CN113820830A

CN113820830A - Optical system, image capturing module, electronic equipment and carrier

Info

Publication number: CN113820830A
Application number: CN202111181894.5A
Authority: CN
Inventors: 乐宇明; 赵迪; 兰宾利; 周芮; 王欢; 朱志鹏; 其他发明人请求不公开姓名
Original assignee: Tianjin OFilm Opto Electronics Co Ltd
Current assignee: Jiangxi Oufei Optics Co ltd
Priority date: 2021-10-11
Filing date: 2021-10-11
Publication date: 2021-12-21
Anticipated expiration: 2041-10-11
Also published as: CN113820830B

Abstract

The invention relates to an optical system, an image capturing module, an electronic device and a carrier. An optical system includes, in order from an object side to an image side along an optical axis: a first lens element with negative refractive power; a second lens element with negative refractive power; a third lens element with positive refractive power having convex object-side and image-side surfaces; a fourth lens element with negative refractive power having a concave image-side surface; a fifth lens element with positive refractive power having a convex image-side surface; a sixth lens element with refractive power having a concave image-side surface; the fourth lens is glued with the fifth lens, and the optical system meets the following requirements: f45/f is more than or equal to 3.2 and less than or equal to 6.2. The optical system has good imaging quality, and is applied to the vehicle-mounted camera lens to be beneficial to improving the driving safety performance.

Description

Optical system, image capturing module, electronic equipment and carrier

Technical Field

The present invention relates to the field of camera shooting, and in particular, to an optical system, an image capturing module, an electronic device and a carrier.

Background

With the development of the automobile industry, vehicle-mounted systems such as ADAS (Advanced Driving assistance System), DMS (Driver Monitor System) and the like have gradually developed and matured and the market demand has gradually increased. The industry generally requires that vehicle-mounted system cooperation mobile unit can monitor the state outside the driver's cabin and discern to comprehensive judgement driver's driving environment changes, thereby proposes safety precaution, reminds the change of driver's driving state, and make the prevention in advance. Of course, the higher the imaging quality of the vehicle-mounted camera lens is, the better the driver can clearly acquire the environment outside the driving cabin.

However, the imaging quality of the current vehicle-mounted camera lens is still to be improved, which is not beneficial to the improvement of the driving safety performance.

Disclosure of Invention

Therefore, it is necessary to provide an optical system, an image capturing module, an electronic device and a carrier for solving the problem that the imaging quality of the conventional vehicle-mounted camera lens is still to be improved.

An optical system includes, in order from an object side to an image side along an optical axis:

a first lens element with negative refractive power;

a second lens element with negative refractive power;

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

a fourth lens element with negative refractive power having a concave image-side surface at paraxial region;

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

a sixth lens element with refractive power having a concave image-side surface at a paraxial region;

and the optical system satisfies the following conditional expression:

3.2≤f45/f≤6.2；

wherein f45 is a combined focal length of the fourth lens and the fifth lens, and f is an effective focal length of the optical system.

In the optical system, the first lens element has negative refractive power, which is beneficial for light rays with large visual angles to enter the optical system, thereby being beneficial for enlarging the field angle of the optical system. The second lens element with negative refractive power can share the negative refractive power of the first lens element, thereby preventing the refractive power of the single lens element from being too strong, and thus facilitating reduction of the sensitivity of the optical system and improving the molding yield of the first lens element and the second lens element. The third lens element with positive refractive power has a convex object-side surface and a convex image-side surface at paraxial region, which is favorable for balancing aberration generated by the first and second lens elements, and is favorable for shortening total length of the optical system and realizing miniaturization design. The fourth lens element with negative refractive power has a concave image-side surface at paraxial region thereof, and is favorable for correcting aberration generated by each lens element at the object side of the fourth lens element. The fifth lens element with positive refractive power has a positive refractive power, and is advantageous for shortening the back focal length of the optical system, thereby further shortening the total length of the optical system. The image-side surface of the fifth lens element is convex at the paraxial region, which is favorable for correcting astigmatism and simultaneously is favorable for light rays to effectively converge on an image plane. The image side surface of the sixth lens element is concave at the paraxial region, which is beneficial to correcting aberration and improving the imaging quality of the optical system.

Meanwhile, the negative refractive power of the fourth lens element is matched with the positive refractive power of the fifth lens element, which is favorable for mutual correction of aberration. When the conditional expressions are satisfied, the refractive power ratio of the fourth lens element to the fifth lens element in the optical system can be reasonably configured, which is beneficial to suppressing the occurrence of astigmatism, and is beneficial to correcting the edge aberration and chromatic aberration, thereby being beneficial to improving the imaging quality of the optical system. If the refractive power of the fourth lens element is less than the upper limit of the conditional expression, the refractive power of the fourth lens element is not sufficient to correct the peripheral aberration and chromatic aberration, thereby improving the resolution performance of the optical system; when the refractive power of the fourth lens element and the refractive power of the fifth lens element are lower than the lower limit of the conditional expression, severe astigmatism is likely to occur, which is not favorable for improving the imaging quality of the optical system.

In one embodiment, the fourth lens is cemented with the fifth lens. The fourth lens and the fifth lens are glued, so that chromatic aberration of the optical system can be corrected, mutual correction of chromatic aberration of the fourth lens and the fifth lens can be further facilitated, and the imaging quality of the optical system can be improved.

In one embodiment, the optical system satisfies the following conditional expression:

CT5-CT4 are more than or equal to 1mm and less than or equal to 1.5 mm. Wherein CT4 is the thickness of the fourth lens element along the optical axis, and CT5 is the thickness of the fifth lens element along the optical axis. When the conditional expressions are met, the difference of the central thicknesses of the fourth lens and the fifth lens can be reasonably configured, the risk of cracking of a cemented lens formed by the fourth lens and the fifth lens is reduced, and the total length of the optical system is reduced.

18mm≤f1*f2/f≤23mm；

wherein f1 is the effective focal length of the first lens, and f2 is the effective focal length of the second lens. When the condition formula is satisfied, the ratio of the product of the effective focal lengths of the first lens and the second lens in the optical system can be reasonably configured, which is beneficial to the large-angle light ray incidence optical system, thereby enlarging the field angle of the optical system, being beneficial to correcting the astigmatism and chromatic aberration of the optical system and improving the imaging quality of the optical system. If the refractive power of the first lens element and the refractive power of the second lens element are not sufficient, the wide-angle light is not incident on the optical system, and the field angle range of the optical system is not enlarged; when the refractive power of the first lens element and the second lens element is lower than the lower limit of the conditional expression, the refractive power of the first lens element and the second lens element is too strong, which tends to generate severe astigmatism and chromatic aberration, which is not favorable for high-resolution imaging characteristics.

