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 comprises: a first lens with positive refractive power, the object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis; a second lens with negative refractive power, the object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis; a third lens with refractive power, the object side surface is convex at the near optical axis; a fourth lens with refractive power, the object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis; a fifth lens with refractive power, the object side surface is concave at the near optical axis, and the image side surface is convex at the near optical axis; a sixth lens with refractive power; a seventh lens with refractive power; an eighth lens with negative refractive power, the image side surface is concave at the near optical axis; the optical system satisfies: 7.2mm≤f*tan(HFOV)≤7.4mm. The above optical system has a large image surface characteristic and good imaging quality.

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 rapid development of camera technology, more and more electronic devices such as smart phones, tablet computers, and e-readers are equipped with optical systems to realize camera functions. In order to meet user needs, the market has higher and higher requirements for the imaging quality of electronic devices. High-quality imaging can bring users a high-quality shooting experience. However, the current optical system imaging quality needs to be improved. Summary of the invention

[0003] Based on this, it is necessary to provide an optical system, an imaging module and an electronic device to improve the imaging quality of the optical system.

[0004] An optical system, comprising, in order from the object side to the image side along the optical axis:

[0005] A first lens having positive refractive power, wherein the object side surface of the first lens is convex at the near optical axis, and the image side surface of the first lens is concave at the near optical axis;

[0006] a second lens having negative refractive power, wherein the object side surface of the second lens is convex at the near optical axis, and the image side surface of the second lens is concave at the near optical axis;

[0007] a third lens having refractive power, wherein the object side surface of the third lens is convex at a position close to the optical axis;

[0008] a fourth lens having a refractive power, wherein the object side surface of the fourth lens is a convex surface at the near optical axis, and the image side surface of the fourth lens is a concave surface at the near optical axis;

[0009] a fifth lens having a refractive power, wherein the object side surface of the fifth lens is a concave surface at the near optical axis, and the image side surface of the fifth lens is a convex surface at the near optical axis;

[0010] a sixth lens having a refractive power;

[0011] a seventh lens having refractive power;

[0012] an eighth lens element having negative refractive power, wherein the image side surface of the eighth lens element is concave at a near optical axis;

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

[0014] 7.2mm≤f*tan(HFOV)≤7.4mm;

[0015] Wherein, f is the effective focal length of the optical system, and HFOV is half of the maximum field of view of the optical system.

[0016] In the above optical system, the first lens has a positive refractive power, which is conducive to shortening the total length of the optical system and realizing a miniaturized design. The second lens has a negative refractive power, which is conducive to correcting the aberration generated by the first lens and improving the imaging quality. The combination of the first lens and the second lens is conducive to correcting the on-axis spherical aberration of the optical system and improving the imaging quality. The object side surfaces of the first lens and the second lens are both convex at the near optical axis, and the image side surfaces are both concave at the near optical axis, which is conducive to the convergence of light in the optical system, thereby shortening the total length of the optical system and improving the imaging quality of the optical system. The object side surface of the third lens is a convex surface at the near optical axis, which is conducive to converging light, thereby shortening the total length of the optical system. The fourth lens and the fifth lens are both meniscus lenses, which are conducive to correcting astigmatism, field curvature and distortion of the optical system. The fifth lens, the sixth lens and the seventh lens with refractive power are provided, which is conducive to correcting the coma of the optical system. The eighth lens has a negative refractive power, which is conducive to correcting the field curvature of the optical system. The image side surface of the eighth lens is a concave surface at the near optical axis, which is conducive to reducing the sensitivity of the optical system and facilitating the engineering manufacturing of the optical system.

[0017] When the above conditions are met, the optical system can achieve a large image surface characteristic, thereby being able to match a larger photosensitive element, so that the optical system has the characteristics of high pixels and high definition, thereby improving the imaging quality of the optical system.

[0018] In one embodiment, the optical system satisfies the following condition:

[0019] 1.2≤TTL / ImgH≤1.3;

[0020] 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 optical length of the optical system, and ImgH is half of the image height corresponding to the maximum field angle of the optical system. When the above conditional formula is met, it is beneficial to shorten the total length of the optical system, thereby facilitating miniaturization design.

[0021] In one embodiment, the optical system satisfies the following condition:

[0022] 1.0≤CT3 / ET3≤1.7;

[0023] Among them, CT3 is the thickness of the third lens on the optical axis, and ET3 is the distance from the maximum effective aperture of the object side of the third lens to the maximum effective aperture of the image side of the third lens in the direction of the optical axis, that is, the edge thickness of the third lens. When the above conditional formula is met, the surface shape of the third lens can be reasonably configured so that the surface shape of the third lens is not too flat or overly curved, which is beneficial to the processing and molding of the third lens and improves the molding yield; at the same time, the surface shape of the third lens is reasonably configured so that the surface shape of the third lens is not too flat or overly curved, which is beneficial to the third lens to better correct the field curvature of the optical system and improve the imaging quality of the optical system.

[0024] In one embodiment, the optical system satisfies the following condition:

[0025] 1.5≤|R7+R8| / |R7-R8|≤8.0;

[0026] Wherein, R7 is the radius of curvature of the object side of the fourth lens at the optical axis, and R8 is the radius of curvature of the image side of the fourth lens at the optical axis. When the above conditional formula is met, the thickness ratio between the center and the edge of the fourth lens can be reasonably configured, so that the surface of the fourth lens will not be too flat or overly curved, which is conducive to reducing the tolerance sensitivity of the fourth lens and improving the molding yield; at the same time, it is also conducive to the fourth lens to better balance the high-order coma of the optical system and improve the imaging quality of the optical system.

[0027] In one embodiment, the optical system satisfies the following condition:

[0028] 0.2≤|f8 / (f2+f3)|≤5.2;

[0029] Wherein, f8 is the effective focal length of the eighth lens, f2 is the effective focal length of the second lens, and f3 is the effective focal length of the third lens. When the above conditional formula is satisfied, the ratio of the refractive power of the eighth lens to the sum of the refractive powers of the second lens and the third lens can be reasonably configured, so that the spherical aberration contribution of the second lens, the third lens and the eighth lens in the optical system can be reasonably allocated, thereby improving the imaging quality of the on-axis area of ​​the optical system.

[0030] In one embodiment, the optical system satisfies the following condition:

[0031] 0.9≤f1 / f≤1.1;

[0032] Wherein, f1 is the effective focal length of the first lens. When the above conditional formula is met, the ratio of the effective focal length of the first lens to the optical system can be reasonably configured, so that the refractive power of the first lens is not too strong, which is conducive to correcting the high-order spherical aberration of the optical system and improving the imaging quality of the optical system.

[0033] In one embodiment, the optical system satisfies the following condition:

[0034] 1.0≤|SAG61 / CT6|≤2.0;

[0035] Wherein, SAG61 is the distance from the intersection of the object side surface of the sixth lens and the optical axis to the maximum effective aperture of the object side surface of the sixth lens in the direction of the optical axis, wherein, when the maximum effective aperture of the object side surface of the sixth lens is located on the image side of the intersection of the object side surface of the sixth lens and the optical axis, the value of SAG61 is positive, and when the maximum effective aperture of the object side surface of the sixth lens is located on the object side of the intersection of the object side surface of the sixth lens and the optical axis, the value of SAG61 is negative, and CT6 is the thickness of the sixth lens on the optical axis. When the above conditional formula is met, the surface shape of the sixth lens can be reasonably configured so that the surface shape of the sixth lens is not too flat or overly curved, which is conducive to reducing the tolerance sensitivity of the sixth lens, and then is conducive to the processing and molding of the sixth lens, and improves the molding yield.

