CN111258035A

CN111258035A - Optical imaging system, imaging module, electronic device and driving device

Info

Publication number: CN111258035A
Application number: CN202010231391.3A
Authority: CN
Inventors: 蔡雄宇; 兰宾利; 周芮
Original assignee: Tianjin OFilm Opto Electronics Co Ltd
Current assignee: Tianjin OFilm Opto Electronics Co Ltd
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2020-06-09

Abstract

The application relates to an optical imaging system, an imaging module, an electronic device and a driving device. The optical imaging system sequentially comprises a first lens group with negative refractive power from an object side to an image side along an optical axis; a second lens group with positive refractive power; a third lens group with positive refractive power; a fourth lens group with positive refractive power; and a diaphragm disposed on an object side of the third lens group. The optical imaging system can give consideration to wide view angle and high resolution capability by grouping the lenses in the system, and has the characteristic of miniaturization.

Description

Optical imaging system, imaging module, electronic device and driving device

Technical Field

The present invention relates to the field of optical imaging technologies, and in particular, to an optical imaging system, an imaging module, an electronic device, and a driving device.

Background

In recent years, with the development of vehicle-mounted technologies, there is an increasing demand for the use of a driving assistance system, a drive recorder, and a back-up camera for a vehicle-mounted camera, and the camera is required to have not only the characteristics of miniaturization and light weight but also higher pixel quality.

However, the quality of the image pixels of the images shot by the conventional vehicle-mounted camera is low, and the vehicle-mounted system or the vehicle-mounted device cannot accurately judge the environmental information around the vehicle in real time so as to prompt the driver to give timely early warning or evasion, so that certain driving risk exists.

Disclosure of Invention

Based on this, it is necessary to provide an improved optical imaging system to solve the problem of low pixel quality of images captured by the conventional vehicle-mounted camera.

An optical imaging system comprises, in order from an object side to an image side along an optical axis, a first lens group with negative refractive power; a second lens group with positive refractive power; a third lens group with positive refractive power; a fourth lens group with positive refractive power; and the diaphragm is arranged on the object side of the third lens group.

According to the optical imaging system, the lenses in the system are grouped, so that the aberration in each lens group can be eliminated, and meanwhile, the mutual correction of the aberration among the lens groups can be realized, so that the aberration of the optical imaging system can be better corrected, and the imaging quality is improved; in addition to this, packetizing the lenses is also advantageous in anti-shake driving of different lens groups, respectively, to further ensure imaging quality.

In one embodiment, the first lens group includes, in order from an object side to an image side along an optical axis, a first lens element with negative refractive power and a second lens element with positive refractive power; the second lens group sequentially comprises a third lens with negative refractive power and a fourth lens with positive refractive power from the object side to the image side along the optical axis; the third lens group sequentially comprises a fifth lens with positive refractive power, a sixth lens with positive refractive power and a seventh lens with negative refractive power from the object side to the image side along the optical axis; the fourth lens group comprises an eighth lens with positive refractive power.

By arranging a proper number of lenses in each lens group and distributing the refractive power of each lens, the imaging resolving power of the optical imaging system can be enhanced, the aberration can be effectively corrected, and the details of the scenery can be captured more accurately.

In one embodiment, both the object-side surface and the image-side surface of the first lens are concave; the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a plane; the third lens and the fourth lens are glued, the object side surface and the image side surface of the third lens are both concave surfaces, and the object side surface and the image side surface of the fourth lens are both convex surfaces; the object side surface and the image side surface of the fifth lens are convex surfaces; the object side surface of the sixth lens is a convex surface at the paraxial region, and the image side surface of the sixth lens is a convex surface at the paraxial region; the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a concave surface; the object side surface of the eighth lens is convex at the paraxial region, and the image side surface of the eighth lens is concave at the paraxial region.

Through carrying out reasonable setting to the face type of each lens in the lens group, be favorable to further suppressing system aberration, eliminating the ghost, also be favorable to realizing the miniaturization of system simultaneously to reduce the sensitivity of system, promote the equipment yield, reduction in production cost.

In one embodiment, the optical imaging system satisfies the following relationship: -5 < f12/f < 0; wherein f12 denotes a combined focal length of the first lens and the second lens, and f denotes an effective focal length of the optical imaging system.

When the relationship is satisfied, the combined focal length of the first lens and the second lens is reasonably configured, so that light rays incident at a large angle can also enter the system, the field angle of the optical imaging system can be enlarged, the sensitivity of the system is reduced, and the miniaturization of the system is realized.

In one embodiment, the optical imaging system satisfies the following relationship:

9mm < (sag S6) > f/(f3+ f4) < 15 mm; wherein sag S6 denotes a sagittal height of a cemented surface of the third lens and the fourth lens, f3 denotes an effective focal length of the third lens, f4 denotes an effective focal length of the fourth lens, and f denotes an effective focal length of the optical imaging system.

The bending degree of the gluing surfaces of the third lens and the fourth lens can be limited through the relation, and the gluing surfaces are prevented from being bent too much, so that the difficulty of the gluing process of the gluing surfaces is reduced, meanwhile, the assembly sensitivity of a system is reduced, and the production yield is improved; in addition, the effective focal lengths of the third lens and the fourth lens are reasonably configured, so that system aberration can be further corrected, and the imaging resolving capability of the system can be improved.

CT4/CT3 is more than or equal to 1 and less than 2.5; wherein CT3 denotes a thickness of the third lens on an optical axis, and CT4 denotes a thickness of the fourth lens on an optical axis.

When the relation is satisfied, the central thickness values of the third lens and the fourth lens can be reasonably configured, the gluing of the third lens and the fourth lens is facilitated, meanwhile, the system aberration can be corrected, and the imaging quality is improved.

f567/f is more than 0 and less than 2.5; wherein f567 denotes a combined focal length of the fifth lens, the sixth lens, and the seventh lens, and f denotes an effective focal length of the optical imaging system.

When the relationship is met, the fifth lens, the sixth lens and the seventh lens can integrally provide positive refractive power for the system, so that the light beams can be favorably contracted, and the image pixels are prevented from being reduced because the light beams passing through the diaphragm are transmitted to the region outside the effective pixel region; meanwhile, the aberration of the system can be corrected, the eccentricity sensitivity can be reduced, and the imaging resolution of the system can be improved; in addition, the assembly sensitivity of the system can be reduced, the problems of lens process manufacturing and lens assembly are solved, and the production yield is improved.

f6/CT6 is more than 6 and less than 13; where f6 denotes an effective focal length of the sixth lens, and CT6 denotes a thickness of the sixth lens on an optical axis.

When the above relation is satisfied, the sixth lens element is a positive lens element, which can provide positive refractive power for the system to correct chromatic aberration of the system and reduce eccentricity sensitivity, thereby facilitating correction of system aberration, improving imaging quality, and ensuring miniaturization of the system.

