color balance of the image surface. Make the effect of taking pictures close to the human eye, and ensure the imaging effect of the optical imaging system.

According to some examples of the present disclosure, the effective focal length of the optical lens group is EFL, and the focal length of the first lens is f1, wherein the EFL and f1 satisfy: 0<f1/EFL<2. Therefore, since the first lens is the first lens from the object side to the image side of the optical imaging system, it provides a positive bending force for the optical imaging system. Therefore, a reasonable configuration of the focal length of the first lens is beneficial to correct the aberrations of the optical imaging system. , Improve system resolution and reduce system sensitivity.

According to some examples of the present disclosure, the effective focal length of the optical lens group is EFL, and the composite focal length of the second lens and the third lens is f23, where the EFL and f23 satisfy: -6<f23/EFL <0. In this way, by constraining the combined focal length of the second lens and the third lens and the effective focal length of the optical lens group, the spherical aberration and distortion of the optical imaging system can be effectively balanced, and the curvature of the field can be corrected, reducing the sensitivity of assembly, and improving the system Resolution.

According to some examples of the present disclosure, the effective focal length of the optical lens group is EFL, and the combined focal length of the fourth lens and the fifth lens is f45, where the EFL and f45 satisfy: -3.6<f45/EFL< 0. Therefore, by setting -3.6<f45/EFL<0, the aberration of the optical lens group can be effectively balanced, which is beneficial to correct the curvature of the field, reduce the sensitivity of assembly, improve the resolution of the system, and improve the imaging quality of the entire optical imaging system. .

According to some examples of the present disclosure, the air separation distance between the sixth lens and the seventh lens on the optical axis is CT6, the focal length of the sixth lens is f6, and the focal length of the seventh lens is f7, where , The CT6, f6, and f7 satisfy: 1<CT6/(1/f6+1/f7)<25. Therefore, by setting 1<CT6/(1/f6+1/f7)<25, the sixth lens and the seventh lens provide positive refractive power to the system, which is beneficial to correct system aberrations, improve system resolution, and reduce sensitivity. Moreover, with this arrangement, the air gap between the sixth lens and the seventh lens on the optical axis can be reasonably controlled, so that the optical imaging system can achieve a compact design while satisfying high pixels.

According to some examples of the present disclosure, the effective focal length of the optical lens group is EFL, and the focal length of the eighth lens is f8, where the EFL and f8 satisfy: -3<f8/EFL<0. Therefore, since the eighth lens is the last lens from the object side to the image side of the optical imaging system, it provides negative refractive power for the optical imaging system, which can strengthen the imaging ability of the optical lens group, and is used to correct the aberrations of the optical imaging system and reduce Temperature sensitivity, and the greater the absolute value of f8, the smaller the amount of back focus change caused by temperature, which is beneficial to avoid defocusing caused by temperature differences, improve image quality, and make the picture clearer.

According to some examples of the present disclosure, the effective focal length of the optical lens group is EFL, and the entrance pupil diameter of the optical imaging system is EPD, where the EFL and EPD satisfy: EFL/EPD<1.7. Therefore, since the smaller the number of apertures, the greater the amount of light passing, and the greater the depth of field, this setting is beneficial to increase the image perception of the optical imaging system, enhance the presentation ability of details, and can capture distant objects and make the image clearer.

According to some examples of the present disclosure, the air separation distance between the image side surface of the third lens and the object side surface of the fourth lens on the optical axis is ΣCT56, and the total length of the optical imaging system is TTL, where Σ CT56 and TTL satisfy: 0＜∑CT56/TTL＜0.3. In this way, by controlling the air gap between the third lens and the fourth lens, the total length of the optical imaging system can be effectively shortened, aberrations can be corrected, and the resolution of the optical imaging system can be improved.

According to some examples of the present disclosure, the effective focal length of the optical lens group is EFL, the maximum field of view of the optical imaging system is FOV, and the image height corresponding to the maximum field of view of the optical imaging system is Imgh, where, The EFL, FOV, and Imgh satisfy: 45≤(FOV×EFL)/Imgh≤70. Such a setting is beneficial to control the incident angle of light, correct aberrations, improve the system's resolution, and ensure that the optical imaging system has high pixels, and the shooting angle and field of view are reasonably set, so that the optical imaging system can be used for long focal length imaging devices.

