Optical systems, camera modules and electronic equipment

Abstract

The present invention relates to an optical system, a camera module and an electronic device. The optical system comprises a first lens with positive refractive power, whose object side surface is convex at the near optical axis and whose image side surface is concave at the near optical axis; a second lens with negative refractive power, whose object side surface is convex at the near optical axis and whose image side surface is concave at the near optical axis; a third lens, whose image side surface is convex at the near optical axis; a fourth lens, whose image side surface is concave at the near optical axis; a fifth lens, whose object side surface is concave at the near optical axis and whose image side surface is convex at the near optical axis; a sixth lens, whose image side surface is convex at the near optical axis; a seventh lens, whose object side surface is convex at the near optical axis and whose image side surface is concave at the near optical axis; an eighth lens with negative refractive power, whose image side surface is concave at the near optical axis; and the system satisfies 1.2<TTL / ImgH<1.3. The above optical system can realize miniaturized design and maintain good imaging quality.

Description

Technical Field

[0001] The present invention relates to the field of photographic imaging technology, and in particular to an optical system, a camera module and an electronic device. Background Art

[0002] As the photography requirements of portable electronic devices such as smartphones and smart watches increase, the industry is facing more and more challenges in improving camera modules. On the one hand, portable electronic devices are becoming thinner and lighter, which requires the size of each module in the device to be compressed as much as possible to save internal space, especially for camera modules with generally longer axial dimensions; on the other hand, it is also necessary to ensure that the camera module still has good imaging quality during the miniaturization design process.

[0003] Therefore, how to configure the number of lenses, refractive power, surface shape, etc. in the camera module so that the camera module can achieve miniaturization design while maintaining good imaging quality has become one of the problems that the industry needs to solve. Summary of the invention

[0004] Based on this, it is necessary to provide an optical system, a camera module and an electronic device to address the problem of how to achieve miniaturized design while maintaining good imaging quality.

[0005] An optical system, comprising, in order from the object side to the image side along the optical axis:

[0006] 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;

[0007] 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;

[0008] A third lens having refractive power, wherein the image side surface of the third lens is convex at the near optical axis;

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

[0010] 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;

[0011] a sixth lens having refractive power, wherein the image side surface of the sixth lens is a convex surface near the optical axis;

[0012] a seventh lens having a refractive power, wherein the object side surface of the seventh lens is convex at the near optical axis, and the image side surface of the seventh lens is concave at the near optical axis, and both the object side surface and the image side surface of the seventh lens are aspherical surfaces, and at least one of them has recurvature;

[0013] an eighth lens having negative refractive power, wherein the image side surface of the eighth lens is concave near the optical axis, and both the object side surface and the image side surface of the eighth lens are aspherical surfaces, and at least one of them has recurvature;

[0014] The optical system also satisfies the relationship:

[0015] 1.2<TTL / ImgH<1.3;

[0016] TTL is the distance from the object side of the first lens to the imaging surface of the optical system on the optical axis, and ImgH is half of the image height corresponding to the maximum field angle of the optical system.

[0017] The above-mentioned lens number, refractive power and surface design will facilitate the smooth transition of light incident at a large angle in the optical system, effectively suppress the generation of spherical aberration and astigmatism, and also facilitate the acquisition of a larger imaging height. When the optical system with an eight-piece structure meets the above-mentioned relationship conditions, due to the restrictions on the number of lenses, refractive power, surface shape and the upper limit of the relationship, the optical system will have a large image plane characteristic, which can be used with a higher pixel image sensor to have a clearer imaging picture. In addition, it can also prevent the axial dimension of the eight-piece optical system from being too long, and thus can take into account the miniaturization design. When the above-mentioned optical system meets the lower limit of the relationship, it can also prevent the total optical length of the eight-piece optical system from being too short relative to the imaging height, so that the incident light has enough space to be deflected when passing through each lens to achieve a smooth transition, reduce the sensitivity of imaging clarity to the total optical length of the system, thereby maintaining the stability of imaging quality, and also help to reduce the design difficulty of the system. The optical system with the above-mentioned design can maintain good or even better imaging quality under the premise of realizing a miniaturization design with a shorter axial total length, and it is also helpful to reduce the design difficulty of the system.

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

[0019] -3<f2 / f12<-2;

[0020] f2 is the effective focal length of the second lens, and f12 is the combined focal length of the first lens and the second lens. When this relationship is satisfied, the refractive power of the first lens and the second lens is reasonably configured, and the second lens with negative refractive power can effectively correct aberrations such as distortion and field curvature generated by the first lens, and reduce the deflection angle of the incident light when passing through the first lens and the second lens, thereby helping to reduce the overall sensitivity of the optical system and improve the overall imaging quality.

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

[0022] 7.5mm<f / tan(semiFOV)<7.95mm;

[0023] f is the effective focal length of the optical system, and semiFOV is half of the maximum field of view of the optical system. When this relationship is satisfied, the field of view and image height of the optical system can be reasonably configured, which can reduce the deflection angle of light in the optical system, thereby better balancing the aberration of the optical system; further compress the axial size of the optical system; and further enable the optical system to achieve a large image surface design; in addition, it is also conducive to reducing the difficulty of injection molding of each lens.

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

[0025] 2.5<sd81 / sd31<3.5;

[0026] sd81 is the maximum effective semi-aperture of the object side of the eighth lens, and sd31 is the maximum effective semi-aperture of the object side of the third lens. When this relationship is satisfied, the aperture of the eighth lens is kept larger than the effective aperture of the third lens but does not cause excessive deflection of the incident light, which is conducive to the optical system to obtain a larger image plane to match the image sensor with higher pixels, thereby improving the resolution. When it is lower than the lower limit of the relationship, it is not only not conducive to the optical system to achieve a large image plane characteristic, but also not conducive to shortening the total length of the system while ensuring the imaging clarity, and it is difficult to achieve a miniaturized design of the optical system; when it is higher than the upper limit of the relationship, the effective aperture of the object side of the third lens is too small, which is not conducive to the optical system to obtain sufficient light flux, thereby reducing the imaging quality.

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

[0028] 3.2<f8 / sag82<5.2;

[0029] f8 is the effective focal length of the eighth lens, and sag82 is the sagittal height of the image side of the eighth lens at the maximum effective aperture. When this relationship is satisfied, it is beneficial for the eighth lens to contribute reasonable negative refractive power to the eight-piece optical system to correct the aberrations produced by the object lens, and it is also beneficial to shorten the total length of the system. When it is lower than the lower limit of the relationship, the negative refractive power provided by the eighth lens is too strong, which is easy to over-correct the aberrations produced by the object lens, and the image side of the eighth lens will be too complicated, which will increase the difficulty of lens molding and processing; when it is higher than the upper limit of the relationship, the negative refractive power provided by the eighth lens is too small, which is not conducive to correcting aberrations and cannot ensure good imaging quality.

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

[0031] 9<R71 / sd67<16;

[0032] R71 is the radius of curvature of the object side of the seventh lens at the optical axis, and sd67 is the difference between the maximum effective semi-aperture of the object side of the seventh lens and the maximum effective semi-aperture of the image side of the sixth lens. When this relationship is satisfied, the surface shape of the seventh lens and the aperture difference between the sixth lens and the seventh lens can be reasonably constrained, so that the step difference can be increased while keeping the deflection angle of the incident light small, which helps the optical system to achieve a large image plane design, and also helps to shorten the total length of the optical system to achieve a miniaturized design of the optical system. When it is higher than the upper limit of the relationship, the step difference from the image side surface of the sixth lens to the object side surface of the seventh lens is too small, which is not conducive to realizing a large image surface design. In addition, it will cause light incident at a large angle to be deflected too much when passing between the sixth lens and the seventh lens, thereby destroying the aberration balance of the optical system, thereby reducing the imaging quality of the optical system; when it is lower than the lower limit of the relationship, the curvature radius of the object side surface of the seventh lens is too small, and the surface shape is too curved, so that the deflection angle of the edge light when passing through the seventh lens is easily too large, resulting in the generation of aberrations that are difficult to correct, increasing the burden of the last lens on the image side on correcting aberrations, and ultimately reducing the imaging quality.

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

[0034] sag81 / sag72<1.75;

[0035] sag81 is the sagitta of the object side of the eighth lens at the maximum effective aperture, and sag72 is the sagitta of the image side of the seventh lens at the maximum effective aperture. When this relationship is satisfied, the surface shapes of the image side of the seventh lens and the object side of the eighth lens can be reasonably constrained to achieve the effect of effectively correcting the system aberration and improving the imaging quality. At the same time, the sagitta of the corresponding lens surface shape at the maximum effective aperture will not be too large, and the surface shape will not be too distorted, so that the lens surface shape is controlled within a range that is easy to process and shape. When it is higher than the upper limit of the relationship, the sagitta of the object side of the eighth lens at the maximum effective aperture is too large, and the surface shape is too distorted, which will inevitably increase the tolerance sensitivity of the lens, and the difficulty of processing, forming and assembling the lens will also increase accordingly.

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

[0037] -60<R52 / sd56<-10;

[0038] R52 is the radius of curvature of the image side surface of the fifth lens at the optical axis, and sd56 is the difference between the maximum effective semi-aperture of the object side surface of the sixth lens and the maximum effective semi-aperture of the image side surface of the fifth lens. When this relationship is satisfied, on the one hand, it is beneficial to constrain the image side surface shape of the fifth lens, so that the incident light can enter the sixth lens with a smaller deflection angle when passing through the image side surface of the fifth lens; on the other hand, it is also beneficial to achieve a large image surface design while shortening the total length of the optical system. When it is lower than the lower limit of the relationship, the image side surface shape of the fifth lens is flat, which is not enough to deflect the edge light to a reasonable direction, thereby easily reducing the edge illumination of the imaging picture, and then dark corners appear; when it is higher than the upper limit of the relationship, it will cause the image side surface shape of the fifth lens to be too curved, and the tolerance sensitivity will increase, which will make it difficult to process and shape.

