Optical System, Camera Module and Electronic Device

Abstract

The present invention relates to an optical system, a camera module and an electronic device. The optical system includes: a diaphragm; a first lens with positive refractive power, the object side surface of which is convex at paraxial region; a second lens; a third lens; a fourth lens with positive refractive power, the object side surface of which is concave and the image side surface of which is convex; a fifth lens, the image side surface of which is concave at paraxial region; a sixth lens with negative refractive power, the object side surface of which is convex at paraxial region and the image side surface of which is concave at paraxial region; the system satisfies the relationship: 1mm<supgt;‑1< / supgt; < tanω / D11 < 2mm<supgt;‑1< / supgt>; 0 < f123 / f456 < 1.0. Above all, the optical system can achieve a small head design. When applied as a front lens in a device, it can effectively reduce the under-screen opening of the device to improve the screen-to-body ratio. In addition, it can also endow the device with a large viewing angle and high-resolution imaging performance.

Description

Technical Field

[0001] The present invention relates to the field of imaging, and particularly to an optical system, an imaging module and an electronic device. Background Art

[0002] Since imaging lenses are applied to electronic devices such as smart phones and tablet computers, the shooting performance of the devices has also changed dramatically with the increasing demand of users for high-quality imaging. Among them, the shooting effect of imaging lenses has also received extensive attention in the market. Especially when the screen-to-body ratio of the device is gradually increasing, how to reduce the under-screen opening of the device to increase the screen-to-body ratio while maintaining good imaging performance (such as large viewing angle and high resolution) has become the focus of market attention. Summary of the Invention

[0003] Based on this, it is necessary to provide an optical system, an imaging module and an electronic device for the problem of how to reduce the under-screen opening of the device while maintaining good imaging performance.

[0004] An optical system sequentially includes, from the object side to the image side:

[0005] A diaphragm;

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

[0007] A second lens with refractive power;

[0008] A third lens with refractive power;

[0009] A fourth lens with positive refractive power, the object side surface of the fourth lens is concave, and the image side surface is convex;

[0010] A fifth lens with refractive power, the image side surface of the fifth lens is concave at the paraxial region;

[0011] A sixth lens with negative refractive power, the object side surface of the sixth lens is convex at the paraxial region, and the image side surface is concave at the paraxial region;

[0012] The optical system satisfies the following relationships:

[0013] 1mm -1 <tanω / D11<2mm -1 ; and

[0014] 0<f123 / f456<1.0;

[0015] Where ω is half of the maximum field of view angle of the optical system, D11 is the maximum effective semi-aperture of the object side surface of the first lens, f123 is the combined focal length of the first lens, the second lens, and the third lens, f456 is the combined focal length of the fourth lens, the fifth lens, and the sixth lens, the unit of ω is degree, and the unit of D11 is millimeter.

[0016] When the optical system satisfies the above conditions of the aperture, lens configuration, and the relationship about tanω / D11, the front aperture of the optical system can be fully compressed, which is beneficial to the external shape design of a small head. In addition, it can also expand the viewing angle range of the system, so that the optical system can obtain a more comprehensive scene. At the same time, when the optical system satisfies the above relationship about f123 / f456, the lens group composed of the first lens, the second lens, and the third lens can provide most of the positive refractive power for the optical system, so that the incident light can be better converged and imaged, thereby shortening the total length of the system. In addition, when the above relationship is satisfied, the resolution ability of the system can also be improved. Above all, the optical system can achieve a small head design by reducing the front aperture. Thus, when the optical system is applied as a front lens in a device, the under-screen opening of the device can be effectively reduced to increase the screen-to-body ratio. In addition, it can also endow the device with large viewing angle and high-resolution imaging performance.

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

[0018] 3.4 < D62 / D11 < 5.1;

[0019] Where D62 is the maximum effective semi-aperture of the image side surface of the sixth lens. When the above relationship is satisfied, it is beneficial to the small-aperture design of the first lens in the system, so that the system has the external shape structure of a small head. When it is higher than the upper limit of the relationship formula, the aperture of the sixth lens is too large, resulting in too large a size of the entire system (or called the lens). When it is lower than the lower limit of the relationship formula, the aperture of the first lens cannot be fully compressed, which is not conducive to the small head design of the system.

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

[0021] 0.40deg -1 <10*FNO / ω<0.52deg -1 ;

[0022] Among them, FNO is the f-number of the optical system. The smaller the f-number, the larger the entrance pupil diameter of the system under the same focal length, the more sufficient the light input, and thus the overall imaging of the system will be brighter and clearer. However, at the same time, it will also make it difficult to increase the field of view angle of the system. When the above relationship is satisfied, the optical system can have both the characteristics of high light input and wide viewing angle.

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

[0024] 0.7 < ImgH / TL < 0.9;

[0025] Among them, ImgH is half of the diagonal length of the effective imaging area of the imaging surface of the optical system, and TL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis. When the above relationship is satisfied, the total length of the optical system can be effectively compressed, which is beneficial to miniaturization design.

[0026] In one embodiment, at least one of the second lens and the third lens has a negative refractive power, and the optical system satisfies the following relationship:

[0027] 1 < (V2 + V3 + V5) / V1 < 2;

[0028] Among them, V1 is the Abbe number of the first lens, V2 is the Abbe number of the second lens, V3 is the Abbe number of the third lens, and V5 is the Abbe number of the fifth lens. The second lens and / or the third lens with negative refractive power can correct the positive spherical aberration of the first lens and improve the imaging quality of the system. When the fifth lens has negative refractive power, it can also share the correction of positive spherical aberration. When the above relationship is satisfied, the spherical chromatic aberration of the system can be corrected, the selection of lens materials can be made uniform, and the system can have good imaging quality. The smaller the Abbe number, the stronger the ability to correct chromatic aberration.

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

[0030] -20 < (R51 + R52) / (R51 - R52) < 1;

[0031] Among them, R51 is the curvature radius of the object side surface of the fifth lens on the optical axis, and R52 is the curvature radius of the image side surface of the fifth lens on the optical axis. When the above relationship is satisfied, the surface shapes of the object side surface and the image side surface of the fifth lens can be reasonably optimized, which is beneficial to correcting the aberration and field curvature of the system and improving the imaging quality.

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

[0033] 1 < f1 / f < 2;

[0034] Wherein, f1 is the effective focal length of the first lens, and f is the total effective focal length of the optical system. The first lens provides positive refractive power to the system. When the above relationship is satisfied, it can effectively correct the field curvature of the system and is beneficial to controlling the length of the system.

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

[0036] 0.7 < SAG51 / SAG61 < 1.6;

[0037] Wherein, SAG51 is the maximum sagitta of the object side of the fifth lens, and SAG61 is the maximum sagitta of the object side of the sixth lens. When the above relationship is satisfied, the object sides of the fifth lens and the sixth lens maintain similar curvatures, so that the fifth lens and the sixth lens can be more closely matched, which is also more beneficial to compressing the length of the system.