8＜f8/CT8＜13；

where f8 denotes an effective focal length of the eighth lens, and CT8 denotes a thickness of the eighth lens on an optical axis.

When satisfying above-mentioned relation, eighth lens set up to positive lens, can provide positive refractive power for the system to be favorable to reducing the chief ray incident angle on the photosensitive element, increase photosensitive element's photosensitive performance, and then promote the formation of image resolution of system, also be favorable to realizing the miniaturization of system simultaneously.

-22mm < R7f f/f7 < -15 mm; wherein R7f denotes a radius of curvature of the object-side surface of the seventh lens at the optical axis, f denotes an effective focal length of the optical imaging system, and f7 denotes an effective focal length of the seventh lens.

When the relation is met, the curvature radius of the object side surface of the seventh lens at the optical axis and the effective focal length of the optical imaging system can be reasonably configured, and when the lower limit of the relation is met, the aberration is favorably optimized, and the resolving power of the system is improved; when the upper limit of the relational expression is satisfied, the probability of generating ghost images due to over-bending of the object side surface of the seventh lens can be avoided.

0.4 <. sigma CT/TTL < 0.7; wherein Σ CT represents the sum of thicknesses of the first lens element to the eighth lens element on the optical axis, and TTL represents the distance on the optical axis from the object-side surface of the first lens element to the imaging surface of the optical imaging system.

When the relation is satisfied, the central thickness of each lens can be reasonably configured, so that the total length of the system can be shortened, and the miniaturization can be realized. When the total length of the system is fixed, if sigma CT/TTL is higher than the upper limit, the total thickness of the lens is larger, which is not beneficial to the light weight of the system; if sigma CT/TTL is lower than the lower limit, the total thickness of the lenses is smaller, the air space between adjacent lenses is too large, the assembly sensitivity of the system is easily increased, the yield is reduced, the temperature sensitivity of the optical system is increased, and the imaging definition of the system is reduced in a high-temperature and low-temperature environment.

5mm＜ImgH/tan(FOV/2)＜8mm；

wherein ImgH represents a half of a diagonal length of an effective pixel area on an imaging surface of the optical imaging system, and FOV represents a diagonal field angle of the optical imaging system.

When the above relation is satisfied, the wide angle of the system is facilitated, so that a large field angle range can be obtained, excessive distortion is avoided, and the imaging quality at the wide angle end is improved.

0.8 < EPD/ImgH < 1.3; wherein EPD represents the diameter of the entrance pupil of the optical imaging system, and ImgH represents half of the diagonal length of the effective pixel area on the imaging plane of the optical imaging system.

By meeting the upper limit of the relational expression, the entrance pupil diameter of the system is increased, so that more light rays can be received by the unit area of the effective pixel area of the imaging surface, the image surface brightness is improved, and the imaging resolution capability of the system is improved; the lower limit of the relational expression is satisfied, so that the area of an effective pixel region of an imaging surface is increased, the pixel number of the image surface is increased, and the high-resolution analytic feature of the system is realized.

The application also provides an imaging module.

An imaging module comprises the optical imaging system and a photosensitive element, wherein the photosensitive element is arranged at the image side of the optical imaging system.

Above-mentioned imaging module utilizes aforementioned optical imaging system can shoot and obtains the image that the pixel is high, the visual angle is wide, and imaging module still has miniaturized, lightweight structural feature simultaneously, makes things convenient for the adaptation to like the limited device of size such as cell-phone, flat board and on-vehicle lens.

The application also provides an electronic device.

An electronic device comprises a shell and the imaging module, wherein the imaging module is installed on the shell.

The electronic device can shoot images with wide visual angle and high pixel by utilizing the imaging module, and can transmit the images to the corresponding processing system in time so that the system can make accurate analysis and judgment.

The application also provides a driving device.

The driving device comprises a vehicle body and the imaging module, wherein the imaging module is arranged on the vehicle body to acquire environmental information around the vehicle body.

The driving device can timely and accurately acquire the surrounding environmental information through the imaging module, and can analyze the surrounding road conditions in real time according to the acquired environmental information, so that the driving safety is improved.

Drawings

Fig. 1 shows a schematic configuration diagram of an optical imaging system of embodiment 1 of the present application;

fig. 2 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical imaging system of example 1;

fig. 3 shows a schematic configuration diagram of an optical imaging system of embodiment 2 of the present application;

fig. 4 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical imaging system of example 2;

fig. 5 is a schematic structural view showing an optical imaging system according to embodiment 3 of the present application;

fig. 6 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical imaging system of example 3;

fig. 7 shows a schematic configuration diagram of an optical imaging system according to embodiment 4 of the present application;

fig. 8 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical imaging system of example 4;

fig. 9 is a schematic structural view showing an optical imaging system according to embodiment 5 of the present application;

fig. 10 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph, respectively, of the optical imaging system of example 5;

FIG. 11 shows a schematic view of an imaging module according to an embodiment of the present application;

FIG. 12 is a schematic view of a driving device using an imaging module according to an embodiment of the present disclosure;

fig. 13 is a schematic view of an electronic device using an imaging module according to an embodiment of the present application.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. As used herein, the terms "vertical," "horizontal," "left," "right," "upper," "lower," "front," "rear," "circumferential," and the like are based on the orientation or positional relationship shown in the drawings for ease of description and simplicity of description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In the present description, the expressions first, second, third and the like are used only for distinguishing one feature from another feature, and do not indicate any limitation on the features. Thus, the first lens discussed below may also be referred to as the second lens or the third lens without departing from the teachings of the present application. For ease of illustration, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings. The figures are purely diagrammatic and not drawn to scale.

In this specification, a space on a side of the optical element where the object is located is referred to as an object side of the optical element, and correspondingly, a space on a side of the optical element where the object is located is referred to as an image side of the optical element. The surface of each lens closest to the object is called the object side surface, and the surface of each lens closest to the image plane is called the image side surface. And defines the positive direction with distance from the object side to the image side.

In addition, in the following description, if it appears that a lens surface is convex and the convex position is not defined, it means that the lens surface is convex at least near the optical axis; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at least at the position near the optical axis. Here, the paraxial region means a region near the optical axis.

The features, principles and other aspects of the present application are described in detail below.

Referring to fig. 1, fig. 3, fig. 5, fig. 7 and fig. 9, an optical imaging system with wide viewing angle, high pixel and miniaturization is provided in the present embodiment. Specifically, the optical imaging system includes four groups of lens groups, which are sequentially a first lens group with negative refractive power, a second lens group with positive refractive power, a third lens group with positive refractive power, and a fourth lens group with positive refractive power. The four groups of lens groups are arranged in sequence from an object side to an image side along an optical axis, and an imaging surface of the optical imaging system is positioned on the image side of the fourth lens group. The optical imaging system further comprises a diaphragm, and the diaphragm is arranged on the object side of the third lens group so as to better control the size of an incident beam and improve the imaging quality of the optical imaging system.

