CN113985578B

CN113985578B - Optical system, image capturing module, electronic equipment and automobile

Info

Publication number: CN113985578B
Application number: CN202111313318.1A
Authority: CN
Inventors: 乐宇明; 兰宾利; 朱志鹏
Original assignee: Jiangxi Jingchao Optical Co Ltd
Current assignee: Jiangxi Jingchao Optical Co Ltd
Priority date: 2021-11-08
Filing date: 2021-11-08
Publication date: 2023-07-04
Anticipated expiration: 2041-11-08
Also published as: CN113985578A

Abstract

The application discloses optical system, image capturing module, electronic equipment and car, optical system includes along the optical axis by the thing sideThe first lens with negative refractive power is sequentially arranged at the image side, and the arrangement of the first lens can meet the light angle required by the optical system; a second lens element with negative refractive power; a third lens element with positive refractive power; a diaphragm; a fourth lens element with positive refractive power; the arrangement of the sixth lens element with positive refractive power can change the incident angle, reduce the incident angle of the incident light beam reaching the chief ray on the imaging surface, improve the relative illuminance, and the sixth lens element is aspheric, which is beneficial to controlling the distortion of the system and the incident angle of the chief ray, and achieves the effects of large aperture and small distortion of the optical system; meanwhile, the optical system satisfies the formula: 3.5 (1/mm) < FNO/AT ₃ < 5.5 (1/mm), wherein AT ₃ The FNO is the f-number of the optical system, which is the distance between the image side of the third lens element and the object side of the fourth lens element on the optical axis.

Description

Optical system, image capturing module, electronic equipment and automobile

Technical Field

The application relates to the technical field of optical imaging, in particular to an optical system, an image capturing module, electronic equipment and an automobile.

Background

In recent years, automobiles are equipped with more and more environmental sensors, such as radar, camera, ultrasonic wave, laser radar, etc., for advanced driving assistance and automatic driving functions. However, each sensor has its own limitations in that it cannot individually provide complete environmental information about the vehicle's need to perform safety functions.

By combining inputs from various sensors, there can be enough data to generate a complete environmental model to enable advanced driving assistance as well as autopilot functionality. The laser radar camera is favorable for an automatic driving system to make a key autonomous decision, so that the importance of the laser radar camera is higher and higher, and the requirement on the imaging quality of an optical system of the laser radar camera is stricter, but the problems of small aperture and large distortion of the laser radar camera are difficult to overcome at present.

Disclosure of Invention

The embodiment of the application provides an optical system, an image capturing module, electronic equipment and an automobile, and can solve the problems that a laser radar camera is small in aperture and large in distortion.

In a first aspect, embodiments of the present application provide an optical system, including, in order from an object side to an image side along an optical axis:

The first lens element with negative refractive power has a convex object-side surface at a paraxial region, a concave image-side surface at a paraxial region, and both the object-side surface and the image-side surface of the first lens element are aspheric;

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

the third lens element with positive refractive power has a convex object-side surface and a convex image-side surface at a paraxial region;

a diaphragm;

the fourth lens element with positive refractive power has a convex object-side surface and a convex image-side surface at a paraxial region;

the object side surface of the fifth lens element is concave at a paraxial region, and the image side surface of the fifth lens element is convex at a paraxial region; the method comprises the steps of,

the object side surface of the sixth lens element with positive refractive power is convex at a paraxial region, and the object side surface and the image side surface of the sixth lens element are aspheric.

Based on the optical system of the embodiment of the application, the first lens has negative refractive power, which is favorable for large-angle light ray intake and increases the angle of view. The object side surface of the first lens is combined to be a convex surface, the image side surface of the first lens is a concave surface, so that light can be grasped conveniently, the angle of light required by laser radar design is met, the first lens is shot in, and meanwhile, the aspheric surface of the first lens is arranged, so that the head caliber of an optical system can be controlled conveniently.

The second lens has negative bending force, which is beneficial to reasonably distributing the focal power of the optical system; and 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 concave surface, so that light rays passing through the first lens can be smoothly incident into the second lens, and the influence of optical off-axis aberration can be effectively reduced.

The third lens has positive bending force, the diaphragm is arranged between the third lens and the fourth lens, the object side surface and the image side surface of the third lens are both convex surfaces, light rays from the second lens can be effectively received, the light rays are fully received into the diaphragm, the illuminance is increased, and the light rays passing through the third lens are incident into the diaphragm with a large aperture.

The fourth lens element with positive refractive power has convex object-side and image-side surfaces, which is beneficial to shrinking light and shortening the total length of the optical system.

The fourth lens element and the fifth lens element are combined to form a lens assembly with negative refractive power, the object-side surface of the fifth lens element is concave, and the image-side surface of the fifth lens element is convex, so that the lens assembly has favorable focal power configuration and reduced sensitivity.

The sixth lens has positive bending force, the object side surface is a convex surface, the incident angle of light can be further changed, the incident angle of the incident light reaching the imaging surface is reduced, and the relative illuminance is improved; the arrangement of the aspheric surface of the sixth lens is beneficial to controlling the distortion of the optical system and the angle of incidence angle of the incident light to the principal ray on the imaging surface, so that the effects of large aperture and small distortion of the optical system can be achieved.

The optical system satisfies the condition (1): 3.5 (1/mm) < FNO/AT ₃ < 5.5 (1/mm), wherein AT ₃ The FNO is the f-number of the optical system, which is the distance between the image side of the third lens element and the object side of the fourth lens element on the optical axis.

Based on the above embodiment, in FNO and AT ₃ Under the condition that the two parameters meet the condition (1), the diaphragm of the optical system is arranged between the third lens and the fourth lens, and the optical effects of large diaphragm and small distortion can be realized by reasonably matching the air intervals between the front surface and the rear surface of the diaphragm and the optical axis of the third lens and the fourth lens and the ratio relation between the air intervals and the diaphragm number of the optical system.

FNO/AT ₃ The lower limit of the optical system is lower than 3.5, the distance between the third lens L3 and the fourth lens and the front and rear surfaces of the diaphragm on the optical axis is increased, the tolerance sensitivity of the optical system is enhanced, and the lens production and processing are not facilitated; FNO/AT ₃ Exceeding the upper limit of 5.5, the aperture number of the optical system increases, the light inlet amount is insufficient, and the imaging efficiency of the optical system is affectedAnd (5) fruits.

In some exemplary embodiments, the optical system satisfies conditional expression (2): 20 DEG/mm < CRA/SAG _s5 < 43 °/mm, wherein CRA is the chief ray incidence angle of the optical system, SAG _s5 Is the sagittal height of the object-side surface of the third lens at the maximum effective radius.

Based on the above embodiments, in CRA and SAG _s5 Under the condition that the two parameters meet the conditional expression (2), the sagittal height of the object side surface of the third lens is controlled, so that the surface shape of the third lens can be effectively controlled, the third lens positioned in front of the diaphragm is not too bent, and the incident light can be smoothly received into the diaphragm.

