CN212364703U - Optical imaging system, camera module, electronic device and automobile - Google Patents

Abstract

The utility model discloses an optical imaging system, module, electron device and car of making a video recording. The optical imaging system includes, in order from an object side to an image side: a first lens group having a negative refracting power, including at least one lens, a surface closest to an image side being concave at a paraxial region; a second lens group having a positive refracting power, including at least two lenses, a surface closest to the image side being convex at a paraxial region; the third lens group with the bending force comprises at least three lenses, the surface closest to the object side is concave at a paraxial region, and the surface closest to the image side is convex at the paraxial region; the optical imaging system satisfies the following conditional expression: SD2/R2< 1. The optical imaging system can keep small and light weight, keep good optical performance and well capture the details of a shot object.

Description

Optical imaging system, camera module, electronic device and automobile

Technical Field

The utility model relates to an optical imaging technical field, concretely relates to optical imaging system, module of making a video recording, electron device and car.

Background

With the development of the vehicle-mounted industry, the technical requirements of vehicle-mounted lenses such as forward-looking lenses, automatic cruising lenses, automobile data recorders and reverse images are higher and higher, and particularly the vehicle-mounted forward-looking lenses are arranged in front of a vehicle, so that a driver can visually see obstacles in front of the vehicle.

Currently, in the existing vehicle-mounted front view lens, in order to meet the requirement of definition, a high requirement is put on the bending degree of the first lens (the lens closest to the object side), which makes the processing of the first lens difficult and costly, and the processed first lens is easy to generate ghost image in use.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is necessary to provide an optical imaging system, a camera module, an electronic device and an automobile to solve the above problems.

An embodiment of the present application provides an optical imaging system, in order from an object side to an image side:

a first lens group with negative refracting power comprising at least one lens, a surface of the first lens group closest to an image side being concave at a paraxial region;

a second lens group with positive refractive power comprising at least two lenses, a surface of the second lens group closest to the image side being convex at a paraxial region; and

a third lens group with a bending force, including at least three lenses, a surface of the third lens group closest to the object side being concave at a paraxial region and a surface closest to the image side being convex at a paraxial region;

wherein the optical imaging system satisfies the following conditional expression:

SD2/R2<1；

SD2 is an effective half aperture of the first lens group with its image-side-closest surface perpendicular to the optical axis direction, and R2 is a radius of curvature of the first lens group with its image-side-closest surface at the optical axis.

The optical imaging system realizes the purposes of keeping small size and light weight, keeping good optical performance and well capturing the details of a shot object by reasonably matching the bending force and the surface shape of each lens group; and by controlling the curvature radius of the surface of the first lens group closest to the image side and the effective half aperture perpendicular to the optical axis direction, the bending degree of the first lens group can be effectively controlled, the processing difficulty of the first lens group is reduced, the problem that the curvature of the first lens group is too large and the coating film is not uniform is avoided, and therefore the risk of generating ghost is reduced.

In some embodiments, the first lens group comprises:

a first lens element with negative dioptric power, the image-side surface of the first lens element being concave at a paraxial region;

the second lens group includes:

a second lens element with positive refractive power, an image-side surface of the second lens element being convex at a paraxial region; and

a third lens element with positive refractive power, the third lens element having convex object-side and image-side surfaces at a paraxial region;

the third lens group includes:

a fourth lens element with negative dioptric power, said fourth lens element having a concave object-side surface and a concave image-side surface at a paraxial region;

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

a sixth lens element with positive refractive power having convex object-side and image-side surfaces at a paraxial region;

the optical imaging system further comprises a diaphragm, and the diaphragm is arranged between the second lens group and the third lens group.

Therefore, through reasonable matching of the bending force and the surface shape of each lens group, the optical imaging system can keep small and light weight, simultaneously has enough large field angle and large f-number, and can realize good optical performance.

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

0.55<EPL/TTL；

the EPL is a distance between an object-side surface of the first lens element and the diaphragm on an optical axis, and the TTL is a distance between the object-side surface of the first lens element and an imaging surface of the optical imaging system on the optical axis.

Satisfy the above formula, can make the diaphragm more be close to the imaging surface on the one hand for wide angle optical imaging system's light is convenient for converge, and on the other hand can the total length size of contracting of limit, reduces optical imaging system and produces the possibility of vignetting, and then promotes the resolving power, more is favorable to realizing the miniaturized characteristic of optical imaging system.

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

|f1/f|<3；

wherein f1 is the focal length of the first lens, and f is the effective focal length of the optical imaging system.

Therefore, the first lens closest to the object side is set as the negative lens, so that negative bending force can be provided for the optical imaging system, and light rays emitted into the optical imaging system at a large angle are captured, so that the camera module has the characteristic of wide visual angle.

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

3mm<f*tan(FOV/2)<5mm；

wherein FOV is the maximum field angle of the optical imaging system, and f is the effective focal length of the optical imaging system.