By grouping the lenses in the optical imaging system, the aberration in each lens group can be eliminated, and the mutual correction of the aberration among the lens groups can be realized, so that the aberration of the optical imaging system can be better corrected, and the imaging quality is improved; in addition to this, packetizing the lenses is also advantageous in anti-shake driving of different lens groups, respectively, to further ensure imaging quality.

Specifically, the first lens group sequentially includes a first lens element with negative refractive power and a second lens element with positive refractive power from an object side to an image side along an optical axis. The object side surface and the image side surface of the first lens are both concave surfaces, the object side surface of the second lens is a convex surface, and the image side surface is a plane.

The first lens is set as a negative lens, so that negative refractive power can be provided for the system, and light rays incident at a large angle can also enter the system and be focused on an imaging surface, so that stable imaging is realized; the object side surface of the first lens is set to be a concave surface, so that the formation of stray light in a system can be reduced, and the generation probability of ghost image is reduced.

The second lens is set as a positive lens, and can provide positive refractive power for the system, so that light rays can be stably transited or converged to the lens at the rear part, and meanwhile, the aberration generated by part of the first lens can be favorably corrected, and the system has higher resolution; the object side surface of the second lens is set to be a convex surface, and the image side surface is set to be a plane surface, so that tolerance sensitivity of a system is favorably reduced, assembly yield is further improved, and production cost is reduced.

The second lens group sequentially comprises a third lens with negative refractive power and a fourth lens with positive refractive power from the object side to the image side along the optical axis. The image side surface of the third lens is glued with the object side surface of the fourth lens, the object side surface and the image side surface of the third lens are both concave surfaces, and the object side surface and the image side surface of the fourth lens are both convex surfaces.

Through the reasonable refractive power and the surface type of setting up third lens and fourth lens, be favorable to preventing the overcorrection of second lens to further make light focus to the imaging surface, guarantee imaging quality. Furthermore, the third lens and the fourth lens are glued to form the cemented lens, so that the overall structure of the optical imaging system is more compact, aberration correction is facilitated, balance between lens volume reduction and lens resolution improvement can be achieved, tolerance sensitivity problems such as inclination or eccentricity and the like generated in the assembling process of the lenses can be reduced, and assembling yield of the lenses is improved.

As known to those skilled in the art, discrete lenses at ray breaks are susceptible to manufacturing errors and/or assembly errors, and the use of cemented lenses can effectively reduce the sensitivity of the lens. The cemented lens is used in the application, so that the sensitivity of the lens can be effectively reduced, the whole length of the lens can be shortened, the whole chromatic aberration and the aberration correction of the lens can be shared, and the resolving power of the optical imaging system can be improved. Further, the cemented lens may include a lens with negative refractive power and a lens with positive refractive power, such as the fourth lens with positive refractive power and the third lens with negative refractive power.

The third lens group sequentially includes, from an object side to an image side along an optical axis, a fifth lens element with positive refractive power, a sixth lens element with positive refractive power, and a seventh lens element with negative refractive power. The object-side surface and the image-side surface of the fifth lens element are convex surfaces, the object-side surface of the sixth lens element is convex at a paraxial region, the image-side surface of the sixth lens element is convex at a paraxial region, the object-side surface of the seventh lens element is convex, and the image-side surface of the seventh lens element is concave.

By reasonably setting the refractive power and the surface type of the fifth lens, the sixth lens and the seventh lens, the whole third lens group can have positive refractive power, so that the light beams can be favorably contracted, and the reduction of imaging pixels caused by the fact that the light beams passing through the diaphragm are transmitted to the region outside the effective pixel region of the imaging surface is avoided; meanwhile, the aberration of the system can be corrected, the eccentricity sensitivity can be reduced, and the imaging resolution of the system can be improved; in addition, the assembly sensitivity of the system can be reduced, the problems of lens process manufacturing and lens assembly are solved, and the production yield is improved.

The fourth lens group comprises an eighth lens with positive refractive power. The object side surface of the eighth lens element is convex at the paraxial region and the image side surface of the eighth lens element is concave at the paraxial region.

Set up the eighth lens element as positive lens element, can provide positive refractive power for the system to be favorable to reducing the chief ray incident angle of light on photosensitive element, increase photosensitive element's photosensitive performance, and then can promote the formation of image resolution of system, also be favorable to realizing the miniaturization of system simultaneously.

Specifically, the stop is disposed between the second lens group and the third lens group, that is, between the fourth lens and the fifth lens. The diaphragms include aperture diaphragms and field diaphragms. Preferably, the diaphragm is an aperture diaphragm. The aperture stop may be located on a surface of the lens (e.g., the object side and the image side) and in operative relationship with the lens, for example, by applying a light blocking coating to the surface of the lens to form the aperture stop at the surface; or the surface of the clamping lens is fixedly clamped by the clamping piece, and the structure of the clamping piece on the surface can limit the width of the imaging light beam of the on-axis object point, so that the aperture stop is formed on the surface.

When the optical imaging system is used for imaging, light rays emitted or reflected by a shot object enter the optical imaging system from the object side direction, sequentially pass through the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens, and finally converge on an imaging surface.

According to the optical imaging system, the refractive power and the surface shape of each lens and the effective focal length of each lens are reasonably distributed by selecting a proper number of lenses, so that the wide-angle shooting performance of the optical imaging system is considered while the pixel image quality of the optical imaging system is improved, and the scene details can be captured in a large range and accurately; in addition, the optical imaging system has the characteristic of miniaturization structure, and is convenient to adapt to light and thin electronic products.

In an exemplary embodiment, the optical imaging system satisfies the following relationship: -5 < f12/f < 0; where f12 denotes a combined focal length of the first lens and the second lens, and f denotes an effective focal length of the optical imaging system. f12/f can be-4.5, -4.4, -4.3, -4.2, -4.1, -4, -3, -2 or-1. When the relationship is satisfied, the combined focal length of the first lens and the second lens is reasonably configured, so that light rays incident at a large angle can also enter the system, the field angle of the optical imaging system can be enlarged, the sensitivity of the system is reduced, and the miniaturization of the system is realized. When f12/f is greater than or equal to 0, negative refractive power cannot be provided for the system, which is not favorable for wide angle; when f12/f is less than or equal to-5, it is not possible to provide sufficient negative refractive power for the system, which is not favorable for decreasing the sensitivity of the system and for miniaturization.