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

[0040] 0.9<f / f1<1.1;

[0041] f is the effective focal length of the optical system, and f1 is the effective focal length of the first lens. When this relationship is satisfied, it will be beneficial for the first lens to contribute appropriate positive refractive power to the entire optical system, so as to effectively reduce the head size of the optical system, shorten the total length of the system, and provide sufficient space for increasing the image plane size.

[0042] A camera module comprises an image sensor and any one of the above optical systems, wherein the image sensor is arranged on the image side of the optical system. By adopting the above optical system, the camera module can maintain good or even better imaging quality while the total axial length is compressed.

[0043] An electronic device comprises a fixing part and the camera module, wherein the camera module is arranged on the fixing part. The camera module can maintain good imaging quality while compressing the total length, thereby reducing the internal space occupied by the electronic device, avoiding the hindrance of the thickness compression of the electronic device, and maintaining the shooting performance of the electronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic diagram of the structure of an optical system provided in the first embodiment of the present application;

[0045] Figure 2 including a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system in the first embodiment;

[0046] Figure 3 A schematic diagram of the structure of an optical system provided in the second embodiment of the present application;

[0047] Figure 4including a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system in the second embodiment;

[0048] Figure 5 A schematic diagram of the structure of an optical system provided in the third embodiment of the present application;

[0049] Figure 6 including a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system in the third embodiment;

[0050] Figure 7 A schematic diagram of the structure of an optical system provided in a fourth embodiment of the present application;

[0051] Figure 8 including a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system in the fourth embodiment;

[0052] Fig. 9 A schematic diagram of the structure of an optical system provided in a fifth embodiment of the present application;

[0053] Fig.10 including a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system in the fifth embodiment;

[0054] Fig.11 A schematic diagram of the structure of an optical system provided in a sixth embodiment of the present application;

[0055] Fig.12 including a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system in the sixth embodiment;

[0056] Fig.13 A schematic diagram of the structure of an optical system provided in the seventh embodiment of the present application;

[0057] Fig.14 including a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system in the seventh embodiment;

[0058] Fig.15 A schematic diagram of a camera module provided in one embodiment of the present application;

[0059] Fig.16 A schematic diagram of the structure of an electronic device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0060] 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.

[0061] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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 do not represent the only implementation method.

[0066] refer to Figure 1 , an embodiment of the present application provides an optical system 10 with an eight-piece structure, and the optical system 10 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 along an optical axis 101 from the object side to the image side. The first lens L1 has a positive refractive power, the second lens L2 has a negative refractive power, and the eighth lens L8 has a negative refractive power. The optical axes of the lenses in the optical system 10 are on the same straight line, and the straight line is the optical axis 101 of the optical system 10. The lenses in the optical system 10 can be assembled in a lens barrel to form a camera lens.

[0067] The first lens L1 has an object-side surface S1 and an image-side surface S2, the second lens L2 has an object-side surface S3 and an image-side surface S4, the third lens L3 has an object-side surface S5 and an image-side surface S6, the fourth lens L4 has an object-side surface S7 and an image-side surface S8, the fifth lens L5 has an object-side surface S9 and an image-side surface S10, the sixth lens L6 has an object-side surface S11 and an image-side surface S12, the seventh lens L7 has an object-side surface S13 and an image-side surface S14, and the eighth lens L8 has an object-side surface S15 and an image-side surface S16. In addition, the optical system 10 also has an imaging surface S17, which is located on the image side of the eighth lens L8. The on-axis object point at infinity can be converged on the imaging surface S17 after being adjusted by the lens group of the optical system 10. Generally, the imaging surface S17 of the optical system 10 coincides with the photosensitive surface of the image sensor. For ease of understanding, the imaging surface S17 can also be regarded as the photosensitive surface of the image sensor.

[0068] In the embodiment of the present application, the object-side surface S1 of the first lens L1 is convex at the near optical axis, and the image-side surface S2 is concave at the near optical axis; the object-side surface S3 of the second lens L2 is convex at the near optical axis, and the image-side surface S4 is concave at the near optical axis; the image-side surface S6 of the third lens L3 is convex at the near optical axis; the image-side surface S8 of the fourth lens L4 is concave at the near optical axis; the object-side surface S9 of the fifth lens L5 is concave at the near optical axis, and the image-side surface S10 is convex at the near optical axis; the image-side surface S12 of the sixth lens L6 is convex at the near optical axis; the object-side surface S13 of the seventh lens L7 is convex at the near optical axis, and the image-side surface S14 is concave at the near optical axis; and the image-side surface S16 of the eighth lens L8 is concave at the near optical axis. In addition, the object-side surface and the image-side surface of the seventh lens L7 and the eighth lens L8 are both aspherical surfaces, and at least one of the object-side surface S13 and the image-side surface S14 of the seventh lens L7 is recurved, and at least one of the object-side surface S15 and the image-side surface S16 of the eighth lens L8 is recurved. It should be noted that when describing that a lens surface has a certain surface shape near the optical axis, that is, the lens surface has the surface shape near the optical axis 101, and the lens surface can have the same surface shape or the opposite surface shape in the area near the maximum effective aperture. When the same lens surface has two opposite surface shapes, it can be said that the surface has recurvature.

[0069] The above-mentioned lens quantity, refractive power and surface design will facilitate smooth transition of light incident at a large angle in the optical system 10, effectively suppress the generation of spherical aberration and astigmatism, and also facilitate obtaining a larger imaging height.

[0070] Furthermore, the optical system 10 in the embodiment of the present application also satisfies the following relationship:

[0071] 1.2<TTL / ImgH<1.3; TTL is the distance from the object side surface S1 of the first lens L1 to the imaging surface S17 of the optical system 10 on the optical axis 101, and ImgH is half of the image height corresponding to the maximum field angle of the optical system 10. ImgH can also be called the maximum imaging circle radius of the optical system 10, and in some embodiments, when the optical system 10 is assembled with an image sensor, half of the diagonal length of the rectangular effective pixel area on the image sensor is equal to or approximately equal to the value of ImgH. When the optical system 10 with an eight-piece structure satisfies the above relationship, due to the limitations of the number of lenses, refractive power, surface shape and the upper limit of the relationship, the optical system 10 will have a large image surface characteristic, and can be used with an image sensor with a higher pixel to have a clearer imaging picture. In addition, it can also prevent the axial dimension of the eight-piece optical system 10 from being too long, thereby taking into account a miniaturized design. When the above optical system 10 satisfies the lower limit of the relationship, it can also prevent the total optical length of the eight-piece optical system 10 from being too short relative to the image height, so that the incident light has enough space to be deflected when passing through each lens to achieve a smooth transition, reduce the sensitivity of imaging clarity to the total optical length of the system, thereby maintaining the stability of imaging quality, and also help to reduce the design difficulty of the system. In summary, the optical system 10 with the above design can maintain good or even better imaging quality under the premise of realizing a miniaturized design with a shorter axial total length, and it is also helpful to reduce the design difficulty of the system. In some embodiments, the relationship satisfied by the optical system 10 can specifically be 1.205, 1.21, 1.215, 1.218, 1.226, 1.234, 1.246, 1.253, 1.263, 1.27 or 1.276. In some embodiments, the total optical length TTL of the optical system 10 satisfies 8.89 mm ≤ TTL ≤ 9.15 mm, for example, it may be 8.9, 8.93, 8.95, 9, 9.04, 9.08 or 9.13, and the numerical unit is mm.

[0072] In addition, in some embodiments, the optical system 10 further satisfies at least one of the following relationships, and when any of the relationships is satisfied, corresponding technical effects can be achieved:

[0073] -3<f2 / f12<-2; f2 is the effective focal length of the second lens L2, and f12 is the combined focal length of the first lens L1 and the second lens L2. When this relationship is satisfied, the refractive power of the first lens L1 and the second lens L2 is reasonably configured, and the second lens L2 with negative refractive power can effectively correct the aberrations such as distortion and field curvature generated by the first lens L1, and reduce the deflection angle of the incident light when passing through the first lens L1 and the second lens L2, thereby helping to reduce the overall sensitivity of the optical system 10 and improve the overall imaging quality. In some embodiments, the relationship satisfied by the optical system 10 can be specifically -2.8, -2.76, -2.7, -2.61, -2.53, -2.39, -2.27, -2.2 or -2.17.

[0074] 7.5mm<f / tan(semiFOV)<7.95mm; f is the effective focal length of the optical system 10, and semiFOV is half of the maximum field of view of the optical system 10. When the image sensor is assembled, semiFOV can also be understood as half of the maximum field of view corresponding to the diagonal direction of the rectangular pixel area of ​​the image sensor. When this relationship is met, the field of view and image height of the above-mentioned optical system 10 can be reasonably configured. On the one hand, the deflection angle of the light in the optical system 10 can be reduced, thereby better balancing the aberration of the optical system 10; on the other hand, the axial size of the optical system 10 can be further compressed; on the other hand, the optical system 10 can be further designed with a large image surface; in addition, it is also beneficial to reduce the difficulty of injection molding of each lens. In some embodiments, the relationship satisfied by the optical system 10 can be specifically 7.77, 7.79, 7.83, 7.85, 7.88 or 7.9, and the numerical unit is mm.