2.5≤f456/f123≤4.5；

wherein f456 is a combined focal length of the fourth lens, the fifth lens and the sixth lens, and f123 is a combined focal length of the first lens, the second lens and the third lens. When the conditional expressions are met, the combined focal length of the fourth lens, the fifth lens and the sixth lens and the ratio of the combined focal length of the first lens, the second lens and the third lens can be reasonably configured, so that the reasonable configuration of the capability of the front lens group consisting of the first lens, the second lens and the third lens for converging light rays is facilitated, the large-angle view field light rays can be favorably emitted into the optical system, and the optical system has a wide-angle characteristic; meanwhile, the reasonable configuration of the height of the light rays emitted out of the optical system by the rear lens group consisting of the fourth lens, the fifth lens and the sixth lens is facilitated, so that the generation of high-level aberration of the optical system is inhibited, and the outer diameter of a lens in the optical system is reduced; in addition, the field curvature generated by the front lens group is favorably corrected, so that the resolving power of the optical system is improved.

2≤CT2/|SAGS3|≤4；

wherein, CT2 is the thickness of the second lens on the optical axis, SAGS3 is the distance from the maximum effective aperture of the object side surface of the second lens to the intersection point of the object side surface of the second lens and the optical axis in the optical axis direction, namely the rise of the object side surface of the second lens at the maximum effective aperture. When the condition formula is satisfied, the ratio of the center thickness of the second lens and the rise of the object side surface of the second lens at the maximum effective aperture can be reasonably configured, the condition that the manufacturing difficulty of the lens is increased due to the fact that the center thickness of the second lens is too large or the object side surface of the second lens is too bent is avoided, and therefore the forming yield of the second lens is favorably improved, and the production cost is reduced. Below the lower limit of the conditional expression, the object-side surface shape of the second lens is too curved, which increases the processing difficulty of the second lens; meanwhile, the second lens is easy to generate serious edge aberration, which is not beneficial to improving the imaging quality of the optical system. Exceeding the upper limit of the above conditional expression, the center thickness of the second lens is excessively large, which is disadvantageous for weight reduction and downsizing of the optical system.

TTL is more than or equal to 12mm and less than or equal to 14 mm. 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 system, that is, a total optical length of the optical system. When the condition formula is satisfied, the optical total length of the optical system can be reasonably configured, so that the optical system has the characteristics of compact structure and miniaturization of the optical system.

-6mm*10^-6/℃≤(CT4-CT5)*(α4-α5)≤-4mm*10^-6/℃；

wherein CT4 is the thickness of the fourth lens on the optical axis, CT5 is the thickness of the fifth lens on the optical axis, α 4 is the thermal expansion coefficient of the fourth lens at-30 ℃ -70 ℃, and α 5 is the thermal expansion coefficient of the fifth lens at-30 ℃ -70 ℃. When the conditional expressions are met, the central thickness difference and the material difference of the fourth lens can be reasonably configured, the reasonable material collocation is favorable for reducing the influence of temperature on the optical system, so that the optical system keeps good imaging quality under the high-temperature or low-temperature condition, and simultaneously, the central thickness difference and the material characteristic difference of the fourth lens and the fifth lens are favorable for reducing, thereby reducing the risk of cracking of a cemented lens formed by the fourth lens and the fifth lens, and ensuring that the optical system still has better resolving power under the high-temperature and low-temperature conditions.

0.5≤(CT3+D34)/f≤1；

wherein, CT3 is the thickness of the third lens element on the optical axis, and D34 is the distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element on the optical axis. When the upper limit of the conditional expression is satisfied, the central thickness of the third lens and the air space of the third lens and the fourth lens on the optical axis can be prevented from being too large, so that the miniaturization design of the optical system is facilitated. By meeting the lower limit of the conditional expression, the central thickness of the third lens and the air space between the third lens and the fourth lens on the optical axis are not too small, so that the aberration of the optical system can be corrected favorably, and the imaging quality of the optical system is improved.

11≤SDS5/SAGS5≤14；

wherein SDS5 is the maximum effective aperture of the object side surface of the third lens, SAGS5 is the distance from the maximum effective aperture of the object side surface of the third lens to the intersection point of the object side surface of the third lens and the optical axis in the optical axis direction, namely the rise of the object side surface of the third lens at the maximum effective aperture. By meeting the lower limit of the conditional expression, the object side surface of the third lens is prevented from being excessively bent, so that large-angle light rays can be favorably incident to the optical system, the field angle of the optical system can be favorably enlarged, the imaging quality of the optical system can be favorably improved, the processing difficulty of the third lens can be favorably reduced, and the condition that the coating film is not uniform due to the fact that the object side surface of the third lens is excessively bent can be avoided; through satisfying the upper limit of above-mentioned conditional expression, can avoid the object side face type of third lens too gentle, be favorable to reducing the risk that produces the ghost.

An image capturing module includes a photosensitive element and the optical system of any of the above embodiments, wherein the photosensitive element is disposed at an image side of the optical system. The optical system is adopted in the image capturing module, so that the image capturing module can have good imaging quality.

An electronic device comprises a shell and the image capturing module, wherein the image capturing module is arranged on the shell. Adopt above-mentioned getting for instance module in electronic equipment for electronic equipment can possess good image quality.

A carrier comprises a mounting part and the electronic equipment, wherein the electronic equipment is arranged on the mounting part. Adopt above-mentioned electronic equipment in the carrier, electronic equipment possesses good imaging quality, is favorable to the driver to clearly obtain the environment outside the cockpit to be favorable to promoting the security performance of carrier.

Drawings

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

FIG. 2 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of an optical system in a first embodiment of the present application;

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

FIG. 4 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of an optical system in a second embodiment of the present application;

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

FIG. 6 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of an optical system in 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. 8 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of an optical system in a fourth embodiment of the present application;

fig. 9 is a schematic structural diagram of an image capturing module according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of an electronic device in an embodiment of the present application;

fig. 11 is a schematic structural diagram of a carrier according to an embodiment of the present application.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

In some embodiments of the present disclosure, referring to fig. 1, the optical system 100 includes, in order from an object side to an image side along an optical axis 110, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6. Specifically, the first lens element L1 includes an object-side surface S1 and an image-side surface S2, the second lens element L2 includes an object-side surface S3 and an image-side surface S4, the third lens element L3 includes an object-side surface S5 and an image-side surface S6, the fourth lens element L4 includes an object-side surface S7 and an image-side surface S8, the fifth lens element L5 includes an object-side surface S9 and an image-side surface S10, and the sixth lens element L6 includes an object-side surface S11 and an image-side surface S12. 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 coaxially disposed, and an axis common to the lenses in the optical system 100 is an optical axis 110 of the optical system 100.