In an exemplary embodiment, the optical imaging system satisfies the following relationship:

9mm < (sag S6) > f/(f3+ f4) < 15 mm; wherein sag S6 denotes a rise of a sagittal of a cemented surface of the third lens and the fourth lens, f3 denotes an effective focal length of the third lens, f4 denotes an effective focal length of the fourth lens, and f denotes an effective focal length of the optical imaging system. (sag S6) × f/(f3+ f4) may be 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm or 14 mm. The bending degree of the gluing surfaces of the third lens and the fourth lens can be limited through the relation, and the gluing surfaces are prevented from being bent too much, so that the difficulty of the gluing process of the gluing surfaces is reduced, meanwhile, the assembly sensitivity of a system is reduced, and the production yield is improved; in addition, the effective focal lengths of the third lens and the fourth lens are reasonably configured, so that system aberration can be further corrected, and the imaging resolving capability of the system can be improved.

CT4/CT3 is more than or equal to 1 and less than 2.5; where CT3 denotes the thickness of the third lens on the optical axis, and CT4 denotes the thickness of the fourth lens on the optical axis. CT4/CT3 can be 1, 1.2, 1.3, 1.4, 1.5, 1.6, 2.0, 2.2, or 2.4. When the relation is satisfied, the central thickness values of the third lens and the fourth lens can be reasonably configured, the gluing of the third lens and the fourth lens is facilitated, meanwhile, the system aberration can be corrected, and the imaging quality is improved. When CT4/CT3 is higher than the upper limit or lower than the lower limit, the central thickness of the third lens or the fourth lens is easily too large, which is not favorable for lens gluing and correcting system aberration.

f567/f is more than 0 and less than 2.5; where f567 denotes a combined focal length of the fifth lens, the sixth lens, and the seventh lens, and f denotes an effective focal length of the optical imaging system. f567/f may be 0.5, 0.8, 1, 1.5, 1.7, 1.9, 2.0, 2.05, 2.1, 2.2, or 2.4. When the relationship is met, the fifth lens, the sixth lens and the seventh lens can integrally provide positive refractive power for the system, so that the light beams can be favorably contracted, and the image pixels are prevented from being reduced because the light beams passing through the diaphragm are transmitted to the region outside the effective pixel region; meanwhile, the aberration of the system can be corrected, the eccentricity sensitivity can be reduced, and the imaging resolution of the system can be improved; in addition, the assembly sensitivity of the system can be reduced, the problems of lens process manufacturing and lens assembly are solved, and the production yield is improved. When f567/f is less than or equal to 0, the third lens group cannot provide positive refractive power for the system and cannot shrink the light beam; when f567/f is greater than or equal to 2.5, the third lens group is difficult to ensure sufficient refractive power, so that part of the light beams are easy to transmit to the region outside the effective pixel region to reduce the image pixels, and meanwhile, the system aberration is not easy to correct and the system sensitivity is not easy to reduce.

In an exemplary embodiment, the optical imaging system satisfies the following relationship: f6/CT6 is more than 6 and less than 13; where f6 denotes an effective focal length of the sixth lens, and CT6 denotes a thickness of the sixth lens on the optical axis. f6/CT6 can be 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, or 12. When the above relation is satisfied, the sixth lens element is a positive lens element, which can provide positive refractive power for the system to correct chromatic aberration of the system and reduce eccentricity sensitivity, thereby facilitating correction of system aberration, improving imaging quality, and ensuring miniaturization of the system. When f6/CT6 is less than or equal to 6, the center thickness of the sixth lens is larger, which is not beneficial to system miniaturization; when f6/CT6 is equal to or greater than 13, the positive refractive power of the sixth lens element is not guaranteed, which is not favorable for correcting system aberration and reducing decentration sensitivity.

In an exemplary embodiment, the optical imaging system satisfies the following relationship: 8 < f8/CT8 < 13; where f8 denotes an effective focal length of the eighth lens, and CT8 denotes a thickness of the eighth lens on the optical axis. f8/CT8 can be 9, 9.5, 10, 10.5, 11, 11.5, or 12. When satisfying above-mentioned relation, eighth lens set up to positive lens, can provide positive refractive power for the system to be favorable to reducing the chief ray incident angle on the photosensitive element, increase photosensitive element's photosensitive performance, and then promote the formation of image resolution of system, also be favorable to realizing the miniaturization of system simultaneously. When f8/CT8 is less than or equal to 8, the center thickness of the eighth lens is larger, which is not beneficial to system miniaturization; when f8/CT8 is equal to or greater than 13, it is not ensured that the eighth lens element has sufficient positive refractive power, which is not favorable for reducing the incident angle of the chief ray on the photosensitive element, so that the photosensitive performance of the photosensitive element is low, and the image quality of the image is not favorable for improving.

-22mm < R7f f/f7 < -15 mm; where R7f denotes a radius of curvature of the object-side surface of the seventh lens at the optical axis, f denotes an effective focal length of the optical imaging system, and f7 denotes an effective focal length of the seventh lens. R7f xf 7 may be-21.5 mm, -21mm, -20mm, -19mm, -18.5mm, -18mm, -17mm, -16.5mm or-16 mm. When the relation is met, the curvature radius of the object side surface of the seventh lens at the optical axis and the effective focal length of the optical imaging system can be reasonably configured, and when the lower limit of the relation is met, the aberration is favorably optimized, and the resolving power of the system is improved; when the upper limit of the relational expression is satisfied, the probability of generating ghost images due to over-bending of the object side surface of the seventh lens can be avoided.

0.4 <. sigma CT/TTL < 0.7; wherein Σ CT denotes the sum of thicknesses of the first lens element to the eighth lens element on the optical axis, and TTL denotes the distance on the optical axis from the object-side surface of the first lens element to the imaging surface of the optical imaging system. Σ CT/TTL can be 0.5, 0.54, 0.58, 0.6, 0.62, 0.64, 0.66, or 0.68. When the relation is satisfied, the central thickness of each lens can be reasonably configured, so that the total length of the system can be shortened, and the miniaturization can be realized. When the total length of the system is fixed, if sigma CT/TTL is higher than the upper limit, the total thickness of the lens is larger, which is not beneficial to the light weight of the system; if sigma CT/TTL is lower than the lower limit, the total thickness of the lenses is smaller, the air space between adjacent lenses is too large, the assembly sensitivity of the system is easily increased, the yield is reduced, the temperature sensitivity of the optical system is increased, and the imaging definition of the system is reduced in a high-temperature and low-temperature environment.

5mm < ImgH/tan (FOV/2) < 8 mm; wherein ImgH represents half of the diagonal length of the effective pixel area on the imaging plane of the optical imaging system, and FOV represents the diagonal field angle of the optical imaging system. ImgH/tan (FOV/2) may be 5.5mm, 6mm, 6.5mm, 6.9mm, 7mm, 7.1mm, 7.2mm or 7.5 mm. When the above relation is satisfied, the wide angle of the system is facilitated, so that a large field angle range can be obtained, excessive distortion is avoided, and the imaging quality at the wide angle end is improved. When ImgH/tan (FOV/2) is lower than the lower limit or higher than the upper limit, it is difficult to balance between obtaining a larger field angle range and avoiding generation of larger distortion.