[0075] 2.5<sd81 / sd31<3.5; sd81 is the maximum effective semi-aperture of the object side surface S15 of the eighth lens L8, and sd31 is the maximum effective semi-aperture of the object side surface S5 of the third lens L3. When this relationship is satisfied, the aperture of the eighth lens L8 is kept larger than the effective aperture of the third lens L3 but does not cause excessive deflection of the incident light, which is conducive to enabling the optical system 10 to obtain a larger image surface to match the image sensor with higher pixels, thereby improving the resolution. When it is lower than the lower limit of the relationship, it is not conducive to the optical system 10 to achieve a large image surface characteristic, and it is not conducive to shortening the total length of the system while ensuring the imaging clarity, and it is difficult to achieve a miniaturized design of the optical system 10; when it is higher than the upper limit of the relationship, the effective aperture of the object side surface S5 of the third lens L3 is too small, which is not conducive to the optical system 10 to obtain sufficient light flux, thereby reducing the imaging quality. In some embodiments, the relationship satisfied by the optical system 10 may specifically be 3, 3.04, 3.1, 3.16, 3.2, 3.24, 3.28, 3.3 or 3.32.

[0076] 3.2<f8 / sag82<5.2; f8 is the effective focal length of the eighth lens L8, and sag82 is the sagittal height of the image side surface S16 of the eighth lens L8 at the maximum effective aperture. When this relationship is satisfied, it is beneficial for the eighth lens L8 to contribute a reasonable negative refractive power to the eight-piece optical system 10 to correct the aberrations generated by the object lens, and it is also beneficial to shorten the total length of the system. When it is lower than the lower limit of the relationship, the negative refractive power provided by the eighth lens L8 is too strong, which is easy to over-correct the aberrations generated by the object lens, and the image side surface S16 of the eighth lens L8 will be too complicated, which will increase the difficulty of lens molding processing; when it is higher than the upper limit of the relationship, the negative refractive power provided by the eighth lens L8 is too small, which is not conducive to correcting aberrations and cannot ensure good imaging quality. In some embodiments, the relationship satisfied by the optical system 10 can be 3.5, 3.54, 3.6, 3.67, 3.74, 3.8, 3.89, 3.94, 3.98 or 5.

[0077] 9<R71 / sd67<16; R71 is the radius of curvature of the object side surface S13 of the seventh lens L7 at the optical axis 101, and sd67 is the difference between the maximum effective semi-aperture of the object side surface S13 of the seventh lens L7 and the maximum effective semi-aperture of the image side surface S12 of the sixth lens L6. When sd67 is greater than 0, it means that the maximum effective aperture of the object side surface S13 of the seventh lens L7 is greater than the maximum effective aperture of the image side surface S12 of the sixth lens L6. The value of the maximum effective semi-aperture is half of the maximum effective aperture. When this relationship is satisfied, the surface shape of the seventh lens L7 and the aperture difference between the sixth lens L6 and the seventh lens L7 can be reasonably constrained, so that the step difference can be increased while keeping the deflection angle of the incident light small, thereby helping the optical system 10 to achieve a large image surface design, and also helping to shorten the total length of the optical system 10 to achieve a miniaturized design of the optical system 10. When it is higher than the upper limit of the relational expression, the step difference from the image side surface S12 of the sixth lens L6 to the object side surface S13 of the seventh lens L7 is too small, which is not conducive to realizing a large image surface design. In addition, it will cause the light incident at a large angle to be deflected too much when passing between the sixth lens L6 and the seventh lens L7, thereby destroying the aberration balance of the optical system 10, thereby reducing the imaging quality of the optical system 10; when it is lower than the lower limit of the relational expression, the curvature radius of the object side surface S13 of the seventh lens L7 is too small, and the surface shape is too curved, so that the deflection angle of the edge light when passing through the seventh lens L7 is too large, resulting in the generation of aberrations that are difficult to correct, increasing the burden of the last lens on the image side to correct aberrations, and ultimately reducing the imaging quality. In some embodiments, the relationship satisfied by the optical system 10 can be 9.3, 9.5, 9.8, 10, 10.7, 11.2, 12, 13.4, 14.5 or 15. In some embodiments, a radius of curvature R71 of the object-side surface S13 of the seventh lens L7 at the optical axis 101 satisfies 4.817 mm≤R71≤5.94 mm, and specifically may be 4.85, 4.9, 5, 5.4, 5.55, 5.63, 5.76, 5.8, 5.86 or 5.9, where the value unit is mm.

[0078] sag81 / sag72<1.75; sag81 is the sagitta of the object side surface S15 of the eighth lens L8 at the maximum effective aperture, and sag72 is the sagitta of the image side surface S14 of the seventh lens L7 at the maximum effective aperture. When this relationship is satisfied, the surface shapes of the image side surface S14 of the seventh lens L7 and the object side surface S15 of the eighth lens L8 can be reasonably constrained to achieve the effect of effectively correcting the system aberration and improving the imaging quality. At the same time, the sagitta of the corresponding lens surface shape at the maximum effective aperture will not be too large, and the surface shape will not be too distorted, so that the lens surface shape is controlled within the range of easy processing and molding. When it is higher than the upper limit of the relationship, the sagitta of the object side surface S15 of the eighth lens L8 at the maximum effective aperture is too large, and the surface shape is too distorted, which will inevitably increase the tolerance sensitivity of the lens, and the difficulty of processing, molding and assembly of the lens will also increase accordingly. In some embodiments, the relationship satisfied by the optical system 10 may specifically be 1.4, 1.44, 1.48, 1.52, 1.56, 1.65, 1.7 or 1.72.

[0079] -60<R52 / sd56<-10; R52 is the radius of curvature of the image side surface S10 of the fifth lens L5 at the optical axis 101, and sd56 is the difference between the maximum effective semi-aperture of the object side surface S11 of the sixth lens L6 and the maximum effective semi-aperture of the image side surface S10 of the fifth lens L5. When sd56 is greater than 0, it means that the maximum effective aperture of the object side surface S11 of the sixth lens L6 is greater than the maximum effective aperture of the image side surface S10 of the fifth lens L5. When this relationship is satisfied, on the one hand, it is beneficial to constrain the surface shape of the image side surface S10 of the fifth lens L5, so that the incident light can be incident on the sixth lens L6 with a smaller deflection angle when passing through the image side surface S10 of the fifth lens L5; on the other hand, it is also beneficial to achieve a large image surface design while shortening the total length of the optical system 10. When it is lower than the lower limit of the relationship, the image side surface of the fifth lens L5 is flat, which is not enough to deflect the edge light to a reasonable direction, which can easily reduce the edge illumination of the imaged picture, resulting in dark corners; when it is higher than the upper limit of the relationship, it will cause the image side surface S10 of the fifth lens L5 to be too curved, and the tolerance sensitivity will increase, making it difficult to process and shape. In some embodiments, the relationship satisfied by the optical system 10 can be specifically -55, -50, -45, -36, -25, -20, -15 or -12. In some embodiments, the radius of curvature R52 of the image side surface S10 of the fifth lens L5 at the optical axis 101 satisfies -34.688mm≤R52≤-4.848mm, and can be specifically -32, -30, -26, -20, -15, -12, -9, and the numerical unit is mm.

[0080] 0.9<f / f1<1.1; f is the effective focal length of the optical system 10, and f1 is the effective focal length of the first lens L1. When this relationship is satisfied, it will be beneficial for the first lens L1 to contribute appropriate positive refractive power to the entire optical system 10, so as to effectively reduce the head size of the optical system 10, shorten the total length of the system, and provide sufficient space for increasing the image plane size. In some embodiments, the relationship satisfied by the optical system 10 can specifically be 0.98, 1, 1.02, 1.04 or 1.06.

[0081] Regarding the above sag72, sag81, and sag82, it should be noted that when describing the sag height of a lens surface at the maximum effective aperture, it means the distance from the intersection of the lens surface and the optical axis 101 to the position of the maximum effective aperture of the surface in the direction parallel to the optical axis 101. When the sag height value at the maximum effective aperture is negative, it means that the position of the maximum effective aperture of the surface is closer to the object side than the intersection of the surface and the optical axis 101, and vice versa, it is closer to the image side.

[0082] The reference wavelength of the effective focal length and combined focal length in the above relationship conditions is 555nm, and the effective focal length and combined focal length refer to at least the values ​​of the corresponding lens or lens group at the near optical axis. And the above relationship conditions and the technical effects brought about by them are for the optical system 10 with the above lens design. When it is impossible to ensure that the lens design (number of lenses, refractive power configuration, surface configuration, etc.) of the above optical system 10 is possessed, it will be difficult to ensure that the optical system 10 can still have the corresponding technical effects when satisfying these relationship conditions, and it may even cause a significant decline in camera performance.

[0083] The optical system 10 further includes an aperture stop STO, which can be used to limit the amount of light entering the imaging surface S17, and can also be used to block ineffective light to improve aberrations and control depth of field. In some embodiments, the aperture stop STO is disposed on the object side of the first lens L1, for example, overlapped on the object side surface S1 of the first lens L1.