According to some examples of the present disclosure, the radius of curvature of the object side surface of the eighth lens at the optical axis is R13, and the focal length of the eighth lens is f8, where R13 and f8 satisfy: 0<R13/f8< 1. Therefore, by setting 0<R13/f8<1, it is advantageous to control the degree of curvature of the eighth lens, which is used to correct aberrations and further reduce the generation rate of ghost images.

According to some examples of the present disclosure, the radius of curvature of the image side surface of the fifth lens at the optical axis is R5, and the radius of curvature of the object side surface of the sixth lens at the optical axis is R6, wherein the R5, R6 Satisfies: -7<(R5+R6)/(R5-R6)<-3. Therefore, by making -7<(R5+R6)/(R5-R6)<-3, the optical imaging system has a large viewing angle and a high definition at the same time, and the imaging quality is guaranteed.

The imaging device according to the embodiment of the second aspect of the present disclosure includes: an optical imaging system, the optical imaging system being the optical imaging system according to the embodiment of the first aspect of the present disclosure; a photosensitive element, the photosensitive element is provided in the The image side of the optical imaging system.

According to the imaging device of the embodiment of the present disclosure, by adopting the above-mentioned optical imaging system, long focal length and high pixels can be satisfied at the same time, the imaging quality is high, and the overall performance of the imaging device is improved.

An electronic device according to an embodiment of the third aspect of the present disclosure includes: a housing with a through hole formed on the housing; , The image capturing device is installed at the through hole.

According to the electronic device of the embodiment of the present disclosure, by adopting the above-mentioned image capturing device, the electronic device has the advantages of a long focal length and high pixels, and fully meets the needs of users.

The additional aspects and advantages of the present disclosure will be partially given in the following description, and some will become obvious from the following description, or be understood through the practice of the present disclosure.

Description of the drawings

The above and/or additional aspects and advantages of the present disclosure will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, in which:

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

Fig. 2 is a graph of spherical aberration, astigmatism and distortion of the optical imaging system shown in Fig. 1;

Fig. 3 is a schematic structural diagram of an optical imaging system according to a second embodiment of the present disclosure;

4 is a graph of spherical aberration, astigmatism and distortion of the optical imaging system shown in FIG. 3;

Fig. 5 is a schematic structural diagram of an optical imaging system according to a third embodiment of the present disclosure;

Fig. 6 is a graph of spherical aberration, astigmatism and distortion of the optical imaging system shown in Fig. 5;

Fig. 7 is a schematic structural diagram of an optical imaging system according to a fourth embodiment of the present disclosure;

Fig. 8 is a graph of spherical aberration, astigmatism and distortion of the optical imaging system shown in Fig. 7;

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

Fig. 10 is a graph of spherical aberration, astigmatism and distortion of the optical imaging system shown in Fig. 9.

Reference signs:

100: Optical imaging system;

1: the first lens; 2: the second lens; 3: the third lens; 4: the fourth lens;

5: the fifth lens; 6: the sixth lens; 7: the seventh lens;

8: eighth lens; 9: diaphragm; 10: filter; 11: protective glass.

Detailed ways

The embodiments of the present disclosure are described in detail below. Examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary, and are only used to explain the present disclosure, and cannot be understood as a limitation to the present disclosure.

In the description of the present disclosure, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", The orientation or positional relationship indicated by "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying The device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure.

It should be noted that the terms "first" and "second" are only used for descriptive purposes, and cannot be understood 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 these features. Further, in the description of the present disclosure, unless otherwise specified, "plurality" means two or more than two.

Hereinafter, an optical imaging system 100 according to an embodiment of the first aspect of the present disclosure will be described with reference to FIGS. 1-10.

As shown in FIGS. 1, 3, 5, 7 and 9, the optical imaging system 100 according to the embodiment of the first aspect of the present disclosure includes an optical lens group.

Specifically, the optical lens group includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, and a second lens that are sequentially arranged along the axial direction. Eight lens 8. The first lens 1, the second lens 2, the fifth lens 5, the sixth lens 6, and the seventh lens 7 all have positive refractive power, and the third lens 3, the fourth lens 4 and the eighth lens 8 all have negative refractive power.

It should be noted that the tortuous force means that the direction of propagation of the parallel light will be deflected when the parallel light passes through the optical imaging system, which is used to characterize the tortuous power of the optical imaging system to the incident parallel light beam. The optical imaging system has a positive tortuous force, which indicates that the tortuosity of the light is convergent; the optical imaging system has a negative tortuous force, which indicates that the tortuous of the light is divergent. In the optical imaging system 100 provided in the present disclosure, if the tortuous force or focal length of the lens does not define its area position, it means that the tortuous force or focal length of the lens is the tortuous force or focal length of the lens at the optical axis.

