Optical systems, imaging modules and electronic equipment

Abstract

The present invention relates to an optical system, an imaging module and an electronic device. The optical system includes, from the object side to the image side, a first lens with positive refractive power, the object side surface is convex at the paraxial position; a second lens with negative refractive power, the image side surface is concave at the paraxial position; a third lens, a fourth lens and a fifth lens with refractive power; a sixth lens with positive refractive power, the object side surface is convex at the paraxial position; a seventh lens with negative refractive power, the object side surface is concave at the paraxial position, and the image side surface is concave at the paraxial position; the optical system satisfies the conditional formula: SD2 / SD1>0.5; SD1 is the maximum value of the vertical distance from the intersection of the light corresponding to the central field of view and the image side surface of the seventh lens to the optical axis, and SD2 is the difference between the maximum value and the minimum value of the vertical distance from the intersection of the light corresponding to the maximum field of view and the image side surface of the seventh lens to the optical axis. The above optical system has a high illumination of the edge field of view and can have excellent imaging quality even in a dark environment.

Description

Technical Field

[0001] The present invention relates to the field of photography, and in particular to an optical system, an imaging module and electronic equipment. Background Art

[0002] With the development of camera technology, people have higher and higher requirements for the imaging quality of camera equipment. In camera equipment, the amount of light entering the optical system is also one of the factors affecting the imaging quality of the camera equipment. When the amount of light entering the optical system is large, that is, the edge field of view of the optical system has sufficient illumination, the camera equipment can have excellent imaging quality even in dark environments.

[0003] However, in the process of implementing the present application, the inventors discovered that there are at least the following problems in the traditional optical system: the illumination of the edge field of view of the optical system is usually insufficient, which makes the image formed by the optical system in a dark environment insufficiently bright and the image blurred, affecting the imaging quality of the optical system in a dark environment. Summary of the invention

[0004] Based on this, it is necessary to provide an optical system, an imaging module and an electronic device to address the problem that the traditional optical system has insufficient illumination at the edge of the field of view, which affects the imaging quality of the optical system in a dark environment.

[0005] An optical system, comprising, from the object side to the image side, the following:

[0006] A first lens having positive refractive power, wherein the object side surface of the first lens is convex at the paraxial position;

[0007] A second lens having negative refractive power, wherein the image side surface of the second lens is concave at the paraxial position;

[0008] a third lens having refractive power;

[0009] a fourth lens having a refractive power;

[0010] a fifth lens having refractive power;

[0011] a sixth lens having positive refractive power, wherein the object side surface of the sixth lens is convex at the paraxial position;

[0012] a seventh lens element having negative refractive power, wherein the object side surface of the seventh lens element is concave at the paraxial position, and the image side surface of the seventh lens element is concave at the paraxial position;

[0013] And the optical system satisfies the following conditional formula:

[0014] SD2 / SD1>0.5;

[0015] Among them, SD1 is the maximum value of the vertical distance from the intersection of the light corresponding to the central field of view and the image side surface of the seventh lens to the optical axis, and SD2 is the difference between the maximum and minimum values ​​of the vertical distance from the intersection of the light corresponding to the maximum field of view and the image side surface of the seventh lens to the optical axis.

[0016] In the above optical system, the first lens has positive refractive power, which helps to shorten the total length of the optical system, and the object side of the first lens is convex at the paraxial position, which can further enhance the positive refractive power of the first lens, making the size of the optical system in the optical axis direction shorter, further meeting the needs of miniaturization design. In addition, when the above conditional expression is met, the seventh lens can be reasonably configured to improve the peripheral field illumination of the optical system, so that the optical system can also have excellent imaging quality in a dark environment.

[0017] In one embodiment, the optical system satisfies the following condition:

[0018] TTL / ImgH<1.5;

[0019] Wherein, TTL is the distance from the object side of the first lens to the imaging surface of the optical system on the optical axis, and ImgH is half of the diagonal length of the effective pixel area of ​​the optical system on the imaging surface. When the above conditional formula is met, the values ​​of TTL and ImgH can be reasonably configured to shorten the total length of the optical system when the imaging surface is fixed, thereby realizing a miniaturized design.

[0020] In one embodiment, the optical system satisfies the following condition:

[0021] TTL / f<1.4;

[0022] Wherein, TTL is the distance from the object side of the first lens to the imaging surface of the optical system on the optical axis, that is, the total length of the optical system, and f is the total effective focal length of the optical system. When the above conditional formula is met, the total length of the optical system can be shortened when the total effective focal length of the optical system is fixed, so as to achieve a miniaturized design.

[0023] In one embodiment, the optical system satisfies the following condition:

[0024] 0.5<f / R14<3;

[0025] Wherein, f is the total effective focal length of the optical system, and R14 is the radius of curvature of the image side surface of the seventh lens at the optical axis. When the above conditional formula is met, the values ​​of f and R14 can be reasonably configured to reduce the incident angle of the main light incident on the imaging surface of the optical system, so that the optical system can be better matched with different photosensitive elements.

[0026] In one embodiment, the optical system satisfies the following condition:

[0027] -2<f 16 / f7<-0.5;

[0028] Among them, f 16 is the combined focal length of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens, and f7 is the effective focal length of the seventh lens. When the above conditional formula is met, the refractive power of the optical system can be reasonably allocated to better correct the chromatic aberration of the optical system and improve the imaging quality of the optical system.

[0029] In one embodiment, the optical system satisfies the following condition:

[0030] FNO<2;

[0031] Wherein, FNO is the aperture number of the optical system. When the above conditional formula is satisfied, while maintaining the miniaturized design of the optical system, the optical system can also have a larger aperture to increase the light intensity on the imaging surface of the optical system, thereby enabling the optical system to have excellent imaging quality even in a dark environment.

[0032] In one embodiment, the optical system satisfies the following condition:

[0033] f1 / f2<-0.2;

[0034] Wherein, f1 is the effective focal length of the first lens, and f2 is the effective focal length of the second lens. When the above conditional formula is met, the effective focal lengths of the first lens and the second lens can be reasonably configured to effectively balance the chromatic aberration of the optical system, reduce the performance sensitivity of the optical system, and make the performance of the optical system more stable.

