Optical system, camera module and electronic equipment

Abstract

An optical system, a camera module and an electronic device, the optical system sequentially comprising from an object side to an image side along an optical axis: a first lens to an eighth lens having refractive power, the first lens, the second lens, the fifth lens and the seventh lens having negative refractive power, and the third lens, the fourth lens, the sixth lens and the eighth lens having positive refractive power, the image side surface of the first lens, the object side surface of the second lens, the object side surface of the fifth lens, the object side surface of the seventh lens and the image side surface of the eighth lens are concave surfaces in a paraxial region. The object-side surface of the first lens, the image-side surface of the second lens, the object-side surface of the third lens, the object-side surface and the image-side surface of the fourth lens, the image-side surface of the fifth lens, the object-side surface and the image-side surface of the sixth lens, and the object-side surface of the eighth lens are convex surfaces in a paraxial region. Through reasonable design of the surface type and the refractive power of each lens of the optical system, the characteristics of large field angle and miniaturization can be satisfied.

Description

Technical Field

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

[0002] With the rapid development of automobile assisted driving technology, optical systems have been widely used in automobiles, especially in the fields of vehicle-mounted reversing imaging systems, driving recorders, automatic parking systems, panoramic imaging systems and road navigation. Optical systems have become an indispensable key component.

[0003] Automotive lenses are key components for autonomous driving assistance systems to acquire external information. For safety reasons, they place stringent performance requirements on these lenses. They must offer high image clarity, effectively discerning road environment details. They must also have a wide field of view to better capture road information ahead, meeting the specific requirements of intelligent driving systems. Furthermore, due to the limited installation space available for these systems, the lenses must be compact. Summary of the Invention

[0004] The purpose of the present invention is to provide an optical system, a camera module and an electronic device to solve the problem that the vehicle-mounted optical system needs to have a large field of view and be miniaturized.

[0005] To achieve the purpose of the present invention, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides an optical system comprising eight lenses having refractive power, which comprise, in order from the object side to the image side along the optical axis: a first lens having negative 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 concave at the near optical axis, and the image side surface of the second lens is convex at the near optical axis; a third lens having positive refractive power, wherein the object side surface of the third lens is convex at the near optical axis; a fourth lens having positive refractive power, wherein the object side surface of the fourth lens is concave at the near optical axis; is convex, and the image side surface of the fourth lens is convex at the near optical axis; the fifth lens has negative refractive power, the object side surface of the fifth lens is concave at the near optical axis, and the image side surface of the fifth lens is convex at the near optical axis; the sixth lens has positive refractive power, the object side surface of the sixth lens is convex at the near optical axis, and the image side surface of the sixth lens is convex at the near optical axis; the seventh lens has negative refractive power, and the object side surface of the seventh lens is concave at the near optical axis; the eighth lens has positive refractive power, the object side surface of the eighth lens is convex at the near optical axis, and the image side surface of the eighth lens is concave at the near optical axis.

[0007] The optical system satisfies the relationship: 125deg≤FOV≤139deg, 8.5≤TTL / F≤9.1; wherein FOV is the maximum field of view of the optical system, TTL is the distance from the object side of the first lens to the imaging plane on the optical axis, and F is the effective focal length of the optical system.

[0008] By making the first lens have negative refractive power, and 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, it is beneficial to collect light with a large field angle to enter the rear lens, increase the light throughput of the optical system, and fix the direction of the light with a large angle at the edge; by making the second lens have negative refractive power, and the object side surface of the second lens is concave at the near optical axis, and the image side surface of the second lens is convex at the near optical axis, it is beneficial to further diverge the light, adjust the deflection angle of the light, and reduce the chromatic aberration of the optical system; The third lens has positive refractive power, and the object side of the third lens is convex at the near optical axis, which is conducive to converging light, allowing the light to enter the rear lens smoothly, reducing the sensitivity of the optical system; by making the fourth lens have positive refractive power, and the object side of the fourth lens is convex at the near optical axis, and the image side of the fourth lens is convex at the near optical axis, it is conducive to compressing the angle of the incident light to achieve a smooth transition of the light, allowing the divergent light to enter the rear lens smoothly, further making the light trend transition smoothly, and reducing the diameter of the rear lens; by making the third lens have positive refractive power, and the object side of the fourth lens is convex at the near optical axis, and the image side of the fourth lens is convex at the near optical axis, it is conducive to compressing the angle of the incident light to achieve a smooth transition of the light, allowing the divergent light to enter the rear lens smoothly, further making the light trend transition smoothly, and reducing the diameter of the rear lens; The five lenses have negative refractive power, and the object side of the fifth lens is concave at the near optical axis, and the image side of the fifth lens is convex at the near optical axis, which is conducive to the entry and deflection of marginal light, and can reduce the deflection angle borne by the subsequent lenses, so that the deflection angle of light on each lens is more uniform, and the aberration of the marginal field of view is effectively corrected; by making the sixth lens have positive refractive power, and the object side of the sixth lens is convex at the near optical axis, and the image side of the sixth lens is convex at the near optical axis, it is conducive to further reducing aberrations, improving imaging quality, optimizing distortion, and making Light rays converge effectively and smoothly. By making the seventh lens element have negative refractive power and the object-side surface of the seventh lens element being concave near the optical axis, light rays converge smoothly, facilitating the correction of astigmatism and distortion, and thus improving the imaging quality of the optical system. By making the eighth lens element have positive refractive power and the object-side surface of the eighth lens element being convex near the optical axis and the image-side surface of the eighth lens element being concave near the optical axis, peripheral wide-angle light rays are smoothly transferred as much as possible to the rear optical element, thereby correcting astigmatism and field curvature and improving the resolving power of the optical system.

[0009] By making the optical system satisfy the relationship: 125deg≤FOV≤139deg, the optical system has a large field of view, thereby being able to achieve wide-angle imaging, which is beneficial for the optical system to obtain a sufficient field of view.

[0010] By making the optical system satisfy the relationship: 8.5≤TTL / F≤9.1, the ratio of the total length of the optical system to the focal length of the optical system is controlled within a reasonable range, thereby achieving miniaturization of the optical system, which is conducive to better converging light on the imaging surface and improving the imaging quality of the optical system.

[0011] In one embodiment, the optical system satisfies the relationship: 7.5 ≤ TTL / IMGH ≤ 8.3, where IMGH is half the image height corresponding to the optical system's maximum field of view. By ensuring that the optical system satisfies this relationship, miniaturization of the optical system can be achieved while ensuring imaging quality by controlling the ratio of the image height to the focal length at a given optical system image height.

[0012] In one embodiment, the optical system satisfies the relationship: 0.85≤F / IMGH≤0.95. By making the optical system satisfy the above relationship, the refractive power of the optical system for light is matched with the size of the image plane, thereby improving the imaging quality of the optical system.

[0013] In one embodiment, the optical system satisfies the relationship: 76 degrees ≤ FOV / FNO ≤ 87 degrees, where FNO is the aperture number of the optical system. By ensuring that the optical system satisfies this relationship, the ratio of the field of view angle to the aperture number of the optical system is optimally configured, achieving the combined effect of a large field of view angle and a large aperture. This allows for a reasonable amount of light entering the optical system, improving the overall illumination of the image, and making the optical system adaptable to various lighting environments.

[0014] In one embodiment, the optical system satisfies the relationship: 2.5 ≤ F3 / F ≤ 3, where F3 is the effective focal length of the third lens. By ensuring that the optical system satisfies this relationship and properly setting the effective focal length of the third lens, incident light from the front can be effectively collected and compressed, allowing the light to smoothly transition to the rear optical system, reducing aberrations and thereby improving the imaging quality of the lens.

[0015] In one embodiment, the optical system satisfies the relationship: 1.6 ≤ F4 / F ≤ 2.1, where F4 is the effective focal length of the fourth lens element. Satisfying this relationship facilitates proper coordination of the refractive power of the fourth lens element within the optical system, simplifies and flexibly designs the surface profile of the fourth lens element, reduces aberrations, and simplifies the overall aberration correction and image quality balance of the optical system.

[0016] In one embodiment, the optical system satisfies the relationship: -4.5 ≤ F5 / F ≤ -2.7, where F5 is the effective focal length of the fifth lens element. Satisfying this relationship facilitates proper coordination of the refractive power of the fifth lens element within the optical system, simplifies and flexibly improves the surface design of the fifth lens element, reduces aberrations, and simplifies the overall aberration correction and image quality balance of the optical system.

[0017] In one embodiment, the optical system satisfies the relationship: 1.1 ≤ BFL / F ≤ 1.5, where BFL is the distance along the optical axis from the image-side surface of the seventh lens element to the imaging plane of the optical system. Satisfying this relationship helps strike a balance between good imaging quality and an optical back focal length that facilitates assembly. This ensures imaging quality while reducing design and assembly difficulties and improving yield.

[0018] In one embodiment, the optical system satisfies the relationship: 4.2≤CT4 / CT34≤15; where CT4 is the thickness of the fourth lens on the optical axis, and CT34 is the distance on the optical axis from the image-side surface of the third lens to the object-side surface of the fourth lens. By ensuring that the optical system satisfies this relationship, the thickness of the fourth lens on the optical axis is optimally set, and the spacing between the third and fourth lenses on the optical axis is also optimally set, facilitating control of the incident angle of light while maintaining the compactness of the optical system.

[0019] In one embodiment, the optical system satisfies the relationship: -2.8 ≤ R7 / R8 ≤ -1.5; where R7 is the radius of curvature of the object-side surface of the fourth lens at the optical axis, and R8 is the radius of curvature of the image-side surface of the fourth lens at the optical axis. Satisfying this relationship facilitates optimal configuration of the ratio of the radius of curvature of the object-side surface of the fourth lens at the optical axis to the radius of curvature of the image-side surface of the fourth lens at the optical axis, controls the shape of the fourth lens, comprehensively balances spherical aberration, chromatic aberration, and field curvature of the optical system, reduces the risk of ghosting, and improves the resolving power of the optical system. Furthermore, it facilitates reducing the difficulty of manufacturing the fourth lens.