When CRA/SAG _s5 The value of (2) is lower than the lower limit of 20 DEG, the sagittal height of the third lens is too large, and the third lens is too bent, which is not beneficial to the production and processing of the third lens; when CRA/SAG _s5 The chief ray incidence angle is large beyond the upper limit of 43 deg., which is unfavorable for matching with the chip.

In some exemplary embodiments, the optical system satisfies conditional expression (3): 1.5<f ₄₅₆ /f<3, wherein f ₄₅₆ And f is the effective focal length of the optical system, and is the combined focal length of the fourth lens, the fifth lens and the sixth lens.

Based on the above embodiment, at f ₄₅₆ And f, the fourth lens element provides positive refractive power for the optical system, the fifth lens element provides negative refractive power for the optical system, the sixth lens element provides positive refractive power for the optical system, and the lens assembly comprising the fourth lens element, the fifth lens element and the sixth lens element provides positive refractive power for the optical system, and the lens assembly receives incident light from the aperture stop after the aperture stop, thereby being beneficial to correcting aberration of the optical system.

When f ₄₅₆ The value of/f exceeds the upper limit of 3, the refractive power of the lens group positioned behind the diaphragm is too small, and larger marginal aberration is easy to generate, so that the resolution performance of the lens group is not improved; when f ₄₅₆ The value of/f is lower than the lower limit of 1.5, and the whole refractive power of the rear lens group of the diaphragm is too strong, so that the lens group positioned behind the diaphragm is easy to generate serious astigmatism phenomenon, and the improvement of imaging quality is not facilitated.

In some exemplary embodiments, the optical system satisfies conditional expression (4): TTL/CT of 5.5 < ₂ < 7.5, wherein CT ₂ The thickness of the second lens element on the optical axis is TTL, which is the distance between the object-side surface of the first lens element and the image plane of the optical system on the optical axis.

Based on the above embodiment, in TTL and CT ₂ Under the condition that the two parameters meet the condition (4), the relation between the ratio of the distance between the object side surface and the image side surface of the second lens and the total length of the optical system is reasonably distributed, so that the compactness of the optical system is effectively improved, the total length of the optical system is further reduced, the forming and the assembling of the lens are facilitated, and the decentration sensitivity is also reduced.

In some exemplary embodiments, the optical system satisfies conditional expression (5): 20 DEG/mm < FOV/CT ₂ < 35 °/mm, wherein FOV is the maximum field angle of the optical system, CT ₂ Is the thickness of the second lens on the optical axis.

Based on the above embodiment, the FOV and CT ₂ Under the condition that the two parameters meet the condition (5), the relation between the maximum field angle of the optical system and the spacing between the object side surface and the image side surface of the second lens on the optical axis is controlled, so that the light at the edge of the large field angle of the first lens can be smoothly injected into the second lens, the large field angle required by the optical system is provided, and more image capturing area can be accommodated.

FOV/CT ₂ The value of (2) is lower than the lower limit of 20 degrees, the required field angle of the optical system cannot be achieved, and the view finding area is affected; FOV/CT ₂ The value of (2) exceeds the upper limit of 35 DEG, the thickness of the second lens on the optical axis is too small, and the optical system is too sensitive, which is unfavorable for the production and processing of the lens.

In some exemplary embodiments, the optical system satisfies conditional expression (6): CT is 5 < ₆ /AT ₃ < 7, wherein CT ₆ The thickness of the sixth lens on the optical axis; AT (automatic Transmission) ₃ Is the distance between the image side of the third lens element and the object side of the fourth lens element on the optical axis.

Based on the above embodiment, in CT ₆ With AT ₃ These two parameters satisfy the above conditions(6) Under the condition of the above, the thickness relation among the lenses is reasonably distributed by controlling the ratio relation between the distance between the object side surface of the sixth lens and the image side surface on the optical axis and the air distance between the image side surface of the third lens and the object side surface of the fourth lens on the optical axis, so that the lens processing and production are facilitated; meanwhile, the size of the whole lens group can be compressed to a large extent by matching with the reduction of the distance between the object side surface and the image side surface of the sixth lens on the optical axis, so that the total length of the optical system is reduced; CT (computed tomography) ₆ /AT ₃ Exceeding the upper limit of 7 affects the smooth incidence of light rays into the sixth lens L6, increasing the risk of ghost images.

In some exemplary embodiments, the optical system satisfies conditional expression (7): -3<f ₁ /CT ₂ <-1, wherein f ₁ CT is the effective focal length of the first lens ₂ Is the thickness of the second lens on the optical axis.

By controlling the distance CT between the object side surface and the image side surface of the second lens element ₂ Focal length f of first lens of optical system ₁ The ratio relation in the formula (7) is satisfied, so that the optical power can be reasonably distributed, and the total focal length of the optical system is reduced.

f ₁ /CT ₂ The value of (2) exceeds the upper limit of-1, the refractive power of the first lens is too strong, and the marginal light of the first lens is incident into the image side surface to easily generate larger field curvature so as to influence the imaging quality; f (f) ₁ /CT ₂ The value of (2) is lower than the lower limit of-3, and the thickness of the second lens on the optical axis increases, which is disadvantageous for miniaturization of the optical system.

In a second aspect, an embodiment of the present application provides an image capturing module, where the image capturing module includes a photosensitive element and an optical system as described above, and the photosensitive element is disposed on an image side of the optical system, and is configured to receive light passing through the optical system and convert the light into an image signal.

Based on the image capturing module of this application embodiment, through adopting above-mentioned optical system to make the image capturing module have good formation of image resolving power to and be favorable to making the image capturing module obtain the shooting performance of big light ring, little distortion, still can make simultaneously the image capturing module have miniaturized structural feature, be convenient for install the image capturing module in less installation space.

In a third aspect, an embodiment of the present application provides an electronic device, where the electronic device includes a fixing member and an image capturing module as described above, and the image capturing module is installed on the fixing member to capture an image.

Based on the electronic equipment provided by the embodiment of the application, the shooting performance of large aperture and small distortion can be obtained by installing the image capturing module, so that the electronic equipment has good imaging quality.

In a fourth aspect, an embodiment of the present application provides an automobile, where the automobile includes a mounting portion and an electronic device as described above, and the electronic device is fixed on the mounting portion to obtain information.