According to the optical imaging system 100 of the embodiment of the present disclosure, the first lens 1, the second lens 2, the fifth lens 5, the sixth lens 6, and the seventh lens 7 all have positive refractive power, so that the optical imaging system 100 has sufficient The convergence capability of the optical imaging system 100 makes the structure of the optical imaging system 100 compact, and prevents the total length of the optical lens group from being too long. By making the third lens 3, the fourth lens 4, and the eighth lens 8 have negative refractive power, the light with a large angle of view can enter the optical imaging system 100. At the same time, the first lens 1 to the eighth lens 8 are correspondingly Optimizing the setting makes the configuration of the optical lens group more reasonable, so that the optical imaging system 100 meets the long focal length, and at the same time, it is beneficial to realize the high pixelization of the optical lens group and improve the imaging quality of the optical imaging system 100.

In some embodiments of the present disclosure, referring to FIGS. 1, 3, 5, 7 and 9, the object side of the second lens 2 is convex at the optical axis, and the image side of the second lens 2 is at the optical axis. It is a concave surface, the object side surface of the third lens 3 is convex at the optical axis, the image side surface of the third lens 3 is concave at the optical axis, and the second lens 2 and the third lens 3 are cemented with each other. For example, in the examples of Figure 1, Figure 3, Figure 5, Figure 7 and Figure 9, the second lens 2 and the third lens 3 are cemented with each other to form a cemented structure, and the cemented structure is in the shape of a meniscus, and the cemented surface is convex toward the optical imaging The object side of the system 100. Therefore, by cementing the second lens 2 and the third lens 3 with each other, the optical imaging system 100 has a compact structure, which is beneficial to realize a miniaturized design, and achieves a balance between reducing the volume and improving the system resolution. Moreover, by making the object side surfaces of the second lens 2 and the third lens 3 convex on the optical axis and the image side surface concave on the optical axis, it is beneficial to correct the curvature of the field, reduce the sensitivity of assembly, and improve the resolution of the system.

In some embodiments of the present disclosure, with reference to FIGS. 1, 3, 5, 7 and 9, the object side and the image side of the fourth lens 4 are both concave at the optical axis, and the object side of the fifth lens 5 The image side surface is convex at the optical axis, and the fourth lens 4 and the fifth lens 5 are cemented with each other. Therefore, by cementing the fourth lens 4 and the fifth lens 5 with each other, the structure of the optical imaging system 100 can be made more compact and a miniaturized design can be realized. Moreover, by making the object side surface of the fourth lens 4 concave at the optical axis, it is advantageous to correct astigmatism.

In some embodiments of the present disclosure, referring to FIGS. 1, 3, 5, 7 and 9, the object side of the first lens 1 is convex at the optical axis, and the image side of the first lens 1 is at the optical axis. It is concave. The object side and image side of the sixth lens 6 are convex at the optical axis. The object side of the seventh lens 7 is convex at the optical axis. The image side of the seventh lens 7 is flat or concave at the optical axis. The object side surface of the eighth lens 8 is concave at the optical axis, and the image side surface of the eighth lens 8 is convex or concave at the optical axis. Thus, by making the object side surface of the first lens 1 convex at the optical axis and the first lens 1 has a positive bending force, this arrangement can expand the angle of view. Moreover, by making the image side surface of the first lens 1 a concave surface at the optical axis, it is advantageous for peripheral light with a larger viewing angle to enter the optical lens group, so that the imaging range can be expanded.

Optionally, referring to FIG. 1, one of the object side surface and the image side surface of the sixth lens 6 may be an aspheric surface. For example, in the example of FIG. 1, the object side surface of the sixth lens 6 is an aspherical surface, and the image side surface of the sixth lens 6 is a spherical surface. This setting helps to obtain more control variables to reduce aberrations, improve the system's resolution, and make the system's imaging clearer. Of course, the object side surface and the image side surface of the sixth lens 6 may both be spherical surfaces. It can be understood that the specific shape of the sixth lens 6 can be specifically set according to actual requirements to better meet actual applications.

In some optional embodiments of the present disclosure, one of the first lens 1 to the eighth lens 8 is provided with a filter film (not shown) on the object side or the image side. For example, the filter film may be an IR (Infrared Radiation, infrared) film, which can filter out infrared light and transmit visible light. Therefore, disposing the filter film on the surface of the lens is more conducive to maintaining the color balance of the image plane, so that the effect of taking pictures is close to that of the human eye, so that the imaging quality of the optical imaging system 100 can be improved.