[0038] In one embodiment, the optical system satisfies the following relationship:

[0039] 0.39 < ΣAT / ΣCT < 0.56;

[0040] Wherein, ΣAT is the sum of the air gaps between adjacent lenses on the optical axis in the optical system, and ΣCT is the sum of the thicknesses of the lenses on the optical axis in the optical system. When the above relationship is satisfied, the spacing distances between adjacent lenses can be reasonably optimized. While ensuring that the thickness of the lenses is conducive to processing and forming, the air gaps between adjacent lenses can be more fully compressed, thus meeting the miniaturization design trend of the lens. When below the lower limit of the above relational expression, the thickness of the lens is too thin, which is not conducive to the forming of the lens, or the air gaps between adjacent lenses are too small, and the degree of freedom of lens shape change is insufficient, making it impossible to correct the system aberration well; when above the upper limit of the above relational expression, the air gaps between lenses are too large, which is not conducive to the ultra-thin design.

[0041] An imaging module includes an image sensor and the optical system according to any one of the above embodiments, and the image sensor is disposed on the image side of the optical system. By adopting the above optical system, the imaging module will also have the characteristics of a small head, a large viewing angle, and high resolution.

[0042] An electronic device includes a fixing member and the above imaging module, and the imaging module is disposed on the fixing member. When the above imaging module is used as the front camera module of the device, the under-screen opening of the device can be effectively reduced to increase the screen-to-body ratio. In addition, the device can also have a large viewing angle and high-resolution imaging performance. Description of the Drawings

[0043] Figure 1Schematic diagram of the optical system provided by the first embodiment of the present application;

[0044] Figure 2 Longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the first embodiment;

[0045] Figure 3 Schematic diagram of the optical system provided by the second embodiment of the present application;

[0046] Figure 4 Longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the second embodiment;

[0047] Figure 5 Schematic diagram of the optical system provided by the third embodiment of the present application;

[0048] Figure 6 Longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the third embodiment;

[0049] Figure 7 Schematic diagram of the optical system provided by the fourth embodiment of the present application;

[0050] Figure 8 Longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the fourth embodiment;

[0051] Figure 9 Schematic diagram of the optical system provided by the fifth embodiment of the present application;

[0052] Figure 10 Longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the fifth embodiment;

[0053] Figure 11 Schematic diagram of the optical system provided by the sixth embodiment of the present application;

[0054] Figure 12 Longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the sixth embodiment;

[0055] Figure 13 Schematic diagram of the optical system provided by the seventh embodiment of the present application;

[0056] Figure 14 Longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the seventh embodiment;

[0057] Figure 15 Schematic diagram of the camera module provided by an embodiment of the present application;

[0058] Figure 16 Schematic diagram of the electronic device provided by an embodiment of the present application. Detailed implementation manners

[0059] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0060] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. On the contrary, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for illustrative purposes.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0062] Reference Figure 1 , in some embodiments of the present application, the optical system 10 sequentially includes a stop STO, 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 from the object side to the image side. Each of the first lens L1 to the sixth lens L6 contains only one lens, so that the optical system 10 has a six-piece structure. Among them, the first lens L1 has a positive refractive power, the fourth lens L4 has a positive refractive power, and the sixth lens L6 has a negative refractive power. Each lens in the optical system 10 is coaxially arranged with the stop STO, that is, the optical axes of each lens and the center of the stop STO are all on the same straight line, and this straight line can be called the optical axis of the optical system 10. The stop STO is arranged on the object side of the first lens L1, and the design of placing the stop STO in front is beneficial to the miniaturization design of the optical system 10. In the embodiments of the present application, when it is said that the system sequentially includes optical elements such as the stop STO and the first lens L1 from the object side to the image side, the projections of the stop STO and the first lens L1 on the optical axis of the system may overlap, that is, the object side surface S1 of the first lens L1 passes through the stop STO, or there may be no overlap.

[0063] The first lens L1 includes an object side S1 and an image side S2, the second lens L2 includes an object side S3 and an image side S4, the third lens L3 includes an object side S5 and an image side S6, the fourth lens L4 includes an object side S7 and an image side S8, the fifth lens L5 includes an object side S9 and an image side S10, and the sixth lens L6 includes an object side S11 and an image side S12. Additionally, the optical system 10 further has a virtual imaging surface S13, and the imaging surface S13 is located on the image side of the sixth lens L6. Generally, the imaging surface S13 of the optical system 10 coincides with the photosensitive surface of the photosensitive element. For ease of understanding, the photosensitive surface of the photosensitive element can also be regarded as the imaging surface S13 of the optical system 10.

[0064] The object side S1 of the first lens L1 is convex at the paraxial region; the object side S7 of the fourth lens L4 is concave, and the image side S8 is convex; the image side S10 of the fifth lens L5 is concave at the paraxial region; the object side S11 of the sixth lens L6 is convex at the paraxial region, and the image side S12 is concave at the paraxial region.

[0065] It should be noted that in this application, when it is described that a surface of a lens is convex at the paraxial region (the central region of this surface), it can be understood that the region of this surface near the optical axis is convex. When it is described that a surface of a lens is concave at the circumference, it can be understood that the region of this surface near the maximum effective radius is concave. For example, when this surface is convex at the paraxial region and also convex at the circumference, the shape of this surface from the center (optical axis) to the edge direction can be a purely convex surface, or it can first transition from a convex shape at the center to a concave shape, and then become convex when approaching the maximum effective radius. This is only an example for explaining the relationship between the optical axis and the circumference, and various shape structures (concave-convex relationships) of the surface are not fully reflected, but other situations in some embodiments can be deduced based on the above examples, which will not be elaborated here.

[0066] In the above embodiments, the object sides and image sides of each lens in the optical system 10 are all aspherical surfaces. The aspherical design enables the object side and / or image side of the lens to have a more flexible design, increases the degree of freedom in lens design, improves the system resolution, enables the lens to well solve problems such as unclear imaging, distorted field of view, and narrow field of view in a smaller and thinner size, so that the system can have good imaging quality without setting too many lenses, and helps to shorten the length of the optical system 10. In some embodiments, the object sides and image sides of each lens in the optical system 10 are all spherical surfaces. The manufacturing process of spherical lenses is simple, and the production cost is relatively low. In other embodiments, the object sides of some lenses in the optical system 10 are aspherical surfaces, the object sides of other lenses are spherical surfaces, and the image sides of some lenses are aspherical surfaces, and the image sides of other lenses are spherical surfaces. The specific configurations of spherical and aspherical surfaces in some embodiments are determined according to actual design requirements, which will not be elaborated here.