[0020] In one embodiment, the optical system satisfies the relationship: 0.58≤R15 / R16≤0.85; where R15 is the radius of curvature of the object-side surface of the eighth lens at the optical axis, and R16 is the radius of curvature of the image-side surface of the eighth lens at the optical axis. Satisfying this relationship facilitates optimal configuration of the ratio of the radius of curvature of the object-side surface of the eighth lens at the optical axis to the radius of curvature of the image-side surface of the eighth lens at the optical axis, controls the shape of the eighth lens, comprehensively balances spherical aberration, chromatic aberration, and field curvature of the optical system, reduces the risk of ghosting, and improves the resolving power of the optical system. Furthermore, it facilitates reducing the processing difficulty of the fourth lens.

[0021] In one embodiment, the optical system satisfies the relationship: 2.1 ≤ CT4 / CT5 ≤ 5.4, where CT5 is the thickness of the fifth lens on the optical axis. By ensuring that the optical system satisfies this relationship, the ratio of the thickness of the fourth lens on the optical axis to the thickness of the fifth lens on the optical axis is optimally configured, allowing the fourth and fifth lenses to be mutually controlled, maintaining the compactness of the optical system.

[0022] In one embodiment, the optical system satisfies the relationship: 3.7 ≤ Vd4 / Vd5 ≤ 3.9, where Vd4 is the Abbe number of the fourth lens element, and Vd5 is the Abbe number of the fifth lens element. By ensuring that the optical system satisfies this relationship and that the ratio of the Abbe number of the fourth lens element to the Abbe number of the fifth lens element is within a reasonable range, axial chromatic aberration of the optical system can be effectively corrected.

[0023] In one embodiment, the optical system satisfies the relationship: -0.7mm ≤ F6 / Vd6 + F7 / Vd7 ≤ -0.2mm; where F6 is the effective focal length of the sixth lens element, Vd6 is the Abbe number of the sixth lens element, F7 is the effective focal length of the seventh lens element, and Vd7 is the Abbe number of the seventh lens element. By ensuring that the optical system satisfies this relationship, dispersion in the optical system can be effectively offset, facilitating confocality in both the visible and infrared bands.

[0024] In one embodiment, the optical system satisfies the relationship: 1.45 ≤ SD1 / IMGH ≤ 1.82, where SD1 is half the maximum effective aperture of the object-side surface of the first lens. By ensuring that the optical system satisfies this relationship, a reasonable ratio of half the maximum effective aperture of the object-side surface of the first lens to half the image height corresponding to the maximum field of view of the optical system is achieved. This facilitates reasonable control of the size of the object-side surface of the first lens and achieves miniaturization of the optical system.

[0025] In one embodiment, the optical system satisfies the relationship: 0.17 ≤ SD1 / TTL ≤ 0.25. By ensuring that the optical system satisfies this relationship, the ratio of the optical aperture value of the first lens to the total length of the optical system is optimally configured, which helps limit the volume of the optical system and achieve miniaturization of the optical system.

[0026] In one embodiment, the optical system satisfies the relationship: 1 ≤ SD11 / SD10 ≤ 1.1; where SD11 is half the maximum effective aperture of the object-side surface of the sixth lens element, and SD10 is half the maximum effective aperture of the image-side surface of the fifth lens element. Satisfying this relationship in the optical system allows for a smooth transition between the fifth and sixth lenses, minimizing the step difference between them. This, in turn, facilitates smooth entry of light into the sixth lens element, thereby improving the illumination of the optical system.

[0027] In one embodiment, the optical system satisfies the relationship: -8.5 ≤ F123 / F ≤ -3, where F123 is the combined effective focal length of the first, second, and third lenses. By ensuring that the optical system satisfies this relationship, the ratio of the combined effective focal length of the first, second, and third lenses to the effective focal length of the optical system is optimally configured. This, combined with the front lens focal length of the aperture, facilitates better distortion correction and achieves low distortion in the optical system.

[0028] In one embodiment, the optical system satisfies the relationship: 3.4 ≤ F45 / F ≤ 4.7, where F45 is the combined effective focal length of the fourth and fifth lenses. By ensuring that the optical system satisfies this relationship, the ratio of the effective focal length of the cemented lens formed by the fourth and fifth lenses to the effective focal length of the optical system is optimally configured, which facilitates correcting chromatic aberration and balancing various aberrations, improving the resolving power of the optical system, effectively reducing the tolerance sensitivity of the optical system, and thereby enhancing the imaging quality of the optical system.

[0029] In one embodiment, the optical system satisfies the relationship: 5.5 ≤ F67 / F ≤ 11, where F67 is the combined effective focal length of the sixth and seventh lenses. By ensuring that the optical system satisfies this relationship, the ratio of the effective focal length of the cemented lens (the sixth and seventh lenses) to the effective focal length of the optical system is optimally configured, ensuring a smooth transition of light into the subsequent optical system. This helps balance various aberrations, improves lens resolution, reduces tolerance sensitivity, and increases the production yield of the optical system.

[0030] In one embodiment, the optical system satisfies the relationship: 1.6 ≤ FNO ≤ 1.7, where FNO is the aperture number of the optical system. By ensuring that the optical system satisfies this relationship, the aperture number of the optical system is set within a reasonable range, achieving the combined effect of a large field of view and a large aperture. This allows the optical system to have a reasonable amount of light entering, improves the overall illumination of the image, and makes the optical system suitable for various lighting environments.

[0031] In one embodiment, the optical system satisfies the relationship: 1.7≤F×tan(FOV / 2) / IMGH≤2.3. Ensuring that the optical system satisfies the above relationship helps to better control the optical distortion of the optical system and improve the resolution of the optical system.

[0032] In one embodiment, the optical system satisfies the relationship: 2.8≤∑CT / ∑AT≤4.4; where ∑CT is the sum of the thicknesses of the first through eighth lenses on the optical axis, and ∑AT is the sum of the spacing distances between two adjacent lenses on the optical axis. By ensuring that the optical system satisfies this relationship, the ratio of the sum of the thicknesses of the first through eighth lenses on the optical axis to the sum of the spacing distances between two adjacent lenses on the optical axis is properly configured. This allows for the proper setting of the thickness of each lens and the spacing distance between two adjacent lenses in the optical system, miniaturizing the optical system and improving its manufacturability. This also facilitates the mutual adjustment of the thicknesses of the lenses and the spacing distances between two adjacent lenses in the optical system, reducing the aberration and tolerance sensitivity of the optical system and improving its imaging quality.

[0033] In the second aspect, the present invention further provides a camera module, which includes a photosensitive chip and the optical system described in any one embodiment of the first aspect, wherein the photosensitive chip is arranged on the image side of the optical system. The photosensitive surface of the photosensitive chip is located on the imaging surface of the optical system, and the light of the object incident on the photosensitive surface through the lens can be converted into an electrical signal of the image. The photosensitive chip can be a complementary metal oxide semiconductor (CMOS) or a charge-coupled device (CCD). The camera module can be an imaging module integrated in an electronic device or an independent lens. By adding the optical system provided by the present invention to the camera module, the surface shape and refractive power of each lens in the optical system can be reasonably designed to make the camera module have the characteristics of a large field of view and miniaturization.

[0034] In a third aspect, the present invention further provides an electronic device comprising a housing and the camera module described in the second aspect, the camera module being disposed within the housing. Such electronic devices include, but are not limited to, automobiles, surveillance equipment, smartphones, computers, and smartwatches. By incorporating the camera module provided by the present invention into an electronic device, the electronic device exhibits a wide field of view and is compact. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 is a schematic structural diagram of the optical system of the first embodiment;

[0037] Figure 2 A longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph of the optical system of the first embodiment are shown;

[0038] Figure 3 is a schematic structural diagram of the optical system of the second embodiment;

[0039] Figure 4 A longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph of the optical system of the second embodiment are shown;

[0040] Figure 5 is a schematic structural diagram of an optical system according to a third embodiment;

[0041] Figure 6 A longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph of the optical system of the third embodiment are shown;

[0042] Figure 7 is a schematic structural diagram of an optical system according to a fourth embodiment;

[0043] Figure 8 A longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph of the optical system of the fourth embodiment are shown;

[0044] Figure 9 is a schematic structural diagram of the optical system of the fifth embodiment;

[0045] Figure 10 A longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph of the optical system of the fifth embodiment are shown;

[0046] Figure 11 is a schematic structural diagram of the optical system of the sixth embodiment;

[0047] Figure 12 A longitudinal spherical aberration graph, an astigmatism graph, and a distortion graph of the optical system of the sixth embodiment are shown;

[0048] Figure 13 A schematic structural diagram of a camera module according to an embodiment of the present invention is shown;

[0049] Figure 14 A schematic structural diagram of an electronic device in an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0050] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0051] The embodiment of the present invention provides an optical system, comprising eight lenses with refractive power, which include, in order from the object side to the image side along the optical axis: a first lens having negative 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 concave at the near optical axis, and the image side surface of the second lens is convex at the near optical axis; a third lens having positive refractive power, wherein the object side surface of the third lens is convex at the near optical axis; a fourth lens having positive refractive power, wherein the object side surface of the fourth lens is convex surface, the image side surface of the fourth lens is convex at the near optical axis; the fifth lens has negative refractive power, the object side surface of the fifth lens is concave at the near optical axis, and the image side surface of the fifth lens is convex at the near optical axis; the sixth lens has positive refractive power, the object side surface of the sixth lens is convex at the near optical axis, and the image side surface of the sixth lens is convex at the near optical axis; the seventh lens has negative refractive power, the object side surface of the seventh lens is concave at the near optical axis; the eighth lens has positive refractive power, the object side surface of the eighth lens is convex at the near optical axis, and the image side surface of the eighth lens is concave at the near optical axis.

[0052] The optical system satisfies the following relationship: 125deg ≤ FOV ≤ 139deg, 8.5 ≤ TTL / F ≤ 9.1; where FOV is the maximum field of view of the optical system, TTL is the distance from the object side of the first lens to the imaging plane on the optical axis, and F is the effective focal length of the optical system. Specifically, the FOV value can be 126deg, 128deg, 130deg, 132deg, 134deg, 136deg, 138deg, 139deg, etc. Specifically, the TTL / F value can be 8.553, 8.612, 8.702, 8.769, 8.786, 8.805, 8.941, 8.996, 9.020, 9.095, etc.