Satisfying the above conditional expressions makes it easy to appropriately arrange lenses while securing a distance from the rear end of the lens to the image forming surface, sufficiently heightens the magnification of each lens, and can excellently correct chromatic aberration, curvature of the image forming surface, and distortion aberration; in addition, the optical imaging system can be miniaturized, the camera module provided with the optical imaging system can be miniaturized, the camera module can be contained in a limited space, and low cost is realized.

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

0.3<f23/f456<0.5；

wherein f23 is a combined focal length of the second lens and the third lens, and f456 is a combined focal length of the fourth lens, the fifth lens, and the sixth lens.

Therefore, the distribution proportion of the bending force of the second lens group and the third lens group is reasonably controlled, so that on one hand, the height of the incident light of the second lens group is favorably controlled, and the high-level aberration of the optical imaging system and the outer diameter of the lens are reduced; on the other hand, the emergent angle of the chief ray passing through the third lens group can be reduced, so that the relative brightness of the optical imaging system is improved.

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

-2.05<f1/f23<-1.25；

wherein f1 is the focal length of the first lens, and f23 is the combined focal length of the second lens and the third lens.

Therefore, the distribution proportion of the combined focal length of the second lens and the third lens is reasonably controlled, so that the height of the incident light of the second lens group is favorably controlled, and the high-level aberration of the optical imaging system and the outer diameter of the lens are reduced.

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

2.75<f456/f<4.05；

wherein f456 is a combined focal length of the fourth lens, the fifth lens and the sixth lens, and f is an effective focal length of the optical imaging system.

Therefore, by reasonably controlling the distribution proportion of the combined focal length of the fourth lens to the sixth lens, the emergent angle of the chief ray passing through the third lens group can be reduced, so as to improve the relative brightness of the optical imaging system.

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

2.5<TTL/∑AT<4；

wherein, TTL is a distance on the optical axis from the object-side surface of the first lens element to the imaging surface of the optical imaging system, and Σ AT is a sum of air spaces on the optical axis between two adjacent lens elements in the optical imaging system 10.

Therefore, the ratio of the total length of the optical imaging system to the sum of the air intervals between the adjacent lenses is reasonably configured, the distance between the adjacent lenses on the optical axis can be reduced in a processing range, and the total length of the optical imaging system is further reduced, so that the size of the optical imaging system is reduced.

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

0.5<(R3+R4)/(R3-R4)<9.5；

wherein R3 is a radius of curvature of an object-side surface of the second lens, and R4 is a radius of curvature of an image-side surface of the second lens.

Therefore, the curvature radius of the object side and the curvature radius of the image side of the second lens are reasonably set, so that the bending degree of the second lens can be controlled, the risk of generating ghost is reduced, and the resolution capability of the optical imaging system is improved.

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

4.5<AT1/CT1<8；

wherein AT1 is an air space between the first lens and the second lens on the optical axis, and CT1 is a thickness of the first lens on the optical axis.

Therefore, the optical imaging system is favorable for meeting the characteristics of miniaturization and wide angle, and meanwhile, the risk of ghost generation can be reduced, and the imaging quality is improved.

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

5.5<TTL/f<7；

wherein, TTL is a distance on an optical axis from an object-side surface of the first lens element to an imaging surface of the optical imaging system, and f is an effective focal length of the optical imaging system.

In this way, by defining the relationship between the total optical length of the optical imaging system and the focal length of the optical imaging system, the total optical length of the optical imaging system is controlled while the field angle range of the optical imaging system is satisfied, and the characteristic of miniaturization of the optical imaging system is satisfied.

An embodiment of the present application further provides a camera module, including:

the optical imaging system described above; and

a photosensitive element disposed on an image side of the optical imaging system.

The camera module comprises an optical imaging system, and the optical imaging system realizes the purposes of keeping small size and light weight, keeping good optical performance and well capturing the details of a shot object by reasonably matching the bending force and the surface shape of each lens group; and by controlling the curvature radius of the surface of the first lens group closest to the image side and the effective half aperture perpendicular to the optical axis direction, the bending degree of the first lens group can be effectively controlled, the processing difficulty of the first lens group is reduced, the problem that the curvature of the first lens group is too large and the coating film is not uniform is avoided, and therefore the risk of generating ghost is reduced.

An embodiment of the present application further provides an electronic device, including:

a housing; and

foretell camera module, camera module installs on the casing.

The electronic device comprises the optical imaging system, and the optical imaging system realizes the purposes of keeping small size and light weight, keeping good optical performance and well capturing the details of a shot object by reasonably matching the bending force and the surface shape of each lens group; and by controlling the curvature radius of the surface of the first lens group closest to the image side and the effective half aperture perpendicular to the optical axis direction, the bending degree of the first lens group can be effectively controlled, the processing difficulty of the first lens group is reduced, the problem that the curvature of the first lens group is too large and the coating film is not uniform is avoided, and therefore the risk of generating ghost is reduced.