[0036] In one embodiment, the optical system satisfies the following condition:

[0037] 0.1≤D6 / CT7≤1.0;

[0038] Wherein, D6 is the distance from the image side surface of the sixth lens to the object side surface of the seventh lens on the optical axis, and CT7 is the thickness of the seventh lens on the optical axis. When the above conditional formula is met, the ratio of the air spacing between the sixth lens and the seventh lens on the optical axis and the center thickness of the seventh lens can be reasonably configured, which is beneficial for the sixth lens and the seventh lens to better correct the higher-order aberrations of the optical system; at the same time, it is beneficial for the field curvature adjustment in engineering production, thereby improving the imaging quality of the optical system. Below the lower limit of the above conditional formula, the higher-order aberrations of the optical system are difficult to be effectively balanced. Exceeding the upper limit of the above conditional formula, the main ray angle of the optical system is difficult to match the main ray angle of the photosensitive element, which is not conducive to improving the imaging quality of the optical system.

[0039] In one embodiment, the optical system satisfies the following condition:

[0040] 0.01≤R4 / R5≤0.1;

[0041] Wherein, R4 is the radius of curvature of the image side of the second lens at the optical axis, and R5 is the radius of curvature of the object side of the third lens at the optical axis. When the above conditional formula is met, the ratio of the radius of curvature of the image side of the second lens to the object side of the third lens at the optical axis can be reasonably configured, which is beneficial for the second lens and the third lens as a whole to more effectively balance the aberrations of the optical system, reduce the sensitivity of the optical system, and thus improve the imaging quality of the optical system. Below the lower limit of the above conditional formula, the image side surface of the second lens is too curved, resulting in excessive sensitivity of the optical system, which is not conducive to engineering manufacturing. Exceeding the upper limit of the above conditional formula, the object side surface of the third lens is too curved, which is not conducive to correcting the field curvature of the optical system, and thus is not conducive to improving the imaging quality of the optical system.

[0042] In one embodiment, the optical system satisfies the following condition:

[0043] 1.1≤TTL / f≤1.5;

[0044] 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. When the above conditional formula is met, it is beneficial to shorten the total length of the optical system, and at the same time, the field of view angle of the optical system will not be too large, thereby avoiding serious aberrations in the optical system. Below the lower limit of the above conditional formula, the total optical length of the optical system is too short, resulting in an increase in the sensitivity of the optical system, which is not conducive to the correction of the aberrations of the optical system, and is likely to cause the field of view angle of the optical system to be too small, making it difficult to meet the scene shooting requirements. Above the above conditional formula, the total optical length of the optical system is too long, which is not conducive to the realization of miniaturized design, and the light of the edge field of view is difficult to image in the effective pixel area of ​​the imaging surface, which is likely to cause incomplete imaging information.

[0045] 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 the optical system can realize a large image plane characteristic, which is conducive to improving the imaging quality of the imaging module.

[0046] An electronic device comprises a housing and the above-mentioned imaging module, wherein the imaging module is arranged in the housing. The use of the above-mentioned imaging module in the electronic device is conducive to improving the imaging quality of the electronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a schematic structural diagram of an optical system in the first embodiment of the present application;

[0048] Figure 2 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the first embodiment of the present application;

[0049] Figure 3 is a schematic structural diagram of an optical system in a second embodiment of the present application;

[0050] Figure 4 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the second embodiment of the present application;

[0051] Figure 5 is a schematic structural diagram of an optical system in a third embodiment of the present application;

[0052] Figure 6 A longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram of the optical system in the third embodiment of the present application;

[0053] Figure 7 is a schematic structural diagram of an optical system in a fourth embodiment of the present application;

[0054] Figure 8 A longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram of the optical system in the fourth embodiment of the present application;

[0055] Fig. 9 is a schematic structural diagram of an optical system in a fifth embodiment of the present application;

[0056] Fig.10 A longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram of the optical system in the fifth embodiment of the present application;

[0057] Fig.11 is a schematic structural diagram of an optical system in a sixth embodiment of the present application;

[0058] Fig.12 A longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram of the optical system in the sixth embodiment of the present application;

[0059] Fig.13 is a schematic diagram of an imaging module in an embodiment of the present application;

[0060] Fig.14 It is a schematic diagram of an electronic device in an embodiment of the present application. DETAILED DESCRIPTION

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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, a seventh lens L7, and an eighth lens L8 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, the seventh lens L7 includes an object-side surface S13 and an image-side surface S14, and the eighth lens L8 includes an object-side surface S15 and an image-side surface S16.

[0068] Among them, the first lens L1 has a positive refractive power, which is conducive to shortening the total length of the optical system 100 and realizing a miniaturized design. The object side surface S1 of the first lens L1 is a convex surface at the near optical axis 110, and the image side surface S2 is a concave surface at the near optical axis 110, which is conducive to the convergence of light in the optical system 100, thereby shortening the total length of the optical system 100 and improving the imaging quality of the optical system 100. The second lens L2 has a negative refractive power, which is conducive to correcting the aberration generated by the first lens L1 and improving the imaging quality. The object side surface S3 of the second lens L2 is a convex surface at the near optical axis 110, and the image side surface S4 is a concave surface at the near optical axis 110, which is conducive to the convergence of light in the optical system 100, thereby shortening the total length of the optical system 100 and improving the imaging quality of the optical system 100. The combination of the first lens L1 and the second lens L2 is conducive to correcting the on-axis spherical aberration of the optical system 100 and improving the imaging quality. The object side surface S5 of the third lens L3 is convex at the near optical axis 110, which is conducive to converging light, thereby facilitating shortening the total length of the optical system 100. The fourth lens L4 has a refractive power. The fifth lens L5, the sixth lens L6 and the seventh lens L7 all have a refractive power, which is conducive to correcting the coma of the optical system 100. The object side surface S7 of the fourth lens L4 is convex at the near optical axis 110, and the image side surface S8 is concave at the near optical axis 110. The object side surface S9 of the fifth lens L5 is concave at the near optical axis 110, and the image side surface S10 is convex at the near optical axis 110. The fourth lens L4 and the fifth lens L5 are both meniscus lenses, which are conducive to correcting the astigmatism, field curvature and distortion of the optical system 100. The eighth lens L8 has a negative refractive power, which is conducive to correcting the field curvature of the optical system 100. The image-side surface S16 of the eighth lens L8 is concave near the optical axis 110 , which helps to reduce the sensitivity of the optical system 100 and facilitates the engineering manufacturing of the optical system 100 .

