Wide-angle optical system and camera module using the same

Abstract

The application provides a wide-angle optical system and an application camera module thereof, which are mainly composed of eight lenses. The first lens has negative optical power, the object side is a convex surface, and the image side is a concave surface. The second lens has negative optical power, and the image side is a concave surface. The third lens has optical power, the object side is a concave surface. The fourth lens has optical power, the image side is a convex surface. The fifth lens has optical power, the object side is a convex surface. The sixth lens has positive optical power, the object side is a convex surface, and the image side is a convex surface. The seventh lens has negative optical power, the object side is a concave surface. The eighth lens has positive optical power, and the image side is a concave surface. Through reasonable matching of the shapes and optical powers of the lenses, the application has the advantages of lightness, high pixels, large wide angle, small diameter, low cost, compact structure, easy processing and installation, good performance at high and low temperatures, and stable performance, and effectively meets the design requirements of large field of view and high resolution of the optical system.

Description

Technical Field

[0001] This application relates to the field of optics, and in particular to a camera module for a wide-angle optical system and its application. Background Technology

[0002] In recent years, with the advancement of technology and the development of mobile internet, people have been pursuing diversified imaging effects and optical lenses that can present good image quality over a wide field of view. Therefore, optical imaging lenses have developed rapidly and are now widely used in various fields such as smartphones, tablets, video conferencing, vehicle monitoring, security monitoring, and intelligent transportation systems. However, current imaging lenses on the market are no longer sufficient for use in complex environments such as vibration, high temperature, and high humidity. Therefore, designing and manufacturing wide-angle lenses that are lightweight, provide clear images, and maintain good and stable performance even in harsh environments is of great significance. Summary of the Invention

[0003] This application aims to provide a lightweight, high-image-quality wide-angle optical system with advantages such as high pixel count, wide angle, small aperture and low cost. It has a compact structure, is easy to process and install, and can maintain good and stable performance under high and low temperatures, thus meeting the needs of multiple fields.

[0004] A wide-angle optical system, consisting of a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens in sequence along the optical axis from the object plane to the image plane;

[0005] The first lens has negative optical power, and its object side is convex while its image side is concave.

[0006] The second lens has negative optical power, and its image-side surface is concave.

[0007] The third lens has optical power and its object side is concave.

[0008] The fourth lens has optical power and its image-side surface is convex.

[0009] The fifth lens has optical power and its object side is convex.

[0010] The sixth lens has positive optical power, and its object side is convex, and its image side is convex.

[0011] The seventh lens has negative optical power and its object side is concave.

[0012] The eighth lens has positive optical power and its image-side surface is concave.

[0013] The wide-angle optical system described above satisfies the following relationship: -3.0 <f234 / f678<3.0;

[0014] Where f234 is the effective combined focal length of the second, third, and fourth lenses, and f678 is the effective combined focal length of the sixth, seventh, and eighth lenses.

[0015] The wide-angle optical system described above satisfies the following relationship: |f² / f| < 8.0;

[0016] | f3 / f | < 7.0;

[0017] | f4 / f | < 5.0;

[0018] Where f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, and f4 is the effective focal length of the fourth lens.

[0019] The wide-angle optical system described above satisfies the following relationship: TTL / f < 12;

[0020] Where f is the effective focal length of the optical system, and TTL is the on-axis distance from the object side of the first lens to the imaging plane.

[0021] The wide-angle optical system described above satisfies the following relationship: 15.0 <TTL / EPD<23.0;

[0022] Where TTL is the axial distance from the object side of the first lens to the imaging plane, and EPD is the entrance pupil diameter of the optical system.

[0023] The wide-angle optical system described above satisfies the following relationship: |R11 / R12| < 4.5;

[0024] | R31 / R32 | < 3.3;

[0025] | R41 / R42 | < 2.5;

[0026] | R51 / R52 | < 2.7;

[0027] Wherein, R11 is the object-side radius of curvature of the first lens, R12 is the image-side radius of curvature of the first lens; R31 is the object-side radius of curvature of the third lens, R32 is the image-side radius of curvature of the third lens; R41 is the object-side radius of curvature of the fourth lens, R42 is the image-side radius of curvature of the fourth lens; R51 is the object-side radius of curvature of the fifth lens, R52 is the image-side radius of curvature of the fifth lens.