An embodiment of the present application further provides an automobile, including:

a vehicle body; and

the camera shooting module is arranged on the vehicle body to acquire the environmental information around the vehicle body.

The automobile comprises the camera module, and the camera module realizes that the small size and the light weight are kept, the good optical performance is kept and the details of a shot object can be well captured by reasonably matching the bending force and the surface shape of each lens group; and by controlling the curvature radius of the surface of the first lens group closest to the image side and the effective half aperture perpendicular to the optical axis direction, the bending degree of the first lens group can be effectively controlled, the processing difficulty of the first lens group is reduced, the problem that the curvature of the first lens group is too large and the coating film is not uniform is avoided, and therefore the risk of generating ghost is reduced.

Additional aspects and advantages of embodiments of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

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

fig. 2 is a schematic view of spherical aberration, astigmatism and distortion of the first embodiment of the present invention;

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

fig. 4 is a schematic view of spherical aberration, astigmatism and distortion of a second embodiment of the present invention;

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

fig. 6 is a schematic view of spherical aberration, astigmatism and distortion of a third embodiment of the present invention;

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

fig. 8 is a schematic view of spherical aberration, astigmatism and distortion of a fourth embodiment of the present invention;

fig. 9 is a schematic structural view of an optical imaging system according to a fifth embodiment of the present invention;

fig. 10 is a schematic view of spherical aberration, astigmatism and distortion of a fifth embodiment of the present invention;

fig. 11 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.

Description of the main elements

Electronic device 1000

Camera module 100

Optical imaging system 10, 20, 30, 40, 50

First lens L1

Second lens L2

Third lens L3

Fourth lens L4

Fifth lens L5

Sixth lens L6

Optical filter L7

Stop STO

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

Like sides S2, S4, S6, S8, S10, S12, S14

Image forming surface S15

Photosensitive element 60

Housing 200

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

Referring to fig. 1, an optical imaging system 10 according to an embodiment of the present invention includes, in order from an object side to an image side, a first lens group with negative bending force, a second lens group with positive bending force, and a third lens group with positive bending force; the first lens group comprises at least one lens, and the surface closest to the image side of the first lens group is concave at a paraxial region; the second lens group comprises at least two lenses, and the surface of the second lens group closest to the image side is convex at the paraxial region; the third lens group comprises at least three lenses, and the surface closest to the object side is concave at a paraxial region and the surface closest to the image side is convex at the paraxial region.

Wherein the optical imaging system 10 satisfies the following conditional expressions:

SD2/R2<1；

SD2 is the effective half aperture of the first lens group with its image-side-closest surface perpendicular to the optical axis, and R2 is the radius of curvature of the first lens group with its image-side-closest surface at the optical axis.

The optical imaging system 10 realizes that the small size and the light weight are kept, the good optical performance is kept, and the details of a shot object can be well captured by reasonably matching the bending force and the surface shape of each lens group; and by controlling the curvature radius of the surface of the first lens group closest to the image side and the effective half aperture perpendicular to the optical axis direction, the bending degree of the first lens group can be effectively controlled, the processing difficulty of the first lens group is reduced, the problem that the curvature of the first lens group is too large and the coating film is not uniform is avoided, and therefore the risk of generating ghost is reduced. However, when the SD2/R2 is out of the above range, the degree of curvature of the first lens group is high, so that the processing difficulty is high, the coating film is not uniform, and ghost images are easily generated.

Further, the utility model discloses based on-vehicle foresight camera lens that uses, autopilot, monitoring device etc. have improved optical imaging system 10's imaging quality, when guaranteeing high pixel, widen the formation of image field of vision scope, not only increased the angle of vision scope, can also catch the picture of shooting of wide-angle scope simultaneously, far and near distance in the place ahead, the driving environment of wide range is more clear transmit to optical imaging system 10 and discern, or clear demonstration is on the display screen, make things convenient for the driver to make accurate judgement and avoid the emergence of accident, and promoted the promotion of the yield in the aspect of the camera module production process on this basis; when the optical imaging system is applied to the aspect of driving recording, a clear view can be provided for the driving of a driver, and the distribution proportion of the bending force of the second lens group and the third lens group is reasonably controlled, so that on one hand, the control of the height of incident light of the second lens group is facilitated, and the high-grade aberration of the optical imaging system and the outer diameter of the lens are reduced; on the other hand, the emergent angle of the chief ray passing through the third lens group can be reduced, so that the relative brightness of the optical imaging system is improved, and the safety driving of a driver is guaranteed; when the method is applied to monitoring security, detailed information can be clearly recorded, and the like, and corresponding technical support and application guarantee are provided in the aspect of practical application.