Of course, the present disclosure is not limited to this. In other optional embodiments of the present disclosure, a filter 10 is provided between the image side and the imaging surface of the eighth lens 8. For example, the filter 10 may be an IR plate. Therefore, by arranging the filter 10 on the image side of the eighth lens 8, the filter 10 can also filter out unwanted light in nature, so that the effect of taking pictures is close to that of the human eye, and the imaging effect of the optical imaging system 100 is ensured. And the separate arrangement of the filter 10 is beneficial to the assembly process of the optical lens group.

In some embodiments of the present disclosure, the effective focal length of the optical lens group is EFL, and the focal length of the first lens 1 is f1, where EFL and f1 satisfy: 0<f1/EFL<2. Therefore, since the first lens 1 is the first lens element from the object side to the image side of the optical imaging system 100, it provides positive refractive power for the optical imaging system 100. Therefore, a reasonable configuration of the focal length of the first lens 1 is beneficial to correct optical imaging. The aberration of the system 100 improves the resolution of the system and reduces the sensitivity of the system.

In some embodiments of the present disclosure, the effective focal length of the optical lens group is EFL, and the combined focal length of the second lens 2 and the third lens 3 is f23, where EFL and f23 satisfy: -6<f23/EFL<0. For example, in the examples of Figures 1, 3, 5, 7 and 9, the second lens 2 and the third lens 3 are cemented to form a first cemented lens, the first cemented lens is meniscus-shaped, and the cemented surface is convex On the object side of the optical imaging system 100, the focal length of the first cemented lens is f23. In this way, by constraining the combined focal length of the second lens 2 and the third lens 3 and the effective focal length of the optical lens group, the spherical aberration and distortion of the optical imaging system 100 can be effectively balanced, and the curvature of the field can be corrected, and the sensitivity of assembly can be reduced. , Improve system resolution.

In some embodiments of the present disclosure, the effective focal length of the optical lens group is EFL, and the combined focal length of the fourth lens 4 and the fifth lens 5 is f45, where EFL and f45 satisfy: -3.6<f45/EFL<0. For example, in the examples of FIGS. 1, 3, 5, 7 and 9, the fourth lens 4 and the fifth lens 5 are cemented with each other to form a second cemented lens, and the cemented surface is convex toward the object side of the optical imaging system 100, The focal length of the second cemented lens is f45. Therefore, by setting -3.6<f45/EFL<0, the aberration of the optical lens group can be effectively balanced, which is beneficial to correct field curvature, reduce assembly sensitivity, improve system resolution, and improve the imaging of the entire optical imaging system 100 quality.

In some embodiments of the present disclosure, the air separation distance between the sixth lens 6 and the seventh lens 7 on the optical axis is CT6, the focal length of the sixth lens 6 is f6, and the focal length of the seventh lens 7 is f7, where CT6 , F6, f7 satisfy: 1<CT6/(1/f6+1/f7)<25. Therefore, by making 1<CT6/(1/f6+1/f7)<25, the sixth lens 6 and the seventh lens 7 provide positive tortuosity to the system, which is beneficial to correct system aberrations, improve system resolution and reduce sensitivity Spend. Moreover, with this arrangement, the air gap between the sixth lens 6 and the seventh lens 7 on the optical axis can be reasonably controlled, so that the optical imaging system 100 can achieve a compact design while satisfying high pixels.

In some embodiments of the present disclosure, the effective focal length of the optical lens group is EFL, and the focal length of the eighth lens 8 is f8, where EFL and f8 satisfy: -3<f8/EFL<0. Therefore, since the eighth lens 8 is the last lens from the object side to the image side of the optical imaging system 100, it provides negative refractive power for the optical imaging system 100, which can strengthen the imaging capability of the optical lens group and be used to correct the optical imaging system 100. Aberrations reduce temperature sensitivity, and the larger the absolute value of f8, the smaller the amount of back focus change caused by temperature, which is beneficial to avoid defocusing caused by temperature differences, improve image quality, and make the picture clearer.

In some embodiments of the present disclosure, the effective focal length of the optical lens group is EFL, and the entrance pupil diameter of the optical imaging system 100 is EPD, where EFL and EPD satisfy: EFL/EPD<1.7. Therefore, since the smaller the number of apertures, the greater the amount of light passing, and the greater the depth of field, such a setting is beneficial to increase the image perception of the optical imaging system 100, enhance the presentation ability of details, and can capture distant objects and make the imaging clearer.