Based on the automobile provided by the embodiment of the application, the electronic equipment can be installed to acquire complete environment information required by the automobile to execute the safety function, so that the automatic driving system is facilitated to make a key independent decision.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

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

FIG. 2A is a graph showing spherical aberration curves of an optical system according to an embodiment of the present application;

FIG. 2B is a graph showing an astigmatic curve of an optical system according to an embodiment of the present disclosure;

FIG. 2C is a graph showing distortion curves of an optical system according to an embodiment of the present disclosure;

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

FIG. 4A is a graph showing spherical aberration curves of an optical system according to a second embodiment of the present disclosure;

FIG. 4B is a astigmatic diagram of an optical system according to a second embodiment of the present disclosure;

FIG. 4C is a graph showing distortion curves of an optical system according to a second embodiment of the present disclosure;

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

FIG. 6A is a graph of spherical aberration curves of an optical system according to a third embodiment of the present application;

FIG. 6B is a astigmatic diagram of an optical system according to a third embodiment of the present disclosure;

FIG. 6C is a graph showing distortion curves of an optical system according to a third embodiment of the present application;

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

FIG. 8A is a graph of spherical aberration curves of an optical system according to a fourth embodiment of the present application;

FIG. 8B is a astigmatic diagram of an optical system according to a fourth embodiment of the present disclosure;

FIG. 8C is a graph showing distortion curves of an optical system according to a fourth embodiment of the present application;

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

FIG. 10A is a graph showing spherical aberration curves of an optical system according to a fifth embodiment of the present application;

FIG. 10B is a astigmatic diagram of an optical system according to a fifth embodiment of the present application;

FIG. 10C is a graph showing distortion curves of an optical system according to a fifth embodiment of the present application;

FIG. 11 is a cross-sectional view of an imaging module provided in one embodiment of the present application;

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

fig. 13 is a schematic structural diagram of an automobile with electronic equipment according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the following detailed description of the embodiments of the present application will be given with reference to the accompanying drawings.

When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples are not representative of all implementations consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present application as detailed in the accompanying claims.

Referring to fig. 1, 3, 5, 7 and 9, a schematic structural diagram of an optical system 100 according to an embodiment of the present application is provided, where the optical system 100 includes, in order from an object side to an image side along an optical axis H, a first lens L1 having a negative bending force, a second lens L2 having a negative bending force, a third lens L3 having a positive bending force, a stop STO, a fourth lens L4 having a positive bending force, a fifth lens L5 having a negative bending force and a sixth lens L6 having a positive bending force. When the optical system 100 is used for imaging, light from the object side sequentially passes through the first lens L1, the second lens L2, the third lens L3, the stop STO, the fourth lens L4, the fifth lens L5, and the sixth lens L6 and then is projected into the imaging plane IMG. The imaging plane IMG can be used for setting a photosensitive element, and the light passing through the sixth lens L6 can be received by the photosensitive element in the imaging plane IMG and converted into an image signal, and then the photosensitive element transmits the image signal to other systems at the rear end for processing such as image analysis.

The optical system of the embodiment of the application, the optical imaging system includes:

the first lens element L1 with negative refractive power has an effect of increasing an angle of view and improving a light ray's angle of view. The object side surface of the first lens L1 is set to be a convex surface, the image side surface of the first lens L1 is set to be a concave surface, so that light can be captured, the angle of light required by laser radar design is met, the incidence of the light into the first lens L1 is achieved, and meanwhile, the arrangement of the aspheric surface of the first lens L1 is beneficial to controlling the head caliber of the optical system 100.

The second lens L2 has negative bending force, which is beneficial to reasonably distributing the focal power of the optical system 100; and the object side surface of the second lens L2 is set to be a convex surface, and the image side surface is set to be a concave surface, so that light rays passing through the first lens L1 are smoothly incident into the second lens L2, and the influence of aberration outside the optical axis H is effectively reduced.

The third lens L3 has positive bending force, the aperture stop is disposed between the third lens L3 and the fourth lens L4, and both the object side surface and the image side surface of the third lens L3 are convex, so that the light from the second lens L2 can be effectively received, the light is fully received into the aperture stop, and the illuminance is increased, so that the light passing through the third lens L3 is incident into the aperture stop with a large aperture.

Meanwhile, the stop STO is disposed between the third lens element L3 and the fourth lens element L4, the fourth lens element L4 has positive refractive power, and both the object-side surface and the image-side surface are convex, which is beneficial to shrinking light and shortening the total length of the optical system 100.

The fourth lens element L4 and the fifth lens element L5 are combined to form a lens assembly, and the fifth lens element L5 has negative refractive power, wherein an object-side surface of the fifth lens element L5 is concave, and an image-side surface of the fifth lens element L5 is convex, thereby facilitating power configuration of the lens assembly and reducing sensitivity of the lens assembly. Meanwhile, the fourth lens L4 and the fifth lens L5 are glued to form a glued lens group, so that the spherical aberration of the optical system 100 is reduced, the resolution of the optical system 100 is improved, meanwhile, the aberration caused by the front group lens of the diaphragm STO brings tolerance sensitivity, and the glued lens group can better regulate the tolerance sensitivity.

The sixth lens L6 has positive bending force, and the object side surface is a convex surface, so that the incident angle of light can be further changed, the incident angle of the incident light reaching the imaging surface IMG is reduced, and the relative illuminance is improved; the aspheric surface of the sixth lens L6 is beneficial to controlling the distortion of the optical system 100 and the angle of the incident light beam reaching the image plane IMG, so as to achieve the effects of large aperture and small distortion of the optical system 100.

The optical system 100 satisfies the conditional expression (1): 3.5 (1/mm) < FNO/AT ₃ < 5.5 (1/mm), wherein AT ₃ The f-number of the optical system 100 is indicated by FNO, which is the distance between the image side of the third lens element L3 and the object side of the fourth lens element L4 on the optical axis H.

FNO/AT ₃ The values of (2) may be 3.929 (1/mm), 4.444 (1/mm), 4.444 (1/mm), 4.206 (1/mm) or 4.767 (1/mm), the stop STO of the optical system 100 being arranged between the third lens L3 and the fourth lens L4 by rational adaptation ofThe distance between the three lenses L3 and the fourth lens L4 and the front and rear surfaces of the stop STO on the optical axis H is related to the f-number ratio of the optical system 100, so that the optical effects of large aperture and small distortion can be realized.

FNO/AT ₃ The lower limit of the optical system is lower than 3.5, the distance between the third lens L3 and the fourth lens L4 and the front and the rear surfaces of the diaphragm STO on the optical axis H is increased, the tolerance sensitivity of the optical system 100 is enhanced, and the lens production and processing are not facilitated; FNO/AT ₃ Beyond the upper limit of 5.5, the f-number of the optical system 100 decreases, and the amount of light input is insufficient, affecting the imaging effect of the optical system 100.

In some exemplary embodiments, the optical system 100 satisfies the conditional expression (2): 20 < CRA/SAG _s5 < 43, wherein CRA is the chief ray incidence angle of the optical system 100, SAG _s5 Is the sagittal height of the object-side surface of the third lens L3 at the maximum effective radius. Of these, it should be noted that SAG as described above _s5 The sagittal height of (a) is the distance between the intersection point of the object side surface S5 of the third lens L3 and the optical axis and the maximum effective aperture of that surface (i.e., the maximum effective radius of that surface) in the direction parallel to the optical axis.

When the value is positive, in a direction parallel to the optical axis of the imaging system 100, the maximum effective light-transmitting aperture of the face is closer to the image side of the imaging system 100 than the center of the face; when this value is negative, the maximum effective light transmission aperture of the face is closer to the object side of the imaging system 100 than the center of the face in a direction parallel to the optical axis of the imaging system 100.