[0067] By the cooperation of the spherical surface and the aspherical surface, the aberration of the system can also be effectively eliminated, enabling the optical system 10 to have good imaging quality. At the same time, the flexibility of lens design and assembly is improved, achieving a balance between high image quality and low cost for the system. It should be noted that the specific shapes of the spherical surface and the aspherical surface in the embodiments are not limited to the shapes of the spherical surface and the aspherical surface shown in the drawings. The drawings are mainly for illustrative reference and are not drawn strictly to scale.

[0068] The surface shape calculation of the aspherical surface can refer to the aspherical formula:

[0069]

[0070] Wherein, 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, c is the curvature of the aspherical surface vertex, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th high-order term in the aspherical surface formula.

[0071] In the above embodiments, there are inflection points on both the object side surface S11 and the image side surface S12 of the sixth lens L6. In some embodiments, there is an inflection point on the object side surface S11 of the sixth lens L6, while there is no inflection point on the image side surface S12. In other embodiments, there is no inflection point on the object side surface S11 of the sixth lens L6, while there is an inflection point on the image side surface S12. The design of the inflection point can correct the distortion of a large viewing angle and suppress the excessive angle of the marginal field light incident on the imaging surface S13.

[0072] In the above embodiments, the materials of the lenses in the optical system 10 are all plastics. In other embodiments, the materials of the lenses in the optical system 10 are all glasses. The plastic lenses can reduce the weight of the optical system 10 and lower the preparation cost, while the glass lenses can withstand higher temperatures and have excellent optical effects. In other embodiments, the material of the first lens L1 is glass, while the materials of the second lens L2 to the sixth lens L6 are all plastics. At this time, since the materials of the lenses in the object space of the optical system 10 are glass, these glass lenses in the object space have a good tolerance effect on extreme environments and are not easily affected by the object space environment and age. Therefore, when the optical system 10 is in extreme environments such as intense sunlight and high temperature, this structure can better balance the optical performance and cost of the system. Of course, the configuration relationship of the lens materials in the optical system 10 is not limited to the above embodiments. The material of any one lens can be plastic or glass, and the specific configuration relationship is determined according to actual design requirements and will not be elaborated here.

[0073] In some embodiments, the optical system 10 includes an infrared filter L7. The infrared filter L7 is disposed on the image side of the sixth lens L6 and is fixedly arranged relative to each lens in the optical system 10. The infrared filter L7 is used to filter infrared light to prevent the infrared light from reaching the imaging surface S13 of the system, thereby preventing the infrared light from interfering with normal imaging. The infrared filter L7 can be assembled together with each lens to be a part of the optical system 10. For example, in some embodiments, each lens in the optical system 10 is installed in a lens barrel, and the infrared filter L7 is installed at the image end of the lens barrel. In some other embodiments, the infrared filter L7 does not belong to the components of the optical system 10. At this time, the infrared filter L7 can be installed between the optical system 10 and the photosensitive element when the optical system 10 and the photosensitive element are assembled into a camera module. In some embodiments, the infrared filter L7 can also be disposed on the object side of the first lens L1. Additionally, in some embodiments, the infrared filter L7 may not be provided, but rather an infrared filter film is provided on the object side surface or the image side surface of one of the lenses from the first lens L1 to the sixth lens L6 to achieve the function of filtering infrared light.

[0074] In some embodiments, the first lens L1 may also include two or more lenses. The object side surface of the lens closest to the object side is the object side surface S1 of the first lens L1, and the image side surface of the lens closest to the image side is the image side surface S2 of the first lens L1. Correspondingly, any one of the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 in some embodiments is not limited to the case of only including one lens.

[0075] Furthermore, in some embodiments, the optical system 10 also satisfies the following relationships:

[0076] 1mm -1 <tanω / D11<2mm -1 ;

[0077] 0<f123 / f456<1.0;

[0078] Wherein, ω is half of the maximum field of view angle of the optical system 10, D11 is the maximum effective semi-aperture of the object side surface S1 of the first lens L1, f123 is the combined focal length of the first lens L1, the second lens L2 and the third lens L3, f456 is the combined focal length of the fourth lens L4, the fifth lens L5 and the sixth lens L6, the unit of ω is degree, and the unit of D11 is millimeter. It should be noted that the effective semi-aperture can also be referred to as the effective radius. Specifically, in some embodiments, tanω / D11 can be 1.05, 1.1, 1.15, 1.2, 1.4, 1.5, 1.7, 1.8, 1.9 or 1.95. Specifically, in some embodiments, f123 / f456 can be 0.15, 0.2, 0.25, 0.3, 0.4, 0.5, 0.6, 0.65 or 0.68. When the optical system 10 satisfies the above conditions of the diaphragm, lens configuration and the relationship of tanω / D11, the front aperture of the optical system 10 can be fully compressed, which is beneficial to the design of the small head shape. In addition, it can also expand the viewing angle range of the system, so that the optical system 10 can obtain a more comprehensive scene. At the same time, when the optical system 10 satisfies the above relationship condition of f123 / f456, the lens group composed of the first lens L1, the second lens L2 and the third lens L3 can provide most of the positive refractive power for the optical system 10, so as to better converge and image the incident light, thereby shortening the total length of the system. In addition, when the above relationship is satisfied, the system resolution ability can also be improved. Above all, the optical system 10 can achieve a small head design by reducing the front aperture. Therefore, when the optical system 10 is applied as a front lens in a device, the under-screen opening of the device can be effectively reduced to improve the screen-to-body ratio. In addition, the device can also have a large viewing angle and high-resolution imaging performance.

[0079] 3.4 < D62 / D11 < 5.1; wherein, D62 is the maximum effective semi-aperture of the image side surface S12 of the sixth lens L6. Specifically, in some embodiments, D62 / D11 can be 3.5, 3.7, 4, 4.1, 4.5, 4.8, 4.9 or 5. When the above relationship is satisfied, it is beneficial to the small-aperture design of the first lens L1 in the system, so that the system has a small head shape structure. When it is higher than the upper limit of the relationship formula, the aperture of the sixth lens L6 is too large, resulting in too large size of the entire system (or called lens); when it is lower than the lower limit of the relationship formula, the aperture of the first lens L1 cannot be fully compressed, which is not conducive to the small head design of the system.

[0080] 0.40deg -1 <10*FNO / ω<0.52deg -1; where FNO is the f-number of the optical system 10. Specifically, 10*FNO / ω in some embodiments may be 0.41, 0.42, 0.43, 0.44, 0.45, 0.48, 0.5, or 0.51. The smaller the f-number, the larger the entrance pupil diameter of the system at the same focal length, and the more sufficient the light input, so that the overall imaging of the system will be brighter and clearer. However, at the same time, it will make it difficult to increase the field of view angle of the system. When the above relationship is satisfied, the optical system 10 can have both the characteristics of high light input and wide viewing angle.