[0069] In addition, in some embodiments, the optical system 100 is provided with a stop STO, which can be provided on the object side of the first lens L1 or on the object side surface S1 of the first lens L1. In some embodiments, the optical system 100 further includes an infrared filter L9 provided on the image side of the eighth lens L8, and the infrared filter L9 includes an object side surface S17 and an image side surface S18. Further, the optical system 100 further includes an image plane S19 located on the image side of the eighth lens L8, and the image plane S19 is the imaging plane of the optical system 100. The incident light can be imaged on the image plane S19 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, the seventh lens L7 and the eighth lens L8. It is worth noting that the infrared filter L9 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 S19 of the optical system 100 and affecting normal imaging.

[0070] 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.

[0071] 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 the small size of the optical system 100 can be used to achieve a lightweight design of the optical system 100. 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 have to be all glass or all plastic.

[0072] 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, the seventh lens L7, or the eighth lens L8 can also be greater than or equal to two, and any adjacent lenses can form a cemented lens or a non-cemented lens.

[0073] Further, in some embodiments, the optical system 100 satisfies the conditional formula: 7.2mm≤f*tan(HFOV)≤7.4mm; wherein f is the effective focal length of the optical system 100, and HFOV is half of the maximum field of view of the optical system 100. Specifically, f*tan(HFOV) can be: 7.203, 7.208, 7.210, 7.214, 7.219, 7.225, 7.227, 7.236, 7.238 or 7.243, and the numerical unit is mm. When the above conditional formula is met, the optical system 100 can achieve a large image plane characteristic, thereby being able to match a larger size of photosensitive elements, so that the optical system 100 has the characteristics of high pixels and high definition, and the imaging quality of the optical system 100 is improved.

[0074] In some embodiments, the optical system 100 satisfies the conditional formula: 1.2≤TTL / ImgH≤1.3; 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 ImgH is half of the image height corresponding to the maximum field angle of the optical system 100. Specifically, TTL / ImgH can be: 1.212, 1.213, 1.215, 1.217, 1.218, 1.220, 1.221, 1.223, 1.224 or 1.225. When the above conditional formula is satisfied, it is beneficial to shorten the total length of the optical system 100, thereby facilitating a miniaturized design.

[0075] It should be noted that, in some embodiments, the optical system 100 can match a photosensitive element having a rectangular photosensitive surface, and the imaging surface of the optical system 100 coincides with the photosensitive surface of the photosensitive element. In this case, the effective pixel area on the imaging surface of the optical system 100 has a horizontal direction and a diagonal direction, and HFOV can be understood as half of the maximum field of view angle in the diagonal direction of the optical system 100, and ImgH can be understood as half of the length of the effective pixel area in the diagonal direction on the imaging surface of the optical system 100.

[0076] In some embodiments, the optical system 100 satisfies the conditional formula: 1.8≤FNO≤1.9, where FNO is the aperture number of the optical system 100. Specifically, FNO can be: 1.87 or 1.88. By satisfying the above conditional formula, the optical system 100 can achieve a large aperture characteristic, so that the optical system 100 has a sufficient amount of light entering, which is conducive to making the image captured by the optical system 100 clearer; at the same time, it can also improve the imaging quality of the optical system 100 in a low-light environment.

[0077] In some embodiments, the optical system 100 satisfies the condition: 1.0≤CT3 / ET3≤1.7; wherein CT3 is the thickness of the third lens L3 on the optical axis 110, and ET3 is the distance from the object-side surface S5 of the third lens L3 at the maximum effective aperture to the image-side surface S6 of the third lens L3 at the maximum effective aperture in the direction of the optical axis 110. Specifically, CT3 / ET3 may be: 1.637, 1.639, 1.642, 1.653, 1.655, 1.660, 1.668, 1.673, 1.677, or 1.689. When the above conditional formula is met, the surface shape of the third lens L3 can be reasonably configured so that the surface shape of the third lens L3 is not too flat or too curved, which is beneficial to the processing and molding of the third lens L3 and improves the molding yield; at the same time, the surface shape of the third lens L3 is reasonably configured so that the surface shape of the third lens L3 is not too flat or too curved, which is beneficial to the third lens L3 to better correct the field curvature of the optical system 100 and improve the imaging quality of the optical system 100.

[0078] In some embodiments, the optical system 100 satisfies the condition: 1.5≤|R7+R8| / |R7-R8|≤8.0, wherein R7 is the radius of curvature of the object-side surface S7 of the fourth lens L4 at the optical axis 110, and R8 is the radius of curvature of the image-side surface S8 of the fourth lens L4 at the optical axis 110. Specifically, |R7+R8| / |R7-R8| may be: 1.807, 2.105, 2.654, 3.456, 3.397, 4.284, 5.301, 5.596, 6.372, or 7.644. When the above conditional expression is met, the thickness ratio between the center and the edge of the fourth lens L4 can be reasonably configured, so that the surface of the fourth lens L4 will not be too flat or overly curved, which is beneficial to reducing the tolerance sensitivity of the fourth lens L4 and improving the molding yield; at the same time, it is also beneficial for the fourth lens L4 to better balance the high-order coma of the optical system 100 and improve the imaging quality of the optical system 100.

[0079] In some embodiments, the optical system 100 satisfies the conditional expression: 0.2≤|f8 / (f2+f3)|≤5.2; wherein f8 is the effective focal length of the eighth lens L8, f2 is the effective focal length of the second lens L2, and f3 is the effective focal length of the third lens L3. Specifically, |f8 / (f2+f3)| may be: 0.206, 0.217, 0.229, 0.364, 0.501, 0.663, 0.701, 0.778, 1.364, or 5.148. When the above conditional expression is satisfied, the ratio of the refractive power of the eighth lens L8 to the sum of the refractive powers of the second lens L2 and the third lens L3 can be reasonably configured, so that the spherical aberration contribution of the second lens L2, the third lens L3, and the eighth lens L8 in the optical system 100 can be reasonably allocated, thereby improving the imaging quality of the on-axis region of the optical system 100.

[0080] In some embodiments, the optical system 100 satisfies the conditional formula: 0.9≤f1 / f≤1.1; wherein f1 is the effective focal length of the first lens L1. Specifically, f1 / f may be: 0.981, 0.983, 0.985, 0.986, 0.990, 0.992, 0.995, 0.999, 1.012 or 1.022. When the above conditional formula is satisfied, the ratio of the effective focal length of the first lens L1 to the optical system 100 can be reasonably configured, so that the refractive power of the first lens L1 is not too strong, which is conducive to correcting the high-order spherical aberration of the optical system 100 and improving the imaging quality of the optical system 100.

[0081] In some embodiments, the optical system 100 satisfies the conditional formula: 1.0≤|SAG61 / CT6|≤2.0; wherein SAG61 is the distance from the intersection of the object-side surface S11 of the sixth lens L6 and the optical axis 110 to the maximum effective aperture of the object-side surface S11 of the sixth lens L6 in the direction of the optical axis 110, and CT6 is the thickness of the sixth lens L6 on the optical axis 110. Specifically, |SAG61 / CT6| may be: 1.051, 1.102, 1.235, 1.289, 1.355, 1.436, 1.628, 1.784, 1.883 or 1.929. When the above conditional formula is satisfied, the surface shape of the sixth lens L6 can be reasonably configured, so that the surface shape of the sixth lens L6 is not too flat or too curved, which is conducive to reducing the tolerance sensitivity of the sixth lens L6, and further conducive to the processing and molding of the sixth lens L6, and improving the molding yield.