0.8 < EPD/ImgH < 1.3; wherein EPD represents the diameter of the entrance pupil of the optical imaging system, and ImgH represents half of the diagonal length of the effective pixel area on the imaging plane of the optical imaging system. EPD/ImgH may be 0.85, 0.9, 0.95, 0.99, 1.05, 1.1, 1.15, 1.2 or 1.25. By meeting the upper limit of the relational expression, the entrance pupil diameter of the system is increased, so that more light rays can be received by the unit area of the effective pixel area of the imaging surface, the image surface brightness is improved, and the imaging resolution capability of the system is improved; the lower limit of the relational expression is satisfied, so that the area of an effective pixel region of an imaging surface is increased, the pixel number of the image surface is increased, and the high-resolution analytic feature of the system is realized.

In an exemplary embodiment, an object-side surface and/or an image-side surface of at least one of the first lens to the sixth lens is an aspherical surface. By the mode, the flexibility of lens design can be improved, aberration can be effectively corrected, and the imaging quality of the optical imaging system can be improved. It should be noted that the surfaces of the lenses in the optical imaging system may be any combination of spherical and aspherical surfaces, and are not necessarily both spherical or both aspherical surfaces.

In an exemplary embodiment, each lens in the optical imaging system may be made of glass or plastic, the plastic lens can reduce the weight and production cost of the optical imaging system, and the glass lens can provide the optical imaging system with better temperature tolerance and excellent optical performance. Further, when used in an in-vehicle system, the material of each lens is preferably glass. It should be noted that the material of each lens in the optical imaging system may also be any combination of glass and plastic, and is not necessarily all glass or all plastic.

In an exemplary embodiment, the optical imaging system further comprises an infrared filter. The infrared filter is arranged at the image side of the fourth lens group (namely the eighth lens), and is used for filtering incident light, particularly isolating infrared light and preventing the infrared light from being absorbed by the photosensitive element, so that the influence of the infrared light on the color and the definition of a normal image is avoided, and the imaging quality of the optical imaging system is improved.

In an exemplary embodiment, the optical imaging system may further include a protective glass. The protective glass is arranged at the image side of the infrared filter, plays a role of protecting the photosensitive element, and can also prevent the photosensitive element from being polluted and dust falling, thereby further ensuring the imaging quality. It should be noted that, in the vehicle-mounted system, since each lens in the optical imaging system is preferably a glass lens, in other embodiments, a protective glass may not be provided to reduce the weight of the system or the overall length of the system, which is not limited in the present application.

The optical imaging system of the above-described embodiments of the present application may employ a plurality of lenses, such as the eight lenses described above. Through reasonable distribution of focal length, refractive power, surface type, thickness of each lens, on-axis distance between each lens and the like, the total length of the optical imaging system can be ensured to be small, the weight is light, the imaging resolution is high, and the optical imaging system also has a large aperture (FNO can be 1.65) and a large field angle, so that the application requirements of light-weight electronic equipment such as a lens, a mobile phone and a flat panel of a vehicle-mounted auxiliary system are better met. However, it will be appreciated by those skilled in the art that the number of lenses constituting the optical imaging system may be varied to achieve the various results and advantages described in the present specification without departing from the claimed subject matter.

Specific examples of the optical imaging system that can be applied to the above-described embodiments are further described below with reference to the drawings.

Example 1

An optical imaging system 100 of embodiment 1 of the present application is described below with reference to fig. 1 to 2.

Fig. 1 shows a schematic configuration diagram of an optical imaging system 100 of embodiment 1. As shown in fig. 1, the optical imaging system 100 includes, in order from an object side to an image side along an optical axis, a first lens group, a second lens group, a third lens group, a fourth lens group, and an imaging surface S19. The first lens group comprises a first lens L1 and a second lens L2, the second lens group comprises a third lens L3 and a fourth lens L4, the third lens group comprises a fifth lens L5, a sixth lens L6 and a seventh lens L7, and the fourth lens group comprises an eighth lens L8.

Specifically, the first lens element L1 with negative refractive power has a spherical object-side surface S1 and a spherical image-side surface S2, wherein the object-side surface S1 is concave and the image-side surface S2 is concave.

The second lens element L2 with positive refractive power has a spherical object-side surface S3 and a planar image-side surface S4, wherein the object-side surface S3 is convex.

The third lens element L3 with negative refractive power has a spherical object-side surface S5 and a spherical image-side surface S6, wherein the object-side surface S5 is concave and the image-side surface S6 is concave.

The fourth lens element L4 with positive refractive power has a spherical object-side surface S7 and a spherical image-side surface S8, wherein the object-side surface S7 is convex and the image-side surface S8 is convex.

The fifth lens element L5 with positive refractive power has a spherical object-side surface S9 and a spherical image-side surface S10, wherein the object-side surface S9 is convex and the image-side surface S10 is convex.

The sixth lens element L6 with positive refractive power has an object-side surface S11 and an image-side surface S12 that are aspheric, wherein the object-side surface S11 is convex at a paraxial region thereof and the image-side surface S12 is convex at a paraxial region thereof.

The seventh lens element L7 with negative refractive power has a spherical object-side surface S13 and a spherical image-side surface S14, wherein the object-side surface S13 is convex and the image-side surface S14 is concave.

The eighth lens element L8 with positive refractive power has an object-side surface S15 and an image-side surface S16 that are aspheric, wherein the object-side surface S15 is convex at a paraxial region thereof and the image-side surface S16 is concave at a paraxial region thereof.

The image side surface S6 of the third lens L3 and the object side surface S7 of the fourth lens L4 are cemented to form a cemented lens, so that the overall structure of the optical imaging system 100 is more compact, the tolerance sensitivity problems such as tilt and eccentricity generated in the lens assembling process are reduced, and the assembly yield of the lens is improved.

Since the object-side surface and the image-side surface of the sixth lens element L6 and the eighth lens element L8 are both aspheric, it is advantageous to correct aberrations and solve the problem of image surface distortion, and it is possible to achieve an excellent optical imaging effect even when the lenses are small, thin, and flat, and to provide the optical imaging system 100 with a compact size.

The first lens L1 to the sixth lens L8 are made of glass, and the optical imaging system 100 has good temperature tolerance and excellent optical performance by using the glass lens, so as to further ensure the imaging quality.

A stop STO is further disposed between the second lens group and the third lens group (i.e., between the fourth lens L4 and the fifth lens L5) to limit the size of an incident light beam, thereby further improving the imaging quality of the optical imaging system 100. The optical imaging system 100 further includes a filter 110 disposed on the image side of the eighth lens L8 and having an object-side surface S17 and an image-side surface S18. Light from the object OBJ sequentially passes through the respective surfaces S1 to S18 and is finally imaged on the imaging plane S19. Further, the optical filter 110 is an infrared filter for filtering out infrared light from the external light incident to the optical imaging system 100, so as to avoid color distortion. Specifically, the material of the filter 110 is glass.

