Optical system, image capturing module and terminal device

Abstract

The present application relates to an optical system, an image capturing module and a terminal device. The optical system comprises a first lens with negative refractive power, the object side surface is convex, and the image side surface is concave; a second lens with negative refractive power, the object side surface and the image side surface are concave; a third lens with positive refractive power, the object side surface is concave, and the image side surface is convex; a fourth lens with positive refractive power, the object side surface is convex; a fifth lens with positive refractive power, the object side surface is concave, and the image side surface is convex; a sixth lens with positive refractive power, the object side surface and the image side surface are convex; a seventh lens with negative refractive power, the object side surface is concave, and the image side surface is convex; and an eighth lens with positive refractive power, the object side surface is convex. The optical system satisfies: 5 <= TTL / T45 <= 8. The optical system can balance wide-angle and good optical performance.

Description

Technical Field

[0001] This invention relates to the field of photography, and in particular to an optical system, an image acquisition module, and a terminal device. Background Technology

[0002] In recent years, with the development of the automotive industry, the application of in-vehicle camera devices such as Advanced Driver Assistance Systems (ADAS), dashcams, and reversing cameras has become increasingly widespread. In-vehicle camera devices are equipped with lenses; lenses with a wide field of view and good optical performance can provide drivers with a wider and clearer image, thereby greatly improving driving safety. Therefore, the industry urgently needs to find in-vehicle lenses with a wide viewing angle and good optical performance. However, the image quality of current in-vehicle lenses still needs improvement, making it difficult to balance wide-angle characteristics and good optical performance, thus failing to meet the requirements of driving safety. Summary of the Invention

[0003] Therefore, it is necessary to provide an optical system, an image acquisition module, and a terminal device that can balance wide-angle characteristics and good optical performance.

[0004] An optical system comprising eight lenses having refractive power, the optical system comprising, along the optical axis from the object side to the image side, the following:

[0005] A first lens with negative refractive power, wherein the object side of the first lens is convex near the optical axis and the image side is concave near the optical axis;

[0006] A second lens with negative refractive power, wherein both the object-side and image-side surfaces of the second lens are concave near the optical axis;

[0007] A third lens with positive refractive power, wherein the object side of the third lens is concave near the optical axis and the image side is convex near the optical axis;

[0008] A fourth lens with positive refractive power, wherein the object-side surface of the fourth lens is convex near the optical axis;

[0009] A fifth lens with positive refractive power, wherein the object-side surface of the fifth lens is concave near the optical axis and the image-side surface is convex near the optical axis;

[0010] A sixth lens with positive refractive power, wherein both the object-side and image-side surfaces of the sixth lens are convex near the optical axis;

[0011] A seventh lens with negative refractive power, wherein the object side of the seventh lens is concave near the optical axis and the image side is convex near the optical axis;

[0012] An eighth lens with positive refractive power, wherein the object-side surface of the eighth lens is convex near the optical axis;

[0013] And the optical system satisfies the following condition:

[0014] 5≤TTL / T45≤8;

[0015] Wherein, TTL is the distance on the optical axis from the object side of the first lens to the imaging surface of the optical system, and T45 is the distance on the optical axis from the image side of the fourth lens to the object side of the fifth lens.

[0016] In the aforementioned optical system, the first lens has negative refractive power. Combined with its convex-concave surface near the optical axis, this facilitates the collection of large-angle light rays, thereby expanding the system's field of view and helping to avoid introducing excessively severe aberrations. The second lens also has negative refractive power. Its concave-concave surface near the optical axis helps to expand the light collected by the first lens, ensuring the light fills the pupil and is fully transmitted to the image plane, further enhancing the system's field of view and contributing to a large image area and high pixel count. The third lens has positive refractive power. Its convex-concave surface near the optical axis helps correct aberrations such as field curvature at the edges of the field of view when the first and second lenses collect large-angle light rays, thus improving the system's imaging resolution. The fourth lens has positive refractive power, and its object-side surface is convex near the optical axis, which helps to converge light rays and effectively control the light path after passing through the three front lenses, thereby shortening the overall system length. The fifth lens has positive refractive power. Combined with its concave-convex surface near the optical axis, it further converges light rays, thus reducing the overall system length and enabling miniaturization. It also facilitates proper light deflection at the fifth lens, reducing the deviation in the incident and exit angles of light rays from different fields of view, thereby reducing the system's aberration sensitivity and improving image quality. The sixth lens also has positive refractive power. Its convex-convex surface near the optical axis further shortens the overall system length, enabling miniaturization. The seventh lens has negative refractive power. Its concave-convex surface near the optical axis complements the sixth lens, effectively correcting spherical aberration and other aberrations, thereby improving system resolution and enabling high pixel counts. The eighth lens has positive refractive power. The object side of the eighth lens is convex near the optical axis, which can effectively transmit light to the imaging surface. This is beneficial for the system to achieve a large image surface, thereby matching a higher pixel sensor to obtain high resolution. At the same time, it is also beneficial to reduce the degree of deflection of edge light, thereby correcting the field curvature of the edge field of view and improving the imaging quality of the system.

[0017] When the above conditions are met, it is beneficial to shorten the overall length of the system, making the system structure more compact and thus enabling miniaturization. Simultaneously, a suitable space exists between the fourth and fifth lenses, facilitating a smooth transition and deflection of large-angle light rays, which is beneficial for wide-angle design. Below the lower limit of the above conditions, large-angle light rays are difficult to effectively enter the system, resulting in a reduced object-space imaging range, which is detrimental to wide-angle design. Above the upper limit of the above conditions, the overall optical length of the system is too long, which is detrimental to miniaturization. Possessing the above refractive power and surface characteristics, and satisfying the above conditions, the system can have characteristics such as wide angle and large image plane, thus balancing wide-angle and good optical performance. At the same time, the overall length of the system can be effectively limited, which is beneficial for miniaturization.

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

[0019] 35mm≤f3*f4 / f≤41mm;

[0020] Where f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, and f is the effective focal length of the optical system. When the above condition is satisfied, the refractive power contribution of the third and fourth lenses in the system can be reasonably configured, which is beneficial for correcting astigmatism, chromatic aberration, and edge field aberrations, thereby improving the system's imaging quality. Exceeding the upper limit of the above condition, the refractive power of the third and fourth lenses is insufficient, making it difficult to effectively deflect large-angle light rays introduced by the first and second lenses, easily leading to severe chromatic aberration and edge aberrations, which is detrimental to improving the system's resolving power. Below the lower limit of the above condition, the refractive power of the third and fourth lenses is too strong, the light deflection is too large, easily producing severe astigmatism, which is detrimental to improving imaging quality.

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

[0022] 5.5 ≤ f5 / f ≤ 7.5;

[0023] Where f5 is the effective focal length of the fifth lens, and f is the effective focal length of the optical system. When the above condition is satisfied, the positive refractive power contribution of the fifth lens in the system can be reasonably configured, enabling the fifth lens to effectively correct the chromatic aberration of the system, reduce the system's eccentricity sensitivity, and thus facilitate the correction of system aberrations and improve the system's imaging resolution. Exceeding the range of the above condition, if the refractive power of the fifth lens is too weak or too strong, it is detrimental to the correction of system aberrations, resulting in a decrease in system imaging quality.