The first lens element L1 with negative refractive power is favorable for light rays with a large viewing angle to enter the optical system 100, thereby being favorable for widening the viewing angle of the optical system 100. The second lens element L2 with negative refractive power can share the negative refractive power of the first lens element L1, thereby avoiding over-strong refractive power of the single lens element, which is beneficial to reducing the sensitivity of the optical system 100 and improving the molding yield of the first lens element L1 and the second lens element L2. The third lens element L3 with positive refractive power has a convex object-side surface S5 and an convex image-side surface S6 of the third lens element L3 at a paraxial region 110, which is favorable for balancing the aberrations generated by the first lens element L1 and the second lens element L2, and is also favorable for shortening the total length of the optical system 100 and realizing a compact design. The fourth lens element L4 with negative refractive power has a concave image-side surface S8 at a paraxial region 110 of the fourth lens element L4, which is favorable for correcting aberrations generated by the lens elements at the object side of the fourth lens element L4. The image-side surface S8 of the fourth lens element L4 is concave at the paraxial region 110. The fifth lens element L5 with positive refractive power is advantageous for shortening the back focal length of the optical system 100, thereby further shortening the overall length of the optical system 100. The image-side surface S10 of the fifth lens element L5 is convex at a paraxial region 110, which is favorable for correcting astigmatism and for efficiently converging light rays onto an image plane. The sixth lens element L6 has refractive power. The image-side surface S12 of the sixth lens element L6 is concave at the paraxial region 110, which is favorable for correcting aberration and improving the imaging quality of the optical system 100. The negative refractive power of the fourth lens element L4 is matched with the positive refractive power of the fifth lens element L5 for mutual correction of aberration.

In some embodiments, the image-side surface S8 of the fourth lens element L4 is attached to the object-side surface S9 of the fifth lens element L5, for example, the fourth lens element L4 is glued to the fifth lens element L5, or the fourth lens element L4 is attached to the fifth lens element L5 through a snap-fit structure, which is beneficial to correct chromatic aberration of the optical system 100, and is further beneficial to mutually correct chromatic aberration of the fourth lens element L4 and the fifth lens element L5, thereby being beneficial to improving the imaging quality of the optical system 100.

In addition, in some embodiments, the optical system 100 is provided with a stop STO, which may be disposed between the third lens L3 and the fourth lens L4. In some embodiments, the optical system 100 further includes a filter L7 disposed on the image side of the sixth lens L6. The filter L7 may be an infrared cut filter, and is used to filter out interference light, so as to prevent the interference light from reaching the imaging plane of the optical system 100 and affecting normal imaging. The filter L7 may also be an infrared band pass filter, and the optical system 100 is also suitable for an environment such as night and for an infrared detection lens. In some embodiments, the optical system 100 is suitable for a day and night confocal lens. Of course, in other embodiments, the filter L7 may also be a combination of an infrared cut filter and a protective glass, and the protective glass is used for protecting the photosensitive element at the imaging surface. Furthermore, the optical system 100 further includes an image plane S15 located on the image side of the sixth lens L6, the image plane S15 is an imaging plane of the optical system 100, and incident light is adjusted by 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 and can be imaged on the image plane S15.

In some embodiments, the object-side surface and the image-side surface of each lens of optical system 100 are both aspheric. The adoption of the aspheric surface structure can improve the flexibility of lens design, effectively correct spherical aberration and improve imaging quality. In other embodiments, the object-side surface and the image-side surface of each lens of the optical system 100 may be spherical. It should be noted that the above embodiments are only examples of some embodiments of the present application, and in some embodiments, the surface of each lens in the optical system 100 may be an aspheric surface or any combination of spherical surfaces. Further, in some embodiments, the object-side surface and the image-side surface of the first lens element L1 and the third lens element L3 are both spherical, and the object-side surface and the image-side surface of the second lens element L2, the fourth lens element L4, the fifth lens element L5 and the sixth lens element L6 are both aspheric, so that the optical system 100 can obtain more control variables, and thus aberration can be effectively corrected without increasing the number of lenses, thereby facilitating shortening of the total length of the optical system 100.

In some embodiments, each lens in the optical system 100 may be made of glass or plastic. The lens made of plastic material can reduce the weight of the optical system 100 and the production cost, and the light and thin design of the optical system 100 can be realized by matching with the small size of the optical system 100. The glass lens provides the optical system 100 with excellent optical performance and high temperature resistance. It should be noted that the material of each lens in the optical system 100 may be any combination of glass and plastic, and is not necessarily both glass and plastic. Further, in some embodiments, the first lens element L1, the third lens element L3, and the sixth lens element L6 are made of glass, and the second lens element L2, the fourth lens element L4, and the fifth lens element L5 are made of plastic, so that the reasonable material matching is favorable for reducing the offset of the image plane in the high and low temperature environment, and the optical system 100 can have good resolving power even under the high and low temperature conditions.

It is to be noted that the first lens L1 does not mean that there is only one lens, and in some embodiments, there may be two or more lenses in the first lens L1, and the two or more lenses can form a cemented lens, and a surface of the cemented lens closest to the object side can be regarded as the object side surface S1, and a surface of the cemented lens closest to the image side can be regarded as the image side surface S2. Alternatively, although no cemented lens is formed between the lenses of the first lens L1, the distance between the lenses is relatively fixed, and in this case, the object-side surface of the lens closest to the object side is the object-side surface S1, and the image-side surface of the lens closest to the image side is the image-side surface S2. In addition, the number of lenses in the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, or the sixth lens L6 in some embodiments may also be greater than or equal to two, and a cemented lens may be formed between any two adjacent lenses, or may also be a non-cemented lens.

Further, in some embodiments, the optical system 100 satisfies the conditional expression: f45/f is more than or equal to 3.2 and less than or equal to 6.2; where f45 is the combined focal length of the fourth lens L4 and the fifth lens L5, and f is the effective focal length of the optical system 100. Specifically, f45/f may be: 3.427, 3.652, 3.951, 4.402, 4.655, 5.025, 5.831, 5.944, 5.982, or 6.013. When the above conditional expressions are satisfied, the refractive power ratio of the fourth lens element L4 and the fifth lens element L5 in the optical system 100 can be reasonably configured, which is favorable for suppressing the occurrence of astigmatism, and is favorable for correcting the edge aberration and chromatic aberration, thereby being favorable for improving the imaging quality of the optical system 100. Above the upper limit of the conditional expressions, the refractive powers of the fourth lens element L4 and the fifth lens element L5 are insufficient, which is not favorable for correcting the peripheral aberration and chromatic aberration, and is not favorable for improving the resolution performance of the optical system 100; below the lower limit of the conditional expression, the refractive powers of the fourth lens element L4 and the fifth lens element L5 are too strong, which is likely to generate severe astigmatism, and is not favorable for improving the imaging quality of the optical system 100.