[0081] 0.7 < ImgH / TL < 0.9; where ImgH is half of the diagonal length of the effective imaging area of the imaging surface of the optical system 10, and this diagonal length is the length of the effective imaging area of the imaging surface S13 in the diagonal direction, and TL is the distance from the object side surface S1 of the first lens L1 to the imaging surface of the optical system 10 on the optical axis. Specifically, ImgH / TL in some embodiments may be 0.75, 0.6, 0.65, 0.7, 0.75, 0.8, or 0.85. When the above relationship is satisfied, the total length of the optical system 10 can be effectively compressed, which is beneficial to miniaturized design.

[0082] 1 < (V2 + V3 + V5) / V1 < 2; where V1 is the Abbe number of the first lens L1, V2 is the Abbe number of the second lens L2, V3 is the Abbe number of the third lens L3, and V5 is the Abbe number of the fifth lens L5. Specifically, (V2 + V3 + V5) / V1 in some embodiments may be 1.2, 1.25, 1.3, 1.35, 1.4, 1.5, 1.6, 1.7, 1.8, or 1.9. When the above relationship is satisfied, the longitudinal chromatic aberration of the system can be corrected, the selection of lens materials can be made uniform, and the system can have good imaging quality.

[0083] -20 < (R51 + R52) / (R51 - R52) < 1; where R51 is the curvature radius of the object side surface S9 of the fifth lens L5 at the optical axis, and R52 is the curvature radius of the image side surface S10 of the fifth lens L5 at the optical axis. Specifically, (R51 + R52) / (R51 - R52) in some embodiments may be -17.5, -17, -16.5, -16, -10, -5, -1, 0.2, 0.25, 0.3, 0.4, or 0.45. When the above relationship is satisfied, the surface shapes of the object side surface S9 and the image side surface S10 of the fifth lens L5 can be reasonably optimized, which is beneficial to correcting the aberration and field curvature of the system and improving the imaging quality.

[0084] 1 < f1 / f < 2; where f1 is the effective focal length of the first lens L1, and f is the total effective focal length of the optical system 10. Specifically, in some embodiments, f1 / f can be 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.5, 1.7, 1.8, 1.85, or 1.9. The first lens L1 provides positive refractive power for the system, and when the above relationship is satisfied, it can effectively correct the field curvature of the system and is beneficial to controlling the length of the system.

[0085] 0.7 < SAG51 / SAG61 < 1.6; where SAG51 is the maximum sagitta of the object side surface S9 of the fifth lens L5, and SAG61 is the maximum sagitta of the object side surface S11 of the sixth lens L6. The sagitta is the distance from the center of the corresponding surface (such as the object side surface S9 of the fifth lens L5 or the object side surface S11 of the sixth lens L6 above) (the intersection of this surface and the optical axis) to the maximum effective radius of this surface in the direction parallel to the optical axis. When this value is negative, in the direction parallel to the optical axis of the system, the center of this surface is closer to the image side of the system than the maximum effective radius; when this value is positive, in the direction parallel to the optical axis of the system, the center of this surface is closer to the object side of the system than the maximum effective radius. Specifically, in some embodiments, SAG51 / SAG61 can be 0.75, 0.8, 0.85, 0.9, 1, 1.1, 1.2, 1.3, 1.45, 1.5, or 1.55. When the above relationship is satisfied, the object side surface S9 of the fifth lens L5 and the object side surface S11 of the sixth lens L6 maintain similar curvatures, so that the fifth lens L5 and the sixth lens L6 can be more closely matched, and it is also more beneficial to compress the length of the system.

[0086] 0.39 < ΣAT / ΣCT < 0.56; where ΣAT is the sum of the air gaps between adjacent lenses on the optical axis in the optical system 10, and ΣCT is the sum of the thicknesses of the lenses on the optical axis in the optical system 10. Specifically, in some embodiments, ΣAT / ΣCT can be 0.4, 0.42, 0.45, 0.48, 0.5, 0.52, 0.53, 0.54, or 0.55. When the above relationship is satisfied, the distance between adjacent lenses can be reasonably optimized. While ensuring that the thickness of the lenses is conducive to processing and forming, the air gaps between adjacent lenses can be more fully compressed, thus meeting the miniaturization design trend of the lens. When below the lower limit of the above relationship, the thickness of the lens is too thin, which is not conducive to the forming of the lens, or the air gap between adjacent lenses is too small, and the degree of freedom of lens shape change is insufficient to correct the system aberration well; when above the upper limit of the above relationship, the air gap between lenses is too large, which is not conducive to the ultra-thin design.

[0087] Next, the optical system 10 of the present application will be described with more specific and detailed embodiments:

[0088] First Embodiment

[0089] Reference Figure 1 , in the first embodiment, the optical system 10 includes, in order from the object side to the image side, a stop STO, a first lens L1 with positive refractive power, a second lens L2 with positive refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with negative refractive power, and a sixth lens L6 with negative refractive power. Figure 2 Includes the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system 10 in the first embodiment. The reference wavelength for the astigmatism diagram and distortion diagram of the following embodiments (the first embodiment to the seventh embodiment) is 555 nm.

[0090] The object side surface S1 of the first lens L1 is convex at the paraxial region and concave at the paraxial region; the object side surface S1 is convex at the circumference and the image side surface S2 is concave at the circumference.

[0091] The object side surface S3 of the second lens L2 is concave at the paraxial region and the image side surface S4 is convex at the paraxial region; the object side surface S3 is convex at the circumference and the image side surface S4 is convex at the circumference.

[0092] The object side surface S5 of the third lens L3 is concave at the paraxial region and the image side surface S6 is convex at the paraxial region; the object side surface S5 is concave at the circumference and the image side surface S6 is convex at the circumference.

[0093] The object side surface S7 of the fourth lens L4 is concave at the paraxial region and the image side surface S8 is convex at the paraxial region; the object side surface S7 is concave at the circumference and the image side surface S8 is convex at the circumference.

[0094] The object side surface S9 of the fifth lens L5 is concave at the paraxial region and the image side surface S10 is concave at the paraxial region; the object side surface S9 is concave at the circumference and the image side surface S10 is convex at the circumference.

[0095] The object side surface S11 of the sixth lens L6 is convex at the paraxial region and the image side surface S12 is concave at the paraxial region; the object side surface S11 is convex at the circumference and the image side surface S12 is convex at the circumference.

[0096] The object side surface and the image side surface of each lens in the optical system 10 are aspherical surfaces. The aspherical design enables the lens to well solve the problems of unclear imaging, distorted field of view, narrow field of view, etc. under the conditions of being smaller and thinner, and helps to shorten the length of the optical system 10. In addition, there are inflection points on the object side surface and the image side surface of the fifth lens L5 and the sixth lens L6. The material of each lens in the optical system 10 is plastic.