The first lens group includes a first lens L1 having a negative refracting power, the second lens group includes a second lens L2 having a positive refracting power and a third lens L3 having a positive refracting power, and the third lens group includes a fourth lens L4 having a negative refracting power, a fifth lens L5 having a positive refracting power and a sixth lens L6 having a positive refracting power.

The first lens L1 has an object side surface S1 and an image side surface S2, the second lens L2 has an object side surface S3 and an image side surface S4, the third lens L3 has an object side surface S5 and an image side surface S6, the fourth lens L4 has an object side surface S7 and an image side surface S8, the fifth lens L5 has an object side surface S9 and an image side surface S10, and the sixth lens L6 has an object side surface S11 and an image side surface S12.

The image-side surface of the first lens element L1 is concave at the paraxial region; the image-side surface S4 of the second lens element L2 is convex at the paraxial region, and both the object-side surface S5 and the image-side surface S6 of the third lens element L3 are convex at the paraxial region; the object-side surface S7 and the image-side surface S8 of the fourth lens element L4 are concave at the paraxial region, the image-side surface S10 of the fifth lens element L5 is convex at the paraxial region, and the object-side surface S11 and the image-side surface S12 of the sixth lens element L6 are convex at the paraxial region.

The optical imaging system 10 further includes a stop STO disposed between the second lens group and the third lens group.

In this way, by reasonably matching the bending force and the surface shape of each lens group, the optical imaging system 10 can maintain a small size and a light weight, and can have a sufficiently large field angle and a large f-number, and can realize good optical performance.

In some embodiments, optical imaging system 10 further includes a filter L7, filter L7 having an object side S13 and an image side S14. The filter L7 is disposed on the image side of the sixth lens element L6 to filter out light rays in other wavelength bands, such as visible light.

When the optical imaging system 10 is used for imaging, light emitted or reflected by a subject enters the optical imaging system 10 from the object side direction, sequentially passes through the first lens group, the second lens group, the stop STO and the third lens group, and finally converges on the imaging surface S15.

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

0.55<EPL/TTL；

wherein, EPL is the distance on the optical axis from the object-side surface of the first lens element L1 to the stop, and TTL is the distance on the optical axis from the object-side surface of the first lens element L1 to the image plane of the optical imaging system 10.

So, on the one hand can make diaphragm STO be closer to image plane S15 for wide angle optical imaging system 10' S light is convenient for converge, and on the other hand can the total length size of shortening, reduces optical imaging system 10 and produces the possibility of vignetting, and then promotes the resolving power, more is favorable to realizing the miniaturized characteristic of optical imaging system 10. However, when the EPL/TTL is outside the above range, the optical imaging system 10 is prone to dark corners, poor in resolution, and long in overall length.

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

|f1/f|<3；

where f1 is the focal length of the first lens L1, and f is the effective focal length of the optical imaging system 10.

Thus, the negative lens is disposed on the side closest to the object, which can provide negative bending force for the optical imaging system 10 and catch the light entering the optical imaging system at a large angle, so that the camera module has the characteristic of wide viewing angle. However, when | f1/f | is out of the above range, the optical imaging system 10 cannot well catch the incoming light at a large angle, which is not good for the wide viewing angle of the camera module.

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

3mm<f*tan(FOV/2)<5mm，

where FOV is the maximum field angle of the optical imaging system 10 and f is the effective focal length of the optical imaging system 10.

Satisfying the above conditional expressions makes it easy to appropriately arrange lenses while securing a distance from the rear end of the lens to the image forming surface, sufficiently heightens the magnification of each lens, and can excellently correct chromatic aberration, curvature of the image forming surface, and distortion aberration; further, the optical imaging system 10 can be miniaturized, and the image pickup module in which the optical imaging system 10 is installed can be miniaturized, and the image pickup module can be stored in a limited space, thereby achieving low cost. However, when f × tan (FOV/2) is outside the above range, it is not easy to ensure the distance from the lens rear end to the imaging surface, which is disadvantageous for downsizing of the optical imaging system 10.

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

0.3<f23/f456<0.5；

where f23 is a combined focal length of the second lens L2 and the third lens L3, and f456 is a combined focal length of the fourth lens L4, the fifth lens L5, and the sixth lens L6.

Thus, by reasonably controlling the distribution proportion of the bending force of the second lens group and the third lens group, on one hand, the height of the incident light of the second lens group is favorably controlled so as to reduce the high-level aberration of the optical imaging system 10 and the outer diameter of the lens; on the other hand, the exit angle of the chief ray passing through the third lens group can be reduced to improve the relative brightness of the optical imaging system 10. However, when f23/f456 is outside the above range, it is not favorable to control the incident light height of the second lens group, and the relative brightness of the optical imaging system 10 is dark.