[0084] In some embodiments, at least one lens of the optical system 10 has an aspheric surface type. When at least one side surface (object side or image side) of the lens is an aspheric surface, the lens can be said to have an aspheric surface type. In one embodiment, the object side and image side of each lens can be designed as aspheric surfaces. The aspheric design can help the optical system 10 to eliminate aberrations more effectively and improve imaging quality. In some embodiments, at least one lens of the optical system 10 can have a spherical surface type. The design of the spherical surface type can reduce the difficulty of preparing the lens and reduce the preparation cost. In some embodiments, in order to take into account the preparation cost, preparation difficulty, imaging quality, assembly difficulty, etc., the design of each lens surface in the optical system 10 can be a combination of aspheric and spherical surface types. It should be noted that when the object side or image side of a lens is an aspheric surface, the surface may have a recurved structure. At this time, the type of surface type of the surface from the center to the edge will change. For example, a lens surface is convex near the optical axis and concave near the maximum effective aperture.

[0085] The calculation of the aspheric surface can refer to the aspheric surface formula:

[0086]

[0087] Among them, Z is the distance from the corresponding point on the aspheric surface to the tangent plane of the surface at the optical axis 101, r is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the aspheric surface at the optical axis 101, k is the cone coefficient, and Ai is the coefficient of the high-order term corresponding to the i-th high-order term in the aspheric surface shape formula.

[0088] On the other hand, in some embodiments, at least one lens in the optical system 10 is made of plastic (PC), and the plastic material may be polycarbonate, gum, etc. In some embodiments, at least one lens in the optical system 10 is made of glass (GL). Lenses made of plastic can reduce the production cost of the optical system 10, while lenses made of glass can withstand higher or lower temperatures and have excellent optical effects and better stability. In some embodiments, lenses of different materials can be provided in the optical system 10, that is, a design combining glass lenses and plastic lenses can be adopted, but the specific configuration relationship can be determined according to actual needs, and will not be exhaustively listed here.

[0089] The optical system 10 of the present application is described below through a more specific embodiment:

[0090] First embodiment

[0091] refer to Figure 1In the first embodiment, the optical system 10 includes an aperture stop STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with positive refractive power, a seventh lens L7 with negative refractive power, and an eighth lens L8 with negative refractive power in order from the object side to the image side along the optical axis 101. The surface shapes of the lenses of the optical system 10 are as follows:

[0092] The object-side surface S1 of the first lens L1 is convex near the optical axis, and the image-side surface S2 is concave near the optical axis; the object-side surface S1 is concave near the maximum effective aperture, and the image-side surface S2 is convex near the maximum effective aperture.

[0093] The object-side surface S3 of the second lens L2 is convex near the optical axis, and the image-side surface S4 is concave near the optical axis; the object-side surface S3 is convex near the maximum effective aperture, and the image-side surface S4 is concave near the maximum effective aperture.

[0094] The object-side surface S5 of the third lens L3 is concave near the optical axis, and the image-side surface S6 is convex near the optical axis; the object-side surface S5 is concave near the maximum effective aperture, and the image-side surface S6 is convex near the maximum effective aperture.

[0095] The object-side surface S7 of the fourth lens L4 is concave near the optical axis, and the image-side surface S8 is concave near the optical axis; the object-side surface S7 is concave near the maximum effective aperture, and the image-side surface S8 is concave near the maximum effective aperture.

[0096] The object-side surface S9 of the fifth lens L5 is concave near the optical axis, and the image-side surface S10 is convex near the optical axis; the object-side surface S9 is concave near the maximum effective aperture, and the image-side surface S10 is convex near the maximum effective aperture.

[0097] The object-side surface S11 of the sixth lens L6 is concave near the optical axis, and the image-side surface S12 is convex near the optical axis; the object-side surface S11 is concave near the maximum effective aperture, and the image-side surface S12 is convex near the maximum effective aperture.

[0098] The object-side surface S13 of the seventh lens L7 is convex near the optical axis, and the image-side surface S14 is concave near the optical axis; the object-side surface S13 is convex near the maximum effective aperture, and the image-side surface S14 is concave near the maximum effective aperture.

[0099] The object-side surface S15 of the eighth lens L8 is concave near the optical axis, and the image-side surface S16 is concave near the optical axis; the object-side surface S15 is convex near the maximum effective aperture, and the image-side surface S16 is concave near the maximum effective aperture.

[0100] In the first embodiment, each lens surface of the first lens L1 to the eighth lens L8 is an aspherical surface, and the material of each lens is plastic (PC).

[0101] The lens parameters of the optical system 10 in the first embodiment are shown in the following Table 1. The elements from the object side to the image side of the optical system 10 are arranged in order from top to bottom according to Table 1, wherein the aperture represents the aperture aperture STO. The filter 110 is an infrared cutoff filter, and the filter 110 can be used as a part of the optical system 10 or can be removed from the optical system 10. However, when the filter 110 is removed, the total optical length of the optical system 10 remains unchanged. The Y radius in Table 1 is the radius of curvature of the corresponding surface of the lens at the optical axis 101. The absolute value of the first value of the lens in the "Thickness" parameter column is the thickness of the lens on the optical axis 101 (for example, the surface numbered S1 in Table 1 represents the object side of the first lens, and the surface numbered S2 represents the image side of the first lens), and the absolute value of the second value is the distance from the image side of the lens to the next optical surface (the object side or the aperture surface of the next lens) on the optical axis 101, wherein the thickness parameter of the aperture represents the distance from the aperture surface to the object side of the image-side adjacent lens on the optical axis 101. The reference wavelengths of the refractive index and Abbe number of each lens in the table are all 587.6nm, the reference wavelength of the focal length (effective focal length) is 555nm, and the numerical units of the Y radius, thickness, and focal length (effective focal length) are all millimeters (mm). In addition, the parameter data and lens surface structure used for relationship calculation in the following embodiments shall be based on the data in the lens parameter table in the corresponding embodiment.

[0102] Table 1

[0103]

[0104]

[0105] As can be seen from Table 1, the effective focal length f of the optical system 10 in the first embodiment is 7.606 mm, the aperture number FNO is 1.95, the total optical length TTL is 8.89 mm, the maximum field of view FOV is 87.668°, and the maximum field of view FOV is twice that of the semiFOV. It can be seen that the optical system 10 of this embodiment has a wide-angle characteristic.

[0106] The following Table 2 shows the aspheric coefficients of the corresponding lens surfaces in Table 1, where K is the cone coefficient and Ai is the coefficient corresponding to the i-th order high-order term in the aspheric surface shape formula.

[0107] Table 2

[0108]

[0109]

[0110] In the first embodiment, the optical system 10 satisfies the following relationships:

[0111] TTL / ImgH=1.201;When the optical system 10 with an eight-piece structure satisfies the above relational conditions, due to the restrictions on the number of lenses, refractive power, surface shape and the upper limit of the relational expression, the optical system 10 will have a large image plane characteristic, and can be used with an image sensor with higher pixels to have a clearer imaging picture. In addition, it can also prevent the axial dimension of the eight-piece optical system 10 from being too long, thereby taking into account the miniaturized design. When the above optical system 10 satisfies the lower limit of the relational expression, it can also prevent the total optical length of the eight-piece optical system 10 from being too short relative to the imaging height, so that the incident light has enough space to be deflected when passing through each lens to achieve a smooth transition, reduce the sensitivity of the imaging clarity to the total optical length of the system, thereby maintaining the stability of the imaging quality, and at the same time help reduce the design difficulty of the system.

[0112] f2 / f12=-2.397; when this relationship is satisfied, the refractive powers of the first lens L1 and the second lens L2 are reasonably configured, and the second lens L2 with negative refractive power can effectively correct aberrations such as distortion and field curvature generated by the first lens L1, and reduce the deflection angle of the incident light when passing through the first lens L1 and the second lens L2, thereby helping to reduce the overall sensitivity of the optical system 10 and improve the overall imaging quality.

[0113] f / tan(semiFOV)=7.92mm; when this relationship is satisfied, the field of view angle and image height of the optical system 10 can be reasonably configured, which can reduce the deflection angle of light in the optical system 10 on the one hand, thereby better balancing the aberration of the optical system 10; on the other hand, the axial size of the optical system 10 can be further compressed; on the other hand, the optical system 10 can further realize a large image surface design; in addition, it is also beneficial to reduce the difficulty of injection molding of each lens.

[0114] sd81 / sd31=3.24; when this relationship is satisfied, the aperture of the eighth lens L8 is kept larger than the effective aperture of the third lens L3 but does not cause excessive deflection of the incident light, which is beneficial for the optical system 10 to obtain a larger image plane to match a higher pixel image sensor, thereby improving the resolution.

[0115] f8 / sag82=3.59; when this relationship is satisfied, it is beneficial for the eighth lens L8 to contribute reasonable negative refractive power to the eight-piece optical system 10 to correct the aberration produced by the object-side lens, and it is beneficial to shorten the total length of the system.

[0116] R71 / sd67=9.81; the value of the maximum effective half aperture is half of the maximum effective aperture. When this relationship is satisfied, the surface shape of the seventh lens L7 and the aperture difference between the sixth lens L6 and the seventh lens L7 can be reasonably constrained, so that the step difference can be increased while keeping the deflection angle of the incident light small, thereby helping the optical system 10 to achieve a large image plane design, and also helping to shorten the total length of the optical system 10 to achieve a miniaturized design of the optical system 10.

[0117] sag81 / sag72=1.73; when this relationship is satisfied, the surface shapes of the image-side surface S14 of the seventh lens element L7 and the object-side surface S15 of the eighth lens element L8 can be reasonably constrained, so as to achieve the effect of effectively correcting the system aberration and improving the imaging quality. At the same time, the sag height of the corresponding lens surface at the maximum effective aperture will not be too large, and the surface shape will not be too distorted, so that the lens surface shape is controlled within a range that is easy to process and shape.