[0053] By making the first lens have negative refractive power, and 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, it is beneficial to collect light with a large field angle to enter the rear lens, increase the light throughput of the optical system, and fix the direction of the edge large-angle light; by making the second lens have negative refractive power, and the object side surface of the second lens is concave at the near optical axis, and the image side surface of the second lens is convex at the near optical axis, it is beneficial to further diverge the light, adjust the deflection angle of the light, and reduce the chromatic aberration of the optical system; by making the third lens have positive refractive power, and the object side surface of the third lens is convex at the near optical axis, It is beneficial to converge light, make light enter the rear lens smoothly, and reduce the sensitivity of the optical system; by making the fourth lens have positive refractive power, and the object side surface of the fourth lens is convex at the near optical axis, and the image side surface of the fourth lens is convex at the near optical axis, it is beneficial to compress the angle of the incident light to achieve a smooth transition of light, so that the divergent light can smoothly enter the rear lens, further make the light trend transition smoothly, and reduce the diameter of the rear lens; by making the fifth lens have negative refractive power, and the object side surface of the fifth lens is concave at the near optical axis, and the image side surface of the fifth lens is convex at the near optical axis, it is beneficial to the entry and deflection of marginal light, which can reduce The deflection angle borne by the small rear lens makes the deflection angle of light on each lens more uniform, effectively correcting the aberration of the edge field of view; the fourth lens and the fifth lens are cemented lenses, which are beneficial to correcting chromatic aberration and balancing various aberrations, improving the resolution of the optical system, and can effectively reduce the tolerance sensitivity and improve the imaging quality of the optical system; by making the sixth lens have positive refractive power, and the object side of the sixth lens is convex at the near optical axis, and the image side of the sixth lens is convex at the near optical axis, it is beneficial to further reduce aberrations, improve imaging quality, optimize distortion, and make light converge effectively and smoothly; by making the seventh lens have negative refractive power The refractive power of the eighth lens is positive, and the object-side surface of the seventh lens is concave near the optical axis, which is beneficial to the smooth movement of light, facilitates the correction of astigmatism and distortion, and can improve the imaging quality of the optical system; the sixth lens and the seventh lens are cemented lenses, which is beneficial to reducing chromatic aberration, improving imaging quality, and reducing field curvature, thereby correcting the off-axis point aberration of the system; by making the eighth lens have positive refractive power, and the object-side surface of the eighth lens is convex near the optical axis, and the image-side surface of the eighth lens is concave near the optical axis, it is beneficial to make the peripheral large-angle light transition to the rear optical element as much as possible smoothly, which can correct astigmatism and field curvature, and improve the resolving ability of the optical system.

[0054] By making the optical system satisfy the relationship: 125deg≤FOV≤139deg, the optical system has a large field of view, thereby being able to achieve wide-angle imaging, which is beneficial for the optical system to obtain a sufficient field of view.

[0055] By making the optical system satisfy the relationship: 8.5≤TTL / F≤9.1, the ratio of the total length of the optical system to the focal length of the optical system is controlled within a reasonable range, thereby achieving miniaturization of the optical system, which is conducive to better converging light on the imaging surface and improving the imaging quality of the optical system.

[0056] In one embodiment, the optical system satisfies the relationship: 7.5 ≤ TTL / IMGH ≤ 8.3, where IMGH is half the image height corresponding to the optical system's maximum field of view. Specifically, the value of TTL / IMGH can be 7.502, 7.591, 7.625, 7.759, 7.822, 7.922, 8.025, 8.144, 8.218, 8.258, etc. By ensuring that the optical system satisfies this relationship, the ratio of the image height to the focal length can be controlled at a certain optical system image height, achieving miniaturization while ensuring image quality.

[0057] In one embodiment, the optical system satisfies the relationship: 0.85 ≤ F / IMGH ≤ 0.95. Specifically, the value of F / IMGH can be 0.866, 0.875, 0.886, 0.890, 0.907, 0.911, 0.918, 0.925, 0.939, 0.948, etc. By ensuring that the optical system satisfies this relationship, the refractive power of the optical system for light is matched to the size of the image plane, thereby improving the imaging quality of the optical system.

[0058] In one embodiment, the optical system satisfies the relationship: 76 ≤ FOV / FNO ≤ 87; where FNO is the aperture number of the optical system. Specifically, the FOV / FNO value can be 76.364deg, 76.471deg, 76.829deg, 77.647deg, 79.258deg, 80.258deg, 81.295deg, 83.598deg, 84.225deg, 86.250deg, etc. By ensuring that the optical system satisfies this relationship, the ratio of the field of view angle to the aperture number of the optical system is properly configured, achieving the combined effect of a large field of view angle and a large aperture. The optical system has a reasonable amount of light input, improving the overall illumination of the imaging image, and making the optical system suitable for different lighting environments.

[0059] In one embodiment, the optical system satisfies the relationship: 2.5 ≤ F3 / F ≤ 3, where F3 is the effective focal length of the third lens element. Specifically, the value of F3 / F can be 2.519, 2.546, 2.665, 2.702, 2.785, 2.806, 2.812, 2.843, 2.905, 2.985, etc. By ensuring that the optical system satisfies this relationship and appropriately setting the effective focal length of the third lens element, incident light from the front can be effectively collected and compressed, allowing the light to smoothly transition to the rear optical system, reducing aberrations and thereby improving the imaging quality of the lens.

[0060] In one embodiment, the optical system satisfies the relationship: 1.6 ≤ F4 / F ≤ 2.1, where F4 is the effective focal length of the fourth lens element. Specifically, the value of F4 / F can be 1.632, 1.698, 1.711, 1.756, 1.802, 1.849, 1.912, 1.958, 2.008, 2.051, etc. Satisfying this relationship facilitates proper coordination of the refractive power of the fourth lens element within the optical system, simplifies and flexibly designs the surface profile of the fourth lens element, reduces aberrations, and simplifies the overall aberration correction and image quality balance of the optical system.

[0061] In one embodiment, the optical system satisfies the relationship: -4.5 ≤ F5 / F ≤ -2.7, where F5 is the effective focal length of the fifth lens element. Specifically, the values of F5 / F can be -4.307, -4.158, -3.942, -3.758, -3.568, -3.274, -3.025, -2.887, -2.880, -2.879, etc. Satisfying this relationship facilitates proper coordination of the refractive power of the fifth lens element within the optical system, simplifies and flexibly improves the surface design of the fifth lens element, reduces aberrations, and simplifies the overall aberration correction and image quality balance of the optical system.

[0062] In one embodiment, the optical system satisfies the relationship: 1.1 ≤ BFL / F ≤ 1.5, where BFL is the distance on the optical axis from the image-side surface of the seventh lens element to the imaging plane of the optical system. Specifically, the value of BFL / F can be 1.169, 1.178, 1.185, 1.236, 1.245, 1.287, 1.305, 1.358, 1.415, 1.465, etc. By ensuring that the optical system satisfies this relationship, a balance is achieved between achieving good imaging quality and an optical back focal length that is easy to assemble. This ensures the optical system's imaging quality while reducing the design and assembly difficulties and improving the yield rate.

[0063] In one embodiment, the optical system satisfies the relationship: 4.2≤CT4 / CT34≤15; where CT4 is the thickness of the fourth lens on the optical axis, and CT34 is the distance on the optical axis from the image side of the third lens to the object side of the fourth lens. Specifically, the value of CT4 / CT34 can be 4.287, 6.410, 6.717, 6.985, 7.158, 9.327, 10.258, 12.589, 13.258, 14.543, etc. By ensuring that the optical system satisfies the above relationship, the thickness of the fourth lens on the optical axis is appropriately set, and the distance between the third and fourth lenses on the optical axis is also appropriately set, which facilitates the control of the incident angle of light and maintains the miniaturization of the optical system.

[0064] In one embodiment, the optical system satisfies the relationship: -2.8≤R7 / R8≤-1.5; wherein R7 is the radius of curvature of the object-side surface of the fourth lens at the optical axis, and R8 is the radius of curvature of the image-side surface of the fourth lens at the optical axis. Specifically, the values of R7 / R8 can be -2.620, -2.616, -2.582, -2.523, -2.367, -2.025, -1.856, -1.748, -1.625, -1.563, etc. By ensuring that the optical system satisfies the above relationship, it is beneficial to reasonably configure the ratio of the radius of curvature of the object-side surface of the fourth lens at the optical axis to the radius of curvature of the image-side surface of the fourth lens at the optical axis, control the shape of the fourth lens, comprehensively balance the spherical aberration, chromatic aberration, and field curvature of the optical system, reduce the risk of ghosting, improve the resolving power of the optical system, and reduce the difficulty of processing the fourth lens.

[0065] In one embodiment, the optical system satisfies the relationship: 0.58≤R15 / R16≤0.85; wherein R15 is the radius of curvature of the object-side surface of the eighth lens at the optical axis, and R16 is the radius of curvature of the image-side surface of the eighth lens at the optical axis. Specifically, the value of R15 / R16 can be 0.598, 0.604, 0.643, 0.658, 0.684, 0.700, 0.758, 0.785, 0.820, 0.845, etc. By ensuring that the optical system satisfies the above relationship, it is beneficial to optimize the ratio of the radius of curvature of the object-side surface of the eighth lens at the optical axis to the radius of curvature of the image-side surface of the eighth lens at the optical axis, control the shape of the eighth lens, comprehensively balance the spherical aberration, chromatic aberration, and field curvature of the optical system, reduce the risk of ghosting, and improve the resolving power of the optical system. Furthermore, it is beneficial to reduce the processing difficulty of the fourth lens.

[0066] In one embodiment, the optical system satisfies the relationship: 2.1 ≤ CT4 / CT5 ≤ 5.4, where CT5 is the thickness of the fifth lens on the optical axis. Specifically, the value of CT4 / CT5 can be 2.118, 2.685, 3.106, 3.785, 4.090, 4.325, 4.681, 4.985, 5.176, 5.321, etc. By ensuring that the optical system satisfies this relationship, the ratio of the thickness of the fourth lens on the optical axis to the thickness of the fifth lens on the optical axis is optimally configured, and the fourth and fifth lenses can be mutually controlled, maintaining the miniaturization of the optical system.

[0067] In one embodiment, the optical system satisfies the relationship: 3.7 ≤ Vd4 / Vd5 ≤ 3.9, where Vd4 is the Abbe number of the fourth lens element, and Vd5 is the Abbe number of the fifth lens element. Specifically, the value of Vd4 / Vd5 can be 3.741, 3.782, 3.800, 3.809, 3.811, 3.825, 3.836, 3.855, 3.782, 3.865, etc. By ensuring that the optical system satisfies this relationship and that the ratio of the Abbe number of the fourth lens element to the Abbe number of the fifth lens element is within a reasonable range, the axial chromatic aberration of the optical system can be effectively corrected.