[0082] In some embodiments, the optical system 100 satisfies the conditional formula: 0.1≤D6 / CT7≤1.0; wherein D6 is the distance between the image side surface S12 of the sixth lens L6 and the object side surface S13 of the seventh lens L7 on the optical axis 110, and CT7 is the thickness of the seventh lens L7 on the optical axis 110. Specifically, D6 / CT7 may be: 0.203, 0.245, 0.267, 0.289, 0.301, 0.339, 0.412, 0.453, 0.477 or 0.496. When the above conditional formula is satisfied, the ratio of the air gap between the sixth lens L6 and the seventh lens L7 on the optical axis 110 and the center thickness of the seventh lens L7 can be reasonably configured, which is beneficial for the sixth lens L6 and the seventh lens L7 to better correct the higher-order aberrations of the optical system 100; and is also beneficial for adjusting the field curvature in engineering production, thereby improving the imaging quality of the optical system 100. If the value is lower than the lower limit of the above conditional expression, it is difficult to effectively balance the higher-order aberrations of the optical system 100. If the value is higher than the upper limit of the above conditional expression, it is difficult for the chief ray angle of the optical system 100 to match the chief ray angle of the photosensitive element, which is not conducive to improving the imaging quality of the optical system 100.

[0083] In some embodiments, the optical system 100 satisfies the conditional formula: 0.01≤R4 / R5≤0.1; wherein R4 is the radius of curvature of the image side surface S4 of the second lens L2 at the optical axis 110, and R5 is the radius of curvature of the object side surface S5 of the third lens L3 at the optical axis 110. Specifically, R4 / R5 may be: 0.029, 0.031, 0.032, 0.039, 0.045, 0.061, 0.063, 0.070, 0.078 or 0.088. When the above conditional formula is satisfied, the ratio of the radius of curvature of the image side surface S4 of the second lens L2 to the object side surface S5 of the third lens L3 at the optical axis 110 can be reasonably configured, which is beneficial for the second lens L2 and the third lens L3 as a whole to more effectively balance the aberrations of the optical system 100, reduce the sensitivity of the optical system 100, and thus improve the imaging quality of the optical system 100. If the value is lower than the lower limit of the above conditional expression, the image side surface S4 of the second lens L2 is too curved, resulting in excessive sensitivity of the optical system 100, which is not conducive to engineering manufacturing. If the value is higher than the upper limit of the above conditional expression, the object side surface S5 of the third lens L3 is too curved, which is not conducive to correcting the field curvature of the optical system 100, thereby not conducive to improving the imaging quality of the optical system 100.

[0084] In some embodiments, the optical system 100 satisfies the conditional expression: 1.1≤TTL / f≤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. Specifically, TTL / f may be: 1.185, 1.187, 1.188, 1.195, 1.201, 1.203, 1.208, 1.210, 1.211 or 1.214. When the above conditional expression is satisfied, it is beneficial to shorten the total length of the optical system 100, and at the same time, the field angle of the optical system 100 will not be too large, thereby avoiding serious aberrations in the optical system 100. If the conditional expression is lower than the lower limit, the total optical length of the optical system 100 is too short, resulting in an increase in the sensitivity of the optical system 100, which is not conducive to the correction of the aberrations of the optical system 100, and at the same time, it is easy to cause the field angle of the optical system 100 to be too small, which is difficult to meet the scene shooting requirements. If the above condition is exceeded, the total optical length of the optical system 100 is too long, which is not conducive to the realization of miniaturized design, and the light in the edge field of view is difficult to be imaged in the effective pixel area of ​​the imaging surface, which easily leads to incomplete imaging information.

[0085] The reference wavelength for the above effective focal length values ​​is 555nm.

[0086] Based on the description of the above embodiments, more specific embodiments and drawings are presented below for detailed description.

[0087] First embodiment

[0088] See also Figure 1 and Figure 2 , Figure 1 : is a schematic diagram of the structure of the optical system 100 in the first embodiment. The optical system 100 includes, from the object side to the image side, an aperture 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 negative refractive power, a seventh lens L7 with positive refractive power and an eighth lens L8 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 reference wavelength of the astigmatism graph and the distortion graph is 555 nm, which is the same as in other embodiments.

[0089] The object side surface S1 of the first lens L1 is convex at the near optical axis 110 and is convex at the circumference;

[0090] The image side surface S2 of the first lens L1 is concave at the near optical axis 110 and is concave at the circumference;

[0091] The object side surface S3 of the second lens L2 is convex at the near optical axis 110 and is convex at the circumference;

[0092] The image side surface S4 of the second lens L2 is concave at the near optical axis 110 and is concave at the circumference;

[0093] The object side surface S5 of the third lens L3 is convex at the near optical axis 110 and concave at the circumference;

[0094] The image-side surface S6 of the third lens L3 is convex at the near optical axis 110 and is convex at the circumference;

[0095] The object-side surface S7 of the fourth lens L4 is convex at the near optical axis 110 and concave at the circumference;

[0096] The image-side surface S8 of the fourth lens L4 is concave at the near optical axis 110 and is convex at the circumference;

[0097] The object side surface S9 of the fifth lens L5 is concave at the near optical axis 110 and is concave at the circumference;

[0098] The image-side surface S10 of the fifth lens L5 is convex at the near optical axis 110 and is convex at the circumference;

[0099] The object-side surface S11 of the sixth lens L6 is convex at the near optical axis 110 and concave at the circumference;

[0100] The image-side surface S12 of the sixth lens L6 is concave at the near optical axis 110 and is convex at the circumference;

[0101] The object-side surface S13 of the seventh lens L7 is convex at the near optical axis 110 and concave at the circumference;

[0102] The image-side surface S14 of the seventh lens L7 is concave at the near optical axis 110 and is convex at the circumference;

[0103] The object-side surface S15 of the eighth lens L8 is convex near the optical axis 110 and is convex at the circumference;

[0104] The image-side surface S16 of the eighth lens L8 is concave at the near optical axis 110 and is convex at the circumference.

[0105] The object-side surfaces and the 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, the seventh lens L7 and the eighth lens L8 are all aspherical surfaces.

[0106] It should be noted that in the present application, when a surface of a lens is described as convex at the near optical axis 110 (the central area of ​​the surface), 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 near optical axis 110 and is also convex at the circumference, the shape of the surface from the center (the intersection of the surface and the 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, and 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.

[0107] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7 and the eighth lens L8 are all made of plastic.

[0108] Furthermore, the optical system 100 satisfies the conditional expression: f*tan(HFOV)=7.243mm; wherein f is the effective focal length of the optical system 100, and HFOV is half of the maximum field angle of the optical system 100. When the above conditional expression is satisfied, the optical system 100 can achieve a large image plane characteristic, thereby being able to match a larger-sized photosensitive element, so that the optical system 100 has the characteristics of high pixel and high definition, and the imaging quality of the optical system 100 is improved.