In some embodiments of the present disclosure, the air separation distance between the image side surface of the third lens 3 and the object side surface of the fourth lens 4 on the optical axis is ΣCT56, and the total length of the optical imaging system 100 is TTL, where ΣCT56 TTL satisfies: 0＜∑CT56/TTL＜0.3. In this way, by controlling the air gap between the third lens 3 and the fourth lens 4 on the optical axis, the total length of the optical imaging system 100 can be effectively shortened, aberrations can be corrected, and the resolution of the optical imaging system 100 can be improved.

In some embodiments of the present disclosure, the effective focal length of the optical lens group is EFL, the maximum angle of view of the optical imaging system 100 is FOV, and the image height corresponding to the maximum angle of view of the optical imaging system 100 is Imgh, where EFL, FOV and Imgh satisfy: 45≤(FOV×EFL)/Imgh≤70. It should be noted that “the maximum angle of view of the optical imaging system 100” refers to the angle of view of the optical imaging system 100 in the diagonal direction. Such a setting is beneficial to control the incident angle of light, correct aberrations, and improve the resolution of the system. Under the premise of ensuring that the optical imaging system 100 has high pixels, the shooting angle and field of view can be set reasonably, so that the optical imaging system 100 can be used for long focal length imaging. Device.

In some embodiments of the present disclosure, the radius of curvature of the object side surface of the eighth lens 8 at the optical axis is R13, and the focal length of the eighth lens 8 is f8, where R13 and f8 satisfy: 0<R13/f8<1. Therefore, by setting 0<R13/f8<1, it is advantageous to control the degree of curvature of the eighth lens 8 for correcting aberrations and further reducing the generation rate of ghost images.

In some embodiments of the present disclosure, the radius of curvature of the image side surface of the fifth lens 5 at the optical axis is R5, and the radius of curvature of the object side surface of the sixth lens 6 at the optical axis is R6, where R5 and R6 satisfy: -7<(R5+R6)/(R5-R6)<-3. Specifically, for example, when (R5+R6)/(R5-R6)≤-7, it is easy to reduce the angle at which the chief ray of the peripheral viewing angle enters the image plane; when (R5+R6)/(R5-R6)≥- At 3, it is easy to suppress astigmatism. Therefore, by setting -7<(R5+R6)/(R5-R6)<-3, the optical imaging system 100 has a large viewing angle and a high definition at the same time, and the imaging quality is ensured.

In a further embodiment of the present disclosure, as shown in FIG. 1, FIG. 3, FIG. 5, FIG. 7 and FIG. 9, the optical lens group further includes a diaphragm 9. The diaphragm 9 is provided in the first lens 1 and the eighth lens 8. between. Thus, by providing the diaphragm 9, the influence of stray light on the image can be eliminated, thereby improving the quality of the image. Moreover, the diaphragm 9 helps to reasonably control the angle of view of the optical imaging system 100, so that the system imaging is clearer.

Optionally, the material of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7 and the eighth lens 8 may be plastic or glass Wait. When the material of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7 and the eighth lens 8 is plastic, the optical imaging can be reduced The weight of the system 100 and reduce the production cost; when the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7 and the eighth lens 8 When the material is glass, the optical imaging system 100 has excellent optical performance and high temperature resistance. Of course, the materials of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7 and the eighth lens 8 can also be glass and plastic. Any combination, not necessarily all glass or all plastic.

The optical imaging system 100 according to various embodiments of the present disclosure will be described below with reference to FIGS. 1 to 10.

Example one,

In this embodiment, as shown in FIG. 1, the optical imaging system 100 includes a first lens 1, a second lens 2, a third lens 3, an aperture 9, a fourth lens 4, and a fifth lens in order from the object side to the image side. Refer to FIG. 2 for the spherical aberration, astigmatism and distortion curves of the lens 5, the sixth lens 6, the seventh lens 7 and the eighth lens 8, and the optical imaging system 100.