[0118] R52 / sd56=-19.39; when this relationship is satisfied, on the one hand, it is beneficial to constrain the surface shape of the image-side surface S10 of the fifth lens L5, so that the incident light can be incident on the sixth lens L6 at a smaller deflection angle when passing through the image-side surface S10 of the fifth lens L5; on the other hand, it is also beneficial to achieve a large image surface design while shortening the total length of the optical system 10.

[0119] f / f1=1.04; when this relationship is satisfied, it will be beneficial for the first lens L1 to contribute appropriate positive refractive power to the entire optical system 10, so as to effectively reduce the head size of the optical system 10, shorten the total length of the system, and provide sufficient space for increasing the image plane size.

[0120] Figure 2 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system 10 in the first embodiment are included, wherein the reference wavelength of the astigmatism diagram and the distortion diagram is 555nm. The longitudinal spherical aberration diagram (Longitudinal Spherical Aberration) shows the deviation of the convergent focus of light of different wavelengths after passing through the lens. The ordinate of the longitudinal spherical aberration diagram represents the normalized pupil coordinate (Normalized Pupil Coordinator) from the center of the pupil to the edge of the pupil, and the abscissa represents the distance from the imaging surface to the intersection of the light and the optical axis (in mm). It can be seen from the longitudinal spherical aberration diagram that the degree of deviation of the convergent focus of light of each wavelength in the first embodiment tends to be consistent, and the maximum focus offset of each reference wavelength is controlled within ±0.05mm, and the diffuse spots or color halos in the imaging picture are effectively suppressed. Figure 2It also includes the astigmatic field curvature diagram (Astigmatic Field Curves) of the optical system 10, 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 is small, the maximum field curvature is controlled within ±0.025mm, the image curvature is effectively suppressed, and the sagittal field curvature and meridian field curvature under each field of view tend to be consistent, and the astigmatism of each field of view is better controlled. Therefore, it can be seen that the optical system 10 has clear imaging from the center to the edge of the field of view. In addition, according to the distortion diagram, it can be seen that the maximum distortion of the optical system 10 is controlled within 2.5%, so it can be seen that the distortion degree is well controlled.

[0121] Second embodiment

[0122] refer to Figure 3 In the second embodiment, the optical system 10 includes an aperture stop STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, a fifth lens L5 with negative refractive power, a sixth lens L6 with positive refractive power, a seventh lens L7 with positive refractive power, and an eighth lens L8 with negative refractive power in order from the object side to the image side along the optical axis 101. The surface shapes of the lenses of the optical system 10 are as follows:

[0123] The object-side surface S1 of the first lens L1 is convex near the optical axis, and the image-side surface S2 is concave near the optical axis; the object-side surface S1 is concave near the maximum effective aperture, and the image-side surface S2 is convex near the maximum effective aperture.

[0124] The object-side surface S3 of the second lens L2 is convex near the optical axis, and the image-side surface S4 is concave near the optical axis; the object-side surface S3 is convex near the maximum effective aperture, and the image-side surface S4 is concave near the maximum effective aperture.

[0125] The object-side surface S5 of the third lens L3 is convex near the optical axis, and the image-side surface S6 is convex near the optical axis; the object-side surface S5 is concave near the maximum effective aperture, and the image-side surface S6 is convex near the maximum effective aperture.

[0126] The object-side surface S7 of the fourth lens L4 is convex near the optical axis, and the image-side surface S8 is concave near the optical axis; the object-side surface S7 is concave near the maximum effective aperture, and the image-side surface S8 is concave near the maximum effective aperture.

[0127] The object-side surface S9 of the fifth lens L5 is concave near the optical axis, and the image-side surface S10 is convex near the optical axis; the object-side surface S9 is concave near the maximum effective aperture, and the image-side surface S10 is convex near the maximum effective aperture.

[0128] The object-side surface S11 of the sixth lens L6 is convex near the optical axis, and the image-side surface S12 is convex near the optical axis; the object-side surface S11 is convex near the maximum effective aperture, and the image-side surface S12 is concave near the maximum effective aperture.

[0129] The object-side surface S13 of the seventh lens L7 is convex near the optical axis, and the image-side surface S14 is concave near the optical axis; the object-side surface S13 is convex near the maximum effective aperture, and the image-side surface S14 is concave near the maximum effective aperture.

[0130] The object-side surface S15 of the eighth lens L8 is convex near the optical axis, and the image-side surface S16 is concave near the optical axis; the object-side surface S15 is convex near the maximum effective aperture, and the image-side surface S16 is convex near the maximum effective aperture.

[0131] The lens parameters of the optical system 10 in this embodiment are given in Table 3 and Table 4, wherein the definitions of the component names and parameters can be obtained from the first embodiment and are not described in detail here.

[0132] Table 3

[0133]

[0134] Table 4

[0135] Surface number S1 S2 S3 S4 S5 S6 S7 S8 K -4.147E-04 -2.066E+00 -1.396E+00 6.456E-01 -1.000E+01 7.309E+00 -1.000E+01 9.369E+00 A4 1.527E-05 -1.053E-02 -2.204E-02 -1.247E-02 2.721E-04 2.350E-02 1.557E-02 -2.655E-05 A6 1.904E-03 2.458E-03 5.112E-03 3.242E-03 -7.092E-03 -5.734E-02 -7.005E-02 -2.876E-02 A8 -3.286E-03 -5.813E-04 3.406E-03 5.054E-03 7.315E-03 5.995E-02 6.932E-02 2.085E-02 A10 3.539E-03 2.331E-04 -4.296E-03 -5.901E-03 -8.029E-03 -4.342E-02 -4.693E-02 -9.225E-03 A12 -2.368E-03 -1.057E-04 3.271E-03 4.442E-03 5.461E-03 2.079E-02 2.189E-02 2.335E-03 A14 9.838E-04 1.347E-05 -1.702E-03 -2.237E-03 -2.281E-03 -6.379E-03 -6.822E-03 -2.212E-04 A16 -2.492E-04 4.156E-06 5.607E-04 7.172E-04 5.283E-04 1.165E-03 1.348E-03 -4.164E-05 A18 3.516E-05 -1.408E-06 -1.027E-04 -1.284E-04 -5.108E-05 -1.036E-04 -1.498E-04 1.279E-05 A20 -2.143E-06 8.840E-08 7.916E-06 9.837E-06 0.000E+00 2.084E-06 6.927E-06 -9.072E-07 Surface number S9 S10 S11 S12 S13 S14 S15 S16 K -2.440E+00 5.190E+00 1.000E+01 -2.464E+01 -1.061E+00 -1.864E-02 -9.974E+00 -8.409E-01 A4 -9.240E-03 -2.165E-02 -1.923E-02 -1.596E-02 5.133E-03 1.758E-02 -2.425E-02 -3.262E-02 A6 -2.269E-03 8.592E-03 1.360E-02 1.217E-02 -4.680E-03 -1.004E-02 2.661E-03 5.204E-03 A8 2.271E-04 -5.737E-03 -6.948E-03 -6.300E-03 -3.822E-04 1.773E-03 -2.720E-04 -8.116E-04 A10 1.864E-03 3.439E-03 2.139E-03 1.961E-03 3.464E-04 -1.773E-04 3.313E-05 8.611E-05 A12 -1.609E-03 -1.335E-03 -4.206E-04 -3.837E-04 -6.983E-05 9.173E-06 -2.767E-06 -5.627E-06 A14 6.503E-04 3.219E-04 5.062E-05 4.685E-05 7.333E-06 -8.608E-08 1.360E-07 2.241E-07 A16 -1.484E-04 -4.575E-05 -3.502E-06 -3.431E-06 -4.309E-07 -1.454E-08 -3.849E-09 -5.312E-09 A18 1.840E-05 3.485E-06 1.254E-07 1.374E-07 1.339E-08 6.694E-10 5.848E-11 6.894E-11 A20 -9.583E-07 -1.096E-07 -1.754E-09 -2.310E-09 -1.714E-10 -9.109E-12 -3.708E-13 -3.778E-13

[0136] The optical system 10 in this embodiment satisfies the following relationship:

[0137] TTL / ImgH 1.201 R71 / sd67 11.154 f2 / f12 -2.411 sag81 / sag72 1.558 f / tan(semiFOV)(mm) 7.784 R52 / sd56 -21.301 sd81 / sd31 3.274 f / f1 1.002 f8 / sag82 4.851

[0138] Depend on Figure 4 It can be seen from the aberration diagrams in that the longitudinal spherical aberration, field curvature, astigmatism and distortion of the optical system 10 are all well controlled, wherein the focus shift at each reference wavelength is controlled within ±0.05 mm, while the meridian field curvature and sagittal field curvature under most fields of view are controlled within ±0.025 mm, the image plane curvature is effectively suppressed, and the astigmatism is well adjusted, and the maximum distortion is also controlled within 2.5%. Therefore, it can be judged that the optical system 10 of this embodiment can have clear imaging.

[0139] Third embodiment

[0140] refer to Figure 5In the third embodiment, the optical system 10 includes, from the object side to the image side along the optical axis 101, 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. The surface shapes of the lenses of the optical system 10 are as follows:

[0141] The object-side surface S1 of the first lens L1 is convex near the optical axis, and the image-side surface S2 is concave near the optical axis; the object-side surface S1 is concave near the maximum effective aperture, and the image-side surface S2 is convex near the maximum effective aperture.