[0068] In one embodiment, the optical system satisfies the relationship: -0.7mm ≤ F6 / Vd6 + F7 / Vd7 ≤ -0.2mm; where F6 is the effective focal length of the sixth lens element, Vd6 is the Abbe number of the sixth lens element, F7 is the effective focal length of the seventh lens element, and Vd7 is the Abbe number of the seventh lens element. Specifically, the values of F6 / Vd6 + F7 / Vd7 can be -0.666mm, -0.611mm, -0.512mm, -0.478mm, -0.412mm, -0.354mm, -3.024mm, -0.296mm, -0.237mm, -0.225mm, etc. By ensuring that the optical system satisfies this relationship, dispersion of the optical system can be effectively offset, facilitating confocality in both the visible and infrared bands.

[0069] In one embodiment, the optical system satisfies the relationship: 1.45 ≤ SD1 / IMGH ≤ 1.82, where SD1 is half the maximum effective aperture of the object-side surface of the first lens. Specifically, the value of SD1 / IMGH can be 1.483, 1.486, 1.525, 1.566, 1.577, 1.625, 1.653, 1.694, 1.759, 1.804, etc. By ensuring that the optical system satisfies this relationship, the ratio of half the maximum effective aperture of the object-side surface of the first lens to half the image height corresponding to the maximum field of view of the optical system is optimally configured, which facilitates reasonable control of the size of the object-side surface of the first lens and achieves miniaturization of the optical system.

[0070] In one embodiment, the optical system satisfies the relationship: 0.17 ≤ SD1 / TTL ≤ 0.25. Specifically, the values of SD1 / TTL can be 0.176, 0.181, 0.191, 0.196, 0.202, 0.205, 0.206, 0.222, 0.235, 0.249, etc. By ensuring that the optical system satisfies this relationship, the ratio of the optical aperture of the first lens to the total length of the optical system is optimally configured, which helps limit the volume of the optical system and achieve miniaturization.

[0071] In one embodiment, the optical system satisfies the relationship: 1 ≤ SD11 / SD10 ≤ 1.1; where SD11 is half the maximum effective aperture of the object-side surface of the sixth lens element, and SD10 is half the maximum effective aperture of the image-side surface of the fifth lens element. Specifically, the value of SD11 / SD10 can be 1.015, 1.029, 1.039, 1.042, 1.058, 1.068, 1.075, 1.092, 1.093, 1.099, etc. By ensuring that the optical system satisfies this relationship, the transition between the fifth and sixth lenses is smooth, minimizing the step difference between the two lenses. This, in turn, facilitates smooth entry of light into the sixth lens element, thereby improving the illumination of the optical system.

[0072] In one embodiment, the optical system satisfies the relationship: -8.5 ≤ F123 / F ≤ -3, where F123 is the combined effective focal length of the first, second, and third lenses. Specifically, the value of F123 / F can be -8.101, -7.158, -6.287, -5.527, -5.028, -4.502, -4.172, -3.612, -3.468, -3.382, etc. By ensuring that the optical system satisfies this relationship, the ratio of the combined effective focal length of the first, second, and third lenses to the effective focal length of the optical system is optimally configured. Properly matching the combined focal length of the front lens of the aperture facilitates better distortion correction and achieves low distortion in the optical system.

[0073] In one embodiment, the optical system satisfies the relationship: 3.4 ≤ F45 / F ≤ 4.7; where F45 is the combined effective focal length of the fourth and fifth lenses. Specifically, the value of F45 / F can be 3.499, 3.587, 3.769, 3.882, 3.952, 4.129, 4.234, 4.358, 4.587, 4.611, etc. By ensuring that the optical system satisfies this relationship, the ratio of the effective focal length of the cemented lens formed by the fourth and fifth lenses to the effective focal length of the optical system is optimally configured, which facilitates correcting chromatic aberration and balancing various aberrations, improving the resolving power of the optical system, effectively reducing the tolerance sensitivity of the optical system, and thereby enhancing the imaging quality of the optical system.

[0074] In one embodiment, the optical system satisfies the relationship: 5.5 ≤ F67 / F ≤ 11, where F67 is the combined effective focal length of the sixth and seventh lenses. Specifically, the value of F67 / F can be 5.508, 6.018, 6.748, 6.876, 7.345, 7.958, 8.258, 9.158, 9.768, 10.567, etc. By ensuring that the optical system satisfies this relationship, the ratio of the effective focal length of the cemented lens formed by the sixth and seventh lenses to the effective focal length of the optical system is optimally configured, ensuring a smooth transition of light to the subsequent optical system. This helps balance various aberrations, improves lens resolution, reduces tolerance sensitivity, and improves the production yield of the optical system.

[0075] In one embodiment, the optical system satisfies the relationship: 1.6 ≤ FNO ≤ 1.7; where FNO is the aperture number of the optical system. Specifically, the value of FNO can be 1.600, 1.610, 1.620, 1.640, 1.650, 1.660, 1.670, 1.680, 1.690, 1.700, etc. By ensuring that the optical system satisfies this relationship, the aperture number of the optical system is set within a reasonable range, achieving the combined effect of a large field of view and a large aperture. The optical system has a reasonable amount of light entering, improving the overall illumination of the image, and making the optical system suitable for different lighting environments.

[0076] In one embodiment, the optical system satisfies the relationship: 1.7 ≤ F × tan(FOV / 2) / IMGH ≤ 2.3. Specifically, the value of F × tan(FOV / 2) / IMGH can be 1.747, 1.758, 1.780, 1.788, 1.825, 1.869, 1.969, 2.046, 2.158, 2.255, etc. Satisfying the above relationship helps better control optical distortion and improves the resolution of the optical system.

[0077] In one embodiment, the optical system satisfies the relationship: 2.8≤∑CT / ∑AT≤4.4, where ∑CT is the sum of the thicknesses of the first through eighth lenses on the optical axis, and ∑AT is the sum of the spacing distances between two adjacent lenses on the optical axis. Specifically, the value of ∑CT / ∑AT can be 2.893, 3.263, 3.337, 3.508, 3.784, 3.823, 3.949, 4.125, 4.258, 4.339, etc. By ensuring that the optical system satisfies this relationship, the ratio of the sum of the thicknesses of the first through eighth lenses on the optical axis to the sum of the spacing distances between two adjacent lenses on the optical axis is optimally configured. This allows for optimal setting of the thickness of each lens and the spacing distance between adjacent lenses in the optical system, miniaturization of the optical system, and improved manufacturability. This also facilitates adjustment of the thicknesses of the lenses and the spacing distances between adjacent lenses in the optical system, reduces the aberration and tolerance sensitivity of the optical system, and improves the imaging quality of the optical system.

[0078] In one embodiment, the optical system satisfies the relationship: -2≤F1 / F≤-1.5; wherein F1 is the effective focal length of the first lens. Specifically, the value of F1 / F can be -1.958, -1.853, -1.805, -1.777, -1.722, -1.689, -1.644, -1.612, -1.593, -1.523, etc. By making the optical system satisfy the above relationship, it is beneficial for the refractive power of the first lens in the optical system to be properly coordinated, the surface design of the first lens is simpler and more flexible, so that the first lens can support a larger field of view angle and a large aperture; at the same time, it is also beneficial to converge the light incident from the first lens to the optical system, delay the incident angle of the light, reduce aberrations, and simplify the overall aberration correction and imaging quality balance of the optical system.

[0079] In one embodiment, the optical system satisfies the relationship: -3.4 ≤ F2 / F ≤ -2.4, where F2 is the effective focal length of the second lens. Specifically, the value of F2 / F can be -3.325, -3.238, -3.105, -3.094, -3.089, -2.987, -2.836, -2.707, -2.601, -2.402, etc. Satisfying this relationship facilitates proper coordination of the refractive power of the second lens within the optical system, simplifies and flexibly designs the surface profile of the second lens, reduces aberrations, and simplifies the overall aberration correction and image quality balance of the optical system.

[0080] In one embodiment, the optical system satisfies the relationship: 2.2 ≤ F6 / F ≤ 2.5. Specifically, the value of F6 / F can be 2.293, 2.313, 2.317, 2.358, 2.397, 2.415, 2.449, 2.458, 2.485, 2.495, etc. Satisfying this relationship facilitates proper coordination of the refractive power of the sixth lens within the optical system, simplifies and flexibly designs the sixth lens profile, reduces aberrations, and simplifies the overall balance between aberration correction and imaging quality for the optical system.

[0081] In one embodiment, the optical system satisfies the relationship: -4 ≤ F7 / F ≤ -2.5. Specifically, the values of F7 / F can be -3.985, -3.758, -3.697, -3.450, -3.211, -3.115, -3.061, -2.857, -2.759, -2.616, etc. Satisfying this relationship facilitates proper coordination of the refractive power of the seventh lens element within the optical system, simplifies and flexibly designs the seventh lens element's surface shape, reduces aberrations, and simplifies the overall aberration correction and image quality balance of the optical system.

[0082] In one embodiment, the optical system satisfies the relationship: 7 ≤ F8 / F ≤ 18, where F8 is the effective focal length of the eighth lens element. Specifically, the value of F8 / F can be 7.054, 8.475, 9.522, 10.132, 11.258, 12.117, 13.598, 14.668, 16.532, 17.325, etc. Satisfying this relationship facilitates proper coordination of the refractive power of the eighth lens element within the optical system, making the surface design of the eighth lens element simpler and more flexible, reducing aberrations, and simplifying the overall aberration correction and image quality balance of the optical system.

[0083] In one embodiment, the optical system satisfies the relationship: 3≤R1 / R2≤5.2; wherein R1 is the radius of curvature of the object side surface of the first lens at the optical axis, and R2 is the radius of curvature of the image side surface of the first lens at the optical axis. Specifically, the value of R1 / R2 can be 3.391, 3.633, 3.822, 3.880, 4.029, 4.289, 4.514, 4.789, 5.018, 5.159, etc. By ensuring that the optical system satisfies the above relationship, it is beneficial to reasonably configure the ratio of the radius of curvature of the object side surface of the first lens at the optical axis to the radius of curvature of the image side surface of the first lens at the optical axis, control the shape of the first lens, comprehensively balance the spherical aberration, chromatic aberration, and field curvature of the optical system, reduce the risk of ghosting, improve the resolving power of the optical system, and at the same time, reduce the difficulty of processing the first lens.