CRA/SAG _s5 The values of (2) may be 21.69 °/mm, 41.08 °/mm, 42.53 °/mm, 30.87 °/mm or 29.38 °/mm, and by controlling the sagittal height of the object-side surface of the third lens L3, the plane shape of the third lens L3 can be effectively controlled so that the third lens L3 located in front of the stop STO is not too curved, which is advantageous for smooth entrance of the incident light into the stop STO.

When CRA/SAG _s5 The value of (2) is lower than the 20 DEG lower limit, the sagittal height of the third lens L3 is too large, and the third lens L3 is too bent, which is not beneficial to the production and processing of the third lens L3; when CRA/SAG _s5 The chief ray incidence angle is large beyond the upper limit of 43 deg., which is unfavorable for matching with the chip.

In some exemplary embodiments, the optical system 100 satisfies the conditional expression (3): 1.5<f ₄₅₆ /f<3, wherein f ₄₅₆ The combined focal length of the fourth lens L4, the fifth lens L5, and the sixth lens L6, f is the effective focal length of the optical system 100.

f ₄₅₆ The value of/f may be 2.47, 2.28, 1.90, 2.46 or 2.49, the fourth lens element L4 provides positive refractive power to the optical system 100, the fifth lens element L5 provides negative refractive power to the optical system 100, the sixth lens element L6 provides positive refractive power to the optical system 100, the lens group consisting of the fourth lens element L4, the fifth lens element L5 and the sixth lens element L6 provides positive refractive power to the optical system 100, and the lens group is positioned behind the stop STO and receives incident light from the stop STO, thereby being beneficial for correcting aberration of the optical system 100.

f ₄₅₆ The value of/f exceeds the upper limit of 3, the refractive power of the lens group positioned behind the diaphragm STO is too small, and larger marginal aberration is easy to generate, so that the resolution performance of the lens group is not improved; f (f) ₄₅₆ The value of/f is lower than the lower limit of 1.5, and the whole refractive power of the rear lens group of the diaphragm STO is too strong, so that the lens group positioned behind the diaphragm STO is easy to generate serious astigmatism phenomenon, and the improvement of imaging quality is not facilitated.

In some exemplary embodiments, the optical system 100 satisfies the conditional expression (4): TTL/CT of 5.5 < ₂ < 7.5, wherein CT ₂ For the thickness of the second lens element L2 on the optical axis H, TTL is the distance between the object side surface of the first lens element L1 and the imaging surface IMG of the optical system 100 on the optical axis H.

TTL/CT ₂ The value of (2) may be 6.82, 6.20, 6.60, 6.12 or 6.20, and by reasonably distributing the thickness of the second lens L2 on the optical axis H, the ratio relationship between the thickness and the total length of the optical system 100 can effectively improve the compactness of the optical system 100, so as to reduce the total length of the optical system 100, thereby being beneficial to the forming and assembling of the lens and reducing the decentration sensitivity.

In some exemplary embodiments, the optical system 100 satisfies the conditional expression (5): 20 < FOV/CT ₂ < 35, wherein FOV is the maximum field angle of the optical system 100, CT ₂ Is the thickness of the second lens L2 on the optical axis H.

FOV/CT ₂ The values of (a) may be 29.924 °/mm, 25.371 °/mm, 23.958 °/mm, 26.703 °/mm or 26.703 °/mm, and by controlling the ratio of the maximum angle of view of the optical system 100 to the thickness of the second lens object L2 on the optical axis H, the light beam from the edge of the large angle of view of the first lens element L1 is smoothly incident into the second lens element L2, so as to provide a large angle of view required by the optical system 100, and accommodate a large image capturing area.

FOV/CT ₂ The value of (2) is lower than the lower limit of 20, and the viewing angle required by the optical system 100 is not reached, so that the viewing area is affected; FOV/CT ₂ The second lens L2 has a thickness on the optical axis H too small and the optical system 100 is too sensitive to be useful for lens manufacturing.

In some exemplary embodiments, the optical system 100 satisfies the conditional expression (6): CT is 5 < ₆ /AT ₃ < 7, wherein CT ₆ The thickness of the sixth lens L6 on the optical axis H; AT (automatic Transmission) ₃ The distance from the image side of the third lens element L3 to the object side of the fourth lens element L4 is along the optical axis H.

CT ₆ /AT ₃ The value of (3) may be 6.214, 5.944, 6.389, 5.706 or 6.833, and by controlling the thickness of the sixth lens element L6 on the optical axis H, the relationship between the thicknesses of the lens elements is reasonably distributed according to the ratio of the distance from the image side surface of the third lens element L3 to the object side surface of the fourth lens element L4 on the optical axis H, which is beneficial to processing and production; meanwhile, the thickness of the sixth lens L6 on the optical axis H is reduced, so that the volume of the whole lens group can be compressed to a large extent, and the total length of the optical system 100 is further reduced; CT (computed tomography) ₆ /AT ₃ Exceeding the upper limit of 7 affects the smooth incidence of light rays into the sixth lens L6, increasing the risk of ghost images.

In some exemplary embodiments, the optical system 100 satisfies the conditional expression (7): -3 <f ₁ /CT ₂ <-1, wherein f ₁ CT is the effective focal length of the first lens L1 ₂ Is the thickness of the second lens L2 on the optical axis H.

f ₁ /CT ₂ The values of (2) may be-1.51, -1.85, -2.49, -1.50 or-1.49, and the optical system 1 by controlling the thickness of the second lens L2 on the optical axis HThe ratio of the effective focal lengths of the first lens L1 of 00 is beneficial to reasonably distributing the optical power, thereby reducing the total effective focal length of the optical system 100.

f ₁ /CT ₂ The value of (2) exceeds the upper limit of-1, the refractive power of the first lens element L1 is too strong, and the marginal light of the first lens element L1 is incident into the image side surface to easily generate larger field curvature so as to influence the imaging quality; f (f) ₁ /CT ₂ The value of (2) is lower than the lower limit of-3, and the thickness of the second lens L2 on the optical axis H increases, which is disadvantageous for downsizing of the optical system 100.

In some exemplary embodiments, the optical system 100 satisfies the conditional expression (8): 1.5 < |DIS/FNO| < 16.5, where DIS is the optical distortion of optical system 100 and FNO is the f-number of optical system 100.

The value of DIS/FNO may be 1.79, 10.05, 16.29, 7.34 or 6.99, and by controlling the relationship between the distortion of the optical system 100 and the f-number of the optical system 100, and by combining the setting of the intermediate diaphragm STO, the optical system 100 is structurally symmetrical, so that the distortion of the optical system 100 is better controlled, and a large aperture effect is achieved.