[0142] The object-side surface S3 of the second lens L2 is convex near the optical axis, and the image-side surface S4 is concave near the optical axis; the object-side surface S3 is convex near the maximum effective aperture, and the image-side surface S4 is concave near the maximum effective aperture.

[0143] The object-side surface S5 of the third lens L3 is concave near the optical axis, and the image-side surface S6 is convex near the optical axis; the object-side surface S5 is concave near the maximum effective aperture, and the image-side surface S6 is convex near the maximum effective aperture.

[0144] The object-side surface S7 of the fourth lens L4 is concave near the optical axis, and the image-side surface S8 is concave near the optical axis; the object-side surface S7 is concave near the maximum effective aperture, and the image-side surface S8 is concave near the maximum effective aperture.

[0145] The object-side surface S9 of the fifth lens L5 is concave near the optical axis, and the image-side surface S10 is convex near the optical axis; the object-side surface S9 is concave near the maximum effective aperture, and the image-side surface S10 is concave near the maximum effective aperture.

[0146] The object-side surface S11 of the sixth lens L6 is concave near the optical axis, and the image-side surface S12 is convex near the optical axis; the object-side surface S11 is convex near the maximum effective aperture, and the image-side surface S12 is concave near the maximum effective aperture.

[0147] The object-side surface S13 of the seventh lens L7 is convex near the optical axis, and the image-side surface S14 is concave near the optical axis; the object-side surface S13 is concave near the maximum effective aperture, and the image-side surface S14 is convex near the maximum effective aperture.

[0148] The object-side surface S15 of the eighth lens L8 is concave near the optical axis, and the image-side surface S16 is concave near the optical axis; the object-side surface S15 is convex near the maximum effective aperture, and the image-side surface S16 is convex near the maximum effective aperture.

[0149] The lens parameters of the optical system 10 in this embodiment are given in Table 5 and Table 6, wherein the definitions of the component names and parameters can be obtained from the first embodiment and are not described in detail here.

[0150] Table 5

[0151]

[0152] Table 6

[0153]

[0154]

[0155] The optical system 10 in this embodiment satisfies the following relationship:

[0156] TTL / ImgH 1.209 R71 / sd67 10.357 f2 / f12 -2.827 sag81 / sag72 1.707 f / tan(semiFOV)(mm) 7.823 R52 / sd56 -10.189 sd81 / sd31 3.253 f / f1 1.019 f8 / sag82 3.811

[0157] Depend on Figure 6 It can be seen from the aberration diagrams in that the longitudinal spherical aberration, field curvature, astigmatism and distortion of the optical system 10 are all well controlled, wherein the focus shift at each reference wavelength is controlled within ±0.05 mm, while the meridian field curvature and sagittal field curvature under most fields of view are controlled within ±0.025 mm, the image plane curvature is effectively suppressed, and the astigmatism is well adjusted, and the maximum distortion is also controlled within 2.5%. Therefore, it can be judged that the optical system 10 of this embodiment can have clear imaging.

[0158] Fourth embodiment

[0159] refer to Figure 7 In the fourth embodiment, the optical system 10 includes, from the object side to the image side along the optical axis 101, an aperture stop STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with negative refractive power, a sixth lens L6 with positive refractive power, a seventh lens L7 with negative refractive power, and an eighth lens L8 with negative refractive power. The surface shapes of the lenses of the optical system 10 are as follows:

[0160] The object-side surface S1 of the first lens L1 is convex near the optical axis, and the image-side surface S2 is concave near the optical axis; the object-side surface S1 is concave near the maximum effective aperture, and the image-side surface S2 is convex near the maximum effective aperture.

[0161] The object-side surface S3 of the second lens L2 is convex near the optical axis, and the image-side surface S4 is concave near the optical axis; the object-side surface S3 is convex near the maximum effective aperture, and the image-side surface S4 is concave near the maximum effective aperture.

[0162] The object-side surface S5 of the third lens L3 is concave near the optical axis, and the image-side surface S6 is convex near the optical axis; the object-side surface S5 is concave near the maximum effective aperture, and the image-side surface S6 is convex near the maximum effective aperture.

[0163] The object-side surface S7 of the fourth lens L4 is convex near the optical axis, and the image-side surface S8 is concave near the optical axis; the object-side surface S7 is concave near the maximum effective aperture, and the image-side surface S8 is concave near the maximum effective aperture.

[0164] The object-side surface S9 of the fifth lens L5 is concave near the optical axis, and the image-side surface S10 is convex near the optical axis; the object-side surface S9 is concave near the maximum effective aperture, and the image-side surface S10 is concave near the maximum effective aperture.

[0165] The object-side surface S11 of the sixth lens L6 is concave near the optical axis, and the image-side surface S12 is convex near the optical axis; the object-side surface S11 is convex near the maximum effective aperture, and the image-side surface S12 is concave near the maximum effective aperture.

[0166] The object-side surface S13 of the seventh lens L7 is convex near the optical axis, and the image-side surface S14 is concave near the optical axis; the object-side surface S13 is convex near the maximum effective aperture, and the image-side surface S14 is concave near the maximum effective aperture.

[0167] The object-side surface S15 of the eighth lens L8 is concave near the optical axis, and the image-side surface S16 is concave near the optical axis; the object-side surface S15 is convex near the maximum effective aperture, and the image-side surface S16 is convex near the maximum effective aperture.

[0168] The lens parameters of the optical system 10 in this embodiment are given in Table 7 and Table 8, wherein the definitions of the component names and parameters can be obtained from the first embodiment and are not described in detail here.

[0169] Table 7

[0170]

[0171] Table 8

[0172]

[0173]

[0174] The optical system 10 in this embodiment satisfies the following relationship:

[0175] TTL / ImgH 1.213 R71 / sd67 15.403 f2 / f12 -2.228 sag81 / sag72 1.748 f / tan(semiFOV)(mm) 7.922 R52 / sd56 -18.648 sd81 / sd31 3.199 f / f1 1.055 f8 / sag82 3.437

[0176] Depend on Figure 8It can be seen from the aberration diagrams in that the longitudinal spherical aberration, field curvature, astigmatism and distortion of the optical system 10 are all well controlled, wherein the focus shift at each reference wavelength is controlled within ±0.1 mm, while the meridian field curvature and sagittal field curvature under most fields of view are controlled within ±0.025 mm, the image plane curvature is effectively suppressed, and the astigmatism is well adjusted, and the maximum distortion is also controlled within 2.5%. Therefore, it can be judged that the optical system 10 of this embodiment can have clear imaging.

[0177] Fifth embodiment

[0178] refer to Fig. 9 In the fifth embodiment, the optical system 10 includes, from the object side to the image side along the optical axis 101, an aperture stop STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with negative 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. The surface shapes of the lenses of the optical system 10 are as follows:

[0179] The object-side surface S1 of the first lens L1 is convex near the optical axis, and the image-side surface S2 is concave near the optical axis; the object-side surface S1 is concave near the maximum effective aperture, and the image-side surface S2 is convex near the maximum effective aperture.

[0180] The object-side surface S3 of the second lens L2 is convex near the optical axis, and the image-side surface S4 is concave near the optical axis; the object-side surface S3 is convex near the maximum effective aperture, and the image-side surface S4 is concave near the maximum effective aperture.

[0181] The object-side surface S5 of the third lens L3 is concave near the optical axis, and the image-side surface S6 is convex near the optical axis; the object-side surface S5 is concave near the maximum effective aperture, and the image-side surface S6 is convex near the maximum effective aperture.

[0182] The object-side surface S7 of the fourth lens L4 is convex near the optical axis, and the image-side surface S8 is concave near the optical axis; the object-side surface S7 is concave near the maximum effective aperture, and the image-side surface S8 is concave near the maximum effective aperture.

[0183] The object-side surface S9 of the fifth lens L5 is concave near the optical axis, and the image-side surface S10 is convex near the optical axis; the object-side surface S9 is convex near the maximum effective aperture, and the image-side surface S10 is convex near the maximum effective aperture.

[0184] The object-side surface S11 of the sixth lens L6 is concave near the optical axis, and the image-side surface S12 is convex near the optical axis; the object-side surface S11 is convex near the maximum effective aperture, and the image-side surface S12 is concave near the maximum effective aperture.

[0185] The object-side surface S13 of the seventh lens L7 is convex near the optical axis, and the image-side surface S14 is concave near the optical axis; the object-side surface S13 is concave near the maximum effective aperture, and the image-side surface S14 is convex near the maximum effective aperture.

[0186] The object-side surface S15 of the eighth lens L8 is concave near the optical axis, and the image-side surface S16 is concave near the optical axis; the object-side surface S15 is concave near the maximum effective aperture, and the image-side surface S16 is convex near the maximum effective aperture.

[0187] The lens parameters of the optical system 10 in this embodiment are given in Tables 9 and 10, wherein the definitions of the component names and parameters can be obtained from the first embodiment and are not described in detail here.