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

-2.05<f1/f23<-1.25；

where f1 is the focal length of the first lens L1, and f23 is the combined focal length of the second lens L2 and the third lens L3.

In this way, by reasonably controlling the distribution ratio of the combined focal length of the second lens L2 and the third lens L3, it is beneficial to control the incident ray height of the second lens group, so as to reduce the high-order aberration of the optical imaging system 10 and the outer diameter of the lens. However, when f1/f23 is out of the above range, it is not favorable to control the incident light height of the second lens group.

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

2.75<f456/f<4.05，

where f456 is a combined focal length of the fourth lens L4, the fifth lens L5, and the sixth lens L6, and f is an effective focal length of the optical imaging system 10.

Thus, by reasonably controlling the distribution ratio of the combined focal lengths of the fourth lens L4 to the sixth lens L6, the exit angle of the chief ray passing through the third lens group can be reduced, so as to improve the relative brightness of the optical imaging system 10. However, when f456/f is outside the above range, the exit angle of the chief ray passing through the third lens group cannot be effectively reduced, which is detrimental to the relative brightness of the optical imaging system 10.

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

2.5<TTL/∑AT<4；

wherein, TTL is the distance on the optical axis from the object side surface of the first lens L1 to the imaging surface of the optical imaging system 10, and Σ AT is the sum of the air spaces on the optical axis between two adjacent lenses in the optical imaging system 10.

Therefore, the ratio of the total length of the optical imaging system 10 to the sum of the air intervals between the adjacent lenses is reasonably configured, which is beneficial to reducing the distance between the adjacent lenses and the optical axis in the processing range, and further reducing the total length of the optical imaging system 10, thereby reducing the volume of the optical imaging system 10. However, when TTL/Σ AT is outside the above range, the distance between adjacent lenses AT the optical axis is too small, increasing sensitivity, which is detrimental to lens assembly, thereby increasing processing difficulty.

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

0.5<(R3+R4)/(R3-R4)<9.5；

where R3 is a radius of curvature of the object-side surface of the second lens L2, and R4 is a radius of curvature of the image-side surface of the second lens L2.

In this way, by reasonably setting the object-side and image-side curvature radii of the second lens element L2, the degree of curvature of the second lens element L2 can be controlled, the risk of generating ghost images can be reduced, and the resolution capability of the optical imaging system 10 can be improved. However, when (R3+ R4)/(R3-R4) is outside the above range, it is disadvantageous to control the degree of curvature of the second lens L2, and ghost is easily generated.

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

4.5<AT1/CT1<8；

the AT1 is an air space between the first lens L1 and the second lens L2 on the optical axis, and the CT1 is a thickness of the first lens L1 on the optical axis.

Therefore, the optical imaging system 10 can meet the requirements of miniaturization and wide-angle, and meanwhile, the risk of ghost generation can be reduced, and the imaging quality can be improved. However, when the AT1/CT1 is outside the above range, the optical imaging system 10 is not favorable for satisfying miniaturization and wide-angle characteristics, and the risk of ghost generation cannot be effectively reduced.

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

5.5<TTL/f<7；

wherein, TTL is the distance on the optical axis from the object-side surface of the first lens element L1 to the image plane of the optical imaging system, and f is the effective focal length of the optical imaging system 10.

In this way, by defining the relationship between the total optical length of the optical imaging system 10 and the focal length of the optical imaging system 10, the total optical length of the optical imaging system 10 is controlled while satisfying the field angle range of the optical imaging system 10, thereby satisfying the feature of downsizing the optical imaging system 10. However, when TTL/f is beyond the above range, the focal length of the optical imaging system 10 is too long, which is not favorable for satisfying the field angle range of the optical imaging system 10, and sufficient object space information cannot be obtained.

In some embodiments, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are all made of plastic, and in this case, the plastic lens can reduce the weight of the optical imaging system 10 and reduce the production cost. In some embodiments, the first lens element L1, the second lens element L2, the third lens element L3, the fourth lens element L4, the fifth lens element L5 and the sixth lens element L6 are made of glass, so that the optical imaging system 10 can endure higher temperature and has better optical performance. In other embodiments, only the first lens L1 may be made of glass, and the other lenses are made of plastic, in which case, the first lens L1 closest to the object side can better withstand the influence of the ambient temperature on the object side, and the production cost of the optical imaging system 10 is kept low because the other lenses are made of plastic. Alternatively, in some embodiments, the material of the first lens L1 is glass, and the materials of the other lenses can be combined arbitrarily.

First embodiment

Referring to fig. 1, the optical imaging system 10 in the present embodiment sequentially includes a first lens group, a second lens group, a stop STO, and a third lens group from an object side to an image side.

The first lens group includes a first lens element L1 with negative refractive power, the object-side surface S1 of the first lens element L1 being convex at paraxial region and the image-side surface S2 being concave at paraxial region.