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

[0025] 3≤CT5 / |SAG52|≤12.5;

[0026] Wherein, CT5 is the thickness of the fifth lens on the optical axis, i.e., the center thickness of the fifth lens, and SAG52 is the sag of the image-side surface of the fifth lens at its maximum effective aperture, i.e., the displacement from the intersection of the image-side surface of the fifth lens and the optical axis to the maximum effective aperture of the image-side surface of the fifth lens along the optical axis. Specifically, SAG52 is positive when the displacement points towards the image side and negative when it points towards the object side. Satisfying the above condition allows for a reasonable configuration of the ratio of the center thickness to the sag of the image-side surface of the fifth lens, which is beneficial for optimizing the shape of the fifth lens. This enables the fifth lens to effectively correct aberrations at the edge of the system's field of view, thereby improving the system's imaging quality and reducing the manufacturing difficulty of the fifth lens. Furthermore, it also helps to shorten the overall length of the system, achieving miniaturization. Below the lower limit of the above condition, the image-side surface of the fifth lens is too curved, increasing the processing difficulty and production cost. Simultaneously, an excessively curved image-side surface of the fifth lens is also prone to severe edge aberrations, which is detrimental to improving the system's image quality. If the upper limit of the above condition is exceeded, the center thickness of the fifth lens becomes too large, which is not conducive to shortening the overall length of the system.

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

[0028] 1.5≤CT6 / CT7≤3;

[0029] Wherein, CT6 is the thickness of the sixth lens along the optical axis, i.e., the center thickness of the sixth lens, and CT7 is the thickness of the seventh lens along the optical axis, i.e., the center thickness of the seventh lens. When the above condition is satisfied, the ratio of the center thicknesses of the sixth and seventh lenses can be reasonably configured, so that the positive refractive power of the sixth lens and the negative refractive power of the seventh lens can be better matched, thereby enabling the aberrations generated by the sixth and seventh lenses to be effectively corrected, thus improving the imaging quality of the system.

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

[0031] 0.5≤(CT6+CT7) / T45≤1.05;

[0032] Wherein, CT6 is the thickness of the sixth lens on the optical axis, CT7 is the thickness of the seventh lens on the optical axis, and T45 is the distance on the optical axis from the image side of the fourth lens to the object side of the fifth lens. When the above conditions are met, the center thicknesses of the sixth and seventh lenses, as well as the air gap between the fourth and fifth lenses on the optical axis, can be effectively compressed. This helps to shorten the overall length of the system, enabling miniaturization. Simultaneously, it ensures that the air gap between the fourth and fifth lenses on the optical axis is not too small, facilitating a smooth transition of light between the four lenses and the fifth lens, thus aiding in the correction of system aberrations and improving the system's imaging quality.

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

[0034] 4.5≤R11 / R12≤5.3;

[0035] Wherein, R11 is the radius of curvature of the object-side surface of the first lens at the optical axis, and R12 is the radius of curvature of the image-side surface of the first lens at the optical axis. When the above conditions are satisfied, the ratio of the radii of curvature of the object-side surface and the image-side surface of the first lens at the optical axis can be reasonably configured, ensuring that the surface shape of the first lens is not too flat. This allows the first lens to effectively converge light rays, improving the imaging quality of the system and also facilitating the effective correction of aberrations. Furthermore, while ensuring that the first lens meets optical performance requirements, it also helps to prevent the surface shape of the first lens from being excessively curved, reducing the manufacturing difficulty of the first lens and decreasing the system's eccentricity and tolerance sensitivity, thereby improving the stability of the system's imaging.

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

[0037] 2 ≤ 2 * ImgH / f ≤ 2.2;

[0038] Where ImgH is half the image height corresponding to the maximum field of view of the optical system, and f is the effective focal length of the optical system. When the above conditions are met, the half-image height and effective focal length of the system can be rationally configured, which is beneficial for correcting system distortion and on-axis aberrations, improving the system's imaging quality, increasing the system's imaging plane size, and improving the relative illumination of the system's image. Furthermore, while reducing the system's effective focal length and shortening the overall length of the system, it also helps to reduce the system's tolerance sensitivity, thereby facilitating system manufacturing and assembly.

[0039] In one embodiment, the optical system further includes an aperture stop disposed between the fourth lens and the fifth lens, and the optical system satisfies the following condition:

[0040] 1.5 ≤ TTL / DOS ≤ 2.5;

[0041] Where TTL is the distance along the optical axis from the object-side surface of the first lens to the imaging surface of the optical system, i.e., the total optical length of the optical system, and DOS is the distance along the optical axis from the object-side surface of the first lens to the aperture stop. Satisfying the above conditions helps to shorten the total length of the system, making the system structure more compact and thus achieving miniaturization. Simultaneously, the light rays converged by the object-side lens group (i.e., the first to fourth lenses) at the aperture stop have sufficient transmission space, facilitating the entry of large-angle light rays into the aperture stop, which is beneficial for the system's wide-angle design. Below the lower limit of the above conditions, large-angle light rays are difficult to effectively enter the system, resulting in a reduced object space imaging range, which is detrimental to achieving a wide-angle design. Above the upper limit of the above conditions, the total optical length of the system is too long, which is detrimental to the system's miniaturization design.

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

[0043] f / EPD≤1.5;

[0044] Where f is the effective focal length of the optical system, and EPD is the entrance pupil diameter of the optical system. When the above conditions are met, the aperture of the system can be reasonably configured to give the system a large aperture effect, which is beneficial to increasing the amount of light entering the system, thereby improving the relative illumination of the image and enabling the system to obtain a clear image. At the same time, the system can also have good image quality in low-light environments.

[0045] In one embodiment, the optical system satisfies the following condition:

[0046] 0.9≤CT8 / f≤1.2;

[0047] Wherein, CT8 is the thickness of the eighth lens on the optical axis, i.e., the center thickness of the eighth lens, and f is the effective focal length of the optical system. When the above condition is satisfied, the ratio of the center thickness of the eighth lens to the effective focal length of the optical system can be reasonably configured. This allows the eighth lens to effectively deflect light to the imaging plane to improve image quality, while also helping to limit the center thickness of the eighth lens, thus facilitating the miniaturization design of the optical system.

[0048] An image-capturing module includes a photosensitive element and the optical system described in any of the above embodiments, wherein the photosensitive element is disposed on the image side of the optical system. Using the aforementioned optical system in the image-capturing module can balance wide-angle viewing and good optical performance, while also facilitating miniaturization. When applied to automotive camera equipment, it can effectively improve driving safety.

[0049] A terminal device includes the aforementioned image-capturing module. Using this image-capturing module in the terminal device can balance wide-angle viewing and a good optical system, while also facilitating miniaturization, thereby effectively improving driving safety performance and reducing the space occupied by the terminal device, thus simplifying its installation. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the optical system in the first embodiment of this application;

[0051] Figure 2 The diagrams show the longitudinal spherical aberration, astigmatism, and distortion of the optical system in the first embodiment of this application.