Among them, the first lens 1 to the eighth lens 8 have no inflection point on the object side and the image side, the first lens 1 to the eighth lens 8 are made of glass, and the second lens 2 and the third lens 3 are cemented with each other. , The fourth lens 4 and the fifth lens 5 are cemented with each other. The first lens 1 has a positive refractive power, the object side surface of the first lens 1 is a convex surface, the image side surface of the first lens 1 is a concave surface, and both the object side surface and the image side surface of the first lens 1 are spherical surfaces. The second lens 2 has a positive refractive power, the object side surface of the second lens 2 is a convex surface, the image side surface of the second lens 2 is a concave surface, and both the object side surface and the image side surface of the second lens 2 are spherical surfaces. The third lens 3 has a negative refractive power, the object side surface of the third lens 3 is convex, the image side surface of the third lens 3 is concave, and both the object side surface and the image side surface of the third lens 3 are spherical surfaces. The fourth lens 4 has a negative refractive power, the object side and the image side of the fourth lens 4 are both concave, and the object side and the image side of the fourth lens 4 are both spherical. The fifth lens 5 has a positive bending force, the object side surface and the image side surface of the fifth lens 5 are both convex surfaces, and the object side surface and the image side surface of the fifth lens 5 are both spherical surfaces. The sixth lens 6 has a positive refractive power, the object side surface and the image side surface of the sixth lens 6 are both convex surfaces, the object side surface of the sixth lens 6 is an aspheric surface, and the image side surface of the sixth lens 6 is a spherical surface. The seventh lens 7 has a positive refractive power, the object side surface of the seventh lens 7 is convex, the image side surface of the seventh lens 7 is flat, and both the object side surface and the image side surface of the seventh lens 7 are spherical surfaces. The eighth lens 8 has a negative refractive power, the object side surface of the eighth lens 8 is concave, the image side surface of the eighth lens 8 is convex, and both the object side surface and the image side surface of the eighth lens 8 are spherical surfaces.

The imaging surface is arranged on the image side of the eighth lens 8, an IR sheet and a protective glass 11 are arranged in sequence between the eighth lens 8 and the imaging surface. The IR sheet is made of glass and does not affect the focal length, and the photosensitive element is arranged on the imaging surface. The IR film will filter the imaging light entering the lens and filter out the infrared light.

The detailed optical data of the first embodiment is shown in Table 1, and the aspheric coefficients are shown in Table 2. The units of the radius of curvature, thickness and focal length are millimeters, and the reference wavelength of the optical imaging system 100 is 546.074 nm. Among them, the aspheric surface type formula is:

z is the distance from the corresponding point on the aspheric surface to the plane tangent to the apex of the surface, r is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the aspheric apex, k is the conic constant, and Ai is the aspheric surface type The coefficient corresponding to the higher-order item of the i-th term in the formula.

Table 1

Table 2

In the first embodiment, the effective focal length of the optical lens group is EFL, the focal length of the first lens 1 is f1, the composite focal length of the second lens 2 and the third lens 3 is f23, and the fourth lens 4 and the fifth lens 5 are composite focal lengths. F45, f1/EFL=1.58; f23/EFL=-3.87, f45/EFL=-3.36; the air separation distance between the sixth lens 6 and the seventh lens 7 is CT6, and the focal length of the sixth lens 6 is f6, The focal length of the seventh lens 7 is f7, CT6/(1/f6+1/f7)=1.47; the focal length of the eighth lens 8 is f8, f8/EFL=-2.39; the entrance pupil diameter of the optical imaging system 100 is EPD, EFL/EPD=1.65; the distance between the image side surface of the third lens 3 and the object side surface of the fourth lens 4 on the optical axis is ΣCT56, the total length of the optical imaging system 100 is TTL, ΣCT56/TTL=0.18; optical imaging The maximum angle of view of the system 100 is FOV, and the image height corresponding to the maximum angle of view of the optical imaging system 100 is Imgh, (FOV×EFL)/Imgh=56.363; the radius of curvature of the object side of the eighth lens 8 at the optical axis R13, R13/f8=0.58; the curvature radius of the image side surface of the fifth lens 5 at the optical axis is R5, and the curvature radius of the object side surface of the sixth lens 6 at the optical axis is R6, (R5+R6)/( R5-R6) = -5.31.

Therefore, through the above-mentioned configuration, the optical imaging system 100 can satisfy high-definition shooting while achieving a long focal length, and is conducive to the realization of a miniaturized design.

Example two,

As shown in Figures 3 and 4, the structure of this embodiment is approximately the same as that of the first embodiment, wherein the same components use the same reference numerals, and the difference is that: the object side surface of the sixth lens 6 is a spherical surface, and the eighth lens The image side surface of 8 is a concave surface, and only a protective glass 11 is provided between the eighth lens 8 and the imaging surface, and there is no IR sheet.