The second lens group includes, in order from an object side to an image side, a second lens element L2 with positive refractive power and a third lens element L3 with positive refractive power, wherein an object-side surface S3 of the second lens element L2 is concave at a paraxial region, an image-side surface S4 of the second lens element L2 is convex at a paraxial region, an object-side surface S5 of the third lens element L3 is convex at a paraxial region, and an image-side surface S6 of the third lens element L3 is convex at a paraxial region.

The third lens group includes, in order from the object side to the image side, a fourth lens element L4 with negative refractive power, a fifth lens element L5 with positive refractive power, and a sixth lens element L6 with positive refractive power, wherein an object-side surface S7 of the fourth lens element L4 is concave at a paraxial region, an image-side surface S8 of the fourth lens element L4 is concave at a paraxial region, an object-side surface S9 of the fifth lens element L5 is convex at a paraxial region, an image-side surface S10 of the fifth lens element L5 is convex at a paraxial region, an object-side surface S11 of the sixth lens element L6 is convex at a paraxial region, and an image-side surface S12 of the sixth lens element L6 is convex at a paraxial region.

Referring to fig. 2, the reference wavelengths of the focal length, the refractive index and the abbe number in the first embodiment are 587.5618nm, and the optical imaging system 10 in the first embodiment satisfies the conditions in the following table.

Table 1

Second embodiment

Referring to fig. 3, the optical imaging system 20 in the present embodiment includes, in order from an object side to an image side, a first lens group, a second lens group, a stop STO and a third lens group.

The first lens group includes a first lens element L1 with negative refractive power, the object-side surface S1 of the first lens element L1 being convex at paraxial region and the image-side surface S2 being concave at paraxial region.

The second lens group includes, in order from an object side to an image side, a second lens element L2 with positive refractive power and a third lens element L3 with positive refractive power, wherein an object-side surface S3 of the second lens element L2 is concave at a paraxial region, an image-side surface S4 of the second lens element L2 is convex at a paraxial region, an object-side surface S5 of the third lens element L3 is convex at a paraxial region, and an image-side surface S6 of the third lens element L3 is convex at a paraxial region.

The third lens group includes, in order from the object side to the image side, a fourth lens element L4 with negative refractive power, a fifth lens element L5 with positive refractive power, and a sixth lens element L6 with positive refractive power, wherein an object-side surface S7 of the fourth lens element L4 is concave at a paraxial region, an image-side surface S8 of the fourth lens element L4 is concave at a paraxial region, an object-side surface S9 of the fifth lens element L5 is convex at a paraxial region, an image-side surface S10 of the fifth lens element L5 is convex at a paraxial region, an object-side surface S11 of the sixth lens element L6 is convex at a paraxial region, and an image-side surface S12 of the sixth lens element L6 is convex at a paraxial region.

Referring to fig. 4, the reference wavelengths of the focal length, the refractive index and the abbe number in the second embodiment are all 587.5618nm, and the optical imaging system 20 in the second embodiment satisfies the conditions in the following table.

Table 2

Third embodiment

Referring to fig. 5, the optical imaging system 30 in the present embodiment includes, in order from an object side to an image side, a first lens group, a second lens group, a stop STO and a third lens group.

The first lens group includes a first lens element L1 with negative refractive power, the object-side surface S1 of the first lens element L1 is concave at the paraxial region, and the image-side surface S2 is concave at the paraxial region.

The second lens group includes, in order from an object side to an image side, a second lens element L2 with positive refractive power and a third lens element L3 with positive refractive power, wherein an object-side surface S3 of the second lens element L2 is convex at a paraxial region, an image-side surface S4 of the second lens element L2 is convex at a paraxial region, an object-side surface S5 of the third lens element L3 is convex at a paraxial region, and an image-side surface S6 of the third lens element L3 is convex at a paraxial region.

The third lens group includes, in order from the object side to the image side, a fourth lens element L4 with negative refractive power, a fifth lens element L5 with positive refractive power, and a sixth lens element L6 with positive refractive power, wherein an object-side surface S7 of the fourth lens element L4 is concave at a paraxial region, an image-side surface S8 of the fourth lens element L4 is concave at a paraxial region, an object-side surface S9 of the fifth lens element L5 is convex at a paraxial region, an image-side surface S10 of the fifth lens element L5 is convex at a paraxial region, an object-side surface S11 of the sixth lens element L6 is convex at a paraxial region, and an image-side surface S12 of the sixth lens element L6 is convex at a paraxial region.

Referring to fig. 6, the reference wavelengths of the focal length, the refractive index and the abbe number in the third embodiment are all 587.5618nm, and the optical imaging system 30 in the third embodiment satisfies the conditions in the following table.

Table 3

Fourth embodiment

Referring to fig. 7, the optical imaging system 40 in the present embodiment includes, in order from an object side to an image side, a first lens group, a second lens group, a stop STO and a third lens group.