Table 1 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), and effective focal length of the lens of the optical imaging system 100 of embodiment 1, wherein the unit of the radius of curvature, thickness, and effective focal length of the lens is millimeters (mm). In addition, taking the first lens element L1 as an example, the first numerical value in the "thickness" parameter sequence of the first lens element L1 is the thickness of the lens element on the optical axis, and the second numerical value is the distance between the image-side surface of the lens element and the object-side surface of the subsequent lens element in the image-side direction; the numerical value of the stop ST0 in the "thickness" parameter column is the distance on the optical axis from the stop ST0 to the vertex of the object-side surface of the subsequent lens (the vertex refers to the intersection point of the lens and the optical axis), and we default that the direction from the object-side surface of the first lens L1 to the image-side surface of the last lens is the positive direction of the optical axis, when the value is negative, it indicates that the stop ST0 is disposed on the right side of the vertex of the object-side surface of the lens in fig. 1, and when the thickness of the stop STO is positive, the stop is on the left side of the vertex of the object-.

TABLE 1

The aspherical surface shape in the lens is defined by the following formula:

wherein x is the rise of the distance from the aspheric surface vertex to the aspheric surface vertex when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c being 1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1); k is a conic coefficient; ai is the ith order coefficient of the aspheric surface. Table 2 below gives the coefficients of high-order terms a4, A6, A8, a10, a12, a14, a16, a18, and a20 that can be used for the aspherical surfaces S11 through S12 and S15 through S16 of the lens in example 1.

TABLE 2

The distance TTL on the optical axis from the object side surface S1 of the first lens L1 to the imaging surface S19 of the optical imaging system 100 is 29.25mm, and the diagonal length ImgH of the effective pixel area on the imaging surface S19 of the optical imaging system 100 is 5.15 mm. As can be seen from the data in tables 1 and 2, the optical imaging system 100 in embodiment 1 satisfies:

f12/f — 4.36, where f12 denotes a combined focal length of the first lens L1 and the second lens L2, and f denotes an effective focal length of the optical imaging system 100;

(sag S6) × f/(f3+ f4) ═ 11.98mm, where sag S6 denotes the rise of the sagittal plane of the cemented surfaces of the third lens L3 and the fourth lens L4, f3 denotes the effective focal length of the third lens L3, f4 denotes the effective focal length of the fourth lens L4, and f denotes the effective focal length of the optical imaging system 100;

CT4/CT3 is 1.4, where CT3 denotes the thickness of the third lens L3 on the optical axis, and CT4 denotes the thickness of the fourth lens L4 on the optical axis;

f567/f is 2.07, where f567 denotes a combined focal length of the fifth lens L5, the sixth lens L6, and the seventh lens L7, and f denotes an effective focal length of the optical imaging system 100;

f6/CT6 is 9.52, where f6 denotes an effective focal length of the sixth lens L6, and CT6 denotes a thickness of the sixth lens L6 on the optical axis;

f8/CT8 is 10.33, where f8 denotes an effective focal length of the eighth lens L8, and CT8 denotes a thickness of the eighth lens L8 on the optical axis;

r7f × f/f7 — 16.23mm, where R7f denotes a radius of curvature of the object side S13 of the seventh lens L7 at the optical axis, f denotes an effective focal length of the optical imaging system 100, and f7 denotes an effective focal length of the seventh lens L7;

Σ CT/TTL is 0.6, where Σ CT denotes the sum of the thicknesses of the first lens L1 to the eighth lens L8 on the optical axis, and TTL denotes the distance on the optical axis from the object side surface S1 of the first lens L1 to the imaging surface S19 of the optical imaging system 100;

ImgH/tan (FOV/2) ═ 6.92mm, where ImgH represents half the diagonal length of the effective pixel area on the imaging plane S19 of the optical imaging system 100, and FOV represents the diagonal field angle of the optical imaging system 100;

EPD/ImgH is 0.99, where EPD denotes the entrance pupil diameter of the optical imaging system 100, and ImgH denotes half the diagonal length of the effective pixel area on the imaging plane S19 of the optical imaging system 100.

Fig. 2 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph of the optical imaging system 100 of example 1, respectively, and the reference wavelength of the optical imaging system 100 is 546.07 nm. Wherein the longitudinal spherical aberration plots show the convergent focus shifts for light rays at wavelengths of 450nm, 479.99nm, 546.07nm, 588nm, and 656nm through optical imaging system 100; the astigmatism graphs show the meridional and sagittal image planes of the optical imaging system 100; the distortion plot shows the distortion of the optical imaging system 100 at different image heights. As can be seen from fig. 2, the optical imaging system 100 according to embodiment 1 can achieve good imaging quality.

Example 2

An optical imaging system 100 of embodiment 2 of the present application is described below with reference to fig. 3 to 4. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 3 shows a schematic structural diagram of the optical imaging system 100 according to embodiment 2 of the present application.

As shown in fig. 3, the optical imaging system 100 includes, in order from an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7, an eighth lens element L8, and an image plane S19.

The first lens element L1 with negative refractive power has a spherical object-side surface S1 and a spherical image-side surface S2, wherein the object-side surface S1 is concave and the image-side surface S2 is concave.

The object-side surface and the image-side surface of the sixth lens L6 and the eighth lens L8 are both aspheric. The first lens element L1 to the sixth lens element L8 are all made of glass. A stop STO is further disposed between the second lens group and the third lens group (i.e., between the fourth lens L4 and the fifth lens L5) to limit the size of an incident light beam, thereby further improving the imaging quality of the optical imaging system 100. The optical imaging system 100 further includes a filter 110 disposed on the image side of the eighth lens L8 and having an object-side surface S17 and an image-side surface S18. Light from the object OBJ sequentially passes through the respective surfaces S1 to S18 and is finally imaged on the imaging plane S19. Further, the optical filter 110 is an infrared filter for filtering out infrared light from the external light incident to the optical imaging system 100, so as to avoid color distortion.

Table 3 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), and effective focal length of each lens of the optical imaging system 100 of example 2, wherein the unit of the radius of curvature, thickness, and effective focal length of each lens is millimeters (mm). Table 4 shows high-order term coefficients that can be used for the lens aspheres S11-S12 and S15-S16 in example 2, in which the aspherical surface types can be defined by formula (1) given in example 1; table 5 shows the values of relevant parameters of the optical imaging system 100 given in example 2.