In some embodiments, the optical system 100 satisfies the conditional expression: CT5-CT4 are more than or equal to 1mm and less than or equal to 1.5 mm. The thickness of the fourth lens element L4 along the optical axis 110 is CT4, and the thickness of the fifth lens element L5 along the optical axis 110 is CT 5. Specifically, CT5-CT4 may be: 1.015, 1.017, 1.020, 1.023, 1.033, 1.045, 1.057, 1.111, 1.208 or 1.286. When the above conditional expressions are satisfied, the difference between the center thicknesses of the fourth lens L4 and the fifth lens L5 can be configured reasonably, which is beneficial to reducing the risk of cracking of the cemented lens formed by the fourth lens L4 and the fifth lens L5 and also beneficial to reducing the total length of the optical system 100.

In some embodiments, the optical system 100 satisfies the conditional expression: f1 x f2/f is not less than 18mm and not more than 23 mm; where f1 is the effective focal length of the first lens L1, and f2 is the effective focal length of the second lens L2. Specifically, f1 × f2/f may be: 18.681, 18.722, 18.789, 18.809, 19.325, 21.024, 22.603, 22.617, 22.703 or 22.772, the numerical units being in mm. When the above conditional expressions are satisfied, the ratio of the product of the effective focal lengths of the first lens L1 and the second lens L2 in the optical system 100 can be reasonably configured, which is not only beneficial for the large-angle light to enter the optical system 100, thereby expanding the field angle of the optical system 100, but also beneficial for correcting astigmatism and chromatic aberration of the optical system 100, and improving the imaging quality of the optical system 100. Above the upper limit of the conditional expressions, the refractive powers of the first lens element L1 and the second lens element L2 are insufficient, which is not favorable for the incident of the light beam with large angle to the optical system 100, and is not favorable for the expansion of the field angle range of the optical system 100; below the lower limit of the conditional expression, the refractive powers of the first lens element L1 and the second lens element L2 are too strong, which is likely to generate serious astigmatism and chromatic aberration, and is not favorable for high-resolution imaging characteristics.

In some embodiments, the optical system 100 satisfies the conditional expression: f456/f123 is more than or equal to 2.5 and less than or equal to 4.5; where f456 is a combined focal length of the fourth lens L4, the fifth lens L5, and the sixth lens L6, and f123 is a combined focal length of the first lens L1, the second lens L2, and the third lens L3. Specifically, f456/f123 may be: 2.972, 3.022, 3.055, 3.111, 3.257, 3.514, 3.647, 3.810, 3.996, or 4.113. When the above conditional expressions are satisfied, the ratios of the combined focal lengths of the fourth lens L4, the fifth lens L5, and the sixth lens L6 and the combined focal lengths of the first lens L1, the second lens L2, and the third lens L3 can be reasonably configured, which is favorable for reasonably configuring the ability of the front lens group composed of the first lens L1, the second lens L2, and the third lens L3 to converge light rays, so that the light rays with a large angle field of view can be favorably incident into the optical system 100, and the optical system 100 has a wide-angle characteristic; meanwhile, the reasonable arrangement of the height of the light ray emitted from the optical system by the rear lens group consisting of the fourth lens L4, the fifth lens L5 and the sixth lens L6 is facilitated, so that the generation of high-order aberration of the optical system 100 is suppressed, and the outer diameter of the lens in the optical system 100 is reduced; in addition, the curvature of field generated by the front lens group is also favorably corrected, so that the resolving power of the optical system 100 is improved.

In some embodiments, the optical system 100 satisfies the conditional expression: 2 is less than or equal to CT2/| SAGS3| is less than or equal to 4; the CT2 is the thickness of the second lens L2 on the optical axis 110, and the SAGS3 is the distance from the maximum effective aperture of the object-side surface S3 of the second lens L2 to the intersection point of the object-side surface S1 of the second lens L2 and the optical axis 110 in the direction of the optical axis 110. Specifically, CT2/| SAGS3| may be: 2.620, 2.688, 2.725, 2.826, 3.105, 3.384, 3.504, 3.511, 3.515, or 3.519. When the conditional expressions are met, the ratio of the center thickness of the second lens L2 to the rise of the object side surface S3 of the second lens L2 at the maximum effective aperture can be reasonably configured, and the situation that the manufacturing difficulty of the lens is increased due to the fact that the center thickness of the second lens L2 is too large or the object side surface S3 is too curved is avoided, so that the forming yield of the second lens L2 is improved, and the production cost is reduced. Below the lower limit of the above conditional expression, the object-side surface S3 of the second lens L2 is excessively curved, which increases the difficulty of processing the second lens L2; meanwhile, the second lens L2 is prone to generate serious edge aberration, which is not favorable for improving the imaging quality of the optical system 100. Exceeding the upper limit of the above conditional expression makes the center thickness of the second lens L2 too large, which is disadvantageous for weight reduction and size reduction of the optical system 100.

In some embodiments, the optical system 100 satisfies the conditional expression: TTL is more than or equal to 12mm and less than or equal to 14 mm. Wherein, TTL is a distance from the object-side surface S1 of the first lens element L1 to the image plane of the optical system 100 on the optical axis 110, i.e., the total optical length of the optical system 100. Specifically, TTL may be: 12.496, 12.497, 12.499, 12.500, 12.610, 12.744, 13.028, 13.225, 13.501, or 13.690, the numerical units being mm. When the above conditional expressions are satisfied, the optical total length of the optical system 100 can be reasonably configured, which is beneficial to making the optical system 100 compact in structure and realizing the miniaturization of the optical system 100.

In some embodiments, the optical system 100 satisfies the conditional expression: -6mm 10^-6/℃≤(CT4-CT5)*(α4-α5)≤-4mm*10^-6/° c; wherein CT4 is the fourth lensThe thickness of the L4 on the optical axis 110, the CT5 is the thickness of the fifth lens L5 on the optical axis 110, the α 4 is the thermal expansion coefficient of the fourth lens L4 at-30 ℃ to 70 ℃, and the α 5 is the thermal expansion coefficient of the fifth lens L5 at-30 ℃ to 70 ℃. Specifically, (CT4-CT5) (. alpha.4-a 5) may be: -5.144, -5.001, -4.555, -4.226, -4.155, -4.101, -4.094, -4.074, -4.60 or-4.058, the numerical units being mm 10^-6V. C. When the conditional expressions are satisfied, the central thickness difference and the material difference of the fourth lens L4 can be reasonably configured, and reasonable material matching is favorable for reducing the influence of temperature on the optical system 100, so that the optical system 100 keeps good imaging quality under high-temperature or low-temperature conditions, and simultaneously, the central thickness difference and the material characteristic difference of the fourth lens L4 and the fifth lens L5 are favorable for reducing, thereby reducing the risk of cracking of the cemented lens formed by the fourth lens L4 and the fifth lens L5, and ensuring that the optical system 100 still has good resolving power under high-temperature and low-temperature conditions.