The i DIS/FNO is lower than the lower limit of 1.5, the f-number of the optical system 100 becomes small, and the light entering the optical system 100 is reduced, which is unfavorable for realizing a large aperture effect; when the ratio DIS/FNO exceeds the upper limit of 16.5, distortion of the optical system 100 increases, the risk of image capturing edge distortion increases, and better image quality cannot be obtained.

The optical system 100 in the embodiment of the present application can enhance the imaging resolution capability of the optical system 100 and is beneficial to the optical system 100 to realize the characteristics of large aperture and small distortion by setting the surface type, the bending force of each lens and the reasonable configuration of the distance between each lens.

In some exemplary embodiments, the object-side surfaces and/or the image-side surfaces of the first lens element L1 to the sixth lens element L6 may be aspheric or spherical, and the aspheric design enables the object-side surfaces and/or the image-side surfaces to have a more flexible design, so that the lens element can well solve the problems of poor imaging, distortion of vision, narrow field of view and the like under the condition of being smaller and thinner, and the lens assembly can have good imaging quality without providing too many lens elements, and is helpful for shortening the length of the optical system 100. The spherical lens has simple manufacturing process and low production cost, is convenient for flexibly designing the surface type of each lens, and improves the imaging resolving power of each lens. The combination of the spherical surface and the aspherical surface can also effectively eliminate the aberration of the system, so that the optical system 100 has good imaging quality, and meanwhile, the design and assembly flexibility of each lens in the optical system are improved. The surfaces of the lenses in the optical system 100 may be any combination of spherical surfaces and aspherical surfaces, and are not necessarily spherical surfaces or aspherical surfaces.

The materials of the lenses in the optical system 100 may be glass, plastic, or a combination of glass and plastic. The glass lens can withstand a high temperature and has excellent optical effects, while the plastic lens can reduce the weight of the optical system 100 and reduce the manufacturing cost. Specifically, in the exemplary embodiment of the present application, the materials of the first lens L1 to the sixth lens L6 are all glass, so that the optical performance of each lens can be improved. Of course, the configuration of the lens materials in the optical system 100 is not limited to the above embodiments, and any one of the lenses may be made of plastic or glass, and the specific configuration is determined according to the actual design requirement and will not be described herein.

The optical system 100 further includes a stop STO centered on the optical axis H of the optical system 100, and in some exemplary embodiments, the stop STO is disposed between the third lens L3 and the fourth lens L4 for adjusting the intensity of the passing light, thereby expanding the angle of view while maintaining the miniaturization of the optical system 100. The stop STO may be provided as a light-shielding layer which is coated on the object side or image side of the lens and which leaves a light-passing area to allow light to pass through.

The optical system 100 further includes a filter L7, and the filter L7 is disposed between the image side surface of the sixth lens L6 and the imaging plane IMG. The filter L7 may be assembled with each lens as part of the optical system 100.

For example, in some embodiments, each lens in the optical system 100 is mounted within a barrel, and the filter L7 is mounted at the image end of the barrel. In other embodiments, the filter L7 is not a component of the optical system 100, and the filter L7 may be installed between the optical system 100 and the photosensitive element when the optical system 100 and the photosensitive element are assembled into the image capturing module. In some embodiments, the filter L7 may also be disposed on the object side of the first lens L1. In addition, in some embodiments, the filter L7 may not be disposed, and an infrared filter film may be disposed on the object side surface or the image side surface of at least one of the first lens L1 to the sixth lens L6 to filter infrared light.

The optical system 100 according to the above embodiment of the present application may employ a plurality of lenses, and by reasonably distributing focal length, refractive power, surface thickness, axial spacing between the lenses, etc., the optical system 100 may be ensured to obtain photographing performance with large aperture and small distortion, so as to better satisfy application requirements of lightweight electronic devices such as lenses, mobile phones, tablets, etc. of the vehicle-mounted auxiliary system.

The assembly structure of the optical system 100 according to the present embodiment in each embodiment and the corresponding implementation result will be described below with reference to the drawings and tables in combination with specific numerical values.

The significance of the labels shown in the various embodiments is as follows:

s1, S3, S5, S7, S9, S11, S13 are numbers of object side surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the filter L7, and S2, S4, S6, S8, S10, S12, S14 are numbers of image side surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the filter L7, respectively.

"k" represents a Conic Constant, "A4", "A6", "A8", … … "and" a20 "represent aspherical coefficients of 4 th order, 6 th order, 8 th order, … … th order and 20 th order, respectively.

In the tables showing the conic constant and the aspherical coefficient, the numerical expression is an exponential expression with the base of 10. For example, "0.12E-05" means "0.12× (negative 5 th power of 10)", and "9.87E+03" means "9.87× (3 rd power of 10)".

In the optical system 100 used in each embodiment, specifically, when the distance in the direction perpendicular to the optical axis H is "R", the paraxial curvature at the lens origin is "c" (the paraxial curvature c is the inverse of the upper lens curvature radius R, that is, c=1/R), the conic constant is "k", and the aspherical coefficients of the 4 th, 6 th, 8 th, … …, and i-th steps are "A4", "A6", "A8", … … ", and" Ai ", respectively, the aspherical shape x is defined by the following equation 1, where Z represents the distance sagittal height from the aspherical apex when the aspherical surface is at the position of the height R in the optical axis direction.

Mathematical formula 1:

example 1

As shown in fig. 1, the optical system 100 of the present embodiment includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a filter L7 sequentially arranged from an object side to an image side along an optical axis H, a stop STO is disposed between the third lens L3 and the fourth lens L4, and an imaging plane IMG of the optical system 100 is located on a side of the filter L7 away from the sixth lens L6. The first lens L1 and the sixth lens L6 are aspheric lenses made of glass materials; a spherical lens made of glass and composed of a second lens L2, a third lens L3, a fourth lens L4 and a fifth lens L5; the filter L7 is a spherical infrared cut filter made of glass.

The first lens element L1 with negative refractive power has a convex object-side surface S1 at a paraxial region H and a concave image-side surface S2 at the paraxial region H.

The second lens element L2 with negative refractive power has a concave object-side surface S3 at a paraxial region H and a convex image-side surface S4 at the paraxial region H.

The third lens element L3 with positive refractive power has a convex object-side surface S5 at a paraxial region H and a convex image-side surface S6 at the paraxial region H.

The fourth lens element L4 with positive refractive power has a convex object-side surface S7 at a paraxial region H and a convex image-side surface S8 at the paraxial region H.

The fifth lens element L5 with negative refractive power has a concave object-side surface S9 at a paraxial region H and a convex image-side surface S10 at the paraxial region H.

The sixth lens element L6 with positive refractive power has a convex object-side surface S11 at a paraxial region H and a convex image-side surface S12 at the paraxial region H.

In the first embodiment, the refractive index, abbe number and focal length of the optical system 100 are all referenced to the light with the wavelength of 940nm, and the relevant parameters of the optical system 100 are shown in table 1. Where f is the effective focal length of the optical system 100, FNO is the f-number, FOV is the maximum field angle of the optical system 100, and the units of radius of curvature, thickness, and focal length are all millimeters. Wherein, the curvature radius in table 1 is the curvature radius of the object side or image side of the corresponding surface number at the optical axis. The first value in the "thickness" parameter row of the lens is the thickness of the lens on the optical axis, and the second value is the distance from the image side surface of the lens to the latter surface on the optical axis.