[0097] In the first embodiment, the optical system 10 satisfies the following relationships:

[0098] tanω / D11 = 1.005 mm -1 ;

[0099] f123 / f456 = 0.302;

[0100] Wherein, ω is half of the maximum field of view angle of the optical system 10, D11 is the maximum effective semi-aperture of the object side surface S1 of the first lens L1, f123 is the combined focal length of the first lens L1, the second lens L2 and the third lens L3, f456 is the combined focal length of the fourth lens L4, the fifth lens L5 and the sixth lens L6, the unit of ω is degree, and the unit of D11 is millimeter. When the optical system 10 satisfies the above-mentioned diaphragm STO, lens configuration and the relationship condition of tanω / D11, the front aperture of the optical system 10 can be fully compressed, which is beneficial to the design of the small head shape. In addition, the viewing angle range of the system can be expanded, so that the optical system 10 can obtain a more comprehensive scene. At the same time, when the optical system 10 satisfies the above-mentioned relational expression condition of f123 / f456, the lens group composed of the first lens L1, the second lens L2 and the third lens L3 can provide most of the positive refractive power for the optical system 10, so as to better converge and image the incident light, thereby shortening the total length of the system. In addition, when the above relationship is satisfied, the system resolution ability can also be improved. Above all, the optical system 10 can realize the small head design by reducing the front aperture. Thus, when the optical system 10 is applied as a front lens in the device, the under-screen opening of the device can be effectively reduced to increase the screen-to-body ratio. In addition, the device can also have large viewing angle and high-resolution imaging performance.

[0101] D62 / D11 = 3.454; wherein, D62 is the maximum effective semi-aperture of the image side surface S12 of the sixth lens L6. When the above relationship is satisfied, it is beneficial to the small-aperture design of the first lens L1 in the system, so that the system has a small head shape structure.

[0102] 10 * FNO / ω = 0.404 deg -1 ; wherein, FNO is the f-number of the optical system 10. The smaller the f-number, the larger the entrance pupil diameter of the system under the same focal length, and the more sufficient the light input. Thus, the overall imaging of the system will be brighter and clearer. However, at the same time, it will be difficult to increase the field of view angle of the system. When the above relationship is satisfied, the optical system 10 can have both the characteristics of high light input and wide viewing angle.

[0103] ImgH / TL = 0.76; wherein, ImgH is half of the length of the imaging surface of the optical system 10 in the diagonal direction, and TL is the distance from the object side surface S1 of the first lens L1 to the imaging surface of the optical system 10 on the optical axis. When the above relationship is satisfied, the total length of the optical system 10 can be effectively compressed, which is beneficial to the miniaturization design.

[0104] (V2 + V3 + V5) / V1 = 1.636; where, V1 is the Abbe number of the first lens L1, V2 is the Abbe number of the second lens L2, V3 is the Abbe number of the third lens L3, and V5 is the Abbe number of the fifth lens L5. When the above relationship is satisfied, the longitudinal chromatic aberration of the system can be corrected, and the selection of the lens material can be made uniform, enabling the system to have good imaging quality.

[0105] (R51 + R52) / (R51 - R52) = 0.375; where, R51 is the curvature radius of the object side surface S9 of the fifth lens L5 on the optical axis, and R52 is the curvature radius of the image side surface S10 of the fifth lens L5 on the optical axis. When the above relationship is satisfied, the surface profiles of the object side surface S9 and the image side surface S10 of the fifth lens L5 can be reasonably optimized, which is beneficial to correcting the aberration and field curvature of the system and improving the imaging quality.

[0106] f1 / f = 1.322; where, f1 is the effective focal length of the first lens L1, and f is the total effective focal length of the optical system 10. The first lens L1 provides positive refractive power for the system, and when the above relationship is satisfied, the field curvature of the system can be effectively corrected, and it is beneficial to control the length of the system.

[0107] SAG51 / SAG61 = 0.83; where, SAG51 is the maximum sag of the object side surface S9 of the fifth lens L5, and SAG61 is the maximum sag of the object side surface S11 of the sixth lens L6. When the above relationship is satisfied, the object side surface S9 of the fifth lens L5 and the object side surface S11 of the sixth lens L6 maintain similar curvatures, which can enable the fifth lens L5 and the sixth lens L6 to cooperate more closely and is also more beneficial to compressing the length of the system.

[0108] ΣAT / ΣCT = 0.437; where, ΣAT is the sum of the air gaps between adjacent lenses on the optical axis in the optical system 10, and ΣCT is the sum of the thicknesses of the lenses on the optical axis in the optical system 10. When the above relationship is satisfied, the distance between adjacent lenses can be reasonably optimized. While ensuring that the thickness of the lenses is beneficial for processing and forming, the air gap between adjacent lenses can be more fully compressed, thus meeting the miniaturization design trend of the lens.

[0109] In addition, the lens parameters of the optical system 10 are given in Table 1 and Table 2. Table 2 shows the aspherical coefficients of the corresponding surfaces of each lens in Table 1, where K is the conic coefficient and Ai is the coefficient corresponding to the i-th high-order term in the aspherical surface formula. The components from the object side to the image side are arranged in the order of the components in Table 1 from top to bottom. The image plane (imaging plane S13) can be understood as the photosensitive surface of the photosensitive element during later assembly with the photosensitive element. The surface numbers 2 and 3 correspond to the object side surface S1 and the image side surface S2 of the first lens L1 respectively. That is, in the same lens, the surface with the smaller surface number is the object side surface, and the surface with the larger surface number is the image side surface. The Y radius in Table 1 is the radius of curvature of the object side surface or the image side surface with the corresponding surface number at the optical axis. The first value in the "thickness" parameter column of the lens is the thickness of the lens on the optical axis, and the second value is the distance on the optical axis from the image side surface of the lens to the object side surface of the next optical element. The value in the "thickness" parameter column of the aperture stop ST0 is the distance on the optical axis from the aperture stop ST0 to the vertex of the object side surface of the next lens (the vertex refers to the intersection of the lens and the optical axis). We default that the direction from the object side to the image side is the positive direction of the optical axis. When this value is negative, it indicates that the aperture stop ST0 is set on the right side of the vertex of the object side surface of the lens (that is, the vertex of this object side surface passes through the aperture stop STO, and the right side can also be understood as the image side). When the "thickness" parameter of the aperture stop STO is positive, the aperture stop ST0 is on the left side of the vertex of the object side surface of the lens. The optical axes of the lenses in the embodiments of the present application are on the same straight line, and this straight line serves as the optical axis of the optical system 10. The reference wavelength for the parameter tables in the following embodiments is 555 nm. In addition, the relational calculations and lens structures in each embodiment are based on the data in the parameter tables (such as Table 1, Table 2, Table 3, Table 4, etc.).