In some embodiments, the optical system 100 satisfies the conditional expression: 0.5-1 (CT3+ D34)/f; wherein, CT3 is the thickness of the third lens element L3 on the optical axis 110, and D34 is the distance between the image-side surface S6 of the third lens element L3 and the object-side surface S7 of the fourth lens element L4 on the optical axis 110. Specifically, (CT3+ D34)/f may be: 0.954, 0.956, 0.957, 0.959, 0.961, 0.963, 0.965, 0.967, 0.968, or 0.969. When the upper limit of the above conditional expression is satisfied, the center thickness of the third lens L3 and the air space between the third lens L3 and the fourth lens L4 on the optical axis 110 can be prevented from being excessively large, which is advantageous for realizing the compact design of the optical system 100. By satisfying the lower limit of the conditional expression, the central thickness of the third lens L3 and the air space between the third lens L3 and the fourth lens L4 on the optical axis 110 are not excessively small, which is beneficial to correcting the aberration of the optical system 100 and improving the imaging quality of the optical system 100.

In some embodiments, the optical system 100 satisfies the conditional expression: 11 is less than or equal to SDS5/SAGS5 is less than or equal to 14; the SDS5 is a maximum effective aperture of the object-side surface S5 of the third lens L3, and the SAGS5 is a distance from a maximum effective aperture of the object-side surface S5 of the third lens L3 to an intersection point of the object-side surface S5 of the third lens L3 and the optical axis 110 in the direction of the optical axis 110. Specifically, SDS5/SAGS5 may be: 11.236, 11.441, 11.685, 11.879, 12.102, 12.552, 12.961, 13.047, 13.411, or 13.602. By meeting the lower limit of the conditional expression, the object side surface S5 of the third lens L3 is prevented from being bent too much, so that large-angle light rays can be favorably incident on the optical system 100, the field angle of the optical system 100 can be favorably enlarged, the imaging quality of the optical system 100 can be favorably improved, the processing difficulty of the third lens L3 can be favorably reduced, and the condition that the coating film is not uniform due to the fact that the object side surface S5 of the third lens L3 is bent too much can be avoided; by satisfying the upper limit of the conditional expression, it is possible to avoid the object-side surface S5 of the third lens L3 from being too gentle, which is advantageous for reducing the risk of occurrence of ghost.

The reference wavelengths of the above effective focal length and combined focal length values are both 550 nm.

Based on the above description of the embodiments, more specific embodiments and drawings are set forth below for detailed description.

First embodiment

Referring to fig. 1 and fig. 2, fig. 1 is a schematic structural diagram of the optical system 100 in the first embodiment, and the optical system 100 includes, in order from an object side to an image side, a first lens element L1 with negative refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with positive refractive power, a stop STO, 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 negative refractive power. Fig. 2 is a graph of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the first embodiment, sequentially from left to right, wherein the reference wavelength of the astigmatism graph and the distortion graph is 550nm, and the other embodiments are the same.

The object-side surface S1 of the first lens element L1 is convex, and the image-side surface S2 is concave;

the object-side surface S3 of the second lens element L2 is concave at the paraxial region 110, and the image-side surface S4 is convex at the paraxial region 110;

the object-side surface S5 of the third lens element L3 is convex, and the image-side surface S6 is convex;

the object-side surface S7 of the fourth lens element L4 is convex at the paraxial region 110, and the image-side surface S8 is concave at the paraxial region 110;

the object-side surface S9 of the fifth lens element L5 is convex at the paraxial region 110, and the image-side surface S10 is convex at the paraxial region 110;

the object-side surface S11 of the sixth lens element L6 is convex at the paraxial region 110, and the image-side surface S12 is concave at the paraxial region 110.

The object-side and image-side surfaces of the first lens L1 and the third lens L3 are spherical, and the object-side and image-side surfaces of the second lens L2, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are aspherical.

The first lens L1, the third lens L3 and the sixth lens L6 are all made of glass, and the second lens L2, the fourth lens L4 and the fifth lens L5 are all made of plastic.

Further, the optical system 100 satisfies the conditional expression: f45/f 4.402; where f45 is the combined focal length of the fourth lens L4 and the fifth lens L5, and f is the effective focal length of the optical system 100. When the above conditional expressions are satisfied, the refractive power ratio of the fourth lens element L4 and the fifth lens element L5 in the optical system 100 can be reasonably configured, which is favorable for suppressing the occurrence of astigmatism, and is favorable for correcting the edge aberration and chromatic aberration, thereby being favorable for improving the imaging quality of the optical system 100.

The optical system 100 satisfies the conditional expression: CT5-CT4 is 1.286 mm. The thickness of the fourth lens element L4 along the optical axis 110 is CT4, and the thickness of the fifth lens element L5 along the optical axis 110 is CT 5. When the above conditional expressions are satisfied, the difference between the center thicknesses of the fourth lens L4 and the fifth lens L5 can be configured reasonably, which is beneficial to reducing the risk of cracking of the cemented lens formed by the fourth lens L4 and the fifth lens L5 and also beneficial to reducing the total length of the optical system 100.

The optical system 100 satisfies the conditional expression: f1 × f2/f 18.681 mm; where f1 is the effective focal length of the first lens L1, and f2 is the effective focal length of the second lens L2. When the above conditional expressions are satisfied, the ratio of the product of the effective focal lengths of the first lens L1 and the second lens L2 in the optical system 100 can be reasonably configured, which is not only beneficial for the large-angle light to enter the optical system 100, thereby expanding the field angle of the optical system 100, but also beneficial for correcting astigmatism and chromatic aberration of the optical system 100, and improving the imaging quality of the optical system 100.

