An eight-element large-aperture high-megapixel imaging lens

Abstract

The present invention relates to an eight-element large-aperture high-pixel imaging lens, which sequentially includes, from the object side to the image side: 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; the eight-element large-aperture high-pixel imaging lens satisfies the following relational expression: ImgH / Fno > 3.55; wherein, ImgH is half of the length of the diagonal of the effective imaging area of the eight-element large-aperture high-pixel imaging lens, and Fno is the aperture number of the eight-element large-aperture high-pixel imaging lens. The eight-element large-aperture high-pixel imaging lens of the present invention has high imaging quality, is thin and light in volume, and has the characteristics of a large aperture.

Description

Technical Field

[0001] The present invention relates to the technical field of optical imaging lenses, and in particular to an eight-element large aperture high-pixel imaging lens. Background Art

[0002] In recent years, with the rise of smart phones, the demand for miniaturized camera lenses has been increasing. The photosensitive devices of general camera lenses are nothing more than photosensitive coupled devices or complementary metal oxide semiconductor devices. Due to the improvement of semiconductor manufacturing process technology, the pixel size of photosensitive devices has been reduced. In addition, the current development trend of electronic products is to have good functions and a thin and light appearance. Therefore, miniaturized camera lenses with good imaging quality have become the mainstream in the current market.

[0003] To obtain better imaging quality, the traditional lens mounted on mobile phone cameras mostly adopts four-piece, five-piece, and six-piece lens structures. With the development of technology and the increase of diversified user needs, the pixel area of ​​photosensitive devices continues to shrink, and the system's requirements for imaging quality continue to increase. More lens structures, such as eight-piece structures, are also used in mobile electronic products.

[0004] Although the image quality of the existing eight-element imaging lens is better than that of the general five-element or six-element lens, its volume is relatively large and cannot meet the requirements for thin lenses. In addition, a large aperture is conducive to increasing light flux, and a large field of view is gradually becoming a market trend. The aperture and field of view of the existing eight-element imaging lens cannot meet the growing market demand. Summary of the invention

[0005] The object of the present invention is to provide an eight-element large aperture high pixel imaging lens, which has high imaging quality, is light and thin, and has the characteristics of a large aperture.

[0006] An eight - element large - aperture high - pixel imaging lens, which sequentially includes from the object side to the image side: a first lens, which has a positive refractive power, the object - side surface of the first lens is convex near the optical axis, and the image - side surface is concave near the optical axis; a second lens, which has a negative refractive power, the object - side surface of the second lens is convex near the optical axis, and the image - side surface is concave near the optical axis; a third lens, which has a positive refractive power, the object - side surface of the third lens is convex near the optical axis, and the image - side surface is convex near the optical axis; a fourth lens, which has a negative refractive power, the image - side surface of the fourth lens is concave near the optical axis; a fifth lens, the object - side surface of which is concave near the optical axis, and the image - side surface is convex near the optical axis; a sixth lens, which has a negative refractive power, the object - side surface of the sixth lens is convex near the optical axis, and the image - side surface is concave near the optical axis; a seventh lens, which has a positive refractive power, the object - side surface of the seventh lens is convex near the optical axis, and the image - side surface is concave near the optical axis; an eighth lens, which has a negative refractive power, the object - side surface of the eighth lens is concave near the optical axis, and the image - side surface is concave near the optical axis; the eight - element large - aperture high - pixel imaging lens satisfies the following relationship: ImgH / Fno>3.55; where ImgH is half of the length of the diagonal of the effective imaging area of the eight - element large - aperture high - pixel imaging lens, and Fno is the f - number of the eight - element large - aperture high - pixel imaging lens. By controlling the ratio of ImgH to Fno, it can be ensured that the lens has a large aperture and a large image plane.

[0007] Furthermore, the eight - element large - aperture high - pixel imaging lens satisfies the relationship: TTL / ImgH<1.58; where TTL is the distance from the object - side surface of the first lens at the paraxial position to the image plane, and ImgH is half of the length of the diagonal of the effective imaging area of the eight - element large - aperture high - pixel imaging lens. Satisfying the above relationship can ensure that the lens has a large image plane and is thin - type.