[0110] In the first embodiment, the total effective focal length f of the optical system 10 is 3.73 mm, the f-number FNO is 1.85, half of the maximum field angle in the diagonal direction (1 / 2)ω is 45.777°, and the total optical length TL is 5.26 mm. The total optical length is the distance on the optical axis from the object side surface S1 of the first lens L1 to the imaging surface S13 of the optical system 10.

[0111] Table 1

[0112]

[0113] Table 2

[0114]

[0115]

[0116] Second Embodiment

[0117] Reference Figure 3, in the second embodiment, the optical system 10 includes, in order from the object side to the image side, a stop STO, a first lens L1 with positive refractive power, a second lens L2 with positive refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, and a sixth lens L6 with negative refractive power. Figure 4 Include the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system 10 in the second embodiment.

[0118] The object side surface S1 of the first lens L1 is convex at the paraxial region and concave at the paraxial region; the object side surface S1 is convex at the circumference and the image side surface S2 is concave at the circumference.

[0119] The object side surface S3 of the second lens L2 is convex at the paraxial region and the image side surface S4 is convex at the paraxial region; the object side surface S3 is convex at the circumference and the image side surface S4 is concave at the circumference.

[0120] The object side surface S5 of the third lens L3 is concave at the paraxial region and the image side surface S6 is convex at the paraxial region; the object side surface S5 is concave at the circumference and the image side surface S6 is convex at the circumference.

[0121] The object side surface S7 of the fourth lens L4 is concave at the paraxial region and the image side surface S8 is convex at the paraxial region; the object side surface S7 is concave at the circumference and the image side surface S8 is convex at the circumference.

[0122] The object side surface S9 of the fifth lens L5 is convex at the paraxial region and the image side surface S10 is concave at the paraxial region; the object side surface S9 is concave at the circumference and the image side surface S10 is convex at the circumference.

[0123] The object side surface S11 of the sixth lens L6 is convex at the paraxial region and the image side surface S12 is concave at the paraxial region; the object side surface S11 is concave at the circumference and the image side surface S12 is convex at the circumference.

[0124] In addition, the parameters of each lens of the optical system 10 in the second embodiment are given in Tables 3 and 4, where the definitions of each structure and parameter can be obtained from the first embodiment and will not be elaborated here.

[0125] Table 3

[0126]

[0127]

[0128] Table 4

[0129]

[0130] The optical system 10 in this embodiment satisfies the following relationship:

[0131] tanω / D11 1.036 (V2 + V3 + V5) / V1 1.901 f123 / f456 0.147 (R51 + R52) / (R51 - R52) -17.714 D62 / D11 3.521 f1 / f 1.231 10*FNO / ω 0.502 SAG51 / SAG61 0.704 ImgH / TL 0.742 ΣAT / ΣCT 0.464

[0132] Third Embodiment

[0133] Reference Figure 5 , in the third embodiment, the optical system 10 includes, in order from the object side to the image side, a 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, and a sixth lens L6 with negative refractive power. Figure 6 Include the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system 10 in the third embodiment.

[0134] The object side surface S1 of the first lens L1 is convex at the paraxial region and concave at the paraxial region; the object side surface S1 is convex at the circumference and the image side surface S2 is convex at the circumference.

[0135] The object side surface S3 of the second lens L2 is concave at the paraxial region and the image side surface S4 is concave at the paraxial region; the object side surface S3 is concave at the circumference and the image side surface S4 is concave at the circumference.

[0136] The object side surface S5 of the third lens L3 is convex at the paraxial region and the image side surface S6 is concave at the paraxial region; the object side surface S5 is concave at the circumference and the image side surface S6 is convex at the circumference.

[0137] The object side surface S7 of the fourth lens L4 is concave at the paraxial region and the image side surface S8 is convex at the paraxial region; the object side surface S7 is concave at the circumference and the image side surface S8 is convex at the circumference.

[0138] The object side surface S9 of the fifth lens L5 is concave at the paraxial region and the image side surface S10 is concave at the paraxial region; the object side surface S9 is concave at the circumference and the image side surface S10 is convex at the circumference.

[0139] The object side surface S11 of the sixth lens L6 is convex at the paraxial region and the image side surface S12 is concave at the paraxial region; the object side surface S11 is convex at the circumference and the image side surface S12 is convex at the circumference.

[0140] In addition, the parameters of each lens of the optical system 10 in the third embodiment are given in Table 5 and Table 6, where the definitions of each structure and parameter can be obtained from the first embodiment and will not be elaborated here.

[0141] Table 5

[0142]

[0143] Table 6

[0144]

[0145]

[0146] The optical system 10 in this embodiment satisfies the following relationship:

[0147] tanω / D11 1.154 (V2 + V3 + V5) / V1 1.219 f123 / f456 0.686 (R51 + R52) / (R51 - R52) 0.48 D62 / D11 3.578 f1 / f 1.145 10*FNO / ω 0.424 SAG51 / SAG61 1.595 ImgH / TL 0.763 ΣAT / ΣCT 0.471

[0148] Fourth Embodiment

[0149] Reference Figure 7 , in the fourth embodiment, the optical system 10 sequentially includes a stop STO, a first lens L1 with positive refractive power, a second lens L2 with positive refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with negative refractive power, and a sixth lens L6 with negative refractive power from the object side to the image side. Figure 8 Include the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system 10 in the fourth embodiment.

[0150] The object side surface S1 of the first lens L1 is convex at the paraxial region and concave at the paraxial region; the object side surface S1 is convex at the circumference and the image side surface S2 is concave at the circumference.

[0151] The object side surface S3 of the second lens L2 is convex at the paraxial region and concave at the paraxial region; the object side surface S3 is convex at the circumference and the image side surface S4 is concave at the circumference.

[0152] The object side surface S5 of the third lens L3 is concave at the paraxial region and convex at the paraxial region; the object side surface S5 is concave at the circumference and the image side surface S6 is convex at the circumference.

[0153] The object side surface S7 of the fourth lens L4 is concave at the paraxial region and convex at the paraxial region; the object side surface S7 is concave at the circumference and the image side surface S8 is convex at the circumference.

[0154] The object side surface S9 of the fifth lens L5 is concave at the paraxial region and concave at the paraxial region; the object side surface S9 is concave at the circumference and the image side surface S10 is convex at the circumference.

[0155] The object side surface S11 of the sixth lens L6 is convex at the paraxial region and concave at the paraxial region; the object side surface S11 is concave at the circumference and the image side surface S12 is convex at the circumference.

[0156] In addition, the parameters of each lens of the optical system 10 in the fourth embodiment are given in Tables 7 and 8, where the definitions of each structure and parameter can be obtained from the first embodiment and will not be elaborated here.