[0052] Figure 3 This is a schematic diagram of the optical system in the second embodiment of this application;

[0053] Figure 4 The longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system in the second embodiment of this application are shown.

[0054] Figure 5 This is a schematic diagram of the optical system in the third embodiment of this application;

[0055] Figure 6 The longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system in the third embodiment of this application are shown.

[0056] Figure 7 This is a schematic diagram of the optical system in the fourth embodiment of this application;

[0057] Figure 8 The longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system in the fourth embodiment of this application are shown.

[0058] Figure 9 This is a schematic diagram of the optical system in the fifth embodiment of this application;

[0059] Figure 10 The longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system in the fifth embodiment of this application are shown.

[0060] Figure 11 This is a schematic diagram of the optical system in the sixth embodiment of this application;

[0061] Figure 12 The longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system in the sixth embodiment of this application are shown.

[0062] Figure 13 This is a schematic diagram of an image-capturing module in one embodiment of this application;

[0063] Figure 14This is a schematic diagram of a terminal device in one embodiment of this application;

[0064] Figure 15 This is a schematic diagram of a terminal device in another embodiment of this application. Detailed Implementation

[0065] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0066] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0067] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0068] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0069] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0070] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0071] Please see Figure 1 In some embodiments of this application, the optical system 100 includes, along the optical axis 110 from the object side to the image side, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8. Specifically, the first lens L1 includes an object-side surface S1 and an image-side surface S2; the second lens L2 includes an object-side surface S3 and an image-side surface S4; the third lens L3 includes an object-side surface S5 and an image-side surface S6; the fourth lens L4 includes an object-side surface S7 and an image-side surface S8; the fifth lens L5 includes an object-side surface S9 and an image-side surface S10; the sixth lens L6 includes an object-side surface S11 and an image-side surface S12; the seventh lens L7 includes an object-side surface S13 and an image-side surface S14; and the eighth lens L8 includes an object-side surface S15 and an image-side surface S16. The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are coaxially arranged, and the common axis of all the lenses in the optical system 100 is the optical axis 110 of the optical system 100. In some embodiments, the optical system 100 further includes an imaging surface S19 located on the image side of the eighth lens L8. After the incident light is adjusted by the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8, it can be imaged onto the imaging surface S19.

[0072] The first lens L1 has negative refractive power. Combined with its convex-concave surface near the optical axis 110, it effectively collects large-angle light rays, thereby expanding the system's field of view and helping to avoid introducing excessively severe aberrations. The second lens L2 also has negative refractive power. Its concave-concave surface near the optical axis 110 helps to expand the light collected by the first lens L1, ensuring the light fills the pupil and is fully transmitted to the imaging plane S19, further improving the system's field of view and contributing to a large image area and high pixel count. The third lens L3 has positive refractive power. Its convex-concave surface near the optical axis 110 helps to correct aberrations such as field curvature at the edges of the field of view when the first and second lenses L1 and L2 collect large-angle light rays, thus improving the system's imaging resolution. The fourth lens L4 has positive refractive power. Its object-side surface S7, near the optical axis 110, is convex, which helps converge light rays and rationally control the optical path after passing through the three front lenses, thus shortening the overall system length. The fifth lens L5 also has positive refractive power. Combined with its concave-convex surface near the optical axis 110, it further converges light rays, compressing the overall system length and achieving miniaturization. It also facilitates rational deflection of light rays at the fifth lens L5, reducing the deviation of the incident and exit angles of light rays from different fields of view, thereby reducing the system's aberration sensitivity and improving image quality. The sixth lens L6 also has positive refractive power. Combined with its convex-convex surface near the optical axis 110, it further shortens the overall system length, achieving miniaturization. The seventh lens L7 has negative refractive power. Combined with its concave-convex surface near the optical axis 110, it works in conjunction with the sixth lens L6 to effectively correct spherical aberration and other aberrations, thereby improving system resolution and enabling the system to achieve high pixel count. The eighth lens L8 has positive refractive power. Its object-side surface S15 is convex near the optical axis 110, effectively transmitting light to the imaging surface S19. This facilitates a large image plane and reduces the refraction of edge rays, thus correcting field curvature at the edges and improving the system's image quality.

[0073] In some embodiments, the sixth lens L6 and the seventh lens L7 are cemented together. The positive refractive power of the sixth lens L6 and the negative refractive power of the seventh lens L7 help suppress chromatic aberration in the optical system 100 and correct spherical aberration, thereby improving the resolution of the optical system 100. It should be noted that in this application, the description of the cementation of the sixth lens L6 and the seventh lens L7 can be understood as describing their relative positions, such as the image-side surface S12 of the sixth lens L6 abutting the object-side surface S13 of the seventh lens L7, rather than limiting the cementation process of the sixth lens L6 and the seventh lens L7. Whether the sixth lens L6 and the seventh lens L7 are cemented together with optical adhesive or abutted by structural components or other means, all fall within the scope of the cementation of the sixth lens L6 and the seventh lens L7 described in this application.

[0074] In some embodiments, the optical system 100 is provided with an aperture stop STO, which can be disposed on the object side of the first lens L1 or between any two lenses. For example, in some embodiments, the aperture stop STO is disposed between the fourth lens L4 and the fifth lens L5, which, in conjunction with the refractive power and surface configuration of each lens, is beneficial for the system to achieve large aperture characteristics. In some embodiments, the system also includes a protective glass L9 disposed on the image side of the eighth lens L8. The protective glass L9 is located between the eighth lens L8 and the imaging surface S19, and can protect the photosensitive element disposed on the imaging surface S19. In some embodiments, the optical system 100 also includes an infrared cut-off filter disposed on the image side of the eighth lens. The infrared cut-off filter can be used to filter out interference light and prevent interference light from reaching the imaging surface S19 of the optical system 100 and affecting normal imaging. Of course, the system can also filter out infrared light by providing an infrared filter film on the surface of the protective glass L9.

[0075] In some embodiments, the object-side and image-side surfaces of each lens in the optical system 100 can both be spherical, which helps to reduce the radial dimensions of the system and makes the system more suitable for automotive lenses. In other embodiments, the object-side and image-side surfaces of each lens in the optical system 100 can also be aspherical. The use of aspherical structures can improve the flexibility of lens design and effectively correct spherical aberration, thereby improving image quality. It should be noted that the above embodiments are merely examples of some embodiments of this application. In some embodiments, the surfaces of each lens in the optical system 100 can be any combination of aspherical or spherical surfaces.

[0076] In some embodiments, the lenses in the optical system 100 can be made of either glass or plastic. Using plastic lenses reduces the weight of the optical system 100 and lowers production costs, allowing for a slimmer and lighter design, especially considering the smaller size of the optical system 100. Using glass lenses, on the other hand, provides the optical system 100 with excellent optical performance and high temperature resistance. It should be noted that the lenses in the optical system 100 can also be made of any combination of glass and plastic, and do not necessarily have to be made entirely of either glass or plastic.