[0028] The wide-angle optical system described above satisfies the following relationships: nd1 > 1.7, vd1 < 50;

[0029] nd2 > 1.5, vd2 < 60;

[0030] nd3 > 1.5, vd3 < 40;

[0031] nd4 < 1.9, vd4 < 60;

[0032] nd5 < 1.7, vd5 < 65;

[0033] nd6 < 1.65, vd6 > 45;

[0034] nd7 < 1.7, vd7 < 40;

[0035] nd8 < 1.65, vd8 > 45;

[0036] Wherein, nd1 is the refractive index of the first lens, and vd1 is the Abbe number of the first lens; nd2 is the refractive index of the second lens, and vd2 is the Abbe number of the second lens; nd3 is the refractive index of the third lens, and vd3 is the Abbe number of the third lens; nd4 is the refractive index of the fourth lens, and vd4 is the Abbe number of the fourth lens; nd5 is the refractive index of the fifth lens, and vd5 is the Abbe number of the fifth lens; nd6 is the refractive index of the sixth lens, and vd6 is the Abbe number of the sixth lens; nd7 is the refractive index of the seventh lens, and vd7 is the Abbe number of the seventh lens; nd8 is the refractive index of the seventh lens, and vd8 is the Abbe number of the seventh lens.

[0037] The wide-angle optical system described above satisfies the following relationship: CT3 / ET3 < 2.0;

[0038] CT4 / ET4 < 4.0;

[0039] CT5 / ET5 < 3.0;

[0040] Wherein, CT3 is the center thickness of the third lens, ET3 is the edge thickness of the third lens; CT4 is the center thickness of the fourth lens, ET4 is the edge thickness of the fourth lens; CT5 is the center thickness of the fifth lens, ET5 is the edge thickness of the fifth lens.

[0041] The wide-angle optical system described above satisfies the following relationship: -3.0 < f*tan(FOV) / (DT1 / 2) < 0;

[0042] -6.0<f*tan(FOV) / (DT3 / 2)<-3.0;

[0043] Where f is the effective focal length of the optical system, FOV is half of the maximum field of view of the optical system, DT1 is the effective aperture of the object side of the first lens, and DT3 is the effective aperture of the object side of the third lens.

[0044] On the other hand, embodiments of this application also provide a camera module, which includes at least an optical lens, and the aforementioned wide-angle optical system is installed in the optical lens.

[0045] Compared with the prior art, the beneficial effects of this application are as follows:

[0046] This application provides a wide-angle optical system and its application camera module, which is mainly composed of 8 lenses. Through the reasonable combination of lens shape and optical power, it has the advantages of being lightweight, high-pixel, wide-angle, small-diameter and low-cost. It has a compact structure, is easy to process and install, and can maintain good performance and stable performance under high and low temperatures. It effectively meets the design requirements of optical systems for a large field of view and high resolution, and can meet the needs of multiple fields. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0048] Figure 1 This is a schematic diagram of the structure of the optical system or camera module in Embodiment 1 of this application;

[0049] Figure 2 These are the field curvature curve and f-θ distortion curve of the optical system or camera module in Embodiment 1 of this application;

[0050] Figure 3 This is a schematic diagram of the structure of the optical system or camera module in Embodiment 2 of this application;

[0051] Figure 4 These are the field curvature curve and f-θ distortion curve of the optical system or camera module in Embodiment 2 of this application;

[0052] Figure 5 This is a schematic diagram of the structure of the optical system or camera module in Embodiment 3 of this application;

[0053] Figure 6 These are the field curvature curve and f-θ distortion curve of the optical system or camera module in Embodiment 3 of this application. Detailed Implementation

[0054] like Figure 1-6 As shown, this application provides a wide-angle optical system, which is composed of a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens in sequence along the optical axis from the object plane to the image plane;

[0055] The first lens has negative optical power, and its object side is convex while its image side is concave.

[0056] The second lens has negative optical power, and its image-side surface is concave.

[0057] The third lens has a focal power, and its object side is concave;

[0058] The fourth lens has a focal power, and its image side is convex;

[0059] The fifth lens has a focal power, and its object side is convex;

[0060] The sixth lens has a positive focal power, its object side is convex, and its image side is convex;

[0061] The seventh lens has a negative focal power, and its object side is concave;

[0062] The eighth lens has a positive focal power, and its image side is concave.