[0084] In one embodiment, the optical system satisfies the relationship: 0≤R3 / R4≤0.42; wherein R3 is the radius of curvature of the object-side surface of the second lens at the optical axis, and R4 is the radius of curvature of the image-side surface of the second lens at the optical axis. Specifically, the value of R3 / R4 can be 0.090, 0.195, 0.208, 0.248, 0.289, 0.358, 0.369, 0.384, 0.402, 0.411, etc. By ensuring that the optical system satisfies the above relationship, it is beneficial to reasonably configure the ratio of the radius of curvature of the object-side surface of the second lens at the optical axis to the radius of curvature of the image-side surface of the second lens at the optical axis, control the shape of the second lens, comprehensively balance the spherical aberration, chromatic aberration, and field curvature of the optical system, reduce the risk of ghosting, improve the resolving power of the optical system, and reduce the difficulty of processing the second lens.

[0085] In one embodiment, the optical system satisfies the relationship: |R5 / R6|≤0.12; wherein R5 is the radius of curvature of the object-side surface of the third lens at the optical axis, and R6 is the radius of curvature of the image-side surface of the third lens at the optical axis. Specifically, the value of |R5 / R6| can be 0.012, 0.025, 0.035, 0.058, 0.069, 0.078, 0.080, 0.093, 0.112, 0.120, etc. By ensuring that the optical system satisfies the above relationship, it is beneficial to reasonably configure the ratio of the radius of curvature of the object-side surface of the third lens at the optical axis to the radius of curvature of the image-side surface of the third lens at the optical axis, control the shape of the third lens, comprehensively balance the spherical aberration, chromatic aberration, and field curvature of the optical system, reduce the risk of ghosting, improve the resolving power of the optical system, and reduce the difficulty of processing the third lens.

[0086] In one embodiment, the optical system satisfies the relationship: 0.4≤R9 / R10≤0.55; wherein R9 is the radius of curvature of the object-side surface of the fifth lens at the optical axis, and R10 is the radius of curvature of the image-side surface of the fifth lens at the optical axis. Specifically, the value of R9 / R10 can be 0.403, 0.423, 0.448, 0.461, 0.474, 0.478, 0.498, 0.512, 0.534, 0.548, etc. By ensuring that the optical system satisfies the above relationship, it is beneficial to reasonably configure the ratio of the radius of curvature of the object-side surface of the fifth lens at the optical axis to the radius of curvature of the image-side surface of the fifth lens at the optical axis, control the shape of the fifth lens, comprehensively balance the spherical aberration, chromatic aberration, and field curvature of the optical system, reduce the risk of ghosting, improve the resolving power of the optical system, and at the same time, reduce the difficulty of processing the fifth lens.

[0087] In one embodiment, the optical system satisfies the relationship: -1.2 ≤ R11 / R12 ≤ -0.8, where R11 is the radius of curvature of the object-side surface of the sixth lens at the optical axis, and R12 is the radius of curvature of the image-side surface of the sixth lens at the optical axis. Specifically, the values of R11 / R12 can be -1.117, -1.089, -1.000, -0.986, -0.965, -0.948, -0.905, -0.862, -0.841, -0.805, etc. By ensuring that the optical system satisfies the above relationship, it is beneficial to optimize the ratio of the radius of curvature of the object-side surface of the sixth lens at the optical axis to the radius of curvature of the image-side surface of the sixth lens at the optical axis, control the shape of the sixth lens, comprehensively balance the spherical aberration, chromatic aberration, and field curvature of the optical system, reduce the risk of ghosting, and improve the resolving power of the optical system. Furthermore, it is beneficial to reduce the processing difficulty of the sixth lens.

[0088] In one embodiment, the optical system satisfies the relationship: 0.1≤|R13 / R14|≤0.4; wherein R13 is the radius of curvature of the object-side surface of the seventh lens element at the optical axis, and R14 is the radius of curvature of the image-side surface of the seventh lens element at the optical axis. Specifically, the value of |R13 / R14| can be 0.116, 0.155, 0.157, 0.192, 0.212, 0.238, 0.268, 0.305, 0.350, 0.370, etc. By ensuring that the optical system satisfies this relationship, it is beneficial to optimize the ratio of the radius of curvature of the object-side surface of the seventh lens element at the optical axis to the radius of curvature of the image-side surface of the seventh lens element at the optical axis, control the shape of the seventh lens element, comprehensively balance the spherical aberration, chromatic aberration, and field curvature of the optical system, reduce the risk of ghosting, and improve the resolving power of the optical system. Furthermore, it is beneficial to reduce the processing difficulty of the seventh lens element.

[0089] In some embodiments, the optical system further includes a filter, which can be an infrared cutoff filter, an infrared bandpass filter, or a dual-pass filter. In the present application, the filter is a dual-pass filter, which can simultaneously transmit highly visible light and partially infrared light, thereby achieving different wavelength selection, enabling both visible light and infrared imaging, thus enabling both daytime and nighttime use. Of course, the filter can also be an infrared cutoff filter, which is used to filter out infrared light and only allow visible light to pass, making the imaging more consistent with the human eye's visual experience. Alternatively, an infrared bandpass filter can be fixed relative to each lens in the optical system. Infrared bandpass filters are used to pass infrared light of the center wavelength and filter out background stray light, and are used for infrared lenses. Furthermore, the filter can be assembled with each lens as part of the optical system. In other embodiments, the filter can be a separate component outside the optical system and can be installed between the optical system and the photosensitive chip when the optical system and the photosensitive chip are assembled. It is understood that the filter can be made of optical glass coating, colored glass, or other materials, and can be selected based on actual needs and is not specifically limited in this embodiment. In other embodiments, a filter coating can be provided on at least one of the first to eighth lenses to achieve a filtering effect.

[0090] In some embodiments, at least one lens in the optical system may 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, at least one lens in the optical system may also have an aspherical surface type. When at least one side surface of the lens (object side or image side) is aspherical, the lens can be said to have an aspherical surface type. In some embodiments, the object side and image side of each lens can also be designed as aspherical. The aspherical design can help the optical system to more effectively eliminate aberrations and improve imaging quality. 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 can be a combination of spherical and aspherical surface types. In the present application, the second lens and the eighth lens have aspherical surface types, and the first lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens have spherical surface types.

[0091] In some embodiments, at least one lens in the optical system is made of glass (GL). For example, the first lens L1 closest to the object side can be made of glass. By utilizing the thermal dissipation effect of the glass material of the first lens L1, the impact of ambient temperature changes on the optical system can be effectively reduced, thereby maintaining better and more stable imaging quality. In some embodiments, at least one lens in the optical system can also be made of plastic (PC), and the plastic material can be polycarbonate, resin, etc. Lenses made of plastic can reduce the production cost of the optical system, 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, 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 is not exhaustively listed here.

[0092] First embodiment

[0093] Please refer to Figure 1 The optical system 10 of this embodiment includes, in order from the object side to the image side along the optical axis O, the following:

[0094] The first lens element L1 has negative refractive power. The object-side surface S1 of the first lens element L1 is convex near the optical axis O, and the image-side surface S2 is concave near the optical axis O.

[0095] The second lens element L2 has negative refractive power. The object-side surface S3 of the second lens element L2 is concave at the near optical axis O, and the image-side surface S4 is convex at the near optical axis O.

[0096] The third lens element L3 has positive refractive power. The object-side surface S5 of the third lens element L3 is convex near the optical axis O, and the image-side surface S6 is convex near the optical axis O.

[0097] The fourth lens element L4 has positive refractive power. The object-side surface S7 of the fourth lens element L4 is convex near the optical axis O, and the image-side surface S8 of the fourth lens element L4 is convex near the optical axis O.

[0098] The fifth lens element L5 has negative refractive power. The object-side surface S9 of the fifth lens element L5 is concave near the optical axis O, and the image-side surface S10 is convex near the optical axis O.

[0099] The sixth lens element L6 has positive refractive power. The object-side surface S11 of the sixth lens element L6 is convex near the optical axis O, and the image-side surface S12 of the sixth lens element L6 is convex near the optical axis O.

[0100] The seventh lens element L7 has negative refractive power. The object-side surface S13 of the seventh lens element L7 is concave near the optical axis O, and the image-side surface S14 of the seventh lens element L7 is concave near the optical axis O.

[0101] The eighth lens element L8 has positive refractive power. The object-side surface S15 of the eighth lens element L8 is convex near the optical axis O, and the image-side surface S16 is concave near the optical axis O.

[0102] In this embodiment, the optical system 10 also includes, but is not limited to, an aperture STO, a filter IR, a protective glass CG, and an imaging surface IMG. The aperture STO is disposed between the image-side surface of the third lens L3 and the object-side surface of the fourth lens L4 of the optical system 10 and is used to control the amount of light entering. The filter IR is disposed between the eighth lens L8 and the protective glass CG. The filter IR includes an object-side surface S17 and an image-side surface S18. The filter IR is a dual-pass filter that can simultaneously transmit both visible light and some infrared light, thereby enabling selection of different wavelengths. This allows both visible light imaging and infrared imaging, enabling both daytime and nighttime use. The dual-pass filter can be made of, but is not limited to, glass or plastic. The dual-pass filter can be configured as a monolithic structure. In some embodiments, the double-ended filter includes a filter body and a coating disposed on the filter body. The protective glass CG is disposed between the filter IR and the imaging surface IMG and includes an object-side surface S19 and an image-side surface S20. Lenses L1 through L8 can be made of glass or plastic. The effective pixel area of the photosensitive chip is located on the imaging surface. An infrared photosensitive chip is positioned on the imaging surface IMG to capture information from different wavelengths of an object for subsequent processing. In some embodiments, the optical system 10 may include, but is not limited to, at least one of an aperture stop STO, an optical filter IR, a protective glass CG, and an imaging surface IMG.

[0103] Table 1a shows the various parameters of the optical system 10 of the first embodiment of the present application, where the Y radius is the radius of curvature of the object-side or image-side surface of the corresponding surface number at optical axis O. Surface numbers S1 and S2 represent the object-side surface S1 and image-side surface S2 of first lens L1, respectively. That is, within the same lens, the surface with the smaller surface number is the object-side surface, and the surface with the larger surface number is the image-side surface. The first value in the "Thickness" parameter column for first lens L1 is the thickness of the lens along optical axis O, and the second value is the distance from the image-side surface to the next surface of the lens in the image-side direction along optical axis O. The focal length, material refractive index, and Abbe number are all obtained using visible light with a reference wavelength of 555 nm. The units of the Y radius, thickness, and effective focal length are all millimeters (mm).