[0035] In one embodiment, the optical system satisfies the following condition:

[0036] 1<T57 / (CT56+CT67)<4;

[0037] Wherein, T57 is the distance from the object side of the fifth lens to the image side of the seventh lens on the optical axis, CT56 is the air gap between the fifth lens and the sixth lens on the optical axis, and CT67 is the air gap between the sixth lens and the seventh lens on the optical axis. When T57 / (CT56+CT67)>4, the arrangement between adjacent lenses in the fifth lens, the sixth lens and the seventh lens is too close, and adjacent lenses are prone to collide with each other during the assembly process, increasing the difficulty of assembly. When the above conditional formula is met, the relative positions of the fifth lens, the sixth lens and the seventh lens can be reasonably configured to effectively shorten the total length of the optical system and achieve a miniaturized design. In addition, it is also possible to leave enough space between the fifth lens, the sixth lens and the seventh lens during assembly to avoid the situation where adjacent lenses collide with each other during the assembly process, reduce the difficulty of assembly, and improve the production yield.

[0038] An imaging module comprises a photosensitive element and the optical system described in any one of the above embodiments, wherein the photosensitive element is arranged on the image side of the optical system. The above optical system is adopted in the imaging module, and since the optical system is short in the optical axis direction and the peripheral field illumination of the optical system is high, the imaging module can be miniaturized and has excellent imaging quality even in a dark environment.

[0039] An electronic device comprises a housing and the above-mentioned imaging module, wherein the imaging module is installed in the housing. The use of the above-mentioned imaging module in the electronic device is conducive to miniaturization of the electronic device, and the electronic device can also have excellent imaging quality in a dark environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a schematic structural diagram of an optical system in the first embodiment of the present application;

[0041] Figure 2 A longitudinal spherical aberration curve diagram, an astigmatism curve diagram and a distortion curve diagram of the optical system in the first embodiment of the present application;

[0042] Figure 3 is a schematic structural diagram of an optical system in a second embodiment of the present application;

[0043] Figure 4 A longitudinal spherical aberration curve diagram, an astigmatism curve diagram and a distortion curve diagram of the optical system in the second embodiment of the present application;

[0044] Figure 5 is a schematic structural diagram of an optical system in a third embodiment of the present application;

[0045] Figure 6A longitudinal spherical aberration curve diagram, an astigmatism curve diagram and a distortion curve diagram of the optical system in the third embodiment of the present application;

[0046] Figure 7 is a schematic structural diagram of an optical system in a fourth embodiment of the present application;

[0047] Figure 8 A longitudinal spherical aberration curve diagram, an astigmatism curve diagram and a distortion curve diagram of the optical system in the fourth embodiment of the present application;

[0048] Fig. 9 is a schematic structural diagram of an optical system in a fifth embodiment of the present application;

[0049] Fig.10 A longitudinal spherical aberration curve diagram, an astigmatism curve diagram and a distortion curve diagram of the optical system in the fifth embodiment of the present application;

[0050] Fig.11 is a schematic structural diagram of an optical system in a sixth embodiment of the present application;

[0051] Fig.12 A longitudinal spherical aberration curve diagram, an astigmatism curve diagram and a distortion curve diagram of the optical system in the sixth embodiment of the present application;

[0052] Fig.13 is a schematic structural diagram of an optical system in a seventh embodiment of the present application;

[0053] Fig.14 A longitudinal spherical aberration curve diagram, an astigmatism curve diagram and a distortion curve diagram of the optical system in the seventh embodiment of the present application;

[0054] Fig.15 is a structural schematic diagram of an imaging module in an embodiment of the present application;

[0055] Fig.16 It is a schematic diagram of the structure of an electronic device in one embodiment of the present application. DETAILED DESCRIPTION

[0056] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0057] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0058] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0059] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0061] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0062] See also Figure 1 In some embodiments of the present application, the optical system 100 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 seventh lens L7 in order from the object side to the image side along the optical axis 110. Specifically, the first lens L1 includes an object-side surface S1 and an image-side surface S2, the second lens L2 includes an object-side surface S3 and an image-side surface S4, the third lens L3 includes an object-side surface S5 and an image-side surface S6, the fourth lens L4 includes an object-side surface S7 and an image-side surface S8, the fifth lens L5 includes an object-side surface S9 and an image-side surface S10, the sixth lens L6 includes an object-side surface S11 and an image-side surface S12, and the seventh lens L7 includes an object-side surface S13 and an image-side surface S14.

[0063] Among them, the first lens L1 has a positive refractive power, which helps to shorten the total length of the optical system 100, and the object side surface S1 of the first lens L1 is a convex surface at the paraxial position, which can further strengthen the positive refractive power of the first lens L1, so that the size of the optical system 100 in the direction of the optical axis 110 becomes shorter, which is conducive to the miniaturization design of the optical system 100. The second lens L2 has a negative refractive power, and the image side surface S4 of the second lens L2 is a concave surface at the paraxial position. The third lens L3, the fourth lens L4 and the fifth lens L5 all have refractive power. The sixth lens L6 has a positive refractive power, and the object side surface of the sixth lens L6 is a convex surface at the paraxial position. The seventh lens L7 has a negative refractive power, and the object side surface S13 of the seventh lens L7 is a concave surface at the paraxial position, and the image side surface S14 is a concave surface at the paraxial position.

[0064] In addition, in some embodiments, the optical system 100 is provided with an aperture STO, which can be provided on the object side of the first lens L1. In some embodiments, the optical system 100 further includes an infrared filter L8 provided on the image side of the seventh lens L7, and the infrared filter L8 includes an object side surface S15 and an image side surface S16. Further, the optical system 100 further includes an image plane S17 located on the image side of the seventh lens L7, and the incident light can be imaged on the image plane S17 after being adjusted by 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 seventh lens L7. It is worth noting that the infrared filter L8 can be an infrared cut-off filter, which is used to filter out interference light and prevent the interference light from reaching the image plane S17 of the optical system 100 and affecting normal imaging.

[0065] In some embodiments, the object side and image side of each lens of the optical system 100 are both aspherical. The use of aspherical structures can improve the flexibility of lens design, effectively correct spherical aberration, and improve imaging quality. In other embodiments, the object side and image side of each lens of the optical system 100 can also be spherical. It should be noted that the above embodiments are only examples of some embodiments of the present application. In some embodiments, the surface of each lens in the optical system 100 can be any combination of aspherical or spherical surfaces.