TABLE 3

TABLE 4

TABLE 5

Fig. 4 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph of the optical imaging system 100 of example 2, respectively, and the reference wavelength of the optical imaging system 100 is 546.07 nm. Wherein the longitudinal spherical aberration plots show the convergent focus shifts for light rays at wavelengths of 450nm, 479.99nm, 546.07nm, 588nm, and 656nm through optical imaging system 100; the astigmatism graphs show the meridional and sagittal image planes of the optical imaging system 100; the distortion plot shows the distortion of the optical imaging system 100 at different image heights. As can be seen from fig. 4, the optical imaging system 100 according to embodiment 2 can achieve good imaging quality.

Example 3

An optical imaging system 100 of embodiment 3 of the present application is described below with reference to fig. 5 to 6. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 5 shows a schematic structural diagram of an optical imaging system 100 according to embodiment 3 of the present application.

As shown in fig. 5, the optical imaging system 100 includes, in order from an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7, an eighth lens element L8, and an image plane S19.

Table 6 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), and effective focal length of each lens of the optical imaging system 100 of example 3, wherein the unit of the radius of curvature, thickness, and effective focal length of each lens is millimeters (mm). Table 7 shows high-order term coefficients that can be used for the lens aspheres S11-S12 and S15-S16 in example 3, in which the aspherical surface types can be defined by formula (1) given in example 1; table 8 shows the values of relevant parameters of the optical imaging system 100 given in example 3.

TABLE 6

TABLE 7

TABLE 8

Fig. 6 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph of the optical imaging system 100 of example 3, respectively, and the reference wavelength of the optical imaging system 100 is 546.07 nm. Wherein the longitudinal spherical aberration plots show the convergent focus shifts for light rays at wavelengths of 450nm, 479.99nm, 546.07nm, 588nm, and 656nm through optical imaging system 100; the astigmatism graphs show the meridional and sagittal image planes of the optical imaging system 100; the distortion plot shows the distortion of the optical imaging system 100 at different image heights. As can be seen from fig. 6, the optical imaging system 100 according to embodiment 3 can achieve good imaging quality.

Example 4

An optical imaging system 100 of embodiment 4 of the present application is described below with reference to fig. 7 to 8. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 7 shows a schematic structural diagram of an optical imaging system 100 according to embodiment 4 of the present application.

As shown in fig. 7, the optical imaging system 100 includes, in order from an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7, an eighth lens element L8, and an image plane S19.

Table 9 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), and effective focal length of each lens of the optical imaging system 100 of example 4, wherein the unit of the radius of curvature, thickness, and effective focal length of each lens is millimeters (mm). Table 10 shows high-order term coefficients that can be used for the lens aspheres S11-S12 and S15-S16 in example 4, in which the aspherical surface types can be defined by formula (1) given in example 1; table 11 shows the values of relevant parameters of the optical imaging system 100 given in example 4.

TABLE 9

Watch 10

TABLE 11

Fig. 8 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph of the optical imaging system 100 of example 4, respectively, and the reference wavelength of the optical imaging system 100 is 546.07 nm. Wherein the longitudinal spherical aberration plots show the convergent focus shifts for light rays at wavelengths of 450nm, 479.99nm, 546.07nm, 588nm, and 656nm through optical imaging system 100; the astigmatism graphs show the meridional and sagittal image planes of the optical imaging system 100; the distortion plot shows the distortion of the optical imaging system 100 at different image heights. As can be seen from fig. 8, the optical imaging system 100 according to embodiment 4 can achieve good imaging quality.

Example 5

An optical imaging system 100 of embodiment 5 of the present application is described below with reference to fig. 9 to 10. In this embodiment, a description of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 9 shows a schematic structural diagram of an optical imaging system 100 according to embodiment 5 of the present application.

As shown in fig. 9, the optical imaging system 100 includes, in order from an object side to an image side along an optical axis, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, a seventh lens element L7, an eighth lens element L8, and an image plane S19.

Table 12 shows the surface type, radius of curvature, thickness, material, refractive index, abbe number (i.e., abbe number), and effective focal length of each lens of the optical imaging system 100 of example 5, wherein the unit of the radius of curvature, thickness, and effective focal length of each lens is millimeters (mm). Table 13 shows high-order term coefficients that can be used for the lens aspheres S11-S12 and S15-S16 in example 5, in which the aspherical surface types can be defined by formula (1) given in example 1; table 14 shows the values of relevant parameters of the optical imaging system 100 given in example 5.

TABLE 12

Watch 13

TABLE 14

Fig. 10 shows a longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph of the optical imaging system 100 of example 5, respectively, and the reference wavelength of the optical imaging system 100 is 546.07 nm. Wherein the longitudinal spherical aberration plots show the convergent focus shifts for light rays at wavelengths of 450nm, 479.99nm, 546.07nm, 588nm, and 656nm through optical imaging system 100; the astigmatism graphs show the meridional and sagittal image planes of the optical imaging system 100; the distortion plot shows the distortion of the optical imaging system 100 at different image heights. As can be seen from fig. 10, the optical imaging system 100 according to embodiment 5 can achieve good imaging quality.

As shown in fig. 11, the present application further provides an imaging module 200, which includes the optical imaging system 100 (shown in fig. 1) as described above; and a photosensitive element 210, the photosensitive element 210 being disposed on the image side of the optical imaging system 100, the photosensitive surface of the photosensitive element 210 coinciding with the image forming surface S19. Specifically, the photosensitive element 210 may be a Complementary Metal Oxide Semiconductor (CMOS) image sensor or a Charge-coupled Device (CCD) image sensor.

The imaging module 200 can capture images with high pixels and wide viewing angles by using the optical imaging system 100, and the imaging module 200 has the structural characteristics of miniaturization and light weight. The imaging module 200 can be applied to the fields of mobile phones, automobiles, monitoring, medical treatment and the like. The system can be used as a mobile phone camera, a vehicle-mounted camera, a monitoring camera or an endoscope and the like.

As shown in fig. 12, the imaging module 200 may be applied to a driving device 300 as an in-vehicle camera. Steering device 300 may be an autonomous vehicle or a non-autonomous vehicle. The imaging module 200 may be used as a front camera, a rear camera or a side camera of the driving device 300. Specifically, the driving device 300 includes a vehicle body 310, and the imaging module 200 is mounted at any position of the vehicle body 310, such as a left rear view mirror, a right rear view mirror, a rear box, a front light, and a rear light, so as to obtain a clear environment image around the vehicle body 310. In addition, still be provided with display screen 320 among the controlling device 300, display screen 320 installs in automobile body 310, and imaging module 200 and display screen 320 communication connection, and the image information that imaging module 200 obtained can transmit and show to display screen 320 in to make the driver can obtain more complete peripheral image information, improve the safety guarantee when driving.