[0077] It should be noted that the first lens L1 does not necessarily mean that there is only one lens. In some embodiments, the first lens L1 may contain two or more lenses, which can form a cemented lens. The surface of the cemented lens closest to the object side can be regarded as the object-side surface S1, and the surface closest to the image side can be regarded as the image-side surface S2. Alternatively, the lenses in the first lens L1 may not form a cemented lens, but the distance between the lenses is relatively fixed. In this case, the object-side surface of the lens closest to the object side is the object-side surface S1, and the image-side surface of the lens closest to the image side is the image-side surface S2. In addition, in some embodiments, the number of lenses in the second lens L2, third lens L3, fourth lens L4, fifth lens L5, sixth lens L6, seventh lens L7, or eighth lens L8 may be greater than or equal to two, and any adjacent lenses may form a cemented lens or a non-cemented lens.

[0078] Furthermore, in some embodiments, the optical system 100 satisfies the condition: f / EPD ≤ 1.5; where f is the effective focal length of the optical system 100, and EPD is the entrance pupil diameter of the optical system 100. Specifically, f / EPD can be 1.398, 1.399, 1.400, or 1.401. Satisfying the above condition allows for a reasonable configuration of the system's aperture, resulting in a large aperture effect. This improves the amount of light entering the system, thereby enhancing the relative illumination of the image and enabling the system to obtain a clear image. It also ensures good image quality even in low-light environments.

[0079] In some embodiments, the optical system 100 satisfies the condition: 35mm ≤ f3*f4 / f ≤ 41mm; where f3 is the effective focal length of the third lens L3, f4 is the effective focal length of the fourth lens L4, and f is the effective focal length of the optical system 100. Specifically, f3*f4 / f can be: 37.211, 37.456, 37.669, 37.981, 38.634, 39.154, 39.552, 39.741, 39.951, or 40.825, with the unit being mm. When the above condition is satisfied, the refractive power contribution of the third lens L3 and the fourth lens L4 in the system can be reasonably configured, which is beneficial for correcting astigmatism, chromatic aberration, and aberrations in the edge field of view, thereby improving the imaging quality of the system. If the refractive power of the third lens L3 and the fourth lens L4 exceeds the upper limit of the above conditional expression, they will be insufficient to effectively deflect large-angle light rays introduced by the first lens L1 and the second lens L2, easily leading to severe chromatic aberration and edge aberrations in the system, which is detrimental to improving the system's resolving performance. If the refractive power of the third lens L3 and the fourth lens L4 is below the lower limit of the above conditional expression, the refractive power of the third lens L3 and the fourth lens L4 will be too strong, and the degree of light deflection will be too large, easily producing severe astigmatism, which is detrimental to improving image quality.

[0080] In some embodiments, the optical system 100 satisfies the condition: 5.5 ≤ f5 / f ≤ 7.5; where f5 is the effective focal length of the fifth lens L5, and f is the effective focal length of the optical system 100. Specifically, f5 / f can be: 5.843, 6.114, 6.453, 6.687, 6.814, 6.923, 7.145, 7.232, 7.306, or 7.329. When the above condition is satisfied, the positive refractive power contribution of the fifth lens L5 in the system can be reasonably configured, enabling the fifth lens L5 to effectively correct the chromatic aberration of the system and reduce the system's eccentricity sensitivity, thereby facilitating the correction of system aberrations and improving the system's imaging resolution. If the refractive power of the fifth lens L5 exceeds the range of the above condition, either too weak or too strong, it will be detrimental to the correction of system aberrations, resulting in a decrease in system imaging quality.

[0081] In some embodiments, the optical system 100 satisfies the condition: 3 ≤ CT5 / |SAG52| ≤ 12.5; where CT5 is the thickness of the fifth lens L5 on the optical axis 110, and SAG52 is the sag of the image-side surface S10 of the fifth lens L5 at the maximum effective aperture. Specifically, CT5 / |SAG52| can be: 3.350, 4.254, 5.369, 6.124, 7.415, 8.951, 9.662, 10.351, 11.965, or 12.375. When the above condition is satisfied, the ratio of the center thickness of the fifth lens L5 to the sag of the image-side surface S10 can be reasonably configured, which is beneficial to optimizing the shape of the fifth lens L5, enabling the fifth lens L5 to effectively correct aberrations in the edge field of view of the system, thereby improving the imaging quality of the system. It also helps to reduce the manufacturing difficulty of the fifth lens L5; in addition, it also helps to shorten the overall length of the system and achieve miniaturization design. If the curvature is below the lower limit of the above conditional expression, the image-side surface S10 of the fifth lens L5 becomes excessively curved, increasing the manufacturing difficulty of the fifth lens L5 and thus increasing its production cost. Simultaneously, excessive curvature of the image-side surface S10 of the fifth lens L5 also easily leads to severe marginal aberrations, which is detrimental to improving the system's image quality. If the curvature exceeds the upper limit of the above conditional expression, the center thickness of the fifth lens L5 becomes too large, which is not conducive to shortening the overall length of the system.

[0082] In some embodiments, the optical system 100 satisfies the condition: 1.5 ≤ CT6 / CT7 ≤ 3; where CT6 is the thickness of the sixth lens L6 on the optical axis 110, and CT7 is the thickness of the seventh lens L7 on the optical axis 110. Specifically, CT6 / CT7 can be: 1.550, 1.647, 1.741, 1.895, 2.017, 2.225, 2.537, 2.638, 2.700, or 2.714. When the above condition is satisfied, the ratio of the center thicknesses of the sixth lens L6 and the seventh lens L7 can be reasonably configured, so that the positive refractive power of the sixth lens L6 and the negative refractive power of the seventh lens L7 can be better matched, thereby enabling the aberrations generated by the sixth lens L6 and the seventh lens L7 to be effectively corrected, thus improving the imaging quality of the system.

[0083] In some embodiments, the optical system 100 satisfies the condition: 0.5 ≤ (CT6 + CT7) / T45 ≤ 1.05; where CT6 is the thickness of the sixth lens L6 on the optical axis 110, CT7 is the thickness of the seventh lens L7 on the optical axis 110, and T45 is the distance on the optical axis 110 from the image-side surface S8 of the fourth lens L4 to the object-side surface S9 of the fifth lens L5. Specifically, (CT6 + CT7) / T45 can be: 0.648, 0.677, 0.725, 0.784, 0.865, 0.885, 0.933, 0.967, 0.988, or 1.047. When the above conditions are met, the center thickness of the sixth lens L6 and the seventh lens L7, as well as the air gap between the fourth lens L4 and the fifth lens L5 on the optical axis 110, can be effectively compressed. This helps to shorten the overall length of the system and achieve miniaturization. At the same time, it also helps to ensure that the air gap between the fourth lens L4 and the fifth lens L5 on the optical axis 110 is not too small, which is conducive to the smooth transition of light between the fourth lens L4 and the fifth lens L5. This is beneficial to correcting the aberrations of the system and improving the imaging quality of the system.