The optical system 100 satisfies the conditional expression: f456/f 123-3.111; where f456 is a combined focal length of the fourth lens L4, the fifth lens L5, and the sixth lens L6, and f123 is a combined focal length of the first lens L1, the second lens L2, and the third lens L3. When the above conditional expressions are satisfied, the ratios of the combined focal lengths of the fourth lens L4, the fifth lens L5, and the sixth lens L6 and the combined focal lengths of the first lens L1, the second lens L2, and the third lens L3 can be reasonably configured, which is favorable for reasonably configuring the ability of the front lens group composed of the first lens L1, the second lens L2, and the third lens L3 to converge light rays, so that the light rays with a large angle field of view can be favorably incident into the optical system 100, and the optical system 100 has a wide-angle characteristic; meanwhile, the reasonable arrangement of the height of the light ray emitted from the optical system 100 by the rear lens group consisting of the fourth lens L4, the fifth lens L5 and the sixth lens L6 is facilitated, so that the generation of high-order aberration of the optical system 100 is suppressed, and the outer diameter of the lens in the optical system 100 is reduced; in addition, the curvature of field generated by the front lens group is also favorably corrected, so that the resolving power of the optical system 100 is improved.

The optical system 100 satisfies the conditional expression: CT2/| SAGS3| ═ 2.826; the CT2 is the thickness of the second lens L2 on the optical axis 110, and the SAGS3 is the distance from the maximum effective aperture of the object-side surface S3 of the second lens L2 to the intersection point of the object-side surface S1 of the second lens L2 and the optical axis 110 in the direction of the optical axis 110. When the conditional expressions are met, the ratio of the center thickness of the second lens L2 to the rise of the object side surface S3 of the second lens L2 at the maximum effective aperture can be reasonably configured, and the situation that the manufacturing difficulty of the lens is increased due to the fact that the center thickness of the second lens L2 is too large or the object side surface S3 is too curved is avoided, so that the forming yield of the second lens L2 is improved, and the production cost is reduced.

The optical system 100 satisfies the conditional expression: TTL is 12.500 mm. Wherein, TTL is a distance from the object-side surface S1 of the first lens element L1 to the image plane of the optical system 100 on the optical axis 110, i.e., the total optical length of the optical system 100. When the above conditional expressions are satisfied, the optical total length of the optical system 100 can be reasonably configured, which is beneficial to making the optical system 100 compact in structure and realizing the miniaturization of the optical system 100.

The optical system 100 satisfies the conditional expression: (CT4-CT5) (. alpha.4-. alpha.5) — 5.144mm 10^-6/℃；Wherein CT4 is the thickness of the fourth lens L4 on the optical axis 110, CT5 is the thickness of the fifth lens L5 on the optical axis 110, α 4 is the thermal expansion coefficient of the fourth lens L4 at-30 ℃ to 70 ℃, and α 5 is the thermal expansion coefficient of the fifth lens L5 at-30 ℃ to 70 ℃. When the conditional expressions are satisfied, the central thickness difference and the material difference of the fourth lens L4 can be reasonably configured, and reasonable material matching is favorable for reducing the influence of temperature on the optical system 100, so that the optical system 100 keeps good imaging quality under high-temperature or low-temperature conditions, and simultaneously, the central thickness difference and the material characteristic difference of the fourth lens L4 and the fifth lens L5 are favorable for reducing, thereby reducing the risk of cracking of the cemented lens formed by the fourth lens L4 and the fifth lens L5, and ensuring that the optical system 100 still has good resolving power under high-temperature and low-temperature conditions.

The optical system 100 satisfies the conditional expression: (CT3+ D34)/f ═ 0.954; wherein, CT3 is the thickness of the third lens element L3 on the optical axis 110, and D34 is the distance between the image-side surface S6 of the third lens element L3 and the object-side surface S7 of the fourth lens element L4 on the optical axis 110. When the above conditional expressions are satisfied, the center thickness of the third lens L3 and the air space between the third lens L3 and the fourth lens L4 on the optical axis 110 can be prevented from being too large, which is favorable for realizing the miniaturization design of the optical system 100; meanwhile, the central thickness of the third lens L3 and the air space between the third lens L3 and the fourth lens L4 on the optical axis 110 are not too small, which is beneficial to correcting the aberration of the optical system 100 and improving the imaging quality of the optical system 100.

The optical system 100 satisfies the conditional expression: SDS5/SAGS5 ═ 11.236; the SDS5 is a maximum effective aperture of the object-side surface S5 of the third lens L3, and the SAGS5 is a distance from a maximum effective aperture of the object-side surface S5 of the third lens L3 to an intersection point of the object-side surface S5 of the third lens L3 and the optical axis 110 in the direction of the optical axis 110. When the condition formula is satisfied, the object side surface S5 of the third lens L3 can be prevented from being excessively bent, so that large-angle light rays can be favorably incident on the optical system 100, the field angle of the optical system 100 can be favorably enlarged, the imaging quality of the optical system 100 can be favorably improved, the processing difficulty of the third lens L3 can be favorably reduced, and the condition that the plating film is not uniform due to the excessively bent object side surface S5 of the third lens L3 can be avoided; in addition, the object-side surface S5 of the third lens L3 can be prevented from being too gentle, which is advantageous for reducing the risk of generating ghost images.

In addition, the parameters of the optical system 100 are given in table 1. Among them, the image plane S15 in table 1 may be understood as an imaging plane of the optical system 100. The elements from the object plane (not shown) to the image plane S15 are sequentially arranged in the order of the elements from top to bottom in table 1. The Y radius in table 1 is the radius of curvature of the object-side or image-side surface at the optical axis 110 for the corresponding surface number. Surface numbers S1 and S2 denote an object-side surface S1 and an image-side surface S2 of the first lens L1, respectively, that is, in the same lens, a surface with a smaller surface number is an object-side surface, and a surface with a larger surface number is an image-side surface. The first numerical value in the "thickness" parameter column of the first lens element L1 is the thickness of the lens element along the optical axis 110, and the second numerical value is the distance between the image-side surface and the rear surface of the lens element along the image-side direction along the optical axis 110.

Note that, in this embodiment and the following embodiments, the optical system 100 may not be provided with the filter L7, but the distance from the image-side surface S12 of the sixth lens L6 to the image surface S15 is kept constant at this time.

In the first embodiment, the effective focal length f of the optical system 100 is 2.49mm, the f-number FNO is 2.1, and the maximum field angle FOV is 180 °. In the first embodiment and other embodiments, the maximum field angle of the optical system 100 satisfies 180 ° < FOV > 184 °, and it can be seen that the optical system 100 has a wide-angle characteristic, and can acquire a scene with a sufficiently large object space range, thereby facilitating a driver to grasp more environmental information and improving driving safety when the optical system 100 is applied to a vehicle-mounted device.