[0066] In some embodiments, the material of each lens in the optical system 100 can be glass or plastic. The use of plastic lenses can reduce the weight of the optical system 100 and reduce the production cost, and can achieve a lightweight and compact design of the optical system in conjunction with the smaller size of the optical system. The use of glass lenses enables the optical system 100 to have excellent optical performance and high temperature resistance. It should be noted that the material of each lens in the optical system 100 can also be any combination of glass and plastic, and does not necessarily have to be glass or plastic.

[0067] It should be noted that the first lens L1 does not mean that there is only one lens. In some embodiments, there may be two or more lenses in the first lens L1. The two or more lenses can form a cemented lens. The surface of the cemented lens closest to the object side can be regarded as the object side surface S1, and the surface closest to the image side can be regarded as the image side surface S2. Alternatively, the lenses in the first lens L1 do not form a cemented lens, but the distances between the lenses are relatively fixed. 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, in some embodiments, the number of lenses in the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 can also be greater than or equal to two, and any adjacent lenses can form a cemented lens or a non-cemented lens.

[0068] Further, in some embodiments, the optical system 100 satisfies the conditional formula: SD2 / SD1>0.5; wherein SD1 is the maximum value of the vertical distance from the intersection of the light corresponding to the central field of view and the image side surface S14 of the seventh lens L7 to the optical axis 110, and SD2 is the difference between the maximum value and the minimum value of the vertical distance from the intersection of the light corresponding to the maximum field of view and the image side surface S14 of the seventh lens L7 to the optical axis 110. Specifically, SD2 / SD1 can be: 0.68, 0.69, 0.71, 0.72, 0.74, 0.75, 0.76, 0.77, 0.78 or 0.79. When the above conditional formula is met, the seventh lens L7 can be reasonably configured to improve the illumination of the edge field of view of the optical system 100, so that the optical system 100 can have excellent imaging quality even in a dark environment.

[0069] In some embodiments, the optical system 100 satisfies the conditional formula: TTL / ImgH<1.5; wherein TTL is the distance from the object side surface S1 of the first lens L1 to the imaging surface of the optical system 100 on the optical axis 110, that is, the total length of the optical system 100, and ImgH is half of the diagonal length of the effective pixel area of ​​the optical system 100 on the imaging surface. Specifically, TTL / ImgH can be: 1.386, 1.387, 1.388, 1.389, 1.390, 1.391 or 1.392. When the above conditional formula is met, the values ​​of TTL and ImgH can be reasonably configured to shorten the total length of the optical system 100 when the imaging surface is fixed, thereby achieving a miniaturized design.

[0070] In some embodiments, the optical system 100 satisfies the conditional formula: TTL / f<1.4; wherein TTL is the distance from the object-side surface S1 of the first lens L1 to the imaging surface of the optical system 100 on the optical axis 110, and f is the total effective focal length of the optical system 100. Specifically, TTL / f may be: 1.18, 1.19, 1.20 or 1.21. When the above conditional formula is satisfied, when the total effective focal length of the optical system 100 is fixed, the total length of the optical system 100 can be shortened to achieve a miniaturized design.

[0071] In some embodiments, the optical system 100 satisfies the conditional formula: 0.5<f / R14<3; wherein f is the total effective focal length of the optical system 100, and R14 is the radius of curvature of the image side surface S14 of the seventh lens L7 at the optical axis 110. Specifically, f / R14 can be: 1.53, 1.55, 1.56, 1.57, 1.58, 1.59, 1.61, 1.62, 1.63, 1.64 or 1.65. When the above conditional formula is met, the values ​​of f and R14 can be reasonably configured to reduce the incident angle of the main light incident on the imaging surface of the optical system 100, so that the optical system 100 can be better matched with different photosensitive elements.

[0072] In some embodiments, the optical system 100 satisfies the condition: -2<f 16 / f7<-0.5; where f 16 f is the combined focal length of 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 f7 is the effective focal length of the seventh lens L7. 16 / f7 can be: -1.28, -1.27, -1.26, -1.25, -1.24, -1.23, -1.22, -1.21, -1.20 or -1.19. When the above conditional expression is met, the refractive power of the optical system 100 can be reasonably distributed to better correct the chromatic aberration of the optical system 100 and improve the imaging quality of the optical system 100.

[0073] In some embodiments, the optical system 100 satisfies the conditional expression: FNO<2; wherein FNO is the aperture number of the optical system 100. Specifically, FNO may be: 1.69, 1.71, 1.73, 1.75, 1.76, 1.81, 1.82, 1.85, 1.86 or 1.88. When the above conditional expression is satisfied, while maintaining the miniaturized design of the optical system 100, the optical system 100 can also have a larger aperture to increase the light intensity on the imaging surface of the optical system 100, thereby enabling the optical system 100 to have excellent imaging quality even in a darker environment.

[0074] In some embodiments, the optical system 100 satisfies the conditional formula: f1 / f2<-0.2; wherein 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 can be: -0.50, -0.47, -0.45, -0.43, -0.42, -0.38, -0.36, -0.35, -0.34 or -0.33. When the above conditional formula is met, the effective focal lengths of the first lens L1 and the second lens L2 can be reasonably configured to effectively balance the chromatic aberration of the optical system 100, reduce the performance sensitivity of the optical system 100, and make the performance of the optical system 100 more stable.

[0075] In some embodiments, the optical system 100 satisfies the condition: 1<T57 / (CT56+CT67)<4; wherein T57 is the distance between the object-side surface S9 of the fifth lens L5 and the image-side surface S14 of the seventh lens L7 on the optical axis 110, CT56 is the air gap between the fifth lens L5 and the sixth lens L6 on the optical axis 110, that is, the distance between the image-side surface S10 of the fifth lens L5 and the object-side surface S11 of the sixth lens L6 on the optical axis 110, and CT67 is the air gap between the sixth lens L6 and the seventh lens L7 on the optical axis 110. Specifically, T57 / (CT56+CT67) may be: 2.09, 2.18, 2.21, 2.23, 2.28, 2.31, 2.33, 2.36, 2.40 or 2.60. When T57 / (CT56+CT67)>4, the arrangement of adjacent lenses among the fifth lens L5, the sixth lens L6 and the seventh lens L7 is too close, and the adjacent lenses are easy to collide with each other during the assembly process, which increases the difficulty of assembly. When the above conditional expression is met, the relative positions of the fifth lens L5, the sixth lens L6 and the seventh lens L7 can be reasonably configured to effectively shorten the total length of the optical system 100 and achieve a miniaturized design. In addition, sufficient space can be left between the fifth lens L5, the sixth lens L6 and the seventh lens L7 during assembly to avoid the situation where adjacent lenses collide with each other during the assembly process, reduce the difficulty of assembly, and improve the manufacturing yield.