[0084] In some embodiments, the optical system 100 satisfies the condition: 4.5 ≤ R11 / R12 ≤ 5.3; where R11 is the radius of curvature of the object-side surface S1 of the first lens L1 at the optical axis 110, and R12 is the radius of curvature of the image-side surface S2 of the first lens L1 at the optical axis 110. Specifically, R11 / R12 can be: 4.766, 4.789, 4.814, 4.837, 4.955, 5.013, 5.077, 5.124, 5.187, or 5.231. When the above conditions are met, the ratio of the radii of curvature of the object side surface S1 and the image side surface S2 of the first lens L1 at the optical axis 110 can be reasonably configured, so that the surface shape of the first lens L1 is not too flat, thereby enabling the first lens L1 to effectively converge light rays, improve the imaging quality of the system, and also help the first lens L1 to effectively correct the aberrations of the system. In addition, while ensuring that the first lens L1 meets the requirements of optical performance, it also helps to prevent the surface shape of the first lens L1 from being too curved, which helps to reduce the processing difficulty of the first lens L1 and reduce the system's eccentricity sensitivity and tolerance sensitivity, thereby improving the system's imaging stability.

[0085] In some embodiments, the optical system 100 satisfies the condition: 2 ≤ 2 * ImgH / f ≤ 2.2; where ImgH is half the image height corresponding to the maximum field of view of the optical system 100, and f is the effective focal length of the optical system 100. Specifically, 2 * ImgH / f can be: 2.066, 2.067, 2.069, 2.071, 2.075, 2.077, 2.080, 2.082, 2.084, or 2.085. Satisfying the above condition allows for a reasonable configuration of the system's half-image height and effective focal length, which is beneficial for correcting system distortion and on-axis aberrations, improving the system's imaging quality, increasing the size of the system's imaging plane S19, and improving the relative illumination of the system's imaging. Furthermore, while reducing the system's effective focal length and shortening the overall length of the system, it also helps reduce the system's tolerance sensitivity, thereby facilitating the system's manufacturing and assembly.

[0086] It should be noted that in some embodiments, the optical system 100 can be matched with a photosensitive element having a rectangular photosensitive surface, and the imaging surface S19 of the optical system 100 coincides with the photosensitive surface of the photosensitive element. In this case, the effective pixel area on the imaging surface S19 of the optical system 100 has both a horizontal direction and a diagonal direction. Therefore, the maximum field of view can be understood as the maximum field of view in the diagonal direction of the optical system 100, and ImgH can be understood as half the length of the effective pixel area in the diagonal direction on the imaging surface S19 of the optical system 100.

[0087] In some embodiments, the optical system 100 satisfies the condition: 1.5 ≤ TTL / DOS ≤ 2.5; where TTL is the distance on the optical axis 110 from the object-side surface S1 of the first lens L1 to the imaging surface S19 of the optical system 100, and DOS is the distance on the optical axis 110 from the object-side surface S1 of the first lens L1 to the aperture stop STO. Specifically, TTL / DOS can be: 1.895, 1.911, 1.934, 1.957, 1.998, 2.025, 2.089, 2.103, 2.122, or 2.158. Satisfying the above condition helps to shorten the overall length of the system, making the system structure more compact, thereby achieving miniaturization. At the same time, the light rays converged by the object-side lens group on the aperture stop (i.e., the first lens L1 to the fourth lens L4) have sufficient transmission space, which facilitates the entry of large-angle light rays into the aperture stop, which is beneficial to the wide-angle design of the system. Below the lower limit of the above conditional expression, large-angle light rays are difficult to effectively incident on the system, resulting in a reduced object space imaging range and hindering the realization of wide-angle designs. Above the upper limit of the above conditional expression, the total optical length of the system becomes too long, which is not conducive to the miniaturization of the system.

[0088] In some embodiments, the optical system 100 satisfies the condition: 5 ≤ TTL / T45 ≤ 8; where TTL is the distance on the optical axis 110 from the object-side surface S1 of the first lens L1 to the imaging surface S19 of the optical system 100, and T45 is the distance on the optical axis 110 from the image-side surface S8 of the fourth lens L4 to the object-side surface S9 of the fifth lens L5. Specifically, TTL / T45 can be: 6.112, 6.234, 6.374, 6.485, 6.521, 6.693, 6.721, 6.842, 6.966, or 7.140. Satisfying the above condition helps to shorten the overall length of the system, making the system structure more compact, thereby achieving miniaturization. At the same time, there is a suitable space between the fourth lens L4 and the fifth lens L5, which facilitates the smooth transition and deflection of large-angle light rays, which is beneficial to the wide-angle design of the system. Below the lower limit of the above conditional expression, large-angle light rays are difficult to effectively incident on the system, resulting in a reduced object space imaging range and hindering the realization of wide-angle designs. Above the upper limit of the above conditional expression, the total optical length of the system becomes too long, which is not conducive to the miniaturization of the system.

[0089] In some embodiments, the optical system 100 satisfies the condition: 0.9 ≤ CT8 / f ≤ 1.2; where CT8 is the thickness of the eighth lens L8 on the optical axis 110, and f is the effective focal length of the optical system 100. Specifically, CT8 / f can be: 0.908, 0.912, 0.932, 0.935, 0.946, 0.951, 0.967, 0.993, 1.123, or 1.182. When the above condition is satisfied, the ratio of the center thickness of the eighth lens L8 to the effective focal length of the optical system 100 can be reasonably configured. This allows the eighth lens L8 to effectively deflect light to the imaging plane S19 to improve image quality, while also helping to limit the center thickness of the eighth lens L8, thereby facilitating the miniaturization design of the optical system 100.

[0090] The reference wavelength for the above effective focal length values ​​is 546.0740nm.

[0091] Based on the descriptions of the above embodiments, more specific embodiments and accompanying drawings are provided below for detailed explanation. It should be noted that although the embodiments of this application are described using eight lenses as an example, the number of lenses with refractive power in the optical system 100 is not limited to eight, and the optical system 100 may also include other numbers of lenses. Those skilled in the art should understand that, without departing from the technical solutions claimed in this application, the number of lenses constituting the optical system can be changed to obtain the various results and advantages described in this specification.

[0092] First Embodiment

[0093] Please see Figure 1 and Figure 2 , Figure 1 The diagram below shows the structure of the optical system 100 in the first embodiment. The optical system 100 includes, from the object side to the image side, a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, an aperture STO, a fifth lens L5 with positive refractive power, a sixth lens L6 with positive refractive power, a seventh lens L7 with negative refractive power, and an eighth lens L8 with positive refractive power. The sixth lens L6 and the seventh lens L7 are cemented together. Figure 2 From left to right, the graphs show the longitudinal spherical aberration, astigmatism, and distortion of the optical system 100 in the first embodiment. The reference wavelength for the astigmatism and distortion graphs is 546.0740 nm. The same applies to other embodiments.

[0094] The object-side surface S1 of the first lens L1 is convex near the optical axis 110, and the image-side surface S2 is concave near the optical axis 110.

[0095] The object-side surface S3 of the second lens L2 is concave near the optical axis 110, and the image-side surface S4 is concave near the optical axis 110.

[0096] The object-side surface S5 of the third lens L3 is concave near the optical axis 110, and the image-side surface S6 is convex near the optical axis 110.

[0097] The object-side surface S7 of the fourth lens L4 is convex at near the optical axis 110, and the image-side surface S8 is concave at near the optical axis 110.