[0008] Furthermore, the eight - element large - aperture high - pixel imaging lens satisfies the relationship: 3.43<CT3 / T34≤6.15; where CT3 is the maximum thickness of the third lens on the optical axis, and T34 is the distance between the third lens and the fourth lens on the optical axis. Satisfying the above relationship can appropriately distribute the distance between the lenses, reduce the total length of the camera lens, and reduce the assembly difficulty of the lens, enabling the assembly process to proceed smoothly and simply.

[0009] Furthermore, the eight - element large - aperture high - pixel imaging lens satisfies the relationship: - 14.55<f6 / f<-2.17; where f6 is the focal length of the sixth lens, and f is the focal length of the eight - element large - aperture high - pixel imaging lens. Satisfying the above relationship can avoid excessive optical power of the sixth lens, reduce the sensitivity of the lens, improve the imaging quality, and at the same time make the lens have a shorter optical length.

[0010] Further, the eight-element large-aperture high-pixel imaging lens satisfies the relationship: SAG81 / CT8 ≤ 2.92; where SAG81 is the distance from the intersection of the object-side surface of the eighth lens and the optical axis to the vertex of the effective semi-aperture of the object-side surface of the eighth lens on the optical axis, and CT8 is the maximum thickness of the eighth lens on the optical axis. Satisfying the above relationship can effectively reduce the manufacturing difficulty, reduce the total length of the camera lens, and reduce the assembly difficulty of the camera lens, enabling the assembly process to proceed smoothly and simply.

[0011] Further, the eight-element large-aperture high-pixel imaging lens satisfies the relationship: -23.66 < f4 / f < -9.72; where f4 is the focal length of the fourth lens, and f is the focal length of the eight-element large-aperture high-pixel imaging lens. Satisfying the above relationship can prevent the optical power of the fourth lens from being too large, resulting in low sensitivity and good imaging quality of the optical imaging lens, while also making the lens have a shorter optical length.

[0012] Further, the eight-element large-aperture high-pixel imaging lens satisfies the relationship: -2.06 < R32 / R31 < -0.24; where R31 is the radius of curvature of the object-side surface of the third lens, and R32 is the radius of curvature of the image-side surface of the third lens. Satisfying the above relationship can effectively balance astigmatism and coma, resulting in better imaging quality of the lens.

[0013] Further, the eight-element large-aperture high-pixel imaging lens satisfies the relationship: 0.46 < R62 / R61 < 0.87; where R61 is the radius of curvature of the object-side surface of the sixth lens, and R62 is the radius of curvature of the image-side surface of the sixth lens. Satisfying the above relationship can effectively balance astigmatism and coma, resulting in better imaging quality of the lens.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: By adopting an eight-element lens combination and reasonable bending force matching, while ensuring high imaging quality of the lens, the overall length of the lens is effectively shortened, enabling the lens to meet the requirement of being thin. The reasonable parameter matching between each lens makes the lens have the characteristics of a large aperture, meeting the shooting needs of people in low-light environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic structural diagram of the first embodiment of the eight-element large-aperture high-pixel imaging lens of the present invention.

[0016] Figure 2 It is an astigmatism and distortion curve diagram of the first embodiment of the eight-element large-aperture high-pixel imaging lens of the present invention.

[0017] Figure 3 It is a spherical aberration curve diagram of the first embodiment of the eight-element large-aperture high-pixel imaging lens of the present invention.

[0018] Figure 4 Schematic diagram of the structure of the second embodiment of the eight - element large - aperture high - pixel imaging lens of the present invention.

[0019] Figure 5 Astigmatism and distortion curve graphs of the second embodiment of the eight - element large - aperture high - pixel imaging lens of the present invention.

[0020] Figure 6 Spherical aberration curve graph of the second embodiment of the eight - element large - aperture high - pixel imaging lens of the present invention.

[0021] Figure 7 Schematic diagram of the structure of the third embodiment of the eight - element large - aperture high - pixel imaging lens of the present invention.

[0022] Figure 8 Astigmatism and distortion curve graphs of the third embodiment of the eight - element large - aperture high - pixel imaging lens of the present invention.