[0076] Based on the description of the above embodiments, more specific embodiments and drawings are presented below for detailed description.

[0077] First embodiment

[0078] See also Figure 1 and Figure 2 , Figure 1is a schematic diagram of the optical system 100 in the first embodiment. The optical system 100 includes, along the optical axis 110 from the object side to the image side, an aperture stop STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with positive refractive power, and a seventh lens L7 with negative refractive power. Figure 2 From left to right are graphs of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the first embodiment, wherein the astigmatism graph and the distortion graph are both graphs at 555 nm, which are the same for other embodiments.

[0079] The object side surface S1 of the first lens L1 is convex at the paraxial position and convex at the circumference;

[0080] The image side surface S2 of the first lens L1 is concave at the paraxial position and convex at the circumference;

[0081] The object side surface S3 of the second lens L2 is convex at the paraxial position and convex at the circumference;

[0082] The image side surface S4 of the second lens L2 is concave at the paraxial position and concave at the circumference;

[0083] The object side surface S5 of the third lens L3 is concave at the paraxial position and convex at the circumference;

[0084] The image side surface S6 of the third lens L3 is convex at the paraxial position and convex at the circumference;

[0085] The object side surface S7 of the fourth lens L4 is concave at the paraxial position and convex at the circumference;

[0086] The image side surface S8 of the fourth lens L4 is concave at the paraxial position and is concave at the circumference;

[0087] The object side surface S9 of the fifth lens L5 is convex at the paraxial position and is convex at the circumference;

[0088] The image side surface S10 of the fifth lens L5 is concave at the paraxial position and is concave at the circumference;

[0089] The object-side surface S11 of the sixth lens L6 is convex at the paraxial position and is convex at the circumference;

[0090] The image side surface S12 of the sixth lens L6 is concave at the paraxial position and is concave at the circumference;

[0091] The object-side surface S13 of the seventh lens L7 is concave at the paraxial position and convex at the circumference;

[0092] The image-side surface S14 of the seventh lens L7 is concave at the paraxial position and is concave at the circumference.

[0093] The object-side surfaces and 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 seventh lens L7 are all aspherical surfaces.

[0094] It should be noted that in the present application, when a surface of a lens is described as convex at the near axis (the central area of ​​the side), it can be understood that the area of ​​the surface of the lens near the optical axis 110 is convex. When a surface of a lens is described as concave at the circumference, it can be understood that the area of ​​the surface close to the maximum effective radius is concave. For example, when the surface is convex at the optical axis 110 and also convex at the circumference, the shape of the surface from the center (optical axis 110) to the edge direction can be a pure convex surface; or it first transitions from a convex shape at the center to a concave shape, and then becomes convex when close to the maximum effective radius. This is only an example made to illustrate the relationship between the optical axis 110 and the circumference. The various shape structures (convex-concave relationship) of the surface are not fully reflected, but other situations can be derived based on the above examples.

[0095] The materials 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 seventh lens L7 are all plastic.

[0096] Further, the optical system 100 satisfies the conditional expression: SD2 / SD1=0.71; wherein SD1 is the maximum value of the vertical distance from the intersection of the light corresponding to the central field of view and the image side surface S14 of the seventh lens L7 to the optical axis 110, and SD2 is the difference between the maximum value and the minimum value of the vertical distance from the intersection of the light corresponding to the maximum field of view and the image side surface S14 of the seventh lens L7 to the optical axis 110. When the above conditional expression is satisfied, the seventh lens L7 can be reasonably configured to improve the illumination of the edge field of view of the optical system 100, so that the optical system 100 can have excellent imaging quality even in a dark environment.

[0097] The optical system 100 satisfies the conditional formula: TTL / ImgH=1.392; wherein TTL is the distance from the object side surface S1 of the first lens L1 to the imaging surface of the optical system 100 on the optical axis 110, that is, the total length of the optical system 100, and ImgH is half of the diagonal length of the effective pixel area on the imaging surface of the optical system 100. When the above conditional formula is satisfied, the values ​​of TTL and ImgH can be reasonably configured to shorten the total length of the optical system 100 when the imaging surface is fixed, thereby realizing a miniaturized design.

[0098] The optical system 100 satisfies the conditional expression: TTL / f=1.19, wherein TTL is the distance from the object-side surface S1 of the first lens L1 to the imaging surface of the optical system 100 on the optical axis 110, and f is the total effective focal length of the optical system 100. When the above conditional expression is satisfied, when the total effective focal length of the optical system 100 is fixed, the total length of the optical system 100 can be shortened to achieve a miniaturized design.

[0099] The optical system 100 satisfies the conditional expression: f / R14=1.55, wherein f is the total effective focal length of the optical system 100, and R14 is the radius of curvature of the image-side surface S14 of the seventh lens L7 at the optical axis 110. When the above conditional expression is satisfied, the values ​​of f and R14 can be reasonably configured to reduce the incident angle of the main light incident on the imaging surface of the optical system 100, so that the optical system 100 can be better matched with different photosensitive elements.

[0100] The optical system 100 satisfies the conditional expression: f 16 / f7=-1.20; where f 16 f7 is the combined focal length of 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 f8 is the effective focal length of the seventh lens L7. When the above conditional expression is satisfied, the refractive power of the optical system 100 can be reasonably distributed to better correct the chromatic aberration of the optical system 100 and improve the imaging quality of the optical system 100.