The detailed optical data of the second embodiment is shown in Table 3. The units of the radius of curvature, thickness and focal length are millimeters, and the reference wavelength of the optical imaging system 100 is 546.074 nm.

table 3

In the second embodiment, f1/EFL=1.47, f23/EFL=-3.15, f45/EFL=-2.10, CT6/(1/f6+1/f7)=1.05, f8/EFL=-1.19, EFL/EPD =1.65, ΣCT56/TTL=0.19, (FOV×EFL)/Imgh=56.683, R13/f8=0.79, (R5+R6)/(R5-R6)=-6.42.

The other structures of the optical imaging system 100 of this embodiment are similar to those of the optical imaging system 100 of the first embodiment, and therefore will not be described in detail here.

Example three,

As shown in Figures 5 and 6, the structure of this embodiment is roughly the same as that of the second embodiment. The same components are marked with the same reference numerals. The difference is that the image side surface of the seventh lens 7 is concave, and the eighth lens has a concave surface. The image side of 8 is convex.

The detailed optical data of the third embodiment is shown in Table 4. The units of the radius of curvature, thickness and focal length are millimeters, and the reference wavelength of the optical imaging system 100 is 546.074 nm.

Table 4

In the third embodiment, f1/EFL=1.71, f23/EFL=-5.32, f45/EFL=-2.73, CT6/(1/f6+1/f7)=6.16, f8/EFL=-1.35, EFL/EPD =1.65, ΣCT56/TTL=0.20, (FOV×EFL)/Imgh=56.512, R13/f8=0.63, (R5+R6)/(R5-R6)=-5.49.

The other structure of the optical imaging system 100 of this embodiment is similar to that of the optical imaging system 100 of the second embodiment, so it will not be described in detail here.

Example four,

As shown in Figures 7 and 8, the structure of this embodiment is roughly the same as that of the third embodiment, wherein the same components use the same reference numerals, and the difference is: the object side of the first lens 1 to the seventh lens 7 and The radius of curvature of the image side surface and the object side surface of the eighth lens 8 is different from that of the third embodiment.

The detailed optical data of the fourth embodiment is shown in Table 5. The units of the radius of curvature, thickness and focal length are millimeters, and the reference wavelength of the optical imaging system 100 is 546.074 nm.

table 5

Example five,

As shown in Figs. 9 and 10, the structure of this embodiment is approximately the same as that of the fourth embodiment, wherein the same components are given the same reference numerals, and the difference is that the image side surface of the eighth lens 8 is concave.

The detailed optical data of the fifth embodiment is shown in Table 6. The units of the radius of curvature, thickness and focal length are millimeters, and the reference wavelength of the optical imaging system 100 is 546.074 nm.

Table 6

In the fifth embodiment, f1/EFL=1.76, f23/EFL=-5.3, f45/EFL=-2.55, CT6/(1/f6+1/f7)=9.8, f8/EFL=-1.03, EFL/EPD =1.65, ΣCT56/TTL=0.17, (FOV×EFL)/Imgh=56.614, R13/f8=0.93, (R5+R6)/(R5-R6)=-4.73.

The other structure of the optical imaging system 100 of this embodiment is similar to that of the optical imaging system 100 of the fourth embodiment, so it will not be described in detail here.

An image capturing device (not shown in the figure) according to an embodiment of the second aspect of the present disclosure includes an optical imaging system 100 and a photosensitive element. Specifically, the optical imaging system 100 is the optical imaging system 100 according to the embodiment of the first aspect of the present disclosure, and the photosensitive element is provided on the image side of the optical imaging system 100.

According to the imaging device of the embodiment of the present disclosure, by adopting the above-mentioned optical imaging system 100, long focal length and high pixels can be satisfied at the same time, the imaging quality is high, and the overall performance of the imaging device is improved.

An electronic device (not shown in the figure) according to an embodiment of the third aspect of the present disclosure includes a housing (not shown in the figure) and an image capturing device. A through hole is formed on the housing, and the image capturing device is the image capturing device according to the embodiment of the second aspect of the present disclosure, and the image capturing device is installed at the through hole.

Other configurations and operations of the electronic device according to the embodiments of the present disclosure are known to those of ordinary skill in the art, and will not be described in detail here.

In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "exemplary embodiments", "examples", "specific examples", or "some examples" etc. means to incorporate the implementation The specific features, structures, materials or characteristics described by the examples or examples are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above-mentioned terms do not necessarily refer to the same embodiment or example.

Although the embodiments of the present disclosure have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and modifications can be made to these embodiments without departing from the principle and purpose of the present disclosure. The scope of the present disclosure is defined by the claims and their equivalents.