[0157] Table 7

[0158]

[0159]

[0160] Table 8

[0161]

[0162] The optical system 10 in this embodiment satisfies the following relationship:

[0163]

[0164]

[0165] The Fifth Embodiment

[0166] Reference Figure 9 , in the fifth embodiment, the optical system 10 sequentially includes a 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, and a sixth lens L6 with negative refractive power from the object side to the image side. Figure 10 Include the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system 10 in the fifth embodiment.

[0167] The object side surface S1 of the first lens L1 is convex at the paraxial region and concave at the paraxial region; the object side surface S1 is convex at the circumference and the image side surface S2 is concave at the circumference.

[0168] The object side surface S3 of the second lens L2 is convex at the paraxial region and concave at the paraxial region; the object side surface S3 is convex at the circumference and the image side surface S4 is concave at the circumference.

[0169] The object side surface S5 of the third lens L3 is convex at the paraxial region and concave at the paraxial region; the object side surface S5 is convex at the circumference and the image side surface S6 is concave at the circumference.

[0170] The object side surface S7 of the fourth lens L4 is concave at the paraxial region and convex at the paraxial region; the object side surface S7 is concave at the circumference and the image side surface S8 is convex at the circumference.

[0171] The object side surface S9 of the fifth lens L5 is concave at the paraxial region and concave at the paraxial region; the object side surface S9 is concave at the circumference and the image side surface S10 is convex at the circumference.

[0172] The object side surface S11 of the sixth lens L6 is convex at the paraxial region and concave at the paraxial region; the object side surface S11 is concave at the circumference and the image side surface S12 is convex at the circumference.

[0173] In addition, the lens parameters of the optical system 10 in the fifth embodiment are given in Tables 9 and 10, where the definitions of each structure and parameter can be obtained from the first embodiment and will not be elaborated here.

[0174] Table 9

[0175]

[0176] Table 10

[0177]

[0178] The optical system 10 in this embodiment satisfies the following relationship:

[0179] tanω / D11 1.074 (V2 + V3 + V5) / V1 1.194 f123 / f456 0.405 (R51 + R52) / (R51 - R52) -0.094 D62 / D11 3.455 f1 / f 1.358 10*FNO / ω 0.464 SAG51 / SAG61 0.886 ImgH / TL 0.755 ΣAT / ΣCT 0.558

[0180] Sixth Embodiment

[0181] Reference Figure 11 , in the sixth embodiment, the optical system 10 includes, in order from the object side to the image side, a stop STO, a first lens L1 with positive refractive power, a second lens L2 with positive refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with negative refractive power, and a sixth lens L6 with negative refractive power. Figure 12 Include the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system 10 in the sixth embodiment.

[0182] The object side surface S1 of the first lens L1 is convex at the paraxial region and concave at the paraxial region; the object side surface S1 is convex at the circumference and the image side surface S2 is concave at the circumference.

[0183] The object side surface S3 of the second lens L2 is convex at the paraxial region and the image side surface S4 is convex at the paraxial region; the object side surface S3 is convex at the circumference and the image side surface S4 is convex at the circumference.

[0184] The object side surface S5 of the third lens L3 is concave at the paraxial region and the image side surface S6 is convex at the paraxial region; the object side surface S5 is concave at the circumference and the image side surface S6 is convex at the circumference.

[0185] The object side surface S7 of the fourth lens L4 is concave at the paraxial region and the image side surface S8 is convex at the paraxial region; the object side surface S7 is concave at the circumference and the image side surface S8 is convex at the circumference.

[0186] The object side surface S9 of the fifth lens L5 is concave at the paraxial region and the image side surface S10 is concave at the paraxial region; the object side surface S9 is concave at the circumference and the image side surface S10 is convex at the circumference.

[0187] The object side surface S11 of the sixth lens L6 is convex near the axis, and the image side surface S12 is concave near the axis; the object side surface S11 is convex at the circumference, and the image side surface S12 is convex at the circumference.

[0188] In addition, the lens parameters of the optical system 10 in the sixth embodiment are given in Tables 11 and 12, where the definitions of each structure and parameter can be obtained from the first embodiment and will not be elaborated here.

[0189] Table 11

[0190]

[0191] Table 12

[0192]

[0193]

[0194] The optical system 10 in this embodiment satisfies the following relationships:

[0195] tanω / D11 1.982 (V2 + V3 + V5) / V1 1.686 f123 / f456 0.376 (R51 + R52) / (R51 - R52) 0.229 D62 / D11 5.049 f1 / f 1.942 10*FNO / ω 0.435 SAG51 / SAG61 0.944 ImgH / TL 0.879 ΣAT / ΣCT 0.397

[0196] Seventh Embodiment

[0197] Reference Figure 13 , in the seventh embodiment, the optical system 10 sequentially includes a stop STO, a first lens L1 with positive refractive power, a second lens L2 with positive refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with negative refractive power, and a sixth lens L6 with negative refractive power from the object side to the image side. Figure 14 It includes the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system 10 in the seventh embodiment.

[0198] The object side surface S1 of the first lens L1 is convex near the axis, and the image side surface S2 is concave near the axis; the object side surface S1 is convex at the circumference, and the image side surface S2 is concave at the circumference.

[0199] The object side surface S3 of the second lens L2 is convex near the axis, and the image side surface S4 is convex near the axis; the object side surface S3 is convex at the circumference, and the image side surface S4 is concave at the circumference.

[0200] The object side surface S5 of the third lens L3 is concave near the axis, and the image side surface S6 is convex near the axis; the object side surface S5 is concave at the circumference, and the image side surface S6 is convex at the circumference.

[0201] The object side surface S7 of the fourth lens L4 is concave near the axis, and the image side surface S8 is convex near the axis; the object side surface S7 is concave at the circumference, and the image side surface S8 is convex at the circumference.

[0202] The object side surface S9 of the fifth lens L5 is concave at the paraxial region, and the image side surface S10 is concave at the paraxial region; the object side surface S9 is concave at the peripheral region, and the image side surface S10 is convex at the peripheral region.

[0203] The object side surface S11 of the sixth lens L6 is convex at the paraxial region, and the image side surface S12 is concave at the paraxial region; the object side surface S11 is concave at the peripheral region, and the image side surface S12 is convex at the peripheral region.

[0204] In addition, the parameters of each lens of the optical system 10 in the seventh embodiment are given in Table 13 and Table 14, where the definitions of each structure and parameter can be obtained from the first embodiment and will not be elaborated here.