The first lens group includes a first lens element L1 with negative refractive power, the object-side surface S1 of the first lens element L1 being convex at paraxial region and the image-side surface S2 being concave at paraxial region.

The second lens group includes, in order from an object side to an image side, a second lens element L2 with positive refractive power and a third lens element L3 with positive refractive power, wherein an object-side surface S3 of the second lens element L2 is concave at a paraxial region, an image-side surface S4 of the second lens element L2 is convex at a paraxial region, an object-side surface S5 of the third lens element L3 is convex at a paraxial region, and an image-side surface S6 of the third lens element L3 is convex at a paraxial region.

The third lens group includes, in order from the object side to the image side, a fourth lens element L4 with negative refractive power, a fifth lens element L5 with positive refractive power, and a sixth lens element L6 with positive refractive power, wherein an object-side surface S7 of the fourth lens element L4 is concave at a paraxial region, an image-side surface S8 of the fourth lens element L4 is concave at a paraxial region, an object-side surface S9 of the fifth lens element L5 is convex at a paraxial region, an image-side surface S10 of the fifth lens element L5 is concave at a paraxial region, an object-side surface S11 of the sixth lens element L6 is convex at a paraxial region, and an image-side surface S12 of the sixth lens element L6 is convex at a paraxial region.

Referring to fig. 8, the reference wavelengths of the focal length, refractive index and abbe number in the fourth embodiment are all 587.5618nm, and the optical imaging system 40 in the fourth embodiment satisfies the conditions of the following table.

Table 4

Fifth embodiment

Referring to fig. 9, the optical imaging system 50 in the present embodiment includes, in order from an object side to an image side, a first lens group, a second lens group, a stop STO and a third lens group.

The first lens group includes a first lens element L1 with negative refractive power, the object-side surface S1 of the first lens element L1 being convex at paraxial region and the image-side surface S2 being concave at paraxial region.

The second lens group includes, in order from an object side to an image side, a second lens element L2 with positive refractive power and a third lens element L3 with positive refractive power, wherein an object-side surface S3 of the second lens element L2 is concave at a paraxial region, an image-side surface S4 of the second lens element L2 is convex at a paraxial region, an object-side surface S5 of the third lens element L3 is convex at a paraxial region, and an image-side surface S6 of the third lens element L3 is convex at a paraxial region.

The third lens group includes, in order from the object side to the image side, a fourth lens element L4 with negative refractive power, a fifth lens element L5 with positive refractive power, and a sixth lens element L6 with positive refractive power, wherein an object-side surface S7 of the fourth lens element L4 is concave at a paraxial region, an image-side surface S8 of the fourth lens element L4 is concave at a paraxial region, an object-side surface S9 of the fifth lens element L5 is convex at a paraxial region, an image-side surface S10 of the fifth lens element L5 is convex at a paraxial region, an object-side surface S11 of the sixth lens element L6 is convex at a paraxial region, and an image-side surface S12 of the sixth lens element L6 is convex at a paraxial region.

Referring to fig. 10, the reference wavelengths of the focal length, the refractive index and the abbe number in the fifth embodiment are 587.5618nm, and the optical imaging system 50 in the fifth embodiment satisfies the conditions of the following table.

Table 5

Table 6 shows values of SD2/R2, EPL/TTL, | f1/f |, f × tan (FOV/2), f23/f456, f1/f23, f456/f, TTL/∑ AT, (R3+ R4)/(R3-R4), AT1/CT1, and TTL/f in the image pickup modules of the first to fifth embodiments.

Table 11

Referring to fig. 11, the optical imaging system 10 of the embodiment of the present invention can be applied to the camera module 100 of the embodiment of the present invention. The camera module 100 includes the photosensitive element 60 and the optical imaging system 10 of any of the above embodiments. The photosensitive element 60 is disposed on the image side of the optical imaging system 10.

The photosensitive element 60 may be a Complementary Metal Oxide Semiconductor (CMOS) image sensor or a Charge-coupled Device (CCD).

Referring to fig. 11, the camera module 100 according to the embodiment of the present invention can be applied to the electronic device 1000 according to the embodiment of the present invention. The electronic device 1000 includes a housing 200 and a camera module 100, and the camera module 100 is mounted on the housing 200.

The utility model discloses on-vehicle, autopilot and monitoring device can be applied to electronic device 1000 of embodiment, wherein electronic device 1000 includes but is not limited to for vehicle event data recorder, smart mobile phone, panel computer, notebook computer, electron books read ware, Portable Multimedia Player (PMP), portable phone, videophone, digital still camera, mobile medical device, wearable equipment etc. support the electron device of formation of image.