[0098] The object-side surface S9 of the fifth lens L5 is concave near the optical axis 110, and the image-side surface S10 is convex near the optical axis 110.

[0099] The object-side surface S11 of the sixth lens L6 is convex near the optical axis 110, and the image-side surface S12 is convex near the optical axis 110.

[0100] The object-side surface S13 of the seventh lens L7 is concave near the optical axis 110, and the image-side surface S14 is convex near the optical axis 110.

[0101] The object-side surface S15 of the eighth lens L8 is convex at near the optical axis 110, and the image-side surface S16 is convex at near the optical axis 110.

[0102] The object-side surface and image-side surface of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are all spherical, and the same applies to other embodiments.

[0103] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are all made of glass, and the same applies to other embodiments.

[0104] In addition, the parameters of the optical system 100 are given in Table 1. The elements from the object plane (not shown) to the imaging plane S19 are arranged sequentially from top to bottom according to Table 1. The radii of curvature in Table 1 are the radii of curvature of the object-side or image-side surface of the corresponding surface number at the optical axis 110. Surface numbers S1 and S2 are the object-side surface S1 and image-side surface S2 of the first lens L1, respectively; that is, in the same lens, the surface with 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 of the first lens L1 is the thickness of the lens on the optical axis 110, and the second value is the distance from the image-side surface of the lens to the next surface in the image-side direction on the optical axis 110.

[0105] It should be noted that in this embodiment and the following embodiments, the optical system 100 may not be provided with protective glass L9, but the distance from the image side surface S16 of the eighth lens L8 to the imaging surface S19 remains unchanged.

[0106] In the first embodiment, the optical system 100 has an effective focal length f = 3.35 mm, a maximum field of view (FOV) of 133.6 degrees, and an aperture number (FNO) of 1.4.

[0107] Furthermore, the reference wavelength for the focal length of each lens is 546.0740 nm, and the reference wavelength for the refractive index and Abbe number of each lens is 587.56 nm, and the same applies to other embodiments.

[0108] Table 1

[0109]

[0110] in addition, Figure 2 The optical system 100 includes a longitudinal spherical aberration curve, which represents the deviation of the convergence focus of light rays of different wavelengths after passing through the lens. The vertical axis represents the normalized pupil coordinates from the pupil center to the pupil edge, and the horizontal axis represents the focus shift, i.e., the distance (in mm) from the imaging plane S19 to the intersection of the light ray and the optical axis 110. As shown in the longitudinal spherical aberration curve, in the first embodiment, the degree of focus deviation for each wavelength of light tends to be consistent, effectively suppressing blur spots or color halos in the image. Figure 2The diagram also includes astigmatic field curves for the optical system 100, where the horizontal axis represents focus shift and the vertical axis represents image height, both in mm. The S-curve in the astigmatic curves represents the sagittal field curvature at 546.0740 nm, and the T-curve represents the meridional field curvature at 546.0740 nm. As shown in the diagram, the optical system 100 has low field curvature, and both field curvature and astigmatism are well corrected across all fields of view, resulting in sharp imaging at both the center and edges of the field of view. Figure 2 It also includes a distortion curve diagram of the optical system 100. The distortion curve represents the distortion magnitude corresponding to different field of view angles, where the horizontal axis represents the distortion value in %, and the vertical axis represents the image height in mm. As can be seen from the figure, the image distortion caused by the main beam is small, and the system has excellent imaging quality.

[0111] Second Embodiment

[0112] Please see Figure 3 and Figure 4 , Figure 3 The diagram below shows the structure of the optical system 100 in the second embodiment. The optical system 100 includes, from the object side to the image side, a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, an aperture STO, a fifth lens L5 with positive refractive power, a sixth lens L6 with positive refractive power, a seventh lens L7 with negative refractive power, and an eighth lens L8 with positive refractive power. The sixth lens L6 and the seventh lens L7 are cemented together. Figure 4 From left to right, the graphs show the longitudinal spherical aberration, astigmatism, and distortion of the optical system 100 in the second embodiment.

[0113] The object-side surface S1 of the first lens L1 is convex near the optical axis 110, and the image-side surface S2 is concave near the optical axis 110.

[0114] The object-side surface S3 of the second lens L2 is concave near the optical axis 110, and the image-side surface S4 is concave near the optical axis 110.

[0115] The object-side surface S5 of the third lens L3 is concave near the optical axis 110, and the image-side surface S6 is convex near the optical axis 110.

[0116] The object-side surface S7 of the fourth lens L4 is convex at near the optical axis 110, and the image-side surface S8 is concave at near the optical axis 110.

[0117] The object-side surface S9 of the fifth lens L5 is concave near the optical axis 110, and the image-side surface S10 is convex near the optical axis 110.

[0118] The object-side surface S11 of the sixth lens L6 is convex near the optical axis 110, and the image-side surface S12 is convex near the optical axis 110.

[0119] The object-side surface S13 of the seventh lens L7 is concave near the optical axis 110, and the image-side surface S14 is convex near the optical axis 110.

[0120] The object-side surface S15 of the eighth lens L8 is convex at near the optical axis 110, and the image-side surface S16 is convex at near the optical axis 110.

[0121] In addition, the parameters of the optical system 100 are given in Table 2, and the definitions of each parameter can be derived from the first embodiment, and will not be repeated here.

[0122] Table 2

[0123]

[0124]

[0125] In addition, by Figure 4 As can be seen from the aberration diagram, the longitudinal spherical aberration, astigmatism, and distortion of the optical system 100 are well controlled, thus the optical system 100 of this embodiment has good imaging quality.

[0126] Third Embodiment

[0127] Please see Figure 5 and Figure 6 , Figure 5 The diagram below shows the structure of the optical system 100 in the third embodiment. The optical system 100 includes, from the object side to the image side, a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, an aperture STO, a fifth lens L5 with positive refractive power, a sixth lens L6 with positive refractive power, a seventh lens L7 with negative refractive power, and an eighth lens L8 with positive refractive power. The sixth lens L6 and the seventh lens L7 are cemented together. Figure 6 From left to right, the graphs show the longitudinal spherical aberration, astigmatism, and distortion of the optical system 100 in the third embodiment.

[0128] The object-side surface S1 of the first lens L1 is convex near the optical axis 110, and the image-side surface S2 is concave near the optical axis 110.

[0129] The object-side surface S3 of the second lens L2 is concave near the optical axis 110, and the image-side surface S4 is concave near the optical axis 110.

[0130] The object-side surface S5 of the third lens L3 is concave near the optical axis 110, and the image-side surface S6 is convex near the optical axis 110.

[0131] The object-side surface S7 of the fourth lens L4 is convex at near the optical axis 110, and the image-side surface S8 is concave at near the optical axis 110.

[0132] The object-side surface S9 of the fifth lens L5 is concave near the optical axis 110, and the image-side surface S10 is convex near the optical axis 110.

[0133] The object-side surface S11 of the sixth lens L6 is convex near the optical axis 110, and the image-side surface S12 is convex near the optical axis 110.