[0188] Table 9

[0189]

[0190]

[0191] Table 10

[0192] Surface number S1 S2 S3 S4 S5 S6 S7 S8 K 1.440E-02 -2.541E-01 9.933E-01 1.176E+00 7.711E+00 1.000E+01 -1.000E+01 9.476E+00 A4 5.775E-05 -9.497E-03 -2.048E-02 -1.123E-02 2.345E-03 -2.531E-02 -3.068E-02 -1.100E-02 A6 1.749E-03 1.558E-03 6.121E-03 4.917E-03 -5.088E-03 7.462E-03 4.137E-03 -4.467E-03 A8 -2.773E-03 1.164E-03 1.053E-03 1.390E-03 5.139E-03 -2.269E-03 -2.708E-03 5.881E-04 A10 2.716E-03 -1.915E-03 -1.603E-03 -1.497E-03 -5.540E-03 4.115E-04 1.792E-03 2.106E-04 A12 -1.649E-03 1.455E-03 9.663E-04 7.904E-04 3.703E-03 -6.942E-04 -1.470E-03 -1.913E-04 A14 6.225E-04 -6.812E-04 -4.150E-04 -3.033E-04 -1.502E-03 7.325E-04 9.545E-04 1.004E-04 A16 -1.436E-04 1.907E-04 1.260E-04 9.630E-05 3.343E-04 -3.549E-04 -3.777E-04 -3.386E-05 A18 1.850E-05 -2.917E-05 -2.228E-05 -1.899E-05 -3.085E-05 8.386E-05 7.902E-05 5.554E-06 A20 -1.036E-06 1.865E-06 1.679E-06 1.772E-06 0.000E+00 -7.791E-06 -6.613E-06 -3.044E-07 Surface number S9 S10 S11 S12 S13 S14 S15 S16 K 5.032E+00 5.513E+00 -8.666E+00 -1.058E+01 -1.165E+00 -1.954E-02 -6.822E-02 -7.690E-01 A4 -1.761E-02 -1.945E-02 -1.081E-02 -9.706E-03 8.597E-03 1.269E-02 -2.305E-02 -2.826E-02 A6 2.969E-03 6.029E-03 7.582E-03 3.974E-03 -6.904E-03 -7.606E-03 2.835E-03 4.192E-03 A8 3.331E-04 -2.004E-03 -3.316E-03 -1.664E-03 8.298E-04 1.213E-03 -2.650E-04 -5.985E-04 A10 -1.317E-03 3.855E-04 7.151E-04 3.517E-04 -2.012E-05 -1.041E-04 2.541E-05 5.891E-05 A12 8.492E-04 4.868E-05 -8.284E-05 -4.385E-05 -6.316E-06 3.660E-06 -1.804E-06 -3.582E-06 A14 -2.528E-04 -3.757E-05 3.889E-06 3.711E-06 8.925E-07 1.265E-07 8.006E-08 1.323E-07 A16 3.700E-05 7.107E-06 1.531E-07 -2.160E-07 -5.436E-08 -1.681E-08 -2.102E-09 -2.890E-09 A18 -2.521E-06 -6.032E-07 -2.366E-08 7.633E-09 1.629E-09 5.828E-10 3.003E-11 3.440E-11 A20 6.482E-08 1.977E-08 6.962E-10 -1.186E-10 -1.953E-11 -7.084E-12 -1.803E-13 -1.722E-13

[0193] The optical system 10 in this embodiment satisfies the following relationship:

[0194] TTL / ImgH 1.214 R71 / sd67 9.275 f2 / f12 -2.141 sag81 / sag72 1.581 f / tan(semiFOV)(mm) 7.917 R52 / sd56 -39.256 sd81 / sd31 3.340 f / f1 1.071 f8 / sag82 3.499

[0195] Depend on Fig.10 It can be seen from the aberration diagrams in that the longitudinal spherical aberration, field curvature, astigmatism and distortion of the optical system 10 are all well controlled, wherein the focus shift at each reference wavelength is controlled within ±0.1 mm, while the meridian field curvature and sagittal field curvature under most fields of view are controlled within ±0.025 mm, the image plane curvature is effectively suppressed, and the astigmatism is well adjusted, and the maximum distortion is also controlled within 2.5%. Therefore, it can be judged that the optical system 10 of this embodiment can have clear imaging.

[0196] Sixth embodiment

[0197] refer to Fig.11 In the sixth embodiment, the optical system 10 includes, from the object side to the image side along the optical axis 101, an aperture stop STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, a fifth lens L5 with negative refractive power, a sixth lens L6 with positive refractive power, a seventh lens L7 with positive refractive power, and an eighth lens L8 with negative refractive power. The surface shapes of the lenses of the optical system 10 are as follows:

[0198] The object-side surface S1 of the first lens L1 is convex near the optical axis, and the image-side surface S2 is concave near the optical axis; the object-side surface S1 is concave near the maximum effective aperture, and the image-side surface S2 is convex near the maximum effective aperture.

[0199] The object-side surface S3 of the second lens L2 is convex near the optical axis, and the image-side surface S4 is concave near the optical axis; the object-side surface S3 is convex near the maximum effective aperture, and the image-side surface S4 is concave near the maximum effective aperture.

[0200] The object-side surface S5 of the third lens L3 is concave near the optical axis, and the image-side surface S6 is convex near the optical axis; the object-side surface S5 is concave near the maximum effective aperture, and the image-side surface S6 is convex near the maximum effective aperture.

[0201] The object-side surface S7 of the fourth lens L4 is concave near the optical axis, and the image-side surface S8 is concave near the optical axis; the object-side surface S7 is convex near the maximum effective aperture, and the image-side surface S8 is concave near the maximum effective aperture.

[0202] The object-side surface S9 of the fifth lens L5 is concave near the optical axis, and the image-side surface S10 is convex near the optical axis; the object-side surface S9 is concave near the maximum effective aperture, and the image-side surface S10 is convex near the maximum effective aperture.

[0203] The object-side surface S11 of the sixth lens L6 is concave near the optical axis, and the image-side surface S12 is convex near the optical axis; the object-side surface S11 is convex near the maximum effective aperture, and the image-side surface S12 is concave near the maximum effective aperture.

[0204] The object-side surface S13 of the seventh lens L7 is convex near the optical axis, and the image-side surface S14 is concave near the optical axis; the object-side surface S13 is concave near the maximum effective aperture, and the image-side surface S14 is convex near the maximum effective aperture.

[0205] The object-side surface S15 of the eighth lens L8 is concave near the optical axis, and the image-side surface S16 is concave near the optical axis; the object-side surface S15 is concave near the maximum effective aperture, and the image-side surface S16 is convex near the maximum effective aperture.

[0206] The lens parameters of the optical system 10 in this embodiment are given in Table 11 and Table 12, wherein the definitions of the component names and parameters can be obtained from the first embodiment and are not repeated here.

[0207] Table 11

[0208]

[0209]

[0210] Table 12

[0211] Surface number S1 S2 S3 S4 S5 S6 S7 S8 K 6.126E-02 2.472E+00 -5.083E-01 1.104E-01 -1.000E+01 -1.414E-01 1.000E+01 -1.000E+01 A4 -3.482E-04 -9.502E-03 -1.905E-02 -1.045E-02 -1.532E-03 2.251E-02 3.842E-03 -1.450E-02 A6 2.072E-03 1.701E-03 5.041E-03 3.747E-03 -4.431E-03 -5.905E-02 -5.337E-02 -7.888E-03 A8 -2.966E-03 1.447E-03 2.834E-03 2.704E-03 5.204E-03 6.914E-02 6.141E-02 7.783E-03 A10 2.643E-03 -2.187E-03 -4.020E-03 -3.257E-03 -5.789E-03 -5.625E-02 -4.987E-02 -6.211E-03 A12 -1.463E-03 1.530E-03 2.786E-03 2.069E-03 3.829E-03 3.087E-02 2.784E-02 3.446E-03 A14 5.062E-04 -6.478E-04 -1.222E-03 -8.464E-04 -1.503E-03 -1.113E-02 -1.037E-02 -1.259E-03 A16 -1.072E-04 1.633E-04 3.322E-04 2.236E-04 3.210E-04 2.505E-03 2.444E-03 2.854E-04 A18 1.268E-05 -2.245E-05 -5.012E-05 -3.382E-05 -2.832E-05 -3.153E-04 -3.294E-04 -3.666E-05 A20 -6.514E-07 1.290E-06 3.199E-06 2.349E-06 0.000E+00 1.669E-05 1.937E-05 2.070E-06 Surface number S9 S10 S11 S12 S13 S14 S15 S16 K 1.121E+00 3.723E+00 -1.000E+01 -1.750E+01 -1.194E+00 7.167E-03 1.652E+00 -8.263E-01 A4 -1.235E-02 -1.570E-02 -5.403E-03 -8.795E-03 3.345E-03 8.168E-03 -2.474E-02 -2.978E-02 A6 -3.124E-03 5.143E-04 4.206E-03 3.957E-03 -5.248E-03 -5.961E-03 3.693E-03 4.619E-03 A8 4.651E-03 1.516E-03 -1.577E-03 -1.291E-03 5.618E-04 9.050E-04 -4.664E-04 -6.439E-04 A10 -3.552E-03 -1.273E-03 8.393E-05 1.252E-04 1.349E-05 -6.647E-05 5.078E-05 6.122E-05 A12 1.592E-03 5.765E-04 5.972E-05 1.124E-05 -1.112E-05 3.131E-07 -3.690E-06 -3.646E-06 A14 -4.095E-04 -1.435E-04 -1.555E-05 -3.326E-06 1.467E-06 3.461E-07 1.657E-07 1.337E-07 A16 5.740E-05 2.036E-05 1.717E-06 2.837E-07 -9.503E-08 -2.662E-08 -4.447E-09 -2.939E-09 A18 -3.717E-06 -1.557E-06 -9.245E-08 -1.111E-08 3.107E-09 8.393E-10 6.564E-11 3.561E-11 A20 6.033E-08 4.972E-08 1.977E-09 1.712E-10 -4.091E-11 -9.972E-12 -4.114E-13 -1.837E-13

[0212] The optical system 10 in this embodiment satisfies the following relationship:

[0213] TTL / ImgH 1.216 R71 / sd67 11.919 f2 / f12 -2.582 sag81 / sag72 1.675 f / tan(semiFOV)(mm) 7.752 R52 / sd56 -14.481 sd81 / sd31 3.162 f / f1 1.005 f8 / sag82 3.467

[0214] Depend on Fig.12 It can be seen from the aberration diagrams in that the longitudinal spherical aberration, field curvature, astigmatism and distortion of the optical system 10 are all well controlled, wherein the focus shift at each reference wavelength is controlled within ±0.05 mm, while the meridian field curvature and sagittal field curvature under most fields of view are controlled within ±0.025 mm, the image plane curvature is effectively suppressed, and the astigmatism is well adjusted, and the maximum distortion is also controlled within 2.5%. Therefore, it can be judged that the optical system 10 of this embodiment can have clear imaging.