The camera module 100 of the embodiment of the present invention is also applicable to the automobile (not shown) of the embodiment of the present invention. The automobile comprises an automobile body and a camera shooting module 100, wherein the camera shooting module 100 is arranged on the automobile body so as to acquire environmental information around the automobile body.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims (15)

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

a first lens group with negative refracting power comprising at least one lens, a surface of the first lens group closest to an image side being concave at a paraxial region;

a second lens group with positive refractive power comprising at least two lenses, a surface of the second lens group closest to the image side being convex at a paraxial region; and

a third lens group with positive refractive power, including at least three lenses, a surface of the third lens group closest to the object side being concave at a paraxial region and a surface closest to the image side being convex at a paraxial region;

wherein the optical imaging system satisfies the following conditional expression:

SD2/R2<1，

SD2 is an effective half aperture of the first lens group with its image-side-closest surface perpendicular to the optical axis direction, and R2 is a radius of curvature of the first lens group with its image-side-closest surface at the optical axis.

2. The optical imaging system of claim 1,

the first lens group includes:

a first lens element with negative dioptric power, the image-side surface of the first lens element being concave at a paraxial region;

the second lens group includes:

a second lens element with positive refractive power having a convex image-side surface at a paraxial region,

a third lens element with positive refractive power, the third lens element having convex object-side and image-side surfaces at a paraxial region;

the third lens group includes:

a fourth lens element with negative dioptric power, said fourth lens element having a concave object-side surface and a concave image-side surface at a paraxial region,

a fifth lens element with positive refractive power having a convex image-side surface at a paraxial region,

a sixth lens element with positive refractive power having convex object-side and image-side surfaces at a paraxial region;

the optical imaging system further comprises a diaphragm, and the diaphragm is arranged between the second lens group and the third lens group.

3. The optical imaging system of claim 2, wherein the optical imaging system satisfies the following conditional expression:

0.55<EPL/TTL；

the EPL is a distance between an object-side surface of the first lens element and the diaphragm on an optical axis, and the TTL is a distance between the object-side surface of the first lens element and an imaging surface of the optical imaging system on the optical axis.

4. The optical imaging system of claim 2, wherein the optical imaging system satisfies the following conditional expression:

|f1/f|<3；

wherein f1 is the focal length of the first lens, and f is the effective focal length of the optical imaging system.

5. The optical imaging system of claim 1, wherein the optical imaging system satisfies the following conditional expression:

3mm<f*tan(FOV/2)<5mm；

wherein FOV is the maximum field angle of the optical imaging system, and f is the effective focal length of the optical imaging system.

6. The optical imaging system of claim 2, wherein the optical imaging system satisfies the following conditional expression:

0.3<f23/f456<0.5；

wherein f23 is a combined focal length of the second lens and the third lens, and f456 is a combined focal length of the fourth lens, the fifth lens, and the sixth lens.

7. The optical imaging system of claim 2, wherein the optical imaging system satisfies the following conditional expression:

-2.05<f1/f23<-1.25，

wherein f1 is the focal length of the first lens, and f23 is the combined focal length of the second lens and the third lens.

8. The optical imaging system of claim 2, wherein the optical imaging system satisfies the following conditional expression:

2.75<f456/f<4.05，

wherein f456 is a combined focal length of the fourth lens, the fifth lens and the sixth lens, and f is an effective focal length of the optical imaging system.

9. The optical imaging system of claim 2, wherein the optical imaging system satisfies the following conditional expression:

2.5<TTL/∑AT<4，

wherein, TTL is a distance on an optical axis from an object-side surface of the first lens element to an image plane of the optical imaging system, and Σ AT is a sum of air spaces on the optical axis between two adjacent lens elements in the optical imaging system.

10. The optical imaging system of claim 2, wherein the optical imaging system satisfies the following conditional expression:

0.5<(R3+R4)/(R3-R4)<9.5，

wherein R3 is a radius of curvature of an object-side surface of the second lens, and R4 is a radius of curvature of an image-side surface of the second lens.

11. The optical imaging system of claim 2, wherein the optical imaging system satisfies the following conditional expression:

4.5<AT1/CT1<8，

wherein AT1 is an air space between the first lens and the second lens on the optical axis, and CT1 is a thickness of the first lens on the optical axis.

12. The optical imaging system of claim 2, wherein the optical imaging system satisfies the following conditional expression:

5.5<TTL/f<7，

wherein, TTL is a distance on an optical axis from an object-side surface of the first lens element to an imaging surface of the optical imaging system, and f is an effective focal length of the optical imaging system.

13. The utility model provides a module of making a video recording which characterized in that includes:

the optical imaging system of any one of claims 1 to 12; and

a photosensitive element disposed on an image side of the optical imaging system.

14. An electronic device, comprising:

a housing; the camera module of claim 13, mounted on the housing.

15. An automobile, comprising:

a vehicle body; the camera module of claim 13, wherein the camera module is disposed on the vehicle body to obtain environmental information about the vehicle body.

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