[0109] The optical system 100 satisfies the conditional expression: TTL / ImgH=1.225, 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 ImgH is half of the image height corresponding to the maximum field angle of the optical system 100. When the above conditional expression is satisfied, it is beneficial to shorten the total length of the optical system 100, thereby facilitating miniaturization design.

[0110] The optical system 100 satisfies the conditional formula: FNO=1.87, where FNO is the aperture number of the optical system 100. By satisfying the above conditional formula, the optical system 100 can achieve a large aperture characteristic, so that the optical system 100 has a sufficient amount of light entering, which is conducive to making the image captured by the optical system 100 clearer; at the same time, it can also improve the imaging quality of the optical system 100 in a low-light environment.

[0111] The optical system 100 satisfies the conditional formula: CT3 / ET3=1.637; wherein CT3 is the thickness of the third lens L3 on the optical axis 110, and ET3 is the distance from the maximum effective aperture of the object side surface S5 of the third lens L3 to the maximum effective aperture of the image side surface S6 of the third lens L3 in the direction of the optical axis 110. When the above conditional formula is satisfied, the surface shape of the third lens L3 can be reasonably configured, so that the surface shape of the third lens L3 is not too flat or too curved, which is beneficial to the processing and molding of the third lens L3 and improves the molding yield; at the same time, the surface shape of the third lens L3 is reasonably configured, so that the surface shape of the third lens L3 is not too flat or too curved, which is beneficial to the third lens L3 to better correct the field curvature of the optical system 100 and improve the imaging quality of the optical system 100.

[0112] The optical system 100 satisfies the conditional formula: |R7+R8| / |R7-R8|=3.101; wherein R7 is the radius of curvature of the object side surface S7 of the fourth lens L4 at the optical axis 110, and R8 is the radius of curvature of the image side surface S8 of the fourth lens L4 at the optical axis 110. When the above conditional formula is satisfied, the thickness ratio between the center and the edge of the fourth lens L4 can be reasonably configured, so that the surface of the fourth lens L4 will not be too flat or overly curved, which is beneficial to reducing the tolerance sensitivity of the fourth lens L4 and improving the molding yield; at the same time, it is also beneficial for the fourth lens L4 to better balance the high-order coma of the optical system 100 and improve the imaging quality of the optical system 100.

[0113] The optical system 100 satisfies the conditional expression: |f8 / (f2+f3)|=0.778; wherein f8 is the effective focal length of the eighth lens L8, f2 is the effective focal length of the second lens L2, and f3 is the effective focal length of the third lens L3. When the above conditional expression is satisfied, the ratio of the refractive power of the eighth lens L8 to the sum of the refractive powers of the second lens L2 and the third lens L3 can be reasonably configured, so that the spherical aberration contribution of the second lens L2, the third lens L3 and the eighth lens L8 in the optical system 100 can be reasonably allocated, thereby improving the imaging quality of the on-axis region of the optical system 100.

[0114] The optical system 100 satisfies the conditional formula: f1 / f=0.992; wherein f1 is the effective focal length of the first lens L1. When the above conditional formula is satisfied, the ratio of the effective focal length of the first lens L1 to the optical system 100 can be reasonably configured, so that the refractive power of the first lens L1 is not too strong, which is conducive to correcting the high-order spherical aberration of the optical system 100 and improving the imaging quality of the optical system 100.

[0115] The optical system 100 satisfies the conditional formula: |SAG61 / CT6|=1.292; wherein SAG61 is the distance from the intersection of the object-side surface S11 of the sixth lens L6 and the optical axis 110 to the maximum effective aperture of the object-side surface S11 of the sixth lens L6 in the direction of the optical axis 110, and CT6 is the thickness of the sixth lens L6 on the optical axis 110. When the above conditional formula is satisfied, the surface shape of the sixth lens L6 can be reasonably configured, so that the surface shape of the sixth lens L6 is not too flat or too curved, which is conducive to reducing the tolerance sensitivity of the sixth lens L6, and further conducive to the processing and molding of the sixth lens L6, and improving the molding yield.

[0116] The optical system 100 satisfies the conditional formula: D6 / CT7=0.242; wherein D6 is the distance between the image side surface S12 of the sixth lens L6 and the object side surface S13 of the seventh lens L7 on the optical axis 110, and CT7 is the thickness of the seventh lens L7 on the optical axis 110. When the above conditional formula is satisfied, the ratio of the air interval between the sixth lens L6 and the seventh lens L7 on the optical axis 110 and the center thickness of the seventh lens L7 can be reasonably configured, which is beneficial for the sixth lens L6 and the seventh lens L7 to better correct the higher-order aberrations of the optical system 100; and is also beneficial for the field curvature adjustment in engineering production, thereby improving the imaging quality of the optical system 100. Below the lower limit of the above conditional formula, the higher-order aberrations of the optical system 100 are difficult to be effectively balanced. Exceeding the upper limit of the above conditional formula, the chief ray angle of the optical system 100 is difficult to match the chief ray angle of the photosensitive element, which is not conducive to improving the imaging quality of the optical system 100.

[0117] The optical system 100 satisfies the conditional formula: R4 / R5=0.034; wherein R4 is the curvature radius of the image side surface S4 of the second lens L2 at the optical axis 110, and R5 is the curvature radius of the object side surface S5 of the third lens L3 at the optical axis 110. When the above conditional formula is satisfied, the ratio of the curvature radius of the image side surface S4 of the second lens L2 to the object side surface S5 of the third lens L3 at the optical axis 110 can be reasonably configured, which is beneficial for the second lens L2 and the third lens L3 as a whole to more effectively balance the aberration of the optical system 100, reduce the sensitivity of the optical system 100, and thus improve the imaging quality of the optical system 100. If the sensitivity is lower than the lower limit of the above conditional formula, the sensitivity of the optical system 100 is too large, which is not conducive to engineering manufacturing.

[0118] The optical system 100 satisfies the conditional expression: TTL / f=1.200, 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. When the above conditional expression is satisfied, it is beneficial to shorten the total length of the optical system 100, and at the same time, the field angle of the optical system 100 will not be too large, thereby avoiding serious aberrations of the optical system 100.

[0119] In addition, various parameters of the optical system 100 are given in Table 1. Among them, the image plane S19 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 S19 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 surface or image side surface of the corresponding surface number at the optical axis 110. The surface number S1 and the surface number S2 are 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 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 next surface in the image side direction on the optical axis 110.

[0120] It should be noted that, in this embodiment and the following embodiments, the optical system 100 may not be provided with the infrared filter L9, but in this case the distance from the image side surface S16 to the image surface S19 of the eighth lens L8 remains unchanged.

[0121] In the first embodiment, the effective focal length f of the optical system 100 is 7.5 mm, the aperture number FNO is 1.87, the maximum field of view FOV is 88°, and the total optical length TTL is 9.0 mm.

[0122] The reference wavelength of the focal length of each lens is 555 nm, and the reference wavelength of the refractive index and the Abbe number is 587.56 nm, which is the same for other embodiments.

[0123] Table 1

[0124]

[0125]

[0126] 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 S1-S16 represent the image side or object side S1-S16 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 aspheric coefficient formula is as follows:

[0127]

[0128] 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.