Claims

An optical imaging system, characterized in that it comprises:

An optical lens group, the optical lens group including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens sequentially arranged along the axial direction;

The first lens, the second lens, the fifth lens, the sixth lens, and the seventh lens all have positive refractive power;

The third lens, the fourth lens, and the eighth lens all have negative refractive power.
The optical imaging system of claim 1, wherein the object side surface of the second lens is convex at the optical axis, the image side surface of the second lens is concave at the optical axis, and the third lens The object side surface of the third lens is convex on the optical axis, the image side surface of the third lens is concave on the optical axis, and the second lens and the third lens are cemented with each other.
The optical imaging system according to claim 1, wherein the object side surface and the image side surface of the fourth lens are both concave at the optical axis, and the object side surface and the image side surface of the fifth lens are both concave at the optical axis. It is a convex surface, and the fourth lens and the fifth lens are cemented with each other.
The optical imaging system of claim 1, wherein the object side surface of the first lens is convex at the optical axis, the image side surface of the first lens is concave at the optical axis, and the sixth lens The object side and the image side of the seventh lens are convex at the optical axis, the object side of the seventh lens is convex at the optical axis, the image side of the seventh lens is flat or concave at the optical axis, and the eighth The object side surface of the lens is concave at the optical axis, and the image side surface of the eighth lens is convex or concave at the optical axis.
The optical imaging system according to any one of claims 1 to 4, wherein the object side or the image side of one of the first lens to the eighth lens is provided with a filter film; or

A filter is arranged between the image side and the imaging surface of the eighth lens.
The optical imaging system of claim 1, wherein the effective focal length of the optical lens group is EFL, and the focal length of the first lens is f1, wherein the EFL and f1 satisfy:

0<f1/EFL<2.
The optical imaging system of claim 1, wherein the effective focal length of the optical lens group is EFL, and the combined focal length of the second lens and the third lens is f23, wherein the EFL and f23 satisfy:

-6<f23/EFL<0.
The optical imaging system of claim 1, wherein the effective focal length of the optical lens group is EFL, and the combined focal length of the fourth lens and the fifth lens is f45, wherein the EFL and f45 satisfy :

-3.6<f45/EFL<0.
The optical imaging system according to claim 1, wherein the air separation distance between the sixth lens and the seventh lens on the optical axis is CT6, the focal length of the sixth lens is f6, and the focal length of the sixth lens is f6. The focal length of the seven lens is f7, where the CT6, f6, and f7 satisfy:

1<CT6/(1/f6+1/f7)<25.
The optical imaging system of claim 1, wherein the effective focal length of the optical lens group is EFL, and the focal length of the eighth lens is f8, wherein the EFL and f8 satisfy:

-3<f8/EFL<0.
The optical imaging system according to claim 1, wherein the effective focal length of the optical lens group is EFL, and the entrance pupil diameter of the optical imaging system is EPD, wherein the EFL and EPD satisfy:

EFL/EPD<1.7.
The optical imaging system according to claim 1, wherein the spatial separation distance between the image side surface of the third lens and the object side surface of the fourth lens on the optical axis is ΣCT56, and the total length of the optical imaging system Is TTL, where the ΣCT56 and TTL satisfy:

0<∑CT56/TTL<0.3.
The optical imaging system according to claim 1, wherein the effective focal length of the optical lens group is EFL, the maximum field angle of the optical imaging system is FOV, and the maximum field angle of the optical imaging system corresponds to The image height of is Imgh, where the EFL, FOV, and Imgh satisfy:

45≤(FOV×EFL)/Imgh≤70.
The optical imaging system according to claim 1, wherein the radius of curvature of the object side surface of the eighth lens at the optical axis is R13, and the focal length of the eighth lens is f8, wherein the R13, f8 satisfy:

0<R13/f8<1.
The optical imaging system according to claim 1, wherein the radius of curvature of the image side surface of the fifth lens at the optical axis is R5, and the radius of curvature of the object side surface of the sixth lens at the optical axis is R6 , Wherein said R5 and R6 satisfy:

-7<(R5+R6)/(R5-R6)<-3.
An image capturing device, characterized in that it comprises:

An optical imaging system, the optical imaging system being the optical imaging system according to any one of claims 1-15;

The photosensitive element is arranged on the image side of the optical imaging system.
An electronic device, characterized in that it comprises:

A housing, a through hole is formed on the housing;

An image capturing device, which is the image capturing device according to claim 16, and the image capturing device is installed at the through hole.