[0101] The optical system 100 satisfies the conditional expression: FNO=1.79, where FNO is the aperture number of the optical system 100. When the above conditional expression is satisfied, while maintaining the compact design of the optical system 100, the optical system 100 can also have a larger aperture to increase the light intensity on the imaging surface of the optical system 100, thereby enabling the optical system 100 to have excellent imaging quality even in a dark environment.

[0102] The optical system 100 satisfies the conditional expression: f1 / f2=-0.35; wherein 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 expression is satisfied, the effective focal lengths of the first lens L1 and the second lens L2 can be reasonably configured to effectively balance the chromatic aberration of the optical system 100, reduce the performance sensitivity of the optical system 100, and make the performance of the optical system 100 more stable.

[0103] The optical system 100 satisfies the conditional formula: T57 / (CT56+CT67)=2.12; wherein T57 is the distance between the object side surface S9 of the fifth lens L5 and the image side surface S14 of the seventh lens L7 on the optical axis 110, CT56 is the air gap between the fifth lens L5 and the sixth lens L6 on the optical axis 110, that is, the distance between the image side surface S10 of the fifth lens L5 and the object side surface S11 of the sixth lens L6 on the optical axis 110, and CT67 is the air gap between the sixth lens L6 and the seventh lens L7 on the optical axis 110. When T57 / (CT56+CT67)>4, the arrangement of adjacent lenses among the fifth lens L5, the sixth lens L6 and the seventh lens L7 is too close, and the adjacent lenses are easy to collide with each other during the assembly process, increasing the difficulty of assembly. When the above conditional formula is satisfied, the relative positions of the fifth lens L5, the sixth lens L6 and the seventh lens L7 can be reasonably configured to effectively shorten the total length of the optical system 100 and achieve a miniaturized design. In addition, sufficient space can be left between the fifth lens L5, the sixth lens L6 and the seventh lens L7 during assembly to avoid collision between adjacent lenses during assembly, thereby reducing assembly difficulty and improving manufacturing yield.

[0104] In addition, various parameters of the optical system 100 are given in Table 1. Among them, the image plane S17 in Table 1 can be understood as the imaging plane of the optical system 100. The elements from the object plane (not shown) to the image plane S17 are 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 of the corresponding surface number at the optical axis 110. Surface number 1 and surface number 2 are the object side surface S1 and image side surface S2 of the first lens L1, respectively, that is, in the same lens, the surface with a smaller surface number is the object side surface, and the surface with a larger surface number is the image side surface. The first value in the "thickness" parameter column of the first lens L1 is the thickness of the lens on the optical axis 110, and the second value is the distance from the image side surface of the lens to the object side surface of the next lens in the image side direction on the optical axis 110.

[0105] It should be noted that, in this embodiment and the following embodiments, the optical system 100 may not be provided with the infrared filter L8, but in this case the distance from the image side surface S16 to the image surface S17 of the eighth lens L8 remains unchanged.

[0106] In the first embodiment, the total effective focal length f of the optical system 100 is 6.58 mm, the aperture number FNO is 1.79, the maximum field angle FOV is 80.07°, and the distance TTL from the object side surface S1 of the first lens L1 to the image surface S17 on the optical axis 110 is 7.85 mm.

[0107] The focal length of each lens is a value at a wavelength of 555 nm, and the refractive index and Abbe number of each lens are values ​​at the d-line (587.56 nm). The same is true for other embodiments.

[0108] Table 1

[0109]

[0110]

[0111] Furthermore, the aspheric coefficients of the image side or object side of each lens of the optical system 100 are given in Table 2. Among them, the surface numbers from 1 to 14 represent the image side or object side S1 to S14 respectively. And K-A20 from top to bottom represent the types of aspheric coefficients respectively, among which K represents the cone coefficient, A4 represents the fourth-order aspheric coefficient, A6 represents the sixth-order aspheric coefficient, A8 represents the eighth-order aspheric coefficient, and so on. In addition, the formula of the aspheric coefficient is as follows:

[0112]

[0113] Among them, Z is the distance from the corresponding point on the aspherical surface to the plane tangent to the surface vertex, r is the distance from the corresponding point on the aspherical surface to the optical axis 110, c is the curvature of the aspherical vertex, k is the cone coefficient, and Ai is the coefficient corresponding to the i-th high-order term in the aspherical surface shape formula.

[0114] Table 2

[0115]

[0116] Second embodiment

[0117] See also Figure 3 and Figure 4 , Figure 3 is a schematic diagram of the optical system 100 in the second embodiment. The optical system 100 includes, from the object side to the image side along the optical axis 110, an aperture stop STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with negative refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with positive refractive power, and a seventh lens L7 with negative refractive power. Figure 4 From left to right are graphs of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the second embodiment.

[0118] The object side surface S1 of the first lens L1 is convex at the paraxial position and convex at the circumference;

[0119] The image side surface S2 of the first lens L1 is concave at the paraxial position and convex at the circumference;

[0120] The object side surface S3 of the second lens L2 is convex at the paraxial position and convex at the circumference;

[0121] The image side surface S4 of the second lens L2 is concave at the paraxial position and concave at the circumference;

[0122] The object side surface S5 of the third lens L3 is convex at the paraxial position and convex at the circumference;

[0123] The image side surface S6 of the third lens L3 is concave at the paraxial position and convex at the circumference;

[0124] The object side surface S7 of the fourth lens L4 is convex at the paraxial position and is convex at the circumference;

[0125] The image side surface S8 of the fourth lens L4 is concave at the paraxial position and is concave at the circumference;

[0126] The object side surface S9 of the fifth lens L5 is convex at the paraxial position and is convex at the circumference;

[0127] The image-side surface S10 of the fifth lens L5 is concave at the paraxial position and convex at the circumference;

[0128] The object-side surface S11 of the sixth lens L6 is convex at the paraxial position and is convex at the circumference;

[0129] The image side surface S12 of the sixth lens L6 is concave at the paraxial position and is concave at the circumference;

[0130] The object-side surface S13 of the seventh lens L7 is concave at the paraxial position and is concave at the circumference;

[0131] The image-side surface S14 of the seventh lens L7 is concave at the paraxial position and is convex at the circumference.

[0132] The object-side surfaces and 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 seventh lens L7 are all aspherical surfaces.

[0133] The materials 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 seventh lens L7 are all plastic.