It should be noted that in some embodiments, the optical system 100 may match a photosensitive element having a rectangular photosensitive surface, and the imaging surface of the optical system 100 coincides with the photosensitive surface of the photosensitive element. At this time, the effective pixel area on the imaging plane of the optical system 100 has a horizontal direction and a diagonal direction, and the maximum field angle FOV can be understood as the maximum field angle in the diagonal direction of the optical system 100.

The reference wavelength of the focal length of each lens was 550nm, and the reference wavelengths of the refractive index and the abbe number were 587.56nm (d-wavelength), and the same applies to other examples.

TABLE 1

Further, aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are given by table 2. The surface numbers S3 and S4 respectively indicate object side surfaces S3 and S4 of the second lens L2, the surface number S7 indicates object side surface S7 of the fourth lens L4, and the surface numbers S9 to S12 respectively indicate image side surfaces or object side surfaces S9 to S12. And K-a20 from top to bottom respectively indicate the types of aspheric coefficients, where K indicates a conic coefficient, a4 indicates a quartic aspheric coefficient, a6 indicates a sextic aspheric coefficient, A8 indicates an octal aspheric coefficient, and so on. In addition, the aspherical surface coefficient formula is as follows:

where Z is the distance from the corresponding point on the aspheric surface to the plane tangent to the surface vertex, r is the distance from the corresponding point on the aspheric surface to the optical axis 110, c is the curvature of the aspheric surface vertex, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th high order term in the aspheric surface profile formula.

TABLE 2

In addition, fig. 2 includes a Longitudinal Spherical Aberration diagram (Longitudinal Spherical Aberration) of the optical system 100, which shows the deviation of the converging focal points of the light rays of different wavelengths after passing through the lens. The ordinate of the longitudinal spherical aberration diagram represents the Normalized Pupil coordinate (Normalized Pupil Coordinator) from the Pupil center to the Pupil edge, and the abscissa represents the distance (in mm) of the imaging plane from the intersection of the ray with the optical axis 110. It can be known from the longitudinal spherical aberration diagram that the convergent focus deviation degrees of the light rays with different wavelengths in the first embodiment tend to be consistent, and the diffuse speckle or the chromatic halo in the imaging picture is effectively suppressed. FIG. 2 also includes an astigmatic field curvature diagram (ASTIGMATIC FIELD CURVES) of the optical system 100, in which the S curve represents sagittal field curvature at 550nm and the T curve represents meridional field curvature at 550 nm. As can be seen from the figure, the curvature of field of the optical system 100 is small, the curvature of field and astigmatism of each field are well corrected, and the center and the edge of the field have clear images. Fig. 2 also includes a DISTORTION map (distorsion) of the optical system 100, and it can be seen that the image DISTORTION caused by the main beam is small and the imaging quality of the system is excellent.

Second embodiment

Referring to fig. 3 and 4, fig. 3 is a schematic structural diagram of the optical system 100 in the second embodiment, in which the optical system 100 includes, in order from an object side to an image side, a first lens element L1 with negative refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with positive refractive power, a stop STO, 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. Fig. 4 is a graph of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the second embodiment, which is shown from left to right.

In addition, the parameters of the optical system 100 are given in table 3, and the definitions of the parameters can be obtained from the first embodiment, which is not described herein.

TABLE 3

Further, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are shown in table 4, and the definitions of the parameters can be obtained from the first embodiment, which is not repeated herein.

TABLE 4

According to the provided parameter information, the following data can be deduced:

f45/f	6.013	TTL(mm)	12.496
				CT5-CT4(mm)	1.015	(CT4-CT5)(α4-α5)(mm10-6/℃)	-4.058
f1*f2/f(mm)	22.603	(CT3+D34)/f	0.969
				f456/f123	3.647	SDS5/SAGS5	13.602
CT2/\|SAGS3\|	3.519

in addition, as can be seen from the aberration diagram in fig. 4, the longitudinal spherical aberration, astigmatism and distortion of the optical system 100 are well controlled, so that the optical system 100 of this embodiment has good imaging quality.

Third embodiment

Referring to fig. 5 and 6, fig. 5 is a schematic structural diagram of the optical system 100 in the third embodiment, in which the optical system 100 includes, in order from an object side to an image side, a first lens element L1 with negative refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with positive refractive power, a stop STO, 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 negative refractive power. Fig. 6 is a graph of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the third embodiment, from left to right.

In addition, the parameters of the optical system 100 are given in table 5, and the definitions of the parameters can be obtained from the first embodiment, which is not described herein again.

TABLE 5

Further, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are shown in table 6, and the definitions of the parameters can be obtained from the first embodiment, which is not repeated herein.

TABLE 6

Number of noodles	S3	S4	S7	S9
					K	1.190E+00	-4.334E+00	0.000E+00	-2.085E-01
A4	2.181E-02	8.833E-03	4.872E-04	9.379E-03
					A6	5.268E-04	6.517E-03	1.183E-03	-2.809E-04
A8	7.828E-04	-2.643E-04	-3.876E-03	-4.456E-06
					A10	-5.675E-05	5.296E-04	9.772E-04	5.522E-04
A12	4.865E-05	-2.094E-05	0.000E+00	0.000E+00
					A14	0.000E+00	0.000E+00	0.000E+00	0.000E+00
A16	0.000E+00	0.000E+00	0.000E+00	0.000E+00
					A18	0.000E+00	0.000E+00	0.000E+00	0.000E+00
A20	0.000E+00	0.000E+00	0.000E+00	0.000E+00
					Number of noodles	S10	S11	S12
K	-2.085E-01	0.000E+00	-4.708E+00
					A4	8.894E-03	-6.943E-02	-5.993E-02
A6	-2.809E-04	5.372E-03	7.326E-03
					A8	-4.456E-05	-7.642E-03	-7.774E-03
A10	5.552E-04	9.671E-04	2.589E-04
					A12	0.000E+00	-2.539E-05	-4.383E-06
A14	0.000E+00	0.000E+00	0.000E+00
					A16	0.000E+00	0.000E+00	0.000E+00
A18	0.000E+00	0.000E+00	0.000E+00
					A20	0.000E+00	0.000E+00	0.000E+00

And, according to the above provided parameter information, the following data can be derived:

f45/f	3.427	TTL(mm)	13.690
				CT5-CT4(mm)	1.057	(CT4-CT5)(α4-α5)(mm10-6/℃)	-4.226
f1*f2/f(mm)	18.809	(CT3+D34)/f	0.965
				f456/f123	2.972	SDS5/SAGS5	11.879
CT2/\|SAGS3\|	2.620

in addition, as can be seen from the aberration diagram in fig. 6, the longitudinal spherical aberration, astigmatism and distortion of the optical system 100 are well controlled, so that the optical system 100 of this embodiment has good imaging quality.