[0129] Table 2

[0130]

[0131] in addition, Figure 2 The optical system 100 includes a longitudinal spherical aberration diagram (Longitudinal Spherical Aberration), which indicates the deviation of the convergence focus of light of different wavelengths after passing through the lens. The ordinate of the longitudinal spherical aberration diagram indicates the normalized pupil coordinate (Normalized Pupil Coordinator) from the center of the pupil to the edge of the pupil, and the abscissa indicates the distance (in mm) from the imaging plane to the intersection of the light and the optical axis 110. It can be seen from the longitudinal spherical aberration diagram that the degree of deviation of the convergence focus of light of each wavelength in the first embodiment tends to be consistent, and the diffuse spots or color halos in the imaging picture are effectively suppressed. Figure 2 Also included is a field curvature diagram (ASTIGMATIC FIELD CURVES) of the optical system 100, where the S curve represents the sagittal field curvature at 555nm, and the T curve represents the meridian field curvature at 555nm. As can be seen from the figure, the field curvature of the optical system 100 is small, the field curvature and astigmatism of each field of view are well corrected, and the center and edge of the field of view have clear imaging. Figure 2 The optical system 100 also includes a distortion diagram (DISTORTION). It can be seen from the diagram that the image deformation caused by the main light beam is small and the imaging quality of the system is excellent.

[0132] Second embodiment

[0133] See also Figure 3 and Figure 4 , Figure 3 : is a schematic diagram of the structure of the optical system 100 in the second embodiment. The optical system 100 includes, 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 negative refractive power, a seventh lens L7 with positive refractive power and an eighth lens L8 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.

[0134] The object side surface S1 of the first lens L1 is convex at the near optical axis 110 and is convex at the circumference;

[0135] The image side surface S2 of the first lens L1 is concave at the near optical axis 110 and is concave at the circumference;

[0136] The object side surface S3 of the second lens L2 is convex at the near optical axis 110 and is convex at the circumference;

[0137] The image side surface S4 of the second lens L2 is concave at the near optical axis 110 and is concave at the circumference;

[0138] The object side surface S5 of the third lens L3 is convex at the near optical axis 110 and concave at the circumference;

[0139] The image-side surface S6 of the third lens L3 is convex at the near optical axis 110 and is convex at the circumference;

[0140] The object-side surface S7 of the fourth lens L4 is convex at the near optical axis 110 and concave at the circumference;

[0141] The image-side surface S8 of the fourth lens L4 is concave at the near optical axis 110 and is convex at the circumference;

[0142] The object side surface S9 of the fifth lens L5 is concave at the near optical axis 110 and is concave at the circumference;

[0143] The image-side surface S10 of the fifth lens L5 is convex at the near optical axis 110 and is convex at the circumference;

[0144] The object-side surface S11 of the sixth lens L6 is concave at the near optical axis 110 and is concave at the circumference;

[0145] The image-side surface S12 of the sixth lens L6 is concave at the near optical axis 110 and is convex at the circumference;

[0146] The object-side surface S13 of the seventh lens L7 is concave at the near optical axis 110 and is concave at the circumference;

[0147] The image-side surface S14 of the seventh lens L7 is concave at the near optical axis 110 and is convex at the circumference;

[0148] The object-side surface S15 of the eighth lens L8 is convex at the near optical axis 110 and concave at the circumference;

[0149] The image-side surface S16 of the eighth lens L8 is concave at the near optical axis 110 and is convex at the circumference.

[0150] The object-side surfaces and the 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, the seventh lens L7 and the eighth lens L8 are all aspherical surfaces.

[0151] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7 and the eighth lens L8 are all made of plastic.

[0152] 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.

[0153] Table 3

[0154]

[0155]

[0156] 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.

[0157] Table 4

[0158]

[0159] Based on the above parameter information, the following data can be derived:

[0160] f*tan(HFOV) 7.243mm f1 / f 0.982 TTL / ImgH 1.214 |SAG61 / CT6| 1.316 CT3 / ET3 1.668 D6 / CT7 0.267 |R7+R8| / |R7-R8| 3.581 R4 / R5 0.051 |f8 / (f2+f3)| 0.610 TTL / f 1.189

[0161] In addition, by Figure 4 As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 100 are all well controlled, so that the optical system 100 of this embodiment has good imaging quality.

[0162] Third embodiment

[0163] See also Figure 5 and Figure 6 , Figure 5 : is a structural schematic diagram of the optical system 100 in the third embodiment. The optical system 100 includes, from the object side to the image side, an aperture 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 negative refractive power, a seventh lens L7 with positive refractive power and an eighth lens L8 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.

[0164] The object side surface S1 of the first lens L1 is convex at the near optical axis 110 and is convex at the circumference;

[0165] The image side surface S2 of the first lens L1 is concave at the near optical axis 110 and is concave at the circumference;

[0166] The object side surface S3 of the second lens L2 is convex at the near optical axis 110 and is convex at the circumference;

[0167] The image side surface S4 of the second lens L2 is concave at the near optical axis 110 and is concave at the circumference;

[0168] The object side surface S5 of the third lens L3 is convex at the near optical axis 110 and concave at the circumference;

[0169] The image-side surface S6 of the third lens L3 is convex at the near optical axis 110 and is convex at the circumference;

[0170] The object-side surface S7 of the fourth lens L4 is convex at the near optical axis 110 and concave at the circumference;

[0171] The image-side surface S8 of the fourth lens L4 is concave at the near optical axis 110 and is convex at the circumference;

[0172] The object side surface S9 of the fifth lens L5 is concave at the near optical axis 110 and is concave at the circumference;

[0173] The image-side surface S10 of the fifth lens L5 is convex at the near optical axis 110 and is convex at the circumference;

[0174] The object-side surface S11 of the sixth lens L6 is concave at the near optical axis 110 and is concave at the circumference;

[0175] The image-side surface S12 of the sixth lens L6 is concave at the near optical axis 110 and is convex at the circumference;

[0176] The object-side surface S13 of the seventh lens L7 is concave at the near optical axis 110 and is concave at the circumference;

[0177] The image-side surface S14 of the seventh lens L7 is concave at the near optical axis 110 and is convex at the circumference;

[0178] The object-side surface S15 of the eighth lens L8 is convex at the near optical axis 110 and concave at the circumference;

[0179] The image-side surface S16 of the eighth lens L8 is concave at the near optical axis 110 and is convex at the circumference.

[0180] The object-side surfaces and the 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, the seventh lens L7 and the eighth lens L8 are all aspherical surfaces.

[0181] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7 and the eighth lens L8 are all made of plastic.

[0182] 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.

[0183] Table 5

[0184]

[0185]

[0186] 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.

[0187] Table 6

[0188]

[0189] Furthermore, based on the above-mentioned parameter information, the following data can be derived:

[0190] f*tan(HFOV) 7.223mm f1 / f 0.981 TTL / ImgH 1.213 |SAG61 / CT6| 1.324 CT3 / ET3 1.665 D6 / CT7 0.273 |R7+R8| / |R7-R8| 3.895 R4 / R5 0.060 |f8 / (f2+f3)| 0.574 TTL / f 1.190

[0191] In addition, by Figure 6 As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 100 are all well controlled, so that the optical system 100 of this embodiment has good imaging quality.