[0134] In addition, various parameters of the optical system 100 are given in Table 3, and the definition of each parameter can be obtained from the first embodiment, which will not be repeated here.

[0135] Table 3

[0136]

[0137] Furthermore, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are given in Table 4, and the definition of each parameter therein can be obtained from the first embodiment, which will not be elaborated here.

[0138] Table 4

[0139]

[0140] Furthermore, based on the parameter information provided above, the following relationship can be derived:

[0141] SD2 / SD1=0.77; TTL / ImgH=1.386; TTL / f=1.18; f / R14=1.53; f 16 / f7=-1.19; FNO=1.79; f1 / f2=-0.40; T57 / (CT56+CT67)=2.09.

[0142] Third embodiment

[0143] See also Figure 5 and Figure 6 , Figure 5 is a schematic diagram of the optical system 100 in the third embodiment. The optical system 100 includes, from the object side to the image side along the optical axis 110, an aperture stop STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, a fifth lens L5 with negative refractive power, a sixth lens L6 with positive refractive power, and a seventh lens L7 with negative refractive power. Figure 6 From left to right are graphs of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the third embodiment.

[0144] The object side surface S1 of the first lens L1 is convex at the paraxial position and convex at the circumference;

[0145] The image side surface S2 of the first lens L1 is concave at the paraxial position and convex at the circumference;

[0146] The object side surface S3 of the second lens L2 is convex at the paraxial position and convex at the circumference;

[0147] The image side surface S4 of the second lens L2 is concave at the paraxial position and concave at the circumference;

[0148] The object side surface S5 of the third lens L3 is convex at the paraxial position and convex at the circumference;

[0149] The image side surface S6 of the third lens L3 is convex at the paraxial position and convex at the circumference;

[0150] The object side surface S7 of the fourth lens L4 is concave at the paraxial position and convex at the circumference;

[0151] The image side surface S8 of the fourth lens L4 is convex at the paraxial position and concave at the circumference;

[0152] The object side surface S9 of the fifth lens L5 is concave at the paraxial position and convex at the circumference;

[0153] The image-side surface S10 of the fifth lens L5 is convex at the paraxial position and concave at the circumference;

[0154] The object-side surface S11 of the sixth lens L6 is convex at the paraxial position and is convex at the circumference;

[0155] The image side surface S12 of the sixth lens L6 is concave at the paraxial position and is concave at the circumference;

[0156] The object-side surface S13 of the seventh lens L7 is concave at the paraxial position and convex at the circumference;

[0157] The image-side surface S14 of the seventh lens L7 is concave at the paraxial position and is concave at the circumference.

[0158] The object-side surfaces and 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 seventh lens L7 are all aspherical surfaces.

[0159] The materials 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 seventh lens L7 are all plastic.

[0160] In addition, various parameters of the optical system 100 are given in Table 5, and the definition of each parameter can be obtained from the first embodiment, which will not be repeated here.

[0161] Table 5

[0162]

[0163] Furthermore, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are given in Table 6, and the definition of each parameter therein can be obtained from the first embodiment, which will not be repeated here.

[0164] Table 6

[0165]

[0166]

[0167] Furthermore, based on the parameter information provided above, the following relationship can be derived:

[0168] SD2 / SD1=0.71; TTL / ImgH=1.386; TTL / f=1.20; f / R14=1.64; f 16 / f7=-1.21;FNO=1.79;f1 / f2=-0.34;T57 / (CT56+CT67)=2.29.

[0169] Fourth embodiment

[0170] See also Figure 7 and Figure 8 , Figure 7 is a schematic diagram of an optical system 100 in a fourth embodiment. The optical system 100 includes, along the optical axis 110 from the object side to the image side, an aperture stop STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with negative refractive power, a sixth lens L6 with positive refractive power, and a seventh lens L7 with negative refractive power. Figure 8 From left to right are graphs of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the fourth embodiment.

[0171] The object side surface S1 of the first lens L1 is convex at the paraxial position and convex at the circumference;

[0172] The image side surface S2 of the first lens L1 is concave at the paraxial position and convex at the circumference;

[0173] The object side surface S3 of the second lens L2 is convex at the paraxial position and convex at the circumference;

[0174] The image side surface S4 of the second lens L2 is concave at the paraxial position and concave at the circumference;

[0175] The object side surface S5 of the third lens L3 is concave at the paraxial position and convex at the circumference;

[0176] The image side surface S6 of the third lens L3 is convex at the paraxial position and convex at the circumference;

[0177] The object side surface S7 of the fourth lens L4 is concave at the paraxial position and convex at the circumference;

[0178] The image side surface S8 of the fourth lens L4 is convex at the paraxial position and concave at the circumference;

[0179] The object side surface S9 of the fifth lens L5 is concave at the paraxial position and convex at the circumference;

[0180] The image-side surface S10 of the fifth lens L5 is concave at the paraxial position and convex at the circumference;

[0181] The object-side surface S11 of the sixth lens L6 is convex at the paraxial position and is convex at the circumference;

[0182] The image side surface S12 of the sixth lens L6 is concave at the paraxial position and is concave at the circumference;

[0183] The object-side surface S13 of the seventh lens L7 is concave at the paraxial position and is concave at the circumference;

[0184] The image-side surface S14 of the seventh lens L7 is concave at the paraxial position and is concave at the circumference.

[0185] The object-side surfaces and 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 seventh lens L7 are all aspherical surfaces.

[0186] The materials 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 seventh lens L7 are all plastic.

[0187] In addition, various parameters of the optical system 100 are given in Table 7, and the definition of each parameter can be obtained from the first embodiment, which will not be repeated here.

[0188] Table 7

[0189]

[0190] Furthermore, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are given in Table 8, and the definition of each parameter therein can be obtained from the first embodiment, which will not be repeated here.

[0191] Table 8

[0192]

[0193]

[0194] Furthermore, based on the parameter information provided above, the following relationship can be derived:

[0195] SD2 / SD1=0.73; TTL / ImgH=1.386; TTL / f=1.19; f / R14=1.60; f 16 / f7=-1.21;FNO=1.79;f1 / f2=-0.37;T57 / (CT56+CT67)=2.21.