TABLE 1

Numerical relation calculation results between the respective lens-related parameters in the optical system 100 in the present embodiment are shown in table 2 in combination with the parameters in table 1 and the specific parameter settings in the present embodiment.

TABLE 2

As can be seen from the results in table 2, the numerical relation calculation results of the lens-related parameters in the optical system 100 in the present embodiment satisfy the condition formulas (1) to (8), respectively, in one-to-one correspondence.

The conic constant K and the aspherical coefficient corresponding to the surface of each lens in the first embodiment are shown in table 3.

TABLE 3 Table 3

Fig. 2A, 2B and 2C are a spherical aberration curve chart, an astigmatic curve chart and a distortion curve chart, respectively, in the first embodiment.

The abscissa of the spherical aberration graph represents the focus offset, the ordinate represents the normalized field of view, and the focus offset of different fields of view is within ±0.050mm when the wavelengths given in fig. 2A are 940.0000nm, which indicates that the spherical aberration of the optical system 100 is smaller and the imaging quality is better in this embodiment.

The abscissa of the astigmatic curve shows the focus offset, the ordinate shows the image height, and when the astigmatic curve shown in fig. 2B shows that the wavelength is 940.0000nm, the focus offset of the meridian image plane and the sagittal image plane is within ±0.100mm, which indicates that the astigmatism of the optical system 100 in this embodiment is smaller and the imaging quality is better.

The distortion curve shown in fig. 2C shows that the distortion is within ±10.0% at a wavelength of 940.0000nm, indicating that the distortion of the optical system 100 in this embodiment is better corrected and the imaging quality is better.

As can be seen from fig. 2A, 2B and 2C, the optical system 100 according to the first embodiment can achieve a good imaging effect.

Example two

As shown in fig. 3, the optical system 100 of the present embodiment includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a filter L7 sequentially arranged from an object side to an image side along an optical axis H, a stop STO is disposed between the third lens L3 and the fourth lens L4, and an imaging plane IMG of the optical system 100 is located on a side of the filter L7 away from the sixth lens L6. The first lens L1 and the sixth lens L6 are aspheric lenses made of glass materials; a spherical lens made of glass and composed of a second lens L2, a third lens L3, a fourth lens L4 and a fifth lens L5; the filter L7 is a spherical infrared cut filter made of glass.

In the second embodiment, the refractive index, abbe number and focal length of the optical system 100 are all referenced to the light with the wavelength of 940nm, and the relevant parameters of the optical system 100 are shown in table 4. Where f is the effective focal length of the optical system 100, FNO is the aperture value, FOV is the maximum field angle of the optical system 100, and the units of the radius of curvature, thickness, and focal length are all millimeters. Wherein, the curvature radius in table 4 is the curvature radius of the object side or image side of the corresponding surface number at the optical axis. The first value in the "thickness" parameter row of the lens is the thickness of the lens on the optical axis, and the second value is the distance from the image side surface of the lens to the latter surface on the optical axis.

TABLE 4 Table 4

Numerical relation calculation results between the respective lens-related parameters in the optical system 100 in the present embodiment are shown in table 5 in combination with the parameters in table 4 and the specific parameter settings in the present embodiment.

TABLE 5

Conditional expression	Numerical value	Conditional expression	Numerical value
				(1)FNO/AT ₃	4.444(1/mm)	(5)FOV/CT ₂	25.371°/mm
(2)f ₄₅₆ /f	2.28	(6)CT ₆ /AT ₃	5.944
				(3)CRA/SAG _s5	41.08°/mm	(7)f ₁ /CT ₂	-1.85
(4)TTL/CT ₂	6.20	(8)\|DIS/FNO\|	10.05

As can be seen from the results in table 5, the numerical relation calculation results of the lens-related parameters in the optical system 100 in the present embodiment satisfy the condition formulas (1) to (8), respectively, in one-to-one correspondence.

The conic constant K and the aspherical coefficient corresponding to the surface of each lens in the second example are shown in table 6.

TABLE 6

Fig. 4A, 4B and 4C are a spherical aberration curve chart, an astigmatic curve chart and a distortion curve chart, respectively, in the first embodiment.

The abscissa of the spherical aberration graph shows the focus offset, the ordinate shows the normalized field of view, and the focus offset of different fields of view is within ±0.050mm when the wavelengths given in fig. 4A are 940.0000nm, which indicates that the spherical aberration of the optical system 100 is smaller and the imaging quality is better in this embodiment.

The abscissa of the astigmatic curve shows the focus offset, the ordinate shows the image height, and when the astigmatic curve shown in fig. 4B shows that the wavelength is 940.0000nm, the focus offset of the meridian image plane and the sagittal image plane is within ±0.050mm, which indicates that the astigmatism of the optical system 100 in this embodiment is smaller and the imaging quality is better.

The distortion curve shown in fig. 4C shows that the distortion is within ±20.0% at a wavelength of 940.0000nm, indicating that the distortion of the optical system 100 in this embodiment is better corrected and the imaging quality is better.

As can be seen from fig. 4A, 4B and 4C, the optical system 100 provided in the second embodiment can achieve a good imaging effect.

Example III

As shown in fig. 5, the optical system 100 of the present embodiment includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a filter L7 sequentially arranged from an object side to an image side along an optical axis H, a stop STO is disposed between the third lens L3 and the fourth lens L4, and an imaging plane IMG of the optical system 100 is located on a side of the filter L7 away from the sixth lens L6. The first lens L1 and the sixth lens L6 are aspheric lenses made of glass materials; a spherical lens made of glass and composed of a second lens L2, a third lens L3, a fourth lens L4 and a fifth lens L5; the filter L7 is a spherical infrared cut filter made of glass.

The sixth lens element L6 with positive refractive power has a convex object-side surface S11 at a paraxial region H and a concave image-side surface S12 at the paraxial region H.

In the third embodiment, the refractive index, abbe number and focal length of the optical system 100 are all referenced to the light with the wavelength of 940nm, and the relevant parameters of the optical system 100 are shown in table 7. Where f is the effective focal length of the optical system 100, FNO is the aperture value, FOV is the maximum field angle of the optical system 100, and the units of the radius of curvature, thickness, and focal length are all millimeters. Wherein, the curvature radius in table 7 is the curvature radius of the object side or image side of the corresponding surface number at the optical axis. The first value in the "thickness" parameter row of the lens is the thickness of the lens on the optical axis, and the second value is the distance from the image side surface of the lens to the latter surface on the optical axis.

TABLE 7

Numerical relation calculation results between the respective lens-related parameters in the optical system 100 in the present embodiment are shown in table 8 in combination with the parameters in table 7 and the specific parameter settings in the present embodiment.