[0023] Figure 9 Spherical aberration curve graph of the third embodiment of the eight - element large - aperture high - pixel imaging lens of the present invention.

[0024] Figure 10 Schematic diagram of the structure of the fourth embodiment of the eight - element large - aperture high - pixel imaging lens of the present invention.

[0025] Figure 11 Astigmatism and distortion curve graphs of the fourth embodiment of the eight - element large - aperture high - pixel imaging lens of the present invention.

[0026] Figure 12 Spherical aberration curve graph of the fourth embodiment of the eight - element large - aperture high - pixel imaging lens of the present invention.

[0027] Figure 13 Schematic diagram of the structure of the fifth embodiment of the eight - element large - aperture high - pixel imaging lens of the present invention.

[0028] Figure 14 Astigmatism and distortion curve graphs of the fifth embodiment of the eight - element large - aperture high - pixel imaging lens of the present invention.

[0029] Figure 15 Spherical aberration curve graph of the fifth embodiment of the eight - element large - aperture high - pixel imaging lens of the present invention. Specific embodiments

[0030] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0031] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0032] In the description of the present invention, the object side refers to the side of the lens facing the object to be photographed, and the image side refers to the side of the lens facing the imaging surface. When a tangent plane is made at any point on the surface passing through the object side surface of the lens, the surface is always on the image side of the tangent plane, and its radius of curvature is positive, then the object side surface of the lens is a convex surface; otherwise, the object side surface of the lens is a concave surface, and its radius of curvature is negative.

[0033] When a tangent plane is made at any point on the surface passing through the image side surface of the lens, the surface is always on the object side of the tangent plane, and its radius of curvature is negative, then the image side surface of the lens is a convex surface; otherwise, the image side surface of the lens is a concave surface, and its radius of curvature is positive.

[0034] If a tangent plane is made at any point on the surface passing through the object side surface or the image side surface of the lens, and the surface has a part on the image side of the tangent plane and a part on the object side of the tangent plane, then there is an inflection point on the surface. The above method for judging the convexity and concavity of the object side and image side surfaces near the optical axis is still applicable.

[0035] In addition, the aspheric curve equations of each lens are expressed as follows:

[0036]

[0037] Wherein, Z is the distance sag from the origin of the aspheric surface when the aspheric surface is at a position with a height of r along the optical axis direction, c is the paraxial curvature of the aspheric surface (the radius of curvature R = 1 / c, that is, the reciprocal of the curvature); k is the conic coefficient; Ai is the i-th order coefficient of the aspheric surface. The high-order coefficients applied in the present invention are A4, A6, A8, A10, A12, A14, A16.

[0038] Please refer to Figure 1 , in the first embodiment, the eight-element large-aperture high-pixel imaging lens of the present invention sequentially includes a diaphragm 10, a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, a fifth lens 15, a sixth lens 16, a seventh lens 17, an eighth lens 18, and a filter 19 from the object side to the image side. Among them, there is a spacing distance between two adjacent lenses, and there is no relative movement between the lenses. The object side surfaces and image side surfaces of the first lens 11, the second lens 12, the third lens 13, the fourth lens 14, the fifth lens 15, the sixth lens 16, the seventh lens 17, and the eighth lens 18 are all aspheric surfaces.

[0039] Specifically, the first lens 11 has a positive refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is concave near the optical axis. The second lens 12 has a negative refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is concave near the optical axis. The third lens 13 has a positive refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis. The fourth lens 14 has a negative refractive power. Its object-side surface can be set as convex or concave according to actual needs near the optical axis, and its image-side surface is concave near the optical axis. The refractive power of the fifth lens 15 can be set according to actual needs, which is not limited in this embodiment. The object-side surface of the fifth lens 15 is concave near the optical axis, and its image-side surface is convex near the optical axis. The sixth lens 16 has a negative refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is concave near the optical axis. The seventh lens 17 has a positive refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is concave near the optical axis. The eighth lens 18 has a negative refractive power. Its object-side surface is concave near the optical axis, and its image-side surface is concave near the optical axis.