[0134] The object-side surface S13 of the seventh lens L7 is concave near the optical axis 110, and the image-side surface S14 is convex near the optical axis 110.

[0135] The object-side surface S15 of the eighth lens L8 is convex at near the optical axis 110, and the image-side surface S16 is convex at near the optical axis 110.

[0136] In addition, the various parameters of the optical system 100 are given in Table 3, and the definitions of each parameter can be derived from the first embodiment, and will not be repeated here.

[0137] Table 3

[0138]

[0139]

[0140] In addition, by Figure 6 As can be seen from the aberration diagram, the longitudinal spherical aberration, astigmatism, and distortion of the optical system 100 are well controlled, thus the optical system 100 of this embodiment has good imaging quality.

[0141] Fourth embodiment

[0142] Please see Figure 7 and Figure 8 , Figure 7 The diagram below shows the structure of the optical system 100 in the fourth embodiment. The optical system 100 includes, from the object side to the image side, a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, an aperture STO, a fifth lens L5 with positive refractive power, a sixth lens L6 with positive refractive power, a seventh lens L7 with negative refractive power, and an eighth lens L8 with positive refractive power. The sixth lens L6 and the seventh lens L7 are cemented together. Figure 8 From left to right, the graphs show the longitudinal spherical aberration, astigmatism, and distortion of the optical system 100 in the fourth embodiment.

[0143] The object-side surface S1 of the first lens L1 is convex near the optical axis 110, and the image-side surface S2 is concave near the optical axis 110.

[0144] The object-side surface S3 of the second lens L2 is concave near the optical axis 110, and the image-side surface S4 is concave near the optical axis 110.

[0145] The object-side surface S5 of the third lens L3 is concave near the optical axis 110, and the image-side surface S6 is convex near the optical axis 110.

[0146] The object-side surface S7 of the fourth lens L4 is convex at near the optical axis 110, and the image-side surface S8 is convex at near the optical axis 110.

[0147] The object-side surface S9 of the fifth lens L5 is concave near the optical axis 110, and the image-side surface S10 is convex near the optical axis 110.

[0148] The object-side surface S11 of the sixth lens L6 is convex near the optical axis 110, and the image-side surface S12 is convex near the optical axis 110.

[0149] The object-side surface S13 of the seventh lens L7 is concave near the optical axis 110, and the image-side surface S14 is convex near the optical axis 110.

[0150] The object-side surface S15 of the eighth lens L8 is convex at near the optical axis 110, and the image-side surface S16 is flat at near the optical axis 110.

[0151] In addition, the parameters of the optical system 100 are given in Table 4, and the definitions of each parameter can be derived from the first embodiment, and will not be repeated here.

[0152] Table 4

[0153]

[0154]

[0155] In addition, by Figure 8 As can be seen from the aberration diagram, the longitudinal spherical aberration, astigmatism, and distortion of the optical system 100 are well controlled, thus the optical system 100 of this embodiment has good imaging quality.

[0156] Fifth Embodiment

[0157] Please see Figure 9 and Figure 10 , Figure 9The diagram below shows the structure of the optical system 100 in the fifth embodiment. The optical system 100 includes, from the object side to the image side, a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, an aperture STO, a fifth lens L5 with positive refractive power, a sixth lens L6 with positive refractive power, a seventh lens L7 with negative refractive power, and an eighth lens L8 with positive refractive power. The sixth lens L6 and the seventh lens L7 are cemented together. Figure 10 From left to right, the graphs show the longitudinal spherical aberration, astigmatism, and distortion of the optical system 100 in the fifth embodiment.

[0158] The object-side surface S1 of the first lens L1 is convex near the optical axis 110, and the image-side surface S2 is concave near the optical axis 110.

[0159] The object-side surface S3 of the second lens L2 is concave near the optical axis 110, and the image-side surface S4 is concave near the optical axis 110.

[0160] The object-side surface S5 of the third lens L3 is concave near the optical axis 110, and the image-side surface S6 is convex near the optical axis 110.

[0161] The object-side surface S7 of the fourth lens L4 is convex at near the optical axis 110, and the image-side surface S8 is concave at near the optical axis 110.

[0162] The object-side surface S9 of the fifth lens L5 is concave near the optical axis 110, and the image-side surface S10 is convex near the optical axis 110.

[0163] The object-side surface S11 of the sixth lens L6 is convex near the optical axis 110, and the image-side surface S12 is convex near the optical axis 110.

[0164] The object-side surface S13 of the seventh lens L7 is concave near the optical axis 110, and the image-side surface S14 is convex near the optical axis 110.

[0165] The object-side surface S15 of the eighth lens L8 is convex at near the optical axis 110, and the image-side surface S16 is flat at near the optical axis 110.

[0166] In addition, the various parameters of the optical system 100 are given in Table 5, and the definitions of each parameter can be derived from the first embodiment, and will not be repeated here.

[0167] Table 5

[0168]

[0169]

[0170] In addition, by Figure 10As can be seen from the aberration diagram, the longitudinal spherical aberration, astigmatism, and distortion of the optical system 100 are well controlled, thus the optical system 100 of this embodiment has good imaging quality.

[0171] Sixth Embodiment

[0172] Please see Figure 11 and Figure 12 , Figure 11 The diagram below shows the structure of the optical system 100 in the sixth embodiment. The optical system 100 includes, from the object side to the image side, a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, an aperture STO, a fifth lens L5 with positive refractive power, a sixth lens L6 with positive refractive power, a seventh lens L7 with negative refractive power, and an eighth lens L8 with positive refractive power. The sixth lens L6 and the seventh lens L7 are cemented together. Figure 12 From left to right, the graphs show the longitudinal spherical aberration, astigmatism, and distortion of the optical system 100 in the sixth embodiment.

[0173] The object-side surface S1 of the first lens L1 is convex near the optical axis 110, and the image-side surface S2 is concave near the optical axis 110.

[0174] The object-side surface S3 of the second lens L2 is concave near the optical axis 110, and the image-side surface S4 is concave near the optical axis 110.

[0175] The object-side surface S5 of the third lens L3 is concave near the optical axis 110, and the image-side surface S6 is convex near the optical axis 110.

[0176] The object-side surface S7 of the fourth lens L4 is convex at near the optical axis 110, and the image-side surface S8 is convex at near the optical axis 110.

[0177] The object-side surface S9 of the fifth lens L5 is concave near the optical axis 110, and the image-side surface S10 is convex near the optical axis 110.

[0178] The object-side surface S11 of the sixth lens L6 is convex near the optical axis 110, and the image-side surface S12 is convex near the optical axis 110.

[0179] The object-side surface S13 of the seventh lens L7 is concave near the optical axis 110, and the image-side surface S14 is convex near the optical axis 110.

[0180] The object-side surface S15 of the eighth lens L8 is convex at near the optical axis 110, and the image-side surface S16 is convex at near the optical axis 110.

[0181] In addition, the various parameters of the optical system 100 are given in Table 6, and the definitions of each parameter can be derived from the first embodiment, and will not be repeated here.

[0182] Table 6

[0183]

[0184] In addition, by Figure 12 As can be seen from the aberration diagram, the longitudinal spherical aberration, astigmatism, and distortion of the optical system 100 are well controlled, thus the optical system 100 of this embodiment has good imaging quality.