[0063] The optical system according to the embodiment of the present invention mainly consists of eight lenses. Through reasonable matching of the lens shapes and focal powers, it has the advantages of being lightweight, high-pixel, large wide-angle, small aperture, and low cost. It has a compact structure, is convenient for processing and installation, can maintain good performance and stability at high and low temperatures, effectively meets the design requirements of a large field angle and high resolution of the optical system, and can be used in multiple fields.

[0064] Further, as a preferred embodiment of the present invention rather than a limitation, the optical system satisfies the following condition: TTL / f < 12, where f is the effective focal length of the optical imaging system, and TTL is the axial distance from the object side of the first lens to the imaging surface. By reasonably balancing the relationship between the effective focal length of the optical imaging system and TTL of the optical imaging system, while effectively compressing the size of the optical imaging system, the requirement of an ultra-large wide angle can be achieved.

[0065] Further, as a preferred embodiment of the present invention rather than a limitation, the optical system satisfies the following condition: 15.0 < TTL / EPD < 23.0; where TTL is the axial distance from the object side of the first lens to the imaging surface, and EPD is the entrance pupil diameter of the optical imaging lens. By effectively controlling the range of the ratio of TTL to the entrance pupil diameter of the optical imaging system, while increasing its light transmittance, the requirement of a smaller structural size can be met.

[0066] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, the optical system satisfies the following conditions: |R11 / R12|<4.5, |R31 / R32|<3.3, |R41 / R42|<2.5, |R51 / R52|<2.7, where R11 is the object-side radius of curvature of the first lens, R12 is the image-side radius of curvature of the first lens; R31 is the object-side radius of curvature of the third lens, R32 is the image-side radius of curvature of the third lens; R41 is the object-side radius of curvature of the fourth lens, R42 is the image-side radius of curvature of the fourth lens; R51 is the object-side radius of curvature of the fifth lens, and R52 is the image-side radius of curvature of the fifth lens. By controlling the relationship between the radii of curvature of the object-side and image-side surfaces, the astigmatism generated by each lens can be balanced, aberrations can be corrected, and the imaging quality of the optical system can be improved. Simultaneously, controlling the light angles between the lenses reduces ghosting between lenses, thereby improving ghosting.

[0067] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, the optical system satisfies the following conditions: nd1 > 1.7, vd1 < 50, nd2 > 1.5, vd2 < 60, nd3 > 1.5, vd3 < 40, nd4 < 1.9, vd4 < 60, nd5 < 1.7, vd5 < 65, nd6 < 1.65, vd6 > 45, nd7 < 1.7, vd7 < 40, nd8 < 1.65, vd8 > 45, where nd1 is the refractive index of the first lens, vd1 is the Abbe number of the first lens; nd2 is the refractive index of the second lens, vd2 is the Abbe number of the second lens; nd3 is the refractive index of the third lens, vd1 is the refractive index of the second lens, vd2 is the refractive index of the second lens, and nd3 is the refractive index of the third lens. The refractive indices of the lenses are specified, with vd3 being the Abbe number of the third lens; nd4 being the refractive index of the fourth lens and vd4 being the Abbe number of the fourth lens; nd5 being the refractive index of the fifth lens and vd5 being the Abbe number of the fifth lens; nd6 being the refractive index of the sixth lens and vd6 being the Abbe number of the sixth lens; nd7 being the refractive index of the seventh lens and vd7 being the Abbe number of the seventh lens; and nd8 being the refractive index of the seventh lens and vd8 being the Abbe number of the seventh lens. By rationally controlling the refractive indices and Abbe numbers of each lens, aberrations produced by the lens are corrected, and the lens's resolving power is improved. Furthermore, the stability of optical imaging performance under high and low temperatures is ensured to the greatest extent possible.

[0068] Further, as a preferred embodiment of the present invention rather than a limitation, the optical system satisfies the following conditions: |f2 / f| < 8.0, |f3 / f| < 7.0, |f4 / f| < 5.0. Here, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, and f4 is the effective focal length of the fourth lens. By limiting the ratio of the effective focal lengths of the second, third, and fourth lenses to the effective focal length of the optical system, a reasonable light deflection angle is obtained for the optical imaging system, effectively reducing the sensitivity to component tolerances and improving the quality of the optical imaging system.