[0215] Seventh embodiment

[0216] refer to Fig.13 In the seventh embodiment, the optical system 10 includes, from the object side to the image side along the optical axis 101, an aperture stop STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, a fifth lens L5 with negative refractive power, a sixth lens L6 with positive refractive power, a seventh lens L7 with positive refractive power, and an eighth lens L8 with negative refractive power. The surface shapes of the lenses of the optical system 10 are as follows:

[0217] The object-side surface S1 of the first lens L1 is convex near the optical axis, and the image-side surface S2 is concave near the optical axis; the object-side surface S1 is convex near the maximum effective aperture, and the image-side surface S2 is convex near the maximum effective aperture.

[0218] The object-side surface S3 of the second lens L2 is convex near the optical axis, and the image-side surface S4 is concave near the optical axis; the object-side surface S3 is convex near the maximum effective aperture, and the image-side surface S4 is concave near the maximum effective aperture.

[0219] The object-side surface S5 of the third lens L3 is concave near the optical axis, and the image-side surface S6 is convex near the optical axis; the object-side surface S5 is concave near the maximum effective aperture, and the image-side surface S6 is convex near the maximum effective aperture.

[0220] The object-side surface S7 of the fourth lens L4 is convex near the optical axis, and the image-side surface S8 is concave near the optical axis; the object-side surface S7 is convex near the maximum effective aperture, and the image-side surface S8 is concave near the maximum effective aperture.

[0221] The object-side surface S9 of the fifth lens L5 is concave near the optical axis, and the image-side surface S10 is convex near the optical axis; the object-side surface S9 is concave near the maximum effective aperture, and the image-side surface S10 is convex near the maximum effective aperture.

[0222] The object-side surface S11 of the sixth lens L6 is concave near the optical axis, and the image-side surface S12 is convex near the optical axis; the object-side surface S11 is convex near the maximum effective aperture, and the image-side surface S12 is concave near the maximum effective aperture.

[0223] The object-side surface S13 of the seventh lens L7 is convex near the optical axis, and the image-side surface S14 is concave near the optical axis; the object-side surface S13 is concave near the maximum effective aperture, and the image-side surface S14 is convex near the maximum effective aperture.

[0224] The object-side surface S15 of the eighth lens L8 is concave near the optical axis, and the image-side surface S16 is concave near the optical axis; the object-side surface S15 is concave near the maximum effective aperture, and the image-side surface S16 is convex near the maximum effective aperture.

[0225] The lens parameters of the optical system 10 in this embodiment are given in Table 13 and Table 14, wherein the definitions of the component names and parameters can be obtained from the first embodiment and are not repeated here.

[0226] Table 13

[0227]

[0228] Table 14

[0229]

[0230]

[0231] The optical system 10 in this embodiment satisfies the following relationship:

[0232] TTL / ImgH 1.281 R71 / sd67 9.293 f2 / f12 -2.407 sag81 / sag72 1.373 f / tan(semiFOV)(mm) 7.752 R52 / sd56 -58.447 sd81 / sd31 2.959 f / f1 0.971 f8 / sag82 5.062

[0233] Depend on Fig.14 It can be seen from the aberration diagrams in that the longitudinal spherical aberration, field curvature, astigmatism and distortion of the optical system 10 are all well controlled, wherein the focus shift at each reference wavelength is controlled within ±0.05 mm, while the meridian field curvature and sagittal field curvature under most fields of view are controlled within ±0.025 mm, the image plane curvature is effectively suppressed, and the astigmatism is well adjusted, and the maximum distortion is also controlled within 2.5%. Therefore, it can be judged that the optical system 10 of this embodiment can have clear imaging.

[0234] Compared with the traditional optical system, the optical system 10 in the above embodiments can maintain good or even better imaging quality under the premise of realizing a miniaturized design with a shorter total axial length, and is also conducive to reducing the design difficulty of the system.

[0235] refer to Fig.15 , the embodiment of the present application further provides a camera module 20, the camera module 20 includes an optical system 10 and an image sensor 210, the image sensor 210 is arranged on the image side of the optical system 10, and the two can be fixed by a bracket. The image sensor 210 can be a CCD sensor (Charge Coupled Device) or a CMOS sensor (Complementary Metal Oxide Semiconductor). Generally, during assembly, the imaging surface S17 of the optical system 10 overlaps with the photosensitive surface of the image sensor 210. By adopting the above-mentioned optical system 10, the camera module 20 can also maintain good or even better imaging quality while compressing the total axial length.

[0236] refer to Fig.16 , some embodiments of the present application also provide an electronic device 30. The electronic device 30 includes a fixing part 310, and the camera module 20 is installed on the fixing part 310. The fixing part 310 may be a display screen, a circuit board, a middle frame, a back cover and other components. The electronic device 30 may be, but is not limited to, a smart phone, a smart watch, smart glasses, an e-book reader, a tablet computer, a biometric device (such as a fingerprint recognition device or a pupil recognition device, etc.), a PDA (Personal Digital Assistant), etc. Since the above-mentioned camera module 20 can maintain good imaging quality while compressing the total length, when the above-mentioned camera module 20 is used, the internal space of the electronic device 30 occupied by it can be reduced, thereby avoiding obstacles to the compression of the thickness of the electronic device 30, and at the same time maintaining the shooting performance of the electronic device 30.

[0237] 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.

[0238] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it 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, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on 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 refractive power, wherein the image side surface of the third lens is convex at the near optical axis; a fourth lens having refractive power, wherein the image side surface of the fourth lens is concave 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 a convex surface near the optical axis; a seventh lens having refractive power, wherein the object side surface of the seventh lens is convex at the near optical axis, and the image side surface of the seventh lens is concave at the near optical axis, and both the object side surface and the image side surface of the seventh lens are aspherical surfaces, and at least one of them has recurvature; an eighth lens having negative refractive power, wherein the image side surface of the eighth lens is concave near the optical axis, and both the object side surface and the image side surface of the eighth lens are aspherical surfaces, and at least one of them has recurvature; There are eight lenses with refractive power; All lenses of the optical system have aspherical surface shapes; The optical system also satisfies the relationship: 1.2<TTL / ImgH<1.3; 3.2<f8 / sag82<5.2; 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, ImgH is half of the image height corresponding to the maximum field of view angle of the optical system, f8 is the effective focal length of the eighth lens, and sag82 is the sag height of the image side surface of the eighth lens at the maximum effective aperture.

2. The optical system according to claim 1, characterized in that The optical system satisfies the relationship: -3<f2 / f12<-2; f2 is the effective focal length of the second lens, and f12 is the combined focal length of the first lens and the second lens.

3. The optical system according to claim 1, characterized in that The optical system satisfies the relationship: 7.5 mm<f / tan(semiFOV)<7.95 mm; f is the effective focal length of the optical system, and semiFOV is half of the maximum field of view of the optical system.

4. The optical system according to claim 1, characterized in that The optical system satisfies the relationship: 2.5<sd81 / sd31<3.5; sd81 is the maximum effective half-aperture of the object-side surface of the eighth lens, and sd31 is the maximum effective half-aperture of the object-side surface of the third lens.

5. The optical system according to claim 1, characterized in that The optical system satisfies the relationship: 9<R71 / sd67<16; R71 is the radius of curvature of the object side surface of the seventh lens at the optical axis, and sd67 is the difference between the maximum effective semi-aperture of the object side surface of the seventh lens and the maximum effective semi-aperture of the image side surface of the sixth lens.

6. The optical system according to claim 1, characterized in that The optical system satisfies the relationship: sag81 / sag72<1.75; Sag81 is the sag height of the object side surface of the eighth lens at the maximum effective aperture, and sag72 is the sag height of the image side surface of the seventh lens at the maximum effective aperture.

7. The optical system according to claim 1, characterized in that The optical system satisfies the relationship: -60<R52 / sd56<-10; R52 is the radius of curvature of the image side surface of the fifth lens at the optical axis, and sd56 is the difference between the maximum effective semi-aperture of the object side surface of the sixth lens and the maximum effective semi-aperture of the image side surface of the fifth lens.

8. The optical system according to claim 1, characterized in that The optical system satisfies the relationship: 0.9<f / f1<1.1; f is the effective focal length of the optical system, and f1 is the effective focal length of the first lens.

9. A camera module, characterized in that: The optical system comprises an image sensor and the optical system according to any one of claims 1 to 8, wherein the image sensor is arranged on the image side of the optical system.

10. An electronic device, characterized in that: It comprises a fixing part and the camera module as claimed in claim 9, wherein the camera module is arranged on the fixing part.

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