[0192] Fourth embodiment

[0193] See also Figure 7 and Figure 8 , Figure 7is a structural schematic diagram of the optical system 100 in the fourth embodiment. The optical system 100 includes, from the object side to the image side, an aperture 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 negative refractive power, a seventh lens L7 with positive refractive power and an eighth lens L8 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.

[0194] The object side surface S1 of the first lens L1 is convex at the near optical axis 110 and is convex at the circumference;

[0195] The image side surface S2 of the first lens L1 is concave at the near optical axis 110 and is concave at the circumference;

[0196] The object side surface S3 of the second lens L2 is convex at the near optical axis 110 and is convex at the circumference;

[0197] The image side surface S4 of the second lens L2 is concave at the near optical axis 110 and is concave at the circumference;

[0198] The object side surface S5 of the third lens L3 is convex at the near optical axis 110 and concave at the circumference;

[0199] The image-side surface S6 of the third lens L3 is convex at the near optical axis 110 and is convex at the circumference;

[0200] The object-side surface S7 of the fourth lens L4 is convex at the near optical axis 110 and concave at the circumference;

[0201] The image-side surface S8 of the fourth lens L4 is concave at the near optical axis 110 and is convex at the circumference;

[0202] The object side surface S9 of the fifth lens L5 is concave at the near optical axis 110 and is concave at the circumference;

[0203] The image-side surface S10 of the fifth lens L5 is convex at the near optical axis 110 and is convex at the circumference;

[0204] The object-side surface S11 of the sixth lens L6 is concave at the near optical axis 110 and is concave at the circumference;

[0205] The image-side surface S12 of the sixth lens L6 is concave at the near optical axis 110 and is convex at the circumference;

[0206] The object-side surface S13 of the seventh lens L7 is concave at the near optical axis 110 and is concave at the circumference;

[0207] The image-side surface S14 of the seventh lens L7 is concave at the near optical axis 110 and is convex at the circumference;

[0208] The object-side surface S15 of the eighth lens L8 is convex at the near optical axis 110 and concave at the circumference;

[0209] The image-side surface S16 of the eighth lens L8 is concave at the near optical axis 110 and is convex at the circumference.

[0210] The object-side surfaces and the 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, the seventh lens L7 and the eighth lens L8 are all aspherical surfaces.

[0211] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7 and the eighth lens L8 are all made of plastic.

[0212] 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.

[0213] Table 7

[0214]

[0215]

[0216] 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.

[0217] Table 8

[0218]

[0219] Furthermore, based on the above-mentioned parameter information, the following data can be derived:

[0220] f*tan(HFOV) 7.228mm f1 / f 0.995 TTL / ImgH 1.212 |SAG61 / CT6| 1.075 CT3 / ET3 1.666 D6 / CT7 0.256 |R7+R8| / |R7-R8| 7.644 R4 / R5 0.088 |f8 / (f2+f3)| 0.206 TTL / f 1.199

[0221] In addition, by Figure 8 As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 100 are all well controlled, so that the optical system 100 of this embodiment has good imaging quality.

[0222] Fifth embodiment

[0223] See also Fig. 9 and Fig.10 , Fig. 9is a schematic diagram of the structure of the optical system 100 in the fifth embodiment. The optical system 100 includes, from the object side to the image side, an aperture 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, a seventh lens L7 with positive refractive power and an eighth lens L8 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.

[0224] The object side surface S1 of the first lens L1 is convex at the near optical axis 110 and is convex at the circumference;

[0225] The image side surface S2 of the first lens L1 is concave at the near optical axis 110 and is concave at the circumference;

[0226] The object side surface S3 of the second lens L2 is convex at the near optical axis 110 and is convex at the circumference;

[0227] The image side surface S4 of the second lens L2 is concave at the near optical axis 110 and is concave at the circumference;

[0228] The object side surface S5 of the third lens L3 is convex at the near optical axis 110 and concave at the circumference;

[0229] The image-side surface S6 of the third lens L3 is convex at the near optical axis 110 and is convex at the circumference;

[0230] The object-side surface S7 of the fourth lens L4 is convex at the near optical axis 110 and concave at the circumference;

[0231] The image-side surface S8 of the fourth lens L4 is concave at the near optical axis 110 and is convex at the circumference;

[0232] The object side surface S9 of the fifth lens L5 is concave at the near optical axis 110 and is concave at the circumference;

[0233] The image-side surface S10 of the fifth lens L5 is convex at the near optical axis 110 and is convex at the circumference;

[0234] The object-side surface S11 of the sixth lens L6 is concave at the near optical axis 110 and is concave at the circumference;

[0235] The image-side surface S12 of the sixth lens L6 is concave at the near optical axis 110 and is convex at the circumference;

[0236] The object-side surface S13 of the seventh lens L7 is concave at the near optical axis 110 and is concave at the circumference;

[0237] The image-side surface S14 of the seventh lens L7 is concave at the near optical axis 110 and is convex at the circumference;

[0238] The object-side surface S15 of the eighth lens L8 is convex near the optical axis 110 and is convex at the circumference;

[0239] The image-side surface S16 of the eighth lens L8 is concave at the near optical axis 110 and is convex at the circumference.

[0240] The object-side surfaces and the 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, the seventh lens L7 and the eighth lens L8 are all aspherical surfaces.

[0241] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7 and the eighth lens L8 are all made of plastic.

[0242] 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.

[0243] Table 9

[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 10, and the definition of each parameter therein can be obtained from the first embodiment, which will not be repeated here.

[0246] Table 10

[0247]

[0248] Furthermore, based on the above-mentioned parameter information, the following data can be derived:

[0249] f*tan(HFOV) 7.203mm f1 / f 1.022 TTL / ImgH 1.213 |SAG61 / CT6| 1.051 CT3 / ET3 1.689 D6 / CT7 0.496 |R7+R8| / |R7-R8| 2.527 R4 / R5 0.029 |f8 / (f2+f3)| 0.696 TTL / f 1.214

[0250] In addition, by Fig.10 As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 100 are all well controlled, so that the optical system 100 of this embodiment has good imaging quality.

[0251] Sixth embodiment

[0252] See also Fig.11 and Fig.12 , Fig.11: is a schematic diagram of the structure of the optical system 100 in the sixth embodiment. The optical system 100 includes, from the object side to the image side, an aperture 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, a seventh lens L7 with negative refractive power and an eighth lens L8 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.