[0069] Further, as a preferred embodiment of the present invention rather than a limitation, the optical system satisfies the following conditions: CT3 / ET3 < 2.0, CT4 / ET4 < 4.0, CT5 / ET5 < 3.0, where CT3 is the central thickness of the third lens, ET3 is the edge thickness of the third lens; CT4 is the central thickness of the fourth lens, ET4 is the edge thickness of the fourth lens; CT5 is the central thickness of the fifth lens, and ET5 is the edge thickness of the fifth lens. By controlling the relationship between the central thickness and the edge thickness of the third, fourth, and fifth lenses, the processing difficulty of each lens can be reasonably controlled, which is beneficial to the processing and molding of the lens and cost control. At the same time, the field curvature generated by the optical imaging system is controlled, which is beneficial to improving the imaging quality.

[0070] Further, as a preferred embodiment of the present invention rather than a limitation, the optical system satisfies the following conditions: -3.0 < f*tan(FOV) / (DT1 / 2) < 0, -6.0 < f*tan(FOV) / (DT3 / 2) < -3.0, where f is the effective focal length of the optical system, FOV is half of the maximum field angle of the imaging system of the optical system, DT1 is the effective aperture of the object side of the first lens, and DT3 is the effective aperture of the object side of the third lens. By effectively controlling the relationship between the focal length, half of the maximum field angle, and the lens aperture, the size of the system can be effectively compressed, the characteristics of a large wide angle can be achieved, and at the same time, the aperture of the optical imaging system can be effectively controlled. In addition, distortion can be effectively reduced and the optical imaging quality can be improved.

[0071] Further, as a preferred embodiment of the present invention rather than a limitation, the optical system satisfies the following conditions: -3.0 < f234 / f678 < 3.0; where f234 is the effective combined focal length of the second, third, and fourth lenses, and f678 is the effective combined focal length of the sixth, seventh, and eighth lenses. By controlling the combined focal length between the lenses within a reasonable range, the spherical aberration generated by the entire system can be balanced, and then the spherical aberration of the system can be controlled, which is beneficial to improving the imaging quality of the system.

[0072] Further, as a preferred embodiment rather than a limitation of the present invention, the optical system satisfies the following conditions: 3.5 < TTL / ImagH < 6.5; where TTL is the on-axis distance from the object side surface of the first lens to the imaging surface, and ImagH is half of the diagonal length of the effective pixel area on the imaging surface. By controlling the relationship between the total length of the optical system and the imaging area, it is beneficial to increase the field of view angle and at the same time miniaturize the high-pixel wide-angle lens. Specific embodiments:

[0074] Embodiment 1

[0075] The following refers to Figures 1 to 2 Describe the optical imaging lens according to Embodiment 1 of the present application. Figure 1 Fig. shows a schematic structural diagram of the optical imaging lens according to Embodiment 1 of the present application.

[0076] As Figure 1 shown, the optical imaging lens according to an exemplary embodiment of the present application sequentially includes, from the object side to the image side along the optical axis: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, an aperture STO, a sixth lens E6, a seventh lens E7, an eighth lens E8, a filter E9, and an imaging surface S19.

[0077] The first lens E1 has a negative optical power, its object side surface S1 is convex, and its image side surface S2 is concave. The second lens E2 has a negative optical power, its object side surface S3 is convex, and its image side surface S4 is concave. The third lens E3 has a negative optical power, its object side surface S5 is concave, and its image side surface S6 is convex. The fourth lens E4 has a positive optical power, its object side surface S7 is convex, and its image side surface S8 is convex. The fifth lens E5 has a negative optical power, its object side surface S9 is convex, and its image side surface S10 is concave. The sixth lens E6 has a positive optical power, its object side surface S12 is convex, and its image side surface S13 is convex. The seventh lens E7 has a negative optical power, its object side surface S13 is concave, and its image side surface S14 is convex. The eighth lens E8 has a positive optical power, its object side surface S15 is convex, and its image side surface S16 is concave. The filter E9 has an object side surface S17 and an image side surface S18. Light from the object sequentially passes through each surface S1 to S18 and finally forms an image on the imaging surface S19.

[0078] Table 1 shows the surface types, radii of curvature, thicknesses, and materials of the lenses of the optical imaging lens of Embodiment 1, where the units of the radii of curvature and thicknesses are both millimeters (mm).

[0079] Table 1

[0080]

[0081] In Table 1, the object-side surface and image-side surface of any one of the following lenses—second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, seventh lens E7, and eighth lens E8—are aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formulas:

[0082]

[0083] Where x is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the vertex of the aspherical surface, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspherical surface shape formula. Table 2 gives the conic coefficients and higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 of each aspherical surface that can be used in the first embodiment.