[0196] Fifth embodiment

[0197] See also Fig. 9 and Fig.10 , Fig. 9is a schematic diagram of the optical system 100 in the fifth embodiment. The optical system 100 includes, along the optical axis 110 from the object side to the image side, an aperture stop STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, a fifth lens L5 with negative refractive power, a sixth lens L6 with positive refractive power, and a seventh lens L7 with negative refractive power. Fig.10 From left to right are graphs of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the fifth embodiment.

[0198] The object side surface S1 of the first lens L1 is convex at the paraxial position and convex at the circumference;

[0199] The image side surface S2 of the first lens L1 is convex at the paraxial position and convex at the circumference;

[0200] The object side surface S3 of the second lens L2 is convex at the paraxial position and convex at the circumference;

[0201] The image side surface S4 of the second lens L2 is concave at the paraxial position and concave at the circumference;

[0202] The object side surface S5 of the third lens L3 is concave at the paraxial position and convex at the circumference;

[0203] The image side surface S6 of the third lens L3 is convex at the paraxial position and convex at the circumference;

[0204] The object side surface S7 of the fourth lens L4 is concave at the paraxial position and convex at the circumference;

[0205] The image side surface S8 of the fourth lens L4 is concave at the paraxial position and is concave at the circumference;

[0206] The object side surface S9 of the fifth lens L5 is convex at the paraxial position and is convex at the circumference;

[0207] The image side surface S10 of the fifth lens L5 is concave at the paraxial position and is concave at the circumference;

[0208] The object-side surface S11 of the sixth lens L6 is convex at the paraxial position and is convex at the circumference;

[0209] The image side surface S12 of the sixth lens L6 is convex at the paraxial position and is convex at the circumference;

[0210] The object-side surface S13 of the seventh lens L7 is concave at the paraxial position and is concave at the circumference;

[0211] The image-side surface S14 of the seventh lens L7 is concave at the paraxial position and is convex at the circumference.

[0212] The object-side surfaces and 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 seventh lens L7 are all aspherical surfaces.

[0213] The materials 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 seventh lens L7 are all plastic.

[0214] In addition, various parameters of the optical system 100 are given in Table 9, and the definition of each parameter can be obtained from the first embodiment, which will not be repeated here.

[0215] Table 9

[0216]

[0217]

[0218] Furthermore, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are given in Table 10, and the definition of each parameter therein can be obtained from the first embodiment, which will not be repeated here.

[0219] Table 10

[0220]

[0221] Furthermore, based on the parameter information provided above, the following relationship can be derived:

[0222] SD2 / SD1=0.79; TTL / ImgH=1.386; TTL / f=1.18; f / R14=1.63; f 16 / f7=-1.28;FNO=1.85;f1 / f2=-0.50;T57 / (CT56+CT67)=2.25.

[0223] Sixth embodiment

[0224] See also Fig.11 and Fig.12 , Fig.11 is a schematic diagram of the optical system 100 in the sixth embodiment. The optical system 100 includes, along the optical axis 110 from the object side to the image side, an aperture stop STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with positive refractive power, and a seventh lens L7 with negative refractive power. Fig.12 From left to right are graphs of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the sixth embodiment.

[0225] The object side surface S1 of the first lens L1 is convex at the paraxial position and convex at the circumference;

[0226] The image side surface S2 of the first lens L1 is concave at the paraxial position and convex at the circumference;

[0227] The object side surface S3 of the second lens L2 is concave at the paraxial position and convex at the circumference;

[0228] The image side surface S4 of the second lens L2 is concave at the paraxial position and concave at the circumference;

[0229] The object side surface S5 of the third lens L3 is convex at the paraxial position and convex at the circumference;

[0230] The image side surface S6 of the third lens L3 is convex at the paraxial position and concave at the circumference;

[0231] The object side surface S7 of the fourth lens L4 is concave at the paraxial position and is concave at the circumference;

[0232] The image side surface S8 of the fourth lens L4 is concave at the paraxial position and is concave at the circumference;

[0233] The object side surface S9 of the fifth lens L5 is convex at the paraxial position and is convex at the circumference;

[0234] The image-side surface S10 of the fifth lens L5 is concave at the paraxial position and convex at the circumference;

[0235] The object-side surface S11 of the sixth lens L6 is convex at the paraxial position and is convex at the circumference;

[0236] The image-side surface S12 of the sixth lens L6 is concave at the paraxial position and convex at the circumference;

[0237] The object-side surface S13 of the seventh lens L7 is concave at the paraxial position and is concave at the circumference;

[0238] The image-side surface S14 of the seventh lens L7 is concave at the paraxial position and is concave at the circumference.

[0239] The object-side surfaces and 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 seventh lens L7 are all aspherical surfaces.

[0240] The materials 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 seventh lens L7 are all plastic.

[0241] In addition, various parameters of the optical system 100 are given in Table 11, and the definition of each parameter can be obtained from the first embodiment, which will not be repeated here.

[0242] Table 11

[0243]

[0244]

[0245] Furthermore, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are given in Table 12, and the definition of each parameter therein can be obtained from the first embodiment, which will not be repeated here.

[0246] Table 12

[0247]

[0248] Furthermore, based on the parameter information provided above, the following relationship can be derived:

[0249] SD2 / SD1=0.78; TTL / ImgH=1.386; TTL / f=1.18; f / R14=1.61; f 16 / f7=-1.21;FNO=1.88;f1 / f2=-0.40;T57 / (CT56+CT67)=2.14.

[0250] Seventh embodiment

[0251] See also Fig.13 and Fig.14 , Fig.13 is a schematic diagram of the optical system 100 in the seventh embodiment. The optical system 100 includes, from the object side to the image side along the optical axis 110, an aperture stop STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, a fifth lens L5 with negative refractive power, a sixth lens L6 with positive refractive power, and a seventh lens L7 with negative refractive power. Fig.14 From left to right are graphs of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the seventh embodiment.