Fourth embodiment

Referring to fig. 7 and 8, fig. 7 is a schematic structural diagram of the optical system 100 in the fourth embodiment, in which the optical system 100 includes, in order from an object side to an image side, a first lens element L1 with negative refractive power, a second lens element L2 with negative refractive power, a third lens element L3 with positive refractive power, a stop STO, 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 negative refractive power. Fig. 8 is a graph of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the fourth embodiment, which is shown from left to right.

In addition, the parameters of the optical system 100 are given in table 7, and the definitions of the parameters can be obtained from the first embodiment, which is not described herein.

TABLE 7

Further, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are shown in table 8, and the definitions of the parameters can be obtained from the first embodiment, which is not repeated herein.

TABLE 8

f45/f	5.831	TTL(mm)	12.500
				CT5-CT4(mm)	1.023	(CT4-CT5)(α4-α5)(mm10-6/℃)	-4.094
f1*f2/f(mm)	22.772	(CT3+D34)/f	0.969
				f456/f123	4.113	SDS5/SAGS5	12.961
CT2/\|SAGS3\|	3.504

in addition, as can be seen from the aberration diagram in fig. 8, the longitudinal spherical aberration, astigmatism, and distortion of the optical system 100 are well controlled, so that the optical system 100 of this embodiment has good imaging quality.

Referring to fig. 9, in some embodiments, the optical system 100 may be assembled with the photosensitive element 210 to form the image capturing module 200. At this time, the light-sensing surface of the light-sensing element 210 may be regarded as the image surface S15 of the optical system 100. The image capturing module 200 may further include a filter L7, wherein the filter L7 is disposed between the image side surface S12 and the image surface S15 of the sixth lens element L6. Specifically, the photosensitive element 210 may be a Charge Coupled Device (CCD) or a Complementary Metal-Oxide Semiconductor (CMOS) Device. The optical system 100 is adopted in the image capturing module 200, so that the image capturing module 200 can have good imaging quality, and meanwhile, the image capturing module 200 also has wide-angle characteristics and can meet the requirement of miniaturization design.

Referring to fig. 9 and 10, in some embodiments, the image capturing module 200 may be applied to an electronic device 300, the electronic device includes a housing 310, and the image capturing module 200 is disposed in the housing 310. Specifically, the electronic apparatus 300 may be, but is not limited to, a wearable device such as a mobile phone, a video phone, a smart phone, an electronic book reader, a vehicle-mounted image capturing apparatus such as a car recorder, or a smart watch. When the electronic device 300 is a smartphone, the housing 310 may be a middle frame of the electronic device 300. Of course, in some embodiments, the electronic device 300 may also be an onboard camera device, an aircraft camera device, a surveillance camera device, or the like.

For example, in one embodiment, the electronic device 300 is an unmanned aerial vehicle camera device, and the image capturing module 200 is disposed in a housing 310 of the unmanned aerial vehicle camera device. Electronic equipment 300 can rotate relative to the unmanned aerial vehicle casing to the angle is shot in the adjustment. The electronic device 300 may be electrically connected to a control circuit in the unmanned aerial vehicle, and may transmit the obtained image information to the user in real time in a wireless signal transmission manner.

Adopt above-mentioned module 200 of getting for instance in electronic equipment 300 for electronic equipment 300 can possess good imaging quality, also can possess wide angle characteristic simultaneously and can satisfy the demand of miniaturized design, can clearly acquire the environment scene on a large scale when being applied to in-vehicle equipment, is favorable to the driver to master environmental change, promotes driving safety performance.

Referring to fig. 11, some embodiments of the present application further provide a carrier 400. The carrier 400 includes a mounting member 410 and the electronic apparatus 300, and the electronic apparatus 300 is disposed on the mounting member 410. The carrier can be a land running carrier such as an automobile and a train, a flying carrier such as an unmanned aerial vehicle, or other common carriers capable of carrying people or objects. When the vehicle 400 is an automobile, the mount 410 for setting the electronic apparatus 300 may be an air intake grill, a rear trunk, a rear view mirror, or the like. By adopting the electronic device 30, the shooting function of the carrier 40 is improved, which not only can increase the shooting range, but also can have clear images, thereby being beneficial to improving the driving safety performance.

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

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

Claims

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

a first lens element with negative refractive power;

a second lens element with negative refractive power;

and the optical system satisfies the following conditional expression:

3.2≤f45/f≤6.2；

2. The optical system according to claim 1, wherein the following conditional expression is satisfied:

18mm≤f1*f2/f≤23mm；

wherein f1 is the effective focal length of the first lens, and f2 is the effective focal length of the second lens.

3. The optical system according to claim 1, wherein the following conditional expression is satisfied:

2.5≤f456/f123≤4.5；

wherein f456 is a combined focal length of the fourth lens, the fifth lens and the sixth lens, and f123 is a combined focal length of the first lens, the second lens and the third lens.

4. The optical system according to claim 1, wherein the following conditional expression is satisfied:

2≤CT2/|SAGS3|≤4；

wherein, CT2 is the thickness of the second lens on the optical axis, and SAGS3 is the distance from the maximum effective aperture of the object-side surface of the second lens to the intersection point of the object-side surface of the second lens and the optical axis on the optical axis.

5. The optical system according to claim 1, wherein the following conditional expression is satisfied:

-6mm*10^-6/℃≤(CT4-CT5)*(α4-α5)≤-4mm*10^-6/℃；

wherein CT4 is the thickness of the fourth lens on the optical axis, CT5 is the thickness of the fifth lens on the optical axis, α 4 is the thermal expansion coefficient of the fourth lens at-30 ℃ -70 ℃, and α 5 is the thermal expansion coefficient of the fifth lens at-30 ℃ -70 ℃.

6. The optical system according to claim 1, wherein the following conditional expression is satisfied:

0.5≤(CT3+D34)/f≤1；

wherein, CT3 is the thickness of the third lens element on the optical axis, and D34 is the distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element on the optical axis.

7. The optical system according to claim 1, wherein the following conditional expression is satisfied:

11≤SDS5/SAGS5≤14；

the SDS5 is the maximum effective aperture of the object side surface of the third lens, and the SAGS5 is the distance from the maximum effective aperture of the object side surface of the third lens to the intersection point of the object side surface of the third lens and the optical axis in the optical axis direction.

8. An image capturing module, comprising a photosensitive element and the optical system of any one of claims 1 to 7, wherein the photosensitive element is disposed on an image side of the optical system.

9. An electronic device, comprising a housing and the image capturing module of claim 8, wherein the image capturing module is disposed on the housing.

10. A vehicle comprising a mounting member and the electronic device of claim 9, wherein the electronic device is disposed on the mounting member.