[0084] Table 2

[0085]

[0086] Example 2

[0087] The following is for reference Figures 3 to 4 Describes an optical imaging lens according to Embodiment 2 of this application. Figure 3 A schematic diagram of the structure of an optical imaging lens according to Embodiment 2 of this application is shown.

[0088] like Figure 3 As shown, the optical imaging lens according to an exemplary embodiment of this application includes, in sequence along the optical axis from the object side to the image side: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, an aperture stop STO, a sixth lens E6, a seventh lens E7, a seventh lens E8, a filter E9, and an imaging surface S19.

[0089] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative optical power, with its object-side surface S3 being concave and its image-side surface S4 being concave. The third lens E3 has negative optical power, with its object-side surface S5 being concave and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens E6 has positive optical power, with its object-side surface S12 being convex and its image-side surface S13 being convex. The seventh lens E7 has negative optical power, with its object-side surface S13 being concave and its image-side surface S14 being concave. The eighth lens E8 has positive optical power, with its object-side surface S15 being convex and its image-side surface S16 being concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes sequentially through each surface S1 to S18 and is finally imaged onto the imaging surface S19.

[0090] Table 3 shows the surface type, radius of curvature, thickness, and material of each lens in the optical imaging lens of Example 2, wherein the units for radius of curvature and thickness are millimeters (mm).

[0091] Table 3

[0092]

[0093] In Table 3, the object-side surface and image-side surface of any one of the following lenses—E2, E3, E5, E6, E7, and E8—are aspherical. The surface shape of this aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0094]

[0095] Where x is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the vertex of the aspherical surface, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspherical surface shape formula. Table 4 gives the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, and A16 for each aspherical surface that can be used in the second embodiment.

[0096] Table 4

[0097]

[0098] Example 3

[0099] The following is for reference Figures 5 to 6 Describes an optical imaging lens according to Embodiment 3 of this application. Figure 5 A schematic diagram of the structure of an optical imaging lens according to Embodiment 3 of this application is shown.

[0100] like Figure 5 As shown, the optical imaging lens according to an exemplary embodiment of this application includes, in sequence along the optical axis from the object side to the image side: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, an aperture stop STO, a sixth lens E6, a seventh lens E7, a seventh lens E8, a filter E9, and an imaging surface S19.

[0101] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative optical power, with its object-side surface S3 being concave and its image-side surface S4 being concave. The third lens E3 has negative optical power, with its object-side surface S5 being concave and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens E6 has positive optical power, with its object-side surface S12 being convex and its image-side surface S13 being convex. The seventh lens E7 has negative optical power, with its object-side surface S13 being concave and its image-side surface S14 being concave. The eighth lens E8 has positive optical power, with its object-side surface S15 being convex and its image-side surface S16 being concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes sequentially through each surface S1 to S18 and is finally imaged onto the imaging surface S19.

[0102] Table 5 shows the surface type, radius of curvature, thickness, and material of each lens in the optical imaging lens of Example 3, wherein the units for radius of curvature and thickness are millimeters (mm).

[0103] Table 5

[0104]

[0105] In Table 5, the object-side surface and image-side surface of any one of the following lenses—E2, E3, E5, E6, E7, and E8—are aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formulas:

[0106]

[0107] Where x is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the vertex of the aspherical surface, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspherical surface shape formula. Table 6 gives the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, and A16 for each aspherical surface that can be used in the first embodiment.

[0108] Table 6

[0109]

[0110] In Examples 1-3, each conditional expression satisfies the conditions in the table below:

[0111] Table 7

[0112]

[0113] A camera module includes at least an optical lens, in which the aforementioned wide-angle optical system is installed. It has the advantages of being lightweight, high-pixel, wide-angle, small-diameter, and low-cost. It has a compact structure, is easy to process and install, and can maintain good performance and stable performance at high and low temperatures. It effectively meets the design requirements of a large field of view and high resolution of the optical system and can meet the needs of multiple fields.

[0114] The above description provides one or more embodiments in conjunction with specific content, and does not imply that the specific implementation of the present invention is limited to these descriptions. Any methods or structures that are similar to or identical to those of the present invention, or any technical deductions or substitutions made based on the concept of the present invention, should be considered within the scope of protection of the present invention.