[0104] Table 1a

[0105]

[0106]

[0107] Wherein, F is the effective focal length of the optical system 10, FNO is the aperture number of the optical system 10, FOV is the maximum field angle of the optical system 10, TTL is the distance from the object side surface of the first lens to the imaging plane on the optical axis O, and IMGH is half of the image height corresponding to the maximum field angle of the optical system.

[0108] In this embodiment, both the object-side surface and the image-side surface of the second lens element L2 are aspherical surfaces, and both the object-side surface and the image-side surface of the eighth lens element L8 are aspherical surfaces. The surface shape x of the aspherical surfaces can be defined by, but is not limited to, the following aspherical surface formula:

[0109]

[0110] Where x is the distance from the corresponding point on the aspheric surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspheric surface to the optical axis O, c is the curvature of the aspheric vertex, k is the cone coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspheric surface shape formula. Table 1b shows the higher-order coefficients k, A4, A6, A8, A10, A12, A14, A16, A18, and A20 for the aspheric mirror surfaces S3, S4, S15, and S16 that can be used in the first embodiment.

[0111] Table 1b

[0112] Surface number S3 S4 S15 S16 k -1.88312E+00 -4.70560E+01 -3.14499E+00 -1.37046E+00 A4 1.00768E-03 7.74195E-04 -6.97001E-04 -4.28120E-04 A6 -1.52424E-05 1.04047E-05 -3.32302E-05 -5.92404E-05 A8 -7.85152E-07 -2.47382E-06 1.39488E-06 5.13389E-06 A10 8.91875E-08 1.37751E-07 -4.69687E-08 -9.74004E-08 A12 -4.76081E-10 -2.39513E-09 -3.84955E-09 -1.58017E-08 A14 -2.45572E-10 -8.04042E-11 5.65187E-10 1.35597E-09 A16 1.02115E-11 2.68254E-12 -1.41677E-11 -2.84538E-11 A18 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 A20 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00

[0113] Figure 2 (a) shows the longitudinal spherical aberration curves of the optical system 10 of the first embodiment at wavelengths of 900.0000nm, 870.0000nm, 850.0000nm, 830.0000nm, 800.0000nm, 660.0000nm, 610.0000nm, 555.0000nm, 510.0000nm, and 470.0000nm, wherein the abscissa along the X-axis represents the focus offset, i.e., the distance from the imaging plane to the intersection of the light and the optical axis O (in mm), and the ordinate along the Y-axis represents the normalized field of view. The longitudinal spherical aberration curve represents the deviation of the convergent focus of light of different wavelengths after passing through each lens of the optical system 10. Figure 2 As can be seen in (a), the degree of deviation of the convergent focus of light of each wavelength in the first embodiment tends to be consistent, and the diffuse spots or color halo in the imaging image are effectively suppressed by the optical system 10, indicating that the imaging quality of the optical system 10 in this embodiment is good.

[0114] Figure 2(b) also shows the astigmatism curve of the optical system 10 of the first embodiment at a wavelength of 555.0000nm, where the horizontal axis along the X-axis represents the focus offset, and the vertical axis along the Y-axis represents the image height, both in mm. The S curve in the astigmatism curve represents the sagittal field curvature at 555.0000nm, and the T curve represents the meridional field curvature at 555.0000nm. Figure 2 As can be seen in (b), the field curvature of the optical system 10 is small, the field curvature and astigmatism of each field of view are well corrected, and clear images are obtained at the center and edge of the field of view.

[0115] Figure 2 (c) also shows the distortion curve of the optical system 10 of the first embodiment at a wavelength of 555.0000nm. The horizontal axis along the X-axis represents the distortion value, and the vertical axis along the Y-axis represents the field angle, in degrees. The distortion curve represents the distortion value corresponding to different field angles. Figure 2 As can be seen in (c), at a wavelength of 555.0000 nm, the image deformation caused by the main beam is small, and the imaging quality of the system is excellent.

[0116] Depend on Figure 2 (a) Figure 2 (b) and Figure 2 As can be seen from (c), the optical system 10 of this embodiment has small aberrations, good imaging quality, and excellent imaging quality.

[0117] Second embodiment

[0118] Please refer to Figure 3 The optical system 10 of this embodiment includes, in order from the object side to the image side along the optical axis O, the following:

[0119] The first lens element L1 has negative refractive power. The object-side surface S1 of the first lens element L1 is convex near the optical axis O, and the image-side surface S2 is concave near the optical axis O.

[0120] The second lens element L2 has negative refractive power. The object-side surface S3 of the second lens element L2 is concave at the near optical axis O, and the image-side surface S4 is convex at the near optical axis O.

[0121] The third lens element L3 has positive refractive power. The object-side surface S5 of the third lens element L3 is convex near the optical axis O, and the image-side surface S6 is convex near the optical axis O.

[0122] The fourth lens element L4 has positive refractive power. The object-side surface S7 of the fourth lens element L4 is convex near the optical axis O, and the image-side surface S8 of the fourth lens element L4 is convex near the optical axis O.

[0123] The fifth lens element L5 has negative refractive power. The object-side surface S9 of the fifth lens element L5 is concave near the optical axis O, and the image-side surface S10 is convex near the optical axis O.

[0124] The sixth lens element L6 has positive refractive power. The object-side surface S11 of the sixth lens element L6 is convex near the optical axis O, and the image-side surface S12 of the sixth lens element L6 is convex near the optical axis O.

[0125] The seventh lens element L7 has negative refractive power. The object-side surface S13 of the seventh lens element L7 is concave near the optical axis O, and the image-side surface S14 is convex near the optical axis O.

[0126] The eighth lens element L8 has positive refractive power. The object-side surface S15 of the eighth lens element L8 is convex near the optical axis O, and the image-side surface S16 is concave near the optical axis O.

[0127] The other structures of the second embodiment are the same as those of the first embodiment, and can be used as a reference.

[0128] Table 2a shows various parameters of the optical system 10 of this embodiment, and the meanings of various parameters are the same as those of the first embodiment.

[0129] Table 2a

[0130]

[0131]

[0132] Table 2b gives the high-order coefficients of each aspherical mirror surface that can be used in the second embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0133] Table 2b

[0134] Surface number S3 S4 S15 S16 k -1.88312E+00 -4.70560E+01 -3.14499E+00 -1.37046E+00 A4 7.37444E-04 7.24537E-04 -7.39697E-04 -5.30902E-04 A6 -7.80705E-06 7.82295E-06 -3.06382E-05 -5.21906E-05 A8 -6.78201E-07 -1.91587E-06 1.68069E-06 4.79725E-06 A10 5.99304E-08 1.09235E-07 -3.79583E-08 -7.64409E-08 A12 3.78489E-10 -2.27124E-09 -3.93720E-09 -1.44566E-08 A14 -2.08237E-10 -4.08341E-11 4.35925E-10 1.10726E-09 A16 7.41563E-12 1.73446E-12 -9.92789E-12 -2.18363E-11 A18 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 A20 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00

[0135] Figure 4 (a) Figure 4 (b) Figure 4 (c) shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system 10 of the second embodiment, wherein the longitudinal spherical aberration curve represents the deviation of the convergent focus of light of different wavelengths after passing through each lens of the optical system 10; the astigmatism curve represents the meridional field curvature and sagittal field curvature; and the distortion curve represents the distortion value corresponding to different field angles. Figure 4 As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 10 are all well controlled, so that the optical system 10 of this embodiment has good imaging quality.

[0136] Third embodiment

[0137] Please refer to Figure 5The optical system 10 of this embodiment includes, in order from the object side to the image side along the optical axis O, the following:

[0138] The first lens element L1 has negative refractive power. The object-side surface S1 of the first lens element L1 is convex near the optical axis O, and the image-side surface S2 is concave near the optical axis O.

[0139] The second lens element L2 has negative refractive power. The object-side surface S3 of the second lens element L2 is concave at the near optical axis O, and the image-side surface S4 is convex at the near optical axis O.

[0140] The third lens element L3 has positive refractive power. The object-side surface S5 of the third lens element L3 is convex near the optical axis O, and the image-side surface S6 is convex near the optical axis O.

[0141] The fourth lens element L4 has positive refractive power. The object-side surface S7 of the fourth lens element L4 is convex near the optical axis O, and the image-side surface S8 of the fourth lens element L4 is convex near the optical axis O.

[0142] The fifth lens element L5 has negative refractive power. The object-side surface S9 of the fifth lens element L5 is concave near the optical axis O, and the image-side surface S10 is convex near the optical axis O.

[0143] The sixth lens element L6 has positive refractive power. The object-side surface S11 of the sixth lens element L6 is convex near the optical axis O, and the image-side surface S12 of the sixth lens element L6 is convex near the optical axis O.

[0144] The seventh lens element L7 has negative refractive power. The object-side surface S13 of the seventh lens element L7 is concave near the optical axis O, and the image-side surface S14 is convex near the optical axis O.

[0145] The eighth lens element L8 has positive refractive power. The object-side surface S15 of the eighth lens element L8 is convex near the optical axis O, and the image-side surface S16 is concave near the optical axis O.

[0146] The other structures of the third embodiment are the same as those of the first embodiment, and can be used as a reference.

[0147] Table 3a shows the parameters of the optical system 10 of this embodiment, where the focal length, material refractive index, and Abbe number are all obtained using visible light with a reference wavelength of 800 nm. The units of the Y radius, thickness, and effective focal length are all millimeters (mm). The meanings of the remaining parameters are the same as those of the first embodiment.

[0148] Table 3a

[0149]

[0150] Table 3b gives the high-order coefficients of each aspheric mirror surface that can be used in the third embodiment, wherein each aspheric surface shape can be defined by the formula given in the first embodiment.