[0205] Table 13

[0206]

[0207]

[0208] Table 14

[0209]

[0210] The optical system 10 in this embodiment satisfies the following relationship:

[0211] tanω / D11 1.083 (V2 + V3 + V5) / V1 1.686 f123 / f456 0.277 (R51 + R52) / (R51 - R52) 0.304 D62 / D11 3.716 f1 / f 1.243 10*FNO / ω 0.519 SAG51 / SAG61 0.846 ImgH / TL 0.741 ΣAT / ΣCT 0.492

[0212] Reference Figure 15 , some embodiments of the present application further provide an imaging module 20. The optical system 10 is assembled with the photosensitive element 210 to form the imaging module 20. The photosensitive element 210 is disposed on the image side of the sixth lens L6, that is, on the image side of the optical system 10. Generally, the photosensitive surface of the photosensitive element 210 overlaps with the imaging surface S13 of the optical system 10, or the photosensitive surface can also be understood as the imaging surface S13. The photosensitive element 210 can be a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). By adopting the above optical system 10, the imaging module 20 will also have the characteristics of a small head, a large viewing angle, and high resolution.

[0213] In some embodiments, an infrared filter L7 is further disposed between the sixth lens L6 and the imaging surface S13 of the system. The infrared filter L7 is used to filter infrared light. The infrared filter L7 can be a part of the optical system 10, or can also be installed between the optical system 10 and the photosensitive element 210 when the optical system 10 and the photosensitive element 210 are assembled.

[0214] In some embodiments, the distance between the photosensitive element 210 and each lens in the optical system 10 is relatively fixed. At this time, the imaging module 20 is a fixed-focus module. In other embodiments, a driving mechanism such as a voice coil motor can be provided to enable the photosensitive element 210 to move relative to each lens in the optical system 10, thereby achieving a focusing effect. Specifically, a coil electrically connected to a driving chip is provided on the lens barrel for assembling each of the above lenses. At the same time, a magnet is provided in the imaging module 20. The magnetic force between the energized coil and the magnet is used to drive the lens barrel to move relative to the photosensitive element 210, thereby achieving a focusing effect. In other embodiments, a similar driving mechanism can also be provided to drive some lenses in the optical system 10 to move, thereby achieving an optical zoom effect.

[0215] Reference Figure 16 , some embodiments of the present application further provide an electronic device 30. The imaging module 20 is applied to the electronic device 30 to enable the electronic device 30 to have an imaging function. Specifically, the electronic device 30 includes a fixing member 310, and the imaging module 20 is installed on the fixing member 310. The fixing member 310 can be components such as a circuit board or a middle frame. The electronic device 30 can be, but is not limited to, a smart phone, a smart watch, an e-book reader, a vehicle-mounted imaging device (such as a driving recorder), a monitoring device, a medical device (such as an endoscope), a tablet computer, a biometric device (such as a fingerprint recognition device or a pupil recognition device, etc.), a PDA (Personal Digital Assistant), a drone, etc. Specifically, in one embodiment, the electronic device 30 is a smart phone. The smart phone includes a middle frame and a circuit board. The circuit board is disposed in the middle frame. The imaging module 20 is installed on the middle frame of the smart phone, and the photosensitive element 210 therein is electrically connected to the circuit board. The imaging module 20 can be used as a front camera module or a rear camera module of the smart phone. When the above imaging module 20 is used as the front camera module of the device, the under-screen opening of the device can be effectively reduced to increase the screen-to-body ratio. In addition, the device can also have a large viewing angle and high-resolution imaging performance.

[0216] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered as the scope recorded in this specification.

[0217] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent should be subject to the appended claims.

Claims

1. An optical system, characterized in that, it has a diaphragm and six lenses, and the number of lenses with refractive power in the optical system is six. From the object side to the image side, it successively includes: the diaphragm; a first lens with positive refractive power, the object side surface of the first lens is convex at the paraxial region, and the image side surface is concave at the paraxial region; a second lens with refractive power; a third lens with refractive power; a fourth lens with positive refractive power, the object side surface of the fourth lens is concave, and the image side surface is convex; a fifth lens with refractive power, the image side surface of the fifth lens is concave at the paraxial region; a sixth lens with negative refractive power, the object side surface of the sixth lens is convex at the paraxial region, and the image side surface is concave at the paraxial region; the optical system satisfies the following relationship: 1mm -1 <tanω / D11<2mm -1 ; and 0 < f123 / f456 < 1.0; where ω is half of the maximum field angle of the optical system, D11 is the maximum effective semi-aperture of the object side surface of the first lens, f123 is the combined focal length of the first lens, the second lens and the third lens, and f456 is the combined focal length of the fourth lens, the fifth lens and the sixth lens; the optical system satisfies the following relationship: 3.4 < D62 / D11 < 5.1; where D62 is the maximum effective semi-aperture of the image side surface of the sixth lens.

2. The optical system according to claim 1, characterized in that, it satisfies the following relationship: 0.40deg -1 <10*FNO / ω<0.52deg -1 ; where FNO is the f-number of the optical system.

3. The optical system according to claim 1, characterized in that, it satisfies the following relationship: 0.7 < ImgH / TL < 0.9; where ImgH is half of the diagonal length of the effective imaging area of the imaging surface of the optical system, and TL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis.

4. The optical system according to claim 1, characterized in that, at least one of the second lens and the third lens has negative refractive power, and the optical system satisfies the following relationship: 1 < (V2 + V3 + V5) / V1 < 2; where V1 is the Abbe number of the first lens, V2 is the Abbe number of the second lens, V3 is the Abbe number of the third lens, and V5 is the Abbe number of the fifth lens.

5. The optical system according to claim 1, characterized in that, it satisfies the following relationship: -20 < (R51 + R52) / (R51 - R52) < 1; where R51 is the curvature radius of the object side surface of the fifth lens on the optical axis, and R52 is the curvature radius of the image side surface of the fifth lens on the optical axis.

6. The optical system according to claim 1, characterized in that, it satisfies the following relationship: 1 < f1 / f < 2; where f1 is the effective focal length of the first lens, and f is the total effective focal length of the optical system.

7. The optical system according to claim 1, characterized in that, it satisfies the following relationship: 0.7 < SAG51 / SAG61 < 1.6; where SAG51 is the maximum sagittal height of the object side surface of the fifth lens, and SAG61 is the maximum sagittal height of the object side surface of the sixth lens.

8. The optical system according to claim 1, characterized in that, the following relationship is satisfied: 0.39 < ΣAT / ΣCT < 0.56; wherein, ΣAT is the sum of the air gaps between adjacent lenses on the optical axis in the optical system, and ΣCT is the sum of the thicknesses of the lenses on the optical axis in the optical system.

9. An imaging module, characterized in that, it includes a photosensitive element and the optical system according to any one of claims 1 to 8, and the photosensitive element is disposed on the image side of the optical system.

10. An electronic device, characterized in that, it includes a fixing member and the imaging module according to claim 9, and the imaging module is disposed on the fixing member.

Images