TABLE 8

Conditional expression	Numerical value	Conditional expression	Numerical value
				(1)FNO/AT ₃	4.444(1/mm)	(5)FOV/CT ₂	23.958°/mm
(2)f ₄₅₆ /f	1.90	(6)CT ₆ /AT ₃	6.389
				(3)CRA/SAG _s5	42.53°/mm	(7)f ₁ /CT ₂	-2.49
(4)TTL/CT ₂	6.60	(8)\|DIS/FNO\|	16.29

As can be seen from the results in table 8, the numerical relation calculation results of the lens-related parameters in the optical system 100 in the present embodiment satisfy the condition formulas (1) to (8), respectively, in one-to-one correspondence.

The conic constant K and the aspherical coefficient corresponding to the surface of each lens in the third embodiment are shown in table 9.

TABLE 9

Fig. 6A, 6B and 6C are a spherical aberration curve chart, an astigmatic curve chart and a distortion curve chart, respectively, in the first embodiment.

The abscissa of the spherical aberration graph shows the focus offset, the ordinate shows the normalized field of view, and the focus offset of different fields of view is within ±0.050mm when the wavelengths given in fig. 6A are 940.0000nm, which indicates that the spherical aberration of the optical system 100 is smaller and the imaging quality is better in this embodiment.

The abscissa of the astigmatic curve shows the focus offset, the ordinate shows the image height, and when the astigmatic curve shown in fig. 6B shows the wavelength at 940.0000nm, the focus offset of the sagittal image surface and the meridional image surface are both within ±0.050mm, which indicates that the astigmatism of the optical system 100 in this embodiment is smaller and the imaging quality is better.

The distortion curve shown in fig. 6C shows that the distortion is within ±25.0% at a wavelength of 940.0000nm, indicating that the distortion of the optical system 100 in this embodiment is better corrected and the imaging quality is better.

As can be seen from fig. 6A, 6B, and 6C, the optical system 100 provided in the third embodiment can achieve a good imaging effect.

Example IV

As shown in fig. 7, the optical system 100 of the present embodiment includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a filter L7 sequentially arranged from an object side to an image side along an optical axis H, a stop STO is disposed between the third lens L3 and the fourth lens L4, and an imaging plane IMG of the optical system 100 is located on a side of the filter L7 away from the sixth lens L6. The first lens L1 and the sixth lens L6 are aspheric lenses made of glass materials; a spherical lens made of glass and composed of a second lens L2, a third lens L3, a fourth lens L4 and a fifth lens L5; the filter L7 is a spherical infrared cut filter made of glass.

In the fourth embodiment, the refractive index, abbe number and focal length of the optical system 100 are all referenced to the light with the wavelength of 940nm, and the relevant parameters of the optical system 100 are shown in table 10. Where f is the effective focal length of the optical system 100, FNO is the aperture value, FOV is the maximum field angle of the optical system 100, and the units of the radius of curvature, thickness, and focal length are all millimeters. Wherein, the curvature radius in table 10 is the curvature radius of the object side or image side of the corresponding surface number at the optical axis. The first value in the "thickness" parameter row of the lens is the thickness of the lens on the optical axis, and the second value is the distance from the image side surface of the lens to the latter surface on the optical axis.

Table 10

Numerical relation calculation results between the respective lens-related parameters in the optical system 100 in the present embodiment are shown in table 11 in combination with the parameters in table 10 and the specific parameter settings in the present embodiment.

TABLE 11

Conditional expression	Numerical value	Conditional expression	Numerical value
				(1)FNO/AT ₃	4.206(1/mm)	(5)FOV/CT ₂	26.703°/mm
(2)f ₄₅₆ /f	2.46	(6)CT ₆ /AT ₃	5.706
				(3)CRA/SAG _s5	30.87°/mm	(7)f ₁ /CT ₂	-1.50
(4)TTL/CT ₂	6.12	(8)\|DIS/FNO\|	7.34

As can be seen from the results in table 11, the numerical relation calculation results of the lens-related parameters in the optical system 100 in the present embodiment satisfy the condition formulas (1) to (8), respectively, in one-to-one correspondence.

The conic constant K and the aspherical coefficient corresponding to the surface of each lens in the fourth embodiment are shown in table 12.

Table 12

Fig. 8A, 8B and 8C are a spherical aberration curve chart, an astigmatic curve chart and a distortion curve chart, respectively, in the first embodiment.

The abscissa of the spherical aberration graph shows the focus offset, the ordinate shows the normalized field of view, and the focus offset of different fields of view is within ±0.050mm when the wavelength given in fig. 8A is 940.0000nm, which indicates that the spherical aberration of the optical system 100 is smaller and the imaging quality is better in this embodiment.

The abscissa of the astigmatic curve shows the focus offset, the ordinate shows the image height, and when the astigmatic curve shown in fig. 8B shows that the wavelength is 940.0000nm, the focus offset of the sagittal image surface and the meridional image surface is within ±0.050mm, which indicates that the astigmatism of the optical system 100 is smaller and the imaging quality is better in this embodiment.

The distortion curve shown in fig. 8C shows that the distortion is within ±20.0% at a wavelength of 940.0000nm, indicating that the distortion of the optical system 100 in this embodiment is better corrected and the imaging quality is better.

As can be seen from fig. 8A, 8B, and 8C, the optical system 100 given in the fourth embodiment can achieve a good imaging effect.

Example five

As shown in fig. 9, the optical system 100 of the present embodiment includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a filter L7 sequentially arranged from an object side to an image side along an optical axis H, a stop STO is disposed between the third lens L3 and the fourth lens L4, and an imaging plane IMG of the optical system 100 is located on a side of the filter L7 away from the sixth lens L6. The first lens L1 and the sixth lens L6 are aspheric lenses made of glass materials; a spherical lens made of glass and composed of a second lens L2, a third lens L3, a fourth lens L4 and a fifth lens L5; the filter L7 is a spherical infrared cut filter made of glass.

In the fifth embodiment, the refractive index, abbe number and focal length of the optical system 100 are all referenced to the light with the wavelength of 940nm, and the relevant parameters of the optical system 100 are shown in table 13. Where f is the effective focal length of the optical system 100, FNO is the aperture value, FOV is the maximum field angle of the optical system 100, and the units of the radius of curvature, thickness, and focal length are all millimeters. Wherein, the radius of curvature in table 13 is the radius of curvature of the object side or image side of the corresponding surface number at the optical axis. The first value in the "thickness" parameter row of the lens is the thickness of the lens on the optical axis, and the second value is the distance from the image side surface of the lens to the latter surface on the optical axis.

TABLE 13

Numerical relation calculation results between the respective lens-related parameters in the optical system 100 in the present embodiment are shown in table 14 in combination with the parameters in table 13 and the specific parameter settings in the present embodiment.