[0151] Table 3b

[0152] Surface number S3 S4 S15 S16 k -1.07850E+00 2.89629E-01 -3.41101E+00 1.71494E-01 A4 8.01977E-04 7.47471E-04 -1.50835E-03 -1.49082E-03 A6 5.29151E-06 8.09722E-06 -8.33995E-05 -9.74821E-05 A8 -3.03065E-06 -9.60051E-07 1.43001E-05 3.14941E-05 A10 7.31646E-07 8.81570E-08 -1.06201E-06 -5.63168E-06 A12 -1.04356E-07 -5.87544E-09 1.08083E-08 7.43264E-07 A14 7.82616E-09 1.62073E-10 5.07385E-09 -6.59692E-08 A16 -2.84234E-10 2.97865E-12 -3.62906E-10 3.70447E-09 A18 3.86351E-12 -1.77273E-13 9.54523E-12 -1.16914E-10 A20 0.00000E+00 0.00000E+00 -8.23783E-14 1.56816E-12

[0153] Figure 6 (a) Figure 6 (b) Figure 6 (c) shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system 10 of the third embodiment, wherein the longitudinal spherical aberration curve represents the deviation of the convergent focus of light of different wavelengths after passing through each lens of the optical system 10; the astigmatism curve represents the meridional field curvature and sagittal field curvature; and the distortion curve represents the distortion value corresponding to different field angles. Figure 6 As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 10 are all well controlled, so that the optical system 10 of this embodiment has good imaging quality.

[0154] Fourth embodiment

[0155] Please refer to Figure 7 The optical system 10 of this embodiment includes, in order from the object side to the image side along the optical axis O, the following:

[0156] The first lens element L1 has negative refractive power. The object-side surface S1 of the first lens element L1 is convex near the optical axis O, and the image-side surface S2 is concave near the optical axis O.

[0157] The second lens element L2 has negative refractive power. The object-side surface S3 of the second lens element L2 is concave at the near optical axis O, and the image-side surface S4 is convex at the near optical axis O.

[0158] The third lens element L3 has positive refractive power. The object-side surface S5 of the third lens element L3 is convex near the optical axis O, and the image-side surface S6 is convex near the optical axis O.

[0159] The fourth lens element L4 has positive refractive power. The object-side surface S7 of the fourth lens element L4 is convex near the optical axis O, and the image-side surface S8 of the fourth lens element L4 is convex near the optical axis O.

[0160] The fifth lens element L5 has negative refractive power. The object-side surface S9 of the fifth lens element L5 is concave near the optical axis O, and the image-side surface S10 is convex near the optical axis O.

[0161] The sixth lens element L6 has positive refractive power. The object-side surface S11 of the sixth lens element L6 is convex near the optical axis O, and the image-side surface S12 of the sixth lens element L6 is convex near the optical axis O.

[0162] The seventh lens element L7 has negative refractive power. The object-side surface S13 of the seventh lens element L7 is concave near the optical axis O, and the image-side surface S14 is convex near the optical axis O.

[0163] The eighth lens element L8 has positive refractive power. The object-side surface S15 of the eighth lens element L8 is convex near the optical axis O, and the image-side surface S16 is concave near the optical axis O.

[0164] The other structures of the fourth embodiment are the same as those of the first embodiment, and can be used as a reference.

[0165] Table 4a shows the parameters of the optical system 10 of this embodiment, where the focal length, material refractive index, and Abbe number are all obtained using visible light with a reference wavelength of 800 nm. The units of the Y radius, thickness, and effective focal length are all millimeters (mm). The meanings of the remaining parameters are the same as those of the first embodiment.

[0166] Table 4a

[0167]

[0168] Table 4b gives the high-order coefficients of the aspheric mirror surfaces that can be used in the fourth embodiment, wherein the aspheric surface shapes can be defined by the formula given in the first embodiment.

[0169] Table 4b

[0170] Surface number S3 S4 S15 S16 k -1.07850E+00 2.89629E-01 -3.41101E+00 1.71494E-01 A4 8.01977E-04 7.47471E-04 -1.39797E-03 -1.13446E-03 A6 5.29151E-06 8.09722E-06 -6.71265E-05 -9.10307E-05 A8 -3.03065E-06 -9.60051E-07 1.41758E-05 3.11286E-05 A10 7.31646E-07 8.81570E-08 -1.02544E-06 -5.58748E-06 A12 -1.04356E-07 -5.87544E-09 1.18493E-08 7.44206E-07 A14 7.82616E-09 1.62073E-10 5.00975E-09 -6.60381E-08 A16 -2.84234E-10 2.97865E-12 -3.67872E-10 3.70137E-09 A18 3.86351E-12 -1.77273E-13 9.50677E-12 -1.16832E-10 A20 0.00000E+00 0.00000E+00 -7.27943E-14 1.56973E-12

[0171] Figure 8 (a) Figure 8 (b) Figure 8 (c) shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system 10 of the fourth embodiment, wherein the longitudinal spherical aberration curve represents the deviation of the convergent focus of light of different wavelengths after passing through each lens of the optical system 10; the astigmatism curve represents the meridional field curvature and sagittal field curvature; and the distortion curve represents the distortion value corresponding to different field angles. Figure 8 As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 10 are all well controlled, so that the optical system 10 of this embodiment has good imaging quality.

[0172] Fifth embodiment

[0173] Please refer to Figure 9 The optical system 10 of this embodiment includes, in order from the object side to the image side along the optical axis O, the following:

[0174] The first lens element L1 has negative refractive power. The object-side surface S1 of the first lens element L1 is convex near the optical axis O, and the image-side surface S2 is concave near the optical axis O.

[0175] The second lens element L2 has negative refractive power. The object-side surface S3 of the second lens element L2 is concave at the near optical axis O, and the image-side surface S4 is convex at the near optical axis O.

[0176] The third lens element L3 has positive refractive power. The object-side surface S5 of the third lens element L3 is convex near the optical axis O, and the image-side surface S6 is convex near the optical axis O.

[0177] The fourth lens element L4 has positive refractive power. The object-side surface S7 of the fourth lens element L4 is convex near the optical axis O, and the image-side surface S8 of the fourth lens element L4 is convex near the optical axis O.

[0178] The fifth lens element L5 has negative refractive power. The object-side surface S9 of the fifth lens element L5 is concave near the optical axis O, and the image-side surface S10 is convex near the optical axis O.

[0179] The sixth lens element L6 has positive refractive power. The object-side surface S11 of the sixth lens element L6 is convex near the optical axis O, and the image-side surface S12 of the sixth lens element L6 is convex near the optical axis O.

[0180] The seventh lens element L7 has negative refractive power. The object-side surface S13 of the seventh lens element L7 is concave near the optical axis O, and the image-side surface S14 is convex near the optical axis O.

[0181] The eighth lens element L8 has positive refractive power. The object-side surface S15 of the eighth lens element L8 is convex near the optical axis O, and the image-side surface S16 is concave near the optical axis O.

[0182] The other structures of the fifth embodiment are the same as those of the first embodiment, and can be used as a reference.

[0183] Table 5a shows various parameters of the optical system 10 of this embodiment, and the meanings of various parameters are the same as those of the first embodiment.

[0184] Table 5a

[0185]

[0186]

[0187] Table 5b gives the high-order coefficients of each aspherical mirror surface that can be used in the fifth embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0188] Table 5b

[0189] Surface number S3 S4 S15 S16 k -1.13504E+00 -1.39291E-01 -1.61275E+00 3.50192E+01 A4 8.12886E-04 7.67374E-04 -1.47498E-03 -1.10508E-03 A6 -5.06037E-06 2.39118E-06 -6.08659E-05 -8.41537E-05 A8 -2.75279E-06 -7.87709E-07 1.49113E-05 3.13963E-05 A10 7.50627E-07 8.92942E-08 -1.01226E-06 -5.58502E-06 A12 -1.01966E-07 -5.79693E-09 1.06713E-08 7.44238E-07 A14 7.51361E-09 1.56296E-10 4.92316E-09 -6.60272E-08 A16 -2.86768E-10 2.00967E-12 -3.68254E-10 3.69822E-09 A18 4.42068E-12 -1.99645E-13 9.68374E-12 -1.17104E-10 A20 1.21298E-15 2.86798E-15 -7.32393E-14 1.58560E-12

[0190] Figure 10 (a) Figure 10 (b) Figure 10(c) shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system 10 of the fifth embodiment, wherein the longitudinal spherical aberration curve represents the deviation of the convergent focus of light of different wavelengths after passing through each lens of the optical system 10; the astigmatism curve represents the meridional field curvature and sagittal field curvature; and the distortion curve represents the distortion value corresponding to different field angles. Figure 10 As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 10 are all well controlled, so that the optical system 10 of this embodiment has good imaging quality.

[0191] Sixth embodiment

[0192] Please refer to Figure 11 The optical system 10 of this embodiment includes, in order from the object side to the image side along the optical axis O, the following:

[0193] The first lens element L1 has negative refractive power. The object-side surface S1 of the first lens element L1 is convex near the optical axis O, and the image-side surface S2 is concave near the optical axis O.

[0194] The second lens element L2 has negative refractive power. The object-side surface S3 of the second lens element L2 is concave at the near optical axis O, and the image-side surface S4 is convex at the near optical axis O.

[0195] The third lens element L3 has positive refractive power. The object-side surface S5 of the third lens element L3 is convex near the optical axis O, and the image-side surface S6 is concave near the optical axis O.

[0196] The fourth lens element L4 has positive refractive power. The object-side surface S7 of the fourth lens element L4 is convex near the optical axis O, and the image-side surface S8 of the fourth lens element L4 is convex near the optical axis O.

[0197] The fifth lens element L5 has negative refractive power. The object-side surface S9 of the fifth lens element L5 is concave near the optical axis O, and the image-side surface S10 is convex near the optical axis O.

[0198] The sixth lens element L6 has positive refractive power. The object-side surface S11 of the sixth lens element L6 is convex near the optical axis O, and the image-side surface S12 of the sixth lens element L6 is convex near the optical axis O.

[0199] The seventh lens element L7 has negative refractive power. The object-side surface S13 of the seventh lens element L7 is concave near the optical axis O, and the image-side surface S14 of the seventh lens element L7 is concave near the optical axis O.

[0200] The eighth lens element L8 has positive refractive power. The object-side surface S15 of the eighth lens element L8 is convex near the optical axis O, and the image-side surface S16 is concave near the optical axis O.

[0201] The other structures of the sixth embodiment are the same as those of the first embodiment, and can be referred to for reference.

[0202] Table 6a shows various parameters of the optical system 10 of this embodiment, and the meanings of various parameters are the same as those of the first embodiment.