[0185] Furthermore, the above embodiments satisfy the data in Table 7 below, and the effects that can be obtained by satisfying the following data can be obtained from the above description.

[0186] Table 7

[0187] First Embodiment Second Embodiment Third Embodiment Fourth embodiment Fifth Embodiment Sixth Embodiment f / EPD 1.399 1.400 1.401 1.400 1.399 1.398 f3*f4 / f(mm) 38.867 37.784 38.735 37.211 37.727 40.825 f5 / f 7.329 7.033 6.655 6.232 5.921 5.843 CT5 / |SAG52| 3.350 3.931 3.838 4.578 4.884 12.375 CT6 / CT7 2.049 2.709 2.109 2.075 1.550 2.714 (CT6+CT7) / T45 0.666 0.648 0.733 0.895 1.047 0.727 R11 / R12 5.231 5.191 4.766 4.896 4.816 4.871 2*ImgH / f 2.066 2.066 2.079 2.079 2.079 2.085 TTL / DOS 1.895 1.964 2.001 2.158 2.132 2.146 TTL / T45 6.149 6.112 6.253 6.847 7.140 6.633 CT8 / f 1.006 0.967 0.968 0.965 0.908 1.182

[0188] Please see Figure 13 In some embodiments, the optical system 100 can be assembled with the photosensitive element 210 to form an imaging module 200. In this case, the photosensitive surface of the photosensitive element 210 coincides with the imaging surface S19 of the optical system 100. The imaging module 200 may also be provided with a protective glass L9, which is disposed between the image-side surface S16 of the eighth lens L8 and the imaging surface S19. Specifically, the photosensitive element 210 can be a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor sensor (CMOS sensor). Using the above-described optical system 100 in the imaging module 200 can achieve both wide-angle and good optical performance, while also facilitating miniaturization design. When applied to automotive camera equipment, it can effectively improve driving safety performance.

[0189] Please see Figure 13 and Figure 14In some embodiments, the image-capturing module 200 can be applied to a terminal device 300, which includes a housing 310, and the image-capturing module 200 is disposed in the housing 310. Specifically, the terminal device 300 can be, but is not limited to, a mobile phone, video phone, smartphone, e-book reader, dashcam, or other vehicle-mounted camera device, or a wearable device such as a smartwatch. When the terminal device 300 is a smartphone, the housing 310 can be the mid-frame of the terminal device 300. When the terminal device 300 is a vehicle-mounted camera device, the housing 310 can be a component in the terminal device 300 that is fixed to a vehicle and used to mount the image-capturing module 200. Using the above-mentioned image-capturing module 200 in the terminal device 300 can balance wide-angle and good optical system, while also facilitating miniaturization design, thereby effectively improving driving safety performance and reducing the space occupied by the terminal device 300 in the vehicle, thus facilitating the installation of the terminal device 300 in the vehicle.

[0190] refer to Figure 15 In other embodiments, the terminal device 300 can also be a vehicle. The terminal device 300 includes a mounting component 310 and the aforementioned image-capturing module 200, with the image-capturing module 200 disposed on the mounting component 310. The terminal device 300 can be a land-based vehicle such as a car or train, a flying vehicle such as a drone, or other common vehicles capable of carrying people or goods. When the terminal device 300 is a car, the mounting component 310 for mounting the image-capturing module 200 can be an air intake grille, a rear trunk, a rearview mirror, etc. By employing the aforementioned image-capturing module 200, both wide-angle viewing and good optical performance can be achieved, thereby effectively improving the driving safety performance of the terminal device 300.

[0191] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0192] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An optical system, characterized in that, The optical system comprises eight lenses with refractive power, and the optical system includes, from the object side to the image side, the following components along the optical axis: A first lens with negative refractive power, wherein the object side of the first lens is convex near the optical axis and the image side is concave near the optical axis; A second lens with negative refractive power, wherein both the object-side and image-side surfaces of the second lens are concave near the optical axis; A third lens with positive refractive power, wherein the object side of the third lens is concave near the optical axis and the image side is convex near the optical axis; A fourth lens with positive refractive power, wherein the object-side surface of the fourth lens is convex near the optical axis; A fifth lens with positive refractive power, wherein the object-side surface of the fifth lens is concave near the optical axis and the image-side surface is convex near the optical axis; A sixth lens with positive refractive power, wherein both the object-side and image-side surfaces of the sixth lens are convex near the optical axis; A seventh lens with negative refractive power, wherein the object side of the seventh lens is concave near the optical axis and the image side is convex near the optical axis; An eighth lens with positive refractive power, wherein the object-side surface of the eighth lens is convex near the optical axis; And the optical system satisfies the following condition: 5≤TTL / T45≤8; 3≤CT5 / |SAG52|≤12.5; Wherein, TTL is the distance on the optical axis from the object side of the first lens to the imaging surface of the optical system, T45 is the distance on the optical axis from the image side of the fourth lens to the object side of the fifth lens, CT5 is the thickness of the fifth lens on the optical axis, and SAG52 is the sag of the image side of the fifth lens at the maximum effective aperture.

2. The optical system according to claim 1, characterized in that, The following conditions must be met: 35mm≤f3*f4 / f≤41mm; Wherein, f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, and f is the effective focal length of the optical system.

3. The optical system according to claim 1, characterized in that, The following conditions must be met: 5.5 ≤ f5 / f ≤ 7.5; Where f5 is the effective focal length of the fifth lens, and f is the effective focal length of the optical system.

4. The optical system according to claim 1, characterized in that, The following conditions must be met: 1.5≤CT6 / CT7≤3; and / or, 0.5 ≤ (CT6 + CT7) / T45 ≤ 1.05; and / or, 0.9≤CT8 / f≤1.2; Wherein, CT6 is the thickness of the sixth lens on the optical axis, CT7 is the thickness of the seventh lens on the optical axis, CT8 is the thickness of the eighth lens on the optical axis, and f is the effective focal length of the optical system.

5. The optical system according to claim 1, characterized in that, The following conditions must be met: 4.5≤R11 / R12≤5.3; Wherein, R11 is the radius of curvature of the object side of the first lens at the optical axis, and R12 is the radius of curvature of the image side of the first lens at the optical axis.

6. The optical system according to claim 1, characterized in that, The following conditions must be met: 2 ≤ 2 * ImgH / f ≤ 2.2; Where, ImgH is half the image height corresponding to the maximum field of view of the optical system, and f is the effective focal length of the optical system.

7. The optical system according to claim 1, characterized in that, The following conditions must be met: f / EPD≤1.5; Where f is the effective focal length of the optical system, and EPD is the entrance pupil diameter of the optical system.

8. The optical system according to claim 1, characterized in that, It also includes an aperture stop, which is disposed between the fourth lens and the fifth lens, and the optical system satisfies the following condition: 1.5 ≤ TTL / DOS ≤ 2.5; Wherein, DOS is the distance on the optical axis from the object side of the first lens to the aperture stop.

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

10. A terminal device, characterized in that, Includes the imaging module as described in claim 9.

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