TABLE 14

Conditional expression	Numerical value	Conditional expression	Numerical value
				(1)FNO/AT ₃	4.767(1/mm)	(5)FOV/CT ₂	26.703°/mm
(2)f ₄₅₆ /f	2.49	(6)CT ₆ /AT ₃	6.833
				(3)CRA/SAG _s5	29.38E/mm	(7)f ₁ /CT ₂	-1.49
(4)TTL/CT ₂	6.20	(8)\|DIS/FNO\|	6.99

As can be seen from the results in table 14, the numerical relation calculation results of the lens-related parameters in the optical system 100 in the present embodiment satisfy the condition formulas (1) to (8) in a one-to-one correspondence manner.

The conic constant K and the aspherical coefficient corresponding to the surface of each lens in the fifth embodiment are shown in table 15.

TABLE 15

Fig. 10A, 10B and 10C are a spherical aberration curve chart, an astigmatic curve chart and a distortion curve chart, respectively, in the first embodiment.

The abscissa of the spherical aberration graph shows the focus offset, the ordinate shows the normalized field of view, and the focus offset of different fields of view is within ±0.050mm when the wavelength given in fig. 10A is 940.0000nm, which indicates that the spherical aberration of the optical system 100 is smaller and the imaging quality is better in this embodiment.

The abscissa of the astigmatic curve shows the focus offset, the ordinate shows the image height, and when the astigmatic curve shown in fig. 10B shows the wavelength at 940.0000nm, the focus offset of the sagittal image surface and the meridional image surface are both within ±0.050mm, which indicates that the astigmatism of the optical system 100 is smaller and the imaging quality is better in this embodiment.

The distortion curve shown in fig. 10C shows that the distortion is within ±20.0% at a wavelength of 940.0000nm, indicating that the distortion of the optical system 100 in this embodiment is better corrected and the imaging quality is better.

As can be seen from fig. 10A, 10B, and 10C, the optical system 100 given in the fourth embodiment can achieve a good imaging effect.

As shown in fig. 11, in some embodiments of the present application, an image capturing module 200 is further provided, where the image capturing module 200 includes a photosensitive element 210 and the optical system 100 as described above. The photosensitive element 210 has a photosensitive surface that is positioned in an imaging surface of the optical system 100 to receive light of an image formed by the optical system 100. The photosensitive element 210 may be a CCD (Charge Coupled Device ) or CMOS (Complementary Metal Oxide Semiconductor, complementary metal oxide semiconductor). When assembled, the imaging surface of the optical system 100 overlaps the photosensitive surface 211 of the photosensitive element 210.

As shown in fig. 12, in some embodiments of the present application, an electronic device 300 is also provided, the electronic device 300 including a fixture 310 and a mounting plate 320. The electronic apparatus 300 is an in-vehicle image capturing apparatus, and the image capturing module 200 is disposed in a mount 310 of the in-vehicle image capturing apparatus. The fixing member 310 is rotatably connected with the mounting plate 320, and the mounting plate 320 is fixed to the body of the automobile, so that the fixing member 310 mounted with the camera module 200 can integrally rotate relative to the body, thereby adjusting the photographing range. The electronic device 300 may cooperate with an auxiliary driving system and an automatic driving system to transmit the obtained image information to the terminal to judge the road condition, thereby reminding the driver or automatically executing the driving operation. Alternatively, the electronic device 300 may be coupled to a display screen within the cab, for example, to display the obtained image on the display screen for viewing by the driver.

Referring to fig. 13, some embodiments of the present application also provide an automobile 400. The automobile 400 includes a mounting portion 410 and the electronic device 300, and the electronic device 300 is provided in the mounting portion 410. The mounting portion 410 may be a vehicle body portion suitable for mounting the image pickup apparatus, such as a front grille, an in-vehicle mirror, a left mirror, a right mirror, a roof, a trunk lid, or the like. The automobile 400 may be provided with a plurality of electronic devices 300 to obtain the omnibearing image information of the automobile body, and the image information obtained by the plurality of electronic devices 300 may be displayed on a display screen after being spliced or respectively displayed in different areas on the display screen. The automobile 400 can obtain larger visual field range, larger depth information and clearer road condition images through the electronic equipment 300 with the optical system 100, so that a driver or a driving control system can obtain early warning more timely and accurately, and further the requirements of the industry on driving safety are met.

In the description of the present application, it should be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art in a specific context. Furthermore, in the description of the present application, unless otherwise indicated, "a plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: a exists alone, A and B exist together, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship.

The foregoing disclosure is only illustrative of the preferred embodiments of the present application and is not intended to limit the scope of the claims herein, as the equivalent of the claims herein shall be construed to fall within the scope of the claims herein.

Claims

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

a second lens element with negative refractive power having a concave object-side surface at a paraxial region and a convex image-side surface at a paraxial region;

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

a diaphragm;

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

a fifth lens element with negative refractive power having a concave object-side surface at a paraxial region and a convex image-side surface at a paraxial region; the method comprises the steps of,

a sixth lens element with positive refractive power having a convex object-side surface at a paraxial region, wherein the object-side surface and the image-side surface of the sixth lens element are aspheric;

Six lenses with refractive power;

the optical system satisfies the following conditional expression:

3.5（1/mm）＜FNO/AT ₃ ＜5.5（1/mm）；

5.5＜TTL/

＜7.5；

wherein AT ₃ For the distance on the optical axis from the image side surface of the third lens element to the object side surface of the fourth lens element, FNO is the f-number of the optical system,

and TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis.

2. The optical system of claim 1, wherein the optical system further satisfies the conditional expression:

20°/mm＜CRA/SAG _s5 ＜43°/mm；

wherein CRA is the chief ray incidence angle of the optical system, SAG _s5 Is the sagittal height of the object-side surface of the third lens at the maximum effective radius.

3. The optical system of claim 1, wherein the optical system further satisfies the conditional expression:

1.5< f ₄₅₆ /f<3；

wherein f ₄₅₆ And f is the effective focal length of the optical system, and is the combined focal length of the fourth lens, the fifth lens and the sixth lens.

4. The optical system of claim 1, wherein the optical system further satisfies the conditional expression:

20°/mm＜FOV/CT ₂ ＜35°/mm；

wherein FOV is the maximum field angle of the optical system, CT ₂ Is the thickness of the second lens on the optical axis.

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

5＜CT ₆ /AT ₃ ＜7；

wherein CT ₆ Is the thickness of the sixth lens on the optical axis.

6. The optical system of claim 1, wherein the optical system further satisfies the conditional expression:

-3< f ₁ /CT ₂ <-1；

wherein f ₁ CT for the effective focal length of the first lens ₂ Is the thickness of the second lens on the optical axis.

7. An image capturing module, comprising:

the optical system according to any one of claims 1 to 6, and

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

8. An electronic device, comprising:

the imaging module of claim 7; a kind of electronic device with high-pressure air-conditioning system

The fixing piece, the image capturing module is installed on the fixing piece.

9. An automobile, comprising:

the electronic device of claim 8; a kind of electronic device with high-pressure air-conditioning system

And a mounting portion to which the electronic device is fixed.