[0203] Table 6a

[0204]

[0205] Table 6b gives the high-order coefficients of each aspheric mirror surface that can be used in the sixth embodiment, wherein each aspheric surface shape can be defined by the formula given in the first embodiment.

[0206] Table 6b

[0207]

[0208]

[0209] Figure 12 (a) Figure 12 (b) Figure 12 (c) shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system 10 of the sixth embodiment, wherein the longitudinal spherical aberration curve represents the deviation of the convergent focus of light of different wavelengths after passing through each lens of the optical system 10; the astigmatism curve represents the meridional field curvature and sagittal field curvature; and the distortion curve represents the distortion magnitude corresponding to different field angles. Figure 12 As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 10 are all well controlled, so that the optical system 10 of this embodiment has good imaging quality.

[0210] Table 7 shows the values of FOV, TTL / F, TTL / IMGH, F / IMGH, FOV / FNO, F3 / F, F4 / F, F5 / F, BFL / F, CT4 / CT34, R7 / R8, R15 / R16, CT4 / CT5, Vd4 / Vd5, F6 / Vd6+F7 / Vd7, SD1 / IMGH, SD1 / TTL, SD11 / SD10, F123 / F, F45 / F, F67 / F, FNO, F*tan(FOV / 2) / IMGH, ∑CT / ∑AT, F1 / F, F2 / F, F6 / F, F7 / F, F8 / F, R1 / R2, R3 / R4, |R5 / R6|, R9 / R10, R11 / R12, |R13 / R14| in the optical system 10 of the first to sixth embodiments.

[0211] Table 7

[0212]

[0213]

[0214] As shown in Table 7, the optical systems of the first to sixth embodiments all satisfy the following relationships: 125 ≤ FOV ≤ 139, 8.5 ≤ TTL / F ≤ 9.1, 7.5 ≤ TTL / IMGH ≤ 8.3, 0.85 ≤ F / IMGH ≤ 0.95, 76 deg ≤ FOV / FNO ≤ 87 deg, 2.5 ≤ F3 / F ≤ 3, 1.6 ≤ F4 / F ≤ 2.1, -4.5 ≤ F5 / F ≤-2.7, 1.1≤BFL / F≤1.5, 4.2≤CT4 / CT34≤15, -2.8≤R7 / R8≤-1.5, 0.58≤R15 / R16≤0.85, 2. 1≤CT4 / CT5≤5.4, 3.7≤Vd4 / Vd5≤3.9, -0.7mm≤F6 / Vd6+F7 / Vd7≤-0.2mm, 1.45≤SD1 / IMGH≤ 1.82, 0.17≤SD1 / TTL≤0.25, 1≤SD11 / SD10≤1.1, -8.5≤F123 / F≤-3, 3.4≤F45 / F≤4.7, 5.5≤ F67 / F≤11, 1.6≤FNO≤1.7, 1.7≤F×tan(FOV / 2) / IMGH≤2.3, 2.8≤∑CT / ∑AT≤4.4, -2≤F1 / F≤- 1.5, -3.4≤F2 / F≤-2.4, 2.2≤F6 / F≤2.5, -4≤F7 / F≤-2.5, 7≤F8 / F≤18, 3≤R1 / R2≤5.2, 0≤R3 / R4≤0.42, |R5 / R6|≤0.12, 0.4≤R9 / R10≤0.55, -1.2≤R11 / R12≤-0.8 and 0.1≤|R13 / R14|≤0.4.

[0215] See also Figure 13 The present invention also provides a camera module 20, which includes a photosensitive chip 21 and the optical system 10 described in any one of the above embodiments, wherein the photosensitive chip 21 is arranged on the image side of the optical system 10. The photosensitive surface of the photosensitive chip 21 is located on the imaging surface of the optical system 10, and the light of the object incident on the photosensitive surface through the lens can be converted into an electrical signal of the image. The photosensitive chip 21 can be a complementary metal oxide semiconductor (CMOS) or a charge-coupled device (CCD). The camera module 20 can be an imaging module integrated on the electronic device 30, or it can be an independent lens. By adding the optical system 10 provided by the present invention to the camera module 20, the surface shape and refractive power of each lens in the optical system 10 can be reasonably designed, so that the camera module 20 has the characteristics of a large field of view and miniaturization.

[0216] See also Figure 14The present invention further provides an electronic device 30, comprising a housing 31 and the aforementioned camera module 20, wherein the camera module 20 is disposed within the housing 31. The electronic device 30 includes, but is not limited to, automobiles, surveillance equipment, smartphones, computers, and smartwatches. By incorporating the camera module 20 provided by the present invention into the electronic device 30, the electronic device 30 has a wide field of view and is compact.

[0217] The above disclosures are merely some preferred embodiments of the present invention, and certainly cannot be used to limit the scope of the present invention. A person skilled in the art will understand that all or part of the processes of the above embodiments and equivalent changes made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. An optical system, characterized in that: The optical system includes eight lenses with refractive power, which are as follows from the object side to the image side along the optical axis: a first lens having negative refractive power, an object-side surface of the first lens being convex near the optical axis, and an image-side surface of the first lens being concave near the optical axis; a second lens having negative refractive power, an object-side surface of the second lens being concave near the optical axis, and an image-side surface of the second lens being convex near the optical axis; a third lens having positive refractive power, and an object-side surface of the third lens being convex near the optical axis; a fourth lens having positive refractive power, an object-side surface of the fourth lens being convex near the optical axis, and an image-side surface of the fourth lens being convex near the optical axis; a fifth lens having negative refractive power, wherein the object-side surface of the fifth lens is concave near the optical axis, and the image-side surface of the fifth lens is convex near the optical axis; a sixth lens having positive refractive power, an object-side surface of the sixth lens being convex near the optical axis, and an image-side surface of the sixth lens being convex near the optical axis; a seventh lens element having negative refractive power, wherein the object-side surface of the seventh lens element is concave near the optical axis; an eighth lens having positive refractive power, wherein the object-side surface of the eighth lens is convex near the optical axis, and the image-side surface of the eighth lens is concave near the optical axis; The optical system satisfies the relationship: 125deg≤FOV≤139deg, 8.5≤TTL / F≤9.1; Wherein, FOV is the maximum field of view of the optical system, TTL is the distance from the object side surface of the first lens to the imaging plane on the optical axis, and F is the effective focal length of the optical system.

2. The optical system according to claim 1, wherein The optical system satisfies the relationship: 7.5 ≤ TTL / IMGH ≤ 8.3; and / or, 0.85≤F / IMGH≤0.95; and / or, 76deg≤FOV / FNO≤87deg; Wherein, IMGH is half of the image height corresponding to the maximum field angle of the optical system, and FNO is the aperture number of the optical system.

3. The optical system according to claim 1, wherein The optical system satisfies the relationship: 2.5≤F3 / F≤3; and / or, 1.6≤F4 / F≤2.1; and / or, -4.5≤F5 / F≤-2.7; and / or, 1.1≤BFL / F≤1.5; Among them, F3 is the effective focal length of the third lens, F4 is the effective focal length of the fourth lens, F5 is the effective focal length of the fifth lens, and BFL is the distance from the image side surface of the eighth lens to the imaging plane of the optical system on the optical axis.

4. The optical system according to claim 1, wherein The optical system satisfies the relationship: 4.2≤CT4 / CT34≤15; and / or, -2.8≤R7 / R8≤-1.5; and / or, 0.58≤R15 / R16≤0.85; Among them, CT4 is the thickness of the fourth lens on the optical axis, CT34 is the distance from the image side surface of the third lens to the object side surface of the fourth lens on the optical axis, R7 is the curvature radius of the object side surface of the fourth lens at the optical axis, R8 is the curvature radius of the image side surface of the fourth lens at the optical axis, R15 is the curvature radius of the object side surface of the eighth lens at the optical axis, and R16 is the curvature radius of the image side surface of the eighth lens at the optical axis.

5. The optical system according to claim 1, wherein The optical system satisfies the relationship: 2.1≤CT4 / CT5≤5.4; and / or, 3.7≤Vd4 / Vd5≤3.9; and / or, -0.7mm≤F6 / Vd6+F7 / Vd7≤-0.2mm; Wherein, CT4 is the thickness of the fourth lens on the optical axis, CT5 is the thickness of the fifth lens on the optical axis, Vd4 is the Abbe number of the fourth lens, Vd5 is the Abbe number of the fifth lens, F6 is the effective focal length of the sixth lens, Vd6 is the Abbe number of the sixth lens, F7 is the effective focal length of the seventh lens, and Vd7 is the Abbe number of the seventh lens.

6. The optical system according to claim 1, wherein The optical system satisfies the relationship: 1.45≤SD1 / IMGH≤1.82; and / or, 0.17≤SD1 / TTL≤0.25; and / or, 1≤SD11 / SD10≤1.1; Among them, SD1 is half of the maximum effective aperture of the object side surface of the first lens, IMGH is half of the image height corresponding to the maximum field angle of the optical system, SD11 is half of the maximum effective aperture of the object side surface of the sixth lens, and SD10 is half of the maximum effective aperture of the image side surface of the fifth lens.

7. The optical system according to claim 1, wherein The optical system satisfies the relationship: -8.5≤F123 / F≤-3; and / or, 3.4≤F45 / F≤4.7; and / or, 5.5≤F67 / F≤11; Among them, F123 is the combined effective focal length of the first lens, the second lens and the third lens, F45 is the combined effective focal length of the fourth lens and the fifth lens, and F67 is the combined effective focal length of the sixth lens and the seventh lens.

8. The optical system according to claim 1, wherein: The optical system satisfies the relationship: 1.6≤FNO≤1.7; and / or, 1.7 ≤ F × tan(FOV / 2) / IMGH ≤ 2.3; and / or, 2.8≤∑CT / ∑AT≤4.4; Wherein, FNO is the aperture number of the optical system, IMGH is half of the image height corresponding to the maximum field angle of the optical system, ∑CT is the sum of the thicknesses of the first lens to the eighth lens on the optical axis, and ∑AT is the sum of the spacing distances between two adjacent lenses on the optical axis.

9. A camera module, characterized in that: The optical system comprises a photosensitive chip and any one of claims 1 to 8, wherein the photosensitive chip is located on the image side of the optical system.

10. An electronic device, characterized in that: It comprises a shell and the camera module according to claim 9, wherein the camera module is arranged in the shell.

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