In particular, in some embodiments, the imaging module 200 may be used in an autonomous vehicle. With continued reference to fig. 12, the imaging module 200 is mounted at any position on the body of the autonomous vehicle, and specific reference may be made to the mounting position of the imaging module 200 in the driving device 300 according to the above embodiment. For an autonomous vehicle, the imaging module 200 may also be mounted on top of the vehicle body. At this time, by installing a plurality of imaging modules 200 on the autonomous vehicle to obtain environmental information of a 360 ° view angle around the vehicle body 310, the environmental information obtained by the imaging modules 200 will be transmitted to an analysis processing unit of the autonomous vehicle to analyze road conditions around the vehicle body 310 in real time. Through adopting imaging module 200, can improve the accuracy of analysis processing unit identification and analysis to security performance when promoting autopilot.

As shown in fig. 13, the present application further provides an electronic device 400, which includes a housing 410 and the imaging module 200 as described above, wherein the imaging module 200 is mounted on the housing 410. Specifically, the imaging module 200 is disposed in the housing 410 and exposed from the housing 410 to acquire an image, the housing 410 can provide protection such as dust prevention, water prevention, falling prevention for the imaging module 200, and the housing 410 is provided with a hole corresponding to the imaging module 200, so that light can penetrate into or penetrate out of the housing through the hole.

The electronic device 400 can capture an image with a wide viewing angle and a high pixel height by using the imaging module 200. In other embodiments, the electronic device 400 is further provided with a corresponding processing system, and the electronic device 400 can transmit the image to the corresponding processing system in time after the image of the object is captured, so that the system can make accurate analysis and judgment.

In other embodiments, the use of "electronic device" may also include, but is not limited to, devices configured to receive or transmit communication signals via a wireline connection and/or via a wireless interface. Electronic devices arranged to communicate over a wireless interface may be referred to as "wireless communication terminals", "wireless terminals", or "mobile terminals". Examples of mobile terminals include, but are not limited to, satellite or cellular telephones; personal Communication System (PCS) terminals that may combine a cellular radiotelephone with data processing, facsimile and data communication capabilities; personal Digital Assistants (PDAs) that may include radiotelephones, pagers, internet/intranet access, Web browsers, notepads, calendars, and/or Global Positioning System (GPS) receivers; and conventional laptop and/or palmtop receivers or other electronic devices that include a radiotelephone transceiver.

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

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

Claims

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

a first lens group with negative refractive power;

a second lens group with positive refractive power;

a third lens group with positive refractive power;

a fourth lens group with positive refractive power; and the number of the first and second groups,

and the diaphragm is arranged on the object side of the third lens group.

2. The optical imaging system of claim 1,

the first lens group sequentially comprises a first lens with negative refractive power and a second lens with positive refractive power from the object side to the image side along an optical axis;

the second lens group sequentially comprises a third lens with negative refractive power and a fourth lens with positive refractive power from the object side to the image side along the optical axis;

the third lens group sequentially comprises a fifth lens with positive refractive power, a sixth lens with positive refractive power and a seventh lens with negative refractive power from the object side to the image side along the optical axis;

the fourth lens group comprises an eighth lens with positive refractive power.

3. The optical imaging system of claim 2,

the object side surface and the image side surface of the first lens are both concave surfaces;

the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a plane;

the third lens and the fourth lens are glued, the object side surface and the image side surface of the third lens are both concave surfaces, and the object side surface and the image side surface of the fourth lens are both convex surfaces;

the object side surface and the image side surface of the fifth lens are convex surfaces;

the object side surface of the sixth lens is a convex surface at the paraxial region, and the image side surface of the sixth lens is a convex surface at the paraxial region;

the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a concave surface;

the object side surface of the eighth lens is convex at the paraxial region, and the image side surface of the eighth lens is concave at the paraxial region.

4. The optical imaging system of claim 2 or 3, wherein the optical imaging system satisfies the following relation:

-5＜f12/f＜0；

wherein f12 denotes a combined focal length of the first lens and the second lens, and f denotes an effective focal length of the optical imaging system.

5. The optical imaging system of claim 2 or 3, wherein the optical imaging system satisfies the following relation:

9mm＜(sag S6)*f/(f3+f4)＜15mm；

wherein sag S6 denotes a sagittal height of a cemented surface of the third lens and the fourth lens, f3 denotes an effective focal length of the third lens, f4 denotes an effective focal length of the fourth lens, and f denotes an effective focal length of the optical imaging system.

6. The optical imaging system of claim 2 or 3, wherein the optical imaging system satisfies the following relation:

1≤CT4/CT3＜2.5；

wherein CT3 denotes a thickness of the third lens on an optical axis, and CT4 denotes a thickness of the fourth lens on an optical axis.

7. The optical imaging system of claim 2 or 3, wherein the optical imaging system satisfies the following relation:

0＜f567/f＜2.5；

wherein f567 denotes a combined focal length of the fifth lens, the sixth lens, and the seventh lens, and f denotes an effective focal length of the optical imaging system.

8. The optical imaging system of claim 2 or 3, wherein the optical imaging system satisfies the following relation:

6＜f6/CT6＜13；

where f6 denotes an effective focal length of the sixth lens, and CT6 denotes a thickness of the sixth lens on an optical axis.

9. The optical imaging system of claim 2 or 3, wherein the optical imaging system satisfies the following relation:

8＜f8/CT8＜13；

10. The optical imaging system of claim 2 or 3, wherein the optical imaging system satisfies the following relation:

-22mm＜R7f*f/f7＜-15mm；

wherein R7f denotes a radius of curvature of the object-side surface of the seventh lens at the optical axis, f denotes an effective focal length of the optical imaging system, and f7 denotes an effective focal length of the seventh lens.

11. The optical imaging system of claim 2 or 3, wherein the optical imaging system satisfies the following relation:

0.4＜∑CT/TTL＜0.7；

wherein Σ CT represents the sum of thicknesses of the first lens element to the eighth lens element on the optical axis, and TTL represents the distance on the optical axis from the object-side surface of the first lens element to the imaging surface of the optical imaging system.

12. The optical imaging system of any of claims 1-3, wherein the optical imaging system satisfies the following relationship:

5mm＜ImgH/tan(FOV/2)＜8mm；

13. The optical imaging system of any of claims 1-3, wherein the optical imaging system satisfies the following relationship:

0.8＜EPD/ImgH＜1.3；

wherein EPD represents the diameter of the entrance pupil of the optical imaging system, and ImgH represents half of the diagonal length of the effective pixel area on the imaging plane of the optical imaging system.

14. An imaging module comprising the optical imaging system according to any one of claims 1 to 13 and a photosensitive element disposed on an image side of the optical imaging system.

15. An electronic device comprising a housing and the imaging module of claim 14, wherein the imaging module is mounted on the housing.

16. A driving device comprising a vehicle body and the imaging module of claim 14, wherein the imaging module is disposed on the vehicle body to obtain environmental information around the vehicle body.