[0252] The object side surface S1 of the first lens L1 is convex at the paraxial position and convex at the circumference;

[0253] The image side surface S2 of the first lens L1 is concave at the paraxial position and convex at the circumference;

[0254] The object side surface S3 of the second lens L2 is convex at the paraxial position and convex at the circumference;

[0255] The image side surface S4 of the second lens L2 is concave at the paraxial position and concave at the circumference;

[0256] The object side surface S5 of the third lens L3 is concave at the paraxial position and convex at the circumference;

[0257] The image side surface S6 of the third lens L3 is convex at the paraxial position and convex at the circumference;

[0258] The object side surface S7 of the fourth lens L4 is concave at the paraxial position and is concave at the circumference;

[0259] The image side surface S8 of the fourth lens L4 is concave at the paraxial position and is concave at the circumference;

[0260] The object side surface S9 of the fifth lens L5 is convex at the paraxial position and is convex at the circumference;

[0261] The image side surface S10 of the fifth lens L5 is concave at the paraxial position and is concave at the circumference;

[0262] The object-side surface S11 of the sixth lens L6 is convex at the paraxial position and is convex at the circumference;

[0263] The image-side surface S12 of the sixth lens L6 is convex at the paraxial position and concave at the circumference;

[0264] The object-side surface S13 of the seventh lens L7 is concave at the paraxial position and convex at the circumference;

[0265] The image-side surface S14 of the seventh lens L7 is concave at the paraxial position and is concave at the circumference.

[0266] The object-side surfaces and 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 seventh lens L7 are all aspherical surfaces.

[0267] The materials 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 seventh lens L7 are all plastic.

[0268] In addition, various parameters of the optical system 100 are given in Table 13, and the definition of each parameter can be obtained from the first embodiment, which will not be repeated here.

[0269] Table 13

[0270]

[0271] Furthermore, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are given in Table 14, and the definition of each parameter therein can be obtained from the first embodiment, which will not be repeated here.

[0272] Table 14

[0273]

[0274]

[0275] Furthermore, based on the parameter information provided above, the following relationship can be derived:

[0276] SD2 / SD1=0.68; TTL / ImgH=1.391; TTL / f=1.21; f / R14=1.65; f 16 / f7=-1.27; FNO=1.69; f1 / f2=-0.33; T57 / (CT56+CT67)=2.60.

[0277] See also Fig.15 In some embodiments, the optical system 100 can be assembled with the photosensitive element 210 to form the imaging module 200, and the photosensitive element 210 is arranged on the image side of the optical system 100. At this time, the photosensitive surface of the photosensitive element 210 can be regarded as the image surface S17 of the optical system 100. The imaging module 200 can also be provided with an infrared filter L8, and the infrared filter L8 is arranged between the image side surface S14 of the seventh lens L7 and the image surface S17. Specifically, the photosensitive element 210 can be a charge coupled device (CCD) or a complementary metal oxide semiconductor device (CMOS Sensor). The optical system 100 is used in the imaging module 200. Since the size of the optical system 100 in the direction of the optical axis 110 is short and the edge field illumination of the optical system 100 is high, the imaging module 200 can be miniaturized and can have excellent imaging quality even in a dark environment.

[0278] See also Fig.15 and Fig.16 In some embodiments, the imaging module 200 can be used in an electronic device 300, and the electronic device includes a housing 310, and the imaging module 200 is installed in the housing 310. Specifically, the electronic device 300 can be, but is not limited to, a portable phone, a video phone, a smart phone, an e-book reader, a driving recorder, or other vehicle-mounted imaging devices or a wearable device such as a smart watch. The use of the imaging module 200 in the electronic device 300 is conducive to the miniaturization design of the electronic device 300, and the electronic device 300 can also have excellent imaging quality in a dark environment.

[0279] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0280] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An optical system, characterized in that: There are seven lenses with refractive power, including: A first lens having positive refractive power, wherein the object side surface of the first lens is convex at the paraxial position; A second lens having negative refractive power, wherein the image side surface of the second lens is concave at the paraxial position; a third lens having refractive power; a fourth lens having a refractive power; a fifth lens having refractive power; a sixth lens having positive refractive power, wherein the object side surface of the sixth lens is convex at the paraxial position; a seventh lens element having negative refractive power, wherein the object side surface of the seventh lens element is concave at the paraxial position, and the image side surface of the seventh lens element is concave at the paraxial position; And the optical system satisfies the following conditional formula: SD2 / SD1≥0.68, 1<T57 / (CT56+CT67)≤2.60; Among them, SD1 is the maximum value of the vertical distance from the intersection of the light corresponding to the central field of view and the image side surface of the seventh lens to the optical axis, SD2 is the difference between the maximum and minimum values ​​of the vertical distance from the intersection of the light corresponding to the maximum field of view and the image side surface of the seventh lens to the optical axis, T57 is the distance from the object side surface of the fifth lens to the image side surface of the seventh lens on the optical axis, CT56 is the air gap between the fifth lens and the sixth lens on the optical axis, and CT67 is the air gap between the sixth lens and the seventh lens on the optical axis.

2. The optical system according to claim 1, characterized in that The following conditions are met: TTL / ImgH<1.5; Wherein, TTL is the distance from the object side of the first lens to the imaging plane of the optical system on the optical axis, and ImgH is half of the diagonal length of the effective pixel area of ​​the optical system on the imaging plane.

3. The optical system according to claim 1, characterized in that The following conditions are met: 1.18≤TTL / f<1.4; Wherein, 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, and f is the total effective focal length of the optical system.

4. The optical system according to claim 1, characterized in that The following conditions are met: 0.5<f / R14<3; Wherein, f is the total effective focal length of the optical system, and R14 is the radius of curvature of the image side surface of the seventh lens at the optical axis.

5. The optical system according to claim 1, characterized in that The following conditions are met: -2<f 16 / f7<-0.5; Among them, f 16 f7 is the combined focal length of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens, and f8 is the effective focal length of the seventh lens.

6. The optical system according to claim 1, characterized in that The following conditions are met: 1.69≤FNO<2; Wherein, FNO is the aperture number of the optical system.

7. The optical system according to claim 1, characterized in that The following conditions are met: -0.5≤f1 / f2<-0.2; Wherein, f1 is the effective focal length of the first lens, and f2 is the effective focal length of the second lens.

8. An imaging module, characterized in that: The optical system comprises a photosensitive element and any one of claims 1 to 7, wherein the photosensitive element is arranged on the image side of the optical system.

9. An electronic device, characterized in that: It comprises a shell and the imaging module as claimed in claim 8, wherein the imaging module is installed in the shell.

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