Claims

1. A wide-angle optical system, comprising, sequentially from the object plane to the image plane, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens, characterized in that: The first lens has negative optical power, and its object side is convex while its image side is concave. The second lens has negative optical power, and its object side is concave, as is its image side; The third lens has negative optical power, and its object side is concave, as is its image side; The fourth lens has positive optical power, and its object side is convex, as is its image side; The fifth lens has positive optical power, and its object side is convex, as is its image side; The sixth lens has positive optical power, and its object side is convex, and its image side is convex. The seventh lens has negative optical power, and its object side is concave, as is its image side; The eighth lens has positive optical power, and its object side is convex and its image side is concave. The optical system satisfies the following relationship: -3.0 < f234 / f678 ≤ -0.49; 17.19≤TTL / EPD < 23.0; 3.5 < TTL / ImagH < 6.5; -8.0 < f² / f ≤ -6.01; -2.84≤f³ / f<0; 2.29 ≤ f4 / f ≤ 2.43; -4.82≤f *tan(FOV) / (DT3 / 2)<-3.0; Where f234 is the effective combined focal length of the second, third, and fourth lenses, f678 is the effective combined focal length of the sixth, seventh, and eighth lenses, f is the effective focal length of the optical system, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, FOV is half of the maximum field of view of the optical system, and DT3 is the effective aperture of the object side of the third lens.

2. The wide-angle optical system according to claim 1, characterized in that: The optical system satisfies the following relationship: TTL / f < 12; Where f is the effective focal length of the optical system, and TTL is the on-axis distance from the object side of the first lens to the imaging plane.

3. The wide-angle optical system according to claim 1, characterized in that: The optical system satisfies the following relationship: |R11 / R12| < 4.5; | R31 / R32 | < 3.3; | R41 / R42 | < 2.5; | R51 / R52 | < 2.7; Wherein, R11 is the object-side radius of curvature of the first lens, R12 is the image-side radius of curvature of the first lens; R31 is the object-side radius of curvature of the third lens, R32 is the image-side radius of curvature of the third lens; R41 is the object-side radius of curvature of the fourth lens, R42 is the image-side radius of curvature of the fourth lens; R51 is the object-side radius of curvature of the fifth lens, R52 is the image-side radius of curvature of the fifth lens.

4. The wide-angle optical system according to claim 1, characterized in that: The optical system satisfies the following relationship: nd1 > 1.7, vd1 < 50; nd2 > 1.5, vd2 < 60; nd3 > 1.5, vd3 < 40; nd4 < 1.9, vd4 < 60; nd5 < 1.7, vd5 < 65; nd6 < 1.65, vd6 > 45; nd7 < 1.7, vd7 < 40; nd8 < 1.65, vd8 > 45; Wherein, nd1 is the refractive index of the first lens, and vd1 is the Abbe number of the first lens; nd2 is the refractive index of the second lens, and vd2 is the Abbe number of the second lens; nd3 is the refractive index of the third lens, and vd3 is the Abbe number of the third lens; nd4 is the refractive index of the fourth lens, and vd4 is the Abbe number of the fourth lens; nd5 is the refractive index of the fifth lens, and vd5 is the Abbe number of the fifth lens; nd6 is the refractive index of the sixth lens, and vd6 is the Abbe number of the sixth lens; nd7 is the refractive index of the seventh lens, and vd7 is the Abbe number of the seventh lens; nd8 is the refractive index of the seventh lens, and vd8 is the Abbe number of the seventh lens.

5. The wide-angle optical system according to claim 1, characterized in that: The optical system satisfies the following relationship: CT3 / ET3 < 2.0; CT4 / ET4 < 4.0; CT5 / ET5 < 3.0; Wherein, CT3 is the center thickness of the third lens, ET3 is the edge thickness of the third lens; CT4 is the center thickness of the fourth lens, ET4 is the edge thickness of the fourth lens; CT5 is the center thickness of the fifth lens, ET5 is the edge thickness of the fifth lens.

6. The wide-angle optical system according to claim 1, characterized in that: The optical system satisfies the following relationship: -3.0 < f*tan(FOV) / (DT1 / 2) < 0; Where f is the effective focal length of the optical system, FOV is half of the maximum field of view of the optical system, and DT1 is the effective aperture of the object side of the first lens.

7. A camera module, comprising at least an optical lens, characterized in that: The optical lens is equipped with a wide-angle optical system as described in any one of claims 1-6.

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