[0253] The object side surface S1 of the first lens L1 is convex at the near optical axis 110 and is convex at the circumference;

[0254] The image side surface S2 of the first lens L1 is concave at the near optical axis 110 and is concave at the circumference;

[0255] The object side surface S3 of the second lens L2 is convex at the near optical axis 110 and is convex at the circumference;

[0256] The image side surface S4 of the second lens L2 is concave at the near optical axis 110 and is concave at the circumference;

[0257] The object side surface S5 of the third lens L3 is convex at the near optical axis 110 and concave at the circumference;

[0258] The image-side surface S6 of the third lens L3 is convex at the near optical axis 110 and is convex at the circumference;

[0259] The object-side surface S7 of the fourth lens L4 is convex at the near optical axis 110 and concave at the circumference;

[0260] The image-side surface S8 of the fourth lens L4 is concave at the near optical axis 110 and is convex at the circumference;

[0261] The object side surface S9 of the fifth lens L5 is concave at the near optical axis 110 and is concave at the circumference;

[0262] The image-side surface S10 of the fifth lens L5 is convex at the near optical axis 110 and is convex at the circumference;

[0263] The object-side surface S11 of the sixth lens L6 is concave at the near optical axis 110 and is concave at the circumference;

[0264] The image-side surface S12 of the sixth lens L6 is concave at the near optical axis 110 and is convex at the circumference;

[0265] The object-side surface S13 of the seventh lens L7 is concave at the near optical axis 110 and is concave at the circumference;

[0266] The image-side surface S14 of the seventh lens L7 is concave at the near optical axis 110 and is convex at the circumference;

[0267] The object-side surface S15 of the eighth lens L8 is convex at the near optical axis 110 and concave at the circumference;

[0268] The image-side surface S16 of the eighth lens L8 is concave at the near optical axis 110 and is convex at the circumference.

[0269] The object-side surfaces and the 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, the seventh lens L7 and the eighth lens L8 are all aspherical surfaces.

[0270] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7 and the eighth lens L8 are all made of plastic.

[0271] 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.

[0272] Table 11

[0273]

[0274] 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.

[0275] Table 12

[0276]

[0277]

[0278] Furthermore, based on the above-mentioned parameter information, the following data can be derived:

[0279] f*tan(HFOV) 7.227mm f1 / f 0.986 TTL / ImgH 1.213 |SAG61 / CT6| 1.929 CT3 / ET3 1.684 D6 / CT7 0.203 |R7+R8| / |R7-R8| 1.807 R4 / R5 0.062 |f8 / (f2+f3)| 5.132 TTL / f 1.185

[0280] In addition, by Fig.12 As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 100 are all well controlled, so that the optical system 100 of this embodiment has good imaging quality.

[0281] See also Fig.13In some embodiments, the optical system 100 can be assembled with the photosensitive element 210 to form the imaging module 200. At this time, the photosensitive surface of the photosensitive element 210 can be regarded as the image plane S19 of the optical system 100. The imaging module 200 can also be provided with an infrared filter L9, and the infrared filter L9 is arranged between the image side surface S16 of the eighth lens L8 and the image plane S19. Specifically, the photosensitive element 210 can be a charge coupled device (CCD) or a complementary metal oxide semiconductor device (CMOS Sensor). By using the above optical system 100 in the imaging module 200, the optical system 100 can achieve a large image plane characteristic, which is conducive to improving the imaging quality of the imaging module 200.

[0282] See also Fig.13 and Fig.14 In some embodiments, the imaging module 200 can be applied to an electronic device 300, and the electronic device includes a housing 310, and the imaging module 200 is disposed 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. When the electronic device 300 is a smart phone, the housing 310 can be the middle frame of the electronic device 300. Using the imaging module 200 in the electronic device 300 is conducive to improving the imaging quality of the electronic device 300.

[0283] 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.

[0284] 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: Along the optical axis from the object side to the image side, it includes: A first lens having positive refractive power, wherein the object side surface of the first lens is convex at the near optical axis, and the image side surface of the first lens is concave at the near optical axis; a second lens having negative refractive power, wherein the object side surface of the second lens is convex at the near optical axis, and the image side surface of the second lens is concave at the near optical axis; a third lens having positive refractive power, wherein the object side surface of the third lens is convex at the near optical axis, and the image side surface of the third lens is convex at the near optical axis; a fourth lens having a refractive power, wherein the object side surface of the fourth lens is a convex surface at the near optical axis, and the image side surface of the fourth lens is a concave surface at the near optical axis; a fifth lens having a refractive power, wherein the object side surface of the fifth lens is a concave surface at the near optical axis, and the image side surface of the fifth lens is a convex surface at the near optical axis; a sixth lens having refractive power, wherein the image side surface of the sixth lens is concave at a position near the optical axis; a seventh lens element having a refractive power, wherein the image side surface of the seventh lens element is a concave surface at a position close to the optical axis; an eighth lens element having negative refractive power, wherein the image side surface of the eighth lens element is concave at a near optical axis; There are eight lenses with refractive power; The object side surface and the image side surface of each lens of the optical system are both aspherical surfaces; And the optical system satisfies the following conditional formula: 7.2mm≤f*tan(HFOV) ≤7.4mm; Wherein, f is the effective focal length of the optical system, and HFOV is half of the maximum field of view of the optical system.

2. The optical system according to claim 1, characterized in that The following conditions are met: 1.2≤TTL / ImgH≤1.3; 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 ImgH is half of the image height corresponding to the maximum field angle of the optical system.

3. The optical system according to claim 1, characterized in that The following conditions are met: 1.0≤CT3 / ET3≤1.7; Wherein, CT3 is the thickness of the third lens on the optical axis, and ET3 is the distance from the maximum effective aperture of the object side surface of the third lens to the maximum effective aperture of the image side surface of the third lens in the direction of the optical axis.

4. The optical system according to claim 1, characterized in that The following conditions are met: 1.5≤|R7+R8| / |R7-R8|≤8.0; Wherein, R7 is the curvature radius of the object side surface of the fourth lens at the optical axis, and R8 is the curvature radius of the image side surface of the fourth lens at the optical axis.

5. The optical system according to claim 1, characterized in that The following conditions are met: 0.2≤|f8 / (f2+f3)| ≤5.2; Wherein, f8 is the effective focal length of the eighth lens, f2 is the effective focal length of the second lens, and f3 is the effective focal length of the third lens.

6. The optical system according to claim 1, characterized in that The following conditions are met: 0.9≤f1 / f≤1.1; Wherein, f1 is the effective focal length of the first lens.

7. The optical system according to claim 1, characterized in that The following conditions are met: 1.0≤|SAG61 / CT6|≤2.0; Among them, SAG61 is the distance from the intersection of the object side surface of the sixth lens and the optical axis to the maximum effective aperture of the object side surface of the sixth lens in the direction of the optical axis, and CT6 is the thickness of the sixth lens on the optical axis.

8. The optical system according to claim 1, characterized in that The following conditions are met: 0.1≤D6 / CT7≤1.0; Wherein, D6 is the distance from the image side surface of the sixth lens to the object side surface of the seventh lens on the optical axis, and CT7 is the thickness of the seventh lens on the optical axis.

9. The optical system according to claim 1, characterized in that The following conditions are met: 0.01≤R4 / R5≤0.1; Wherein, R4 is the curvature radius of the image side surface of the second lens at the optical axis, and R5 is the curvature radius of the object side surface of the third lens at the optical axis.

10. The optical system according to claim 1, characterized in that The following conditions are met: 1.1≤TTL / f≤1.5; 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.

11. An imaging module, characterized in that: The optical system comprises a photosensitive element and any one of claims 1 to 10, wherein the photosensitive element is arranged on the image side of the optical system.

12. An electronic device, characterized in that: It comprises a shell and the imaging module according to claim 11, wherein the imaging module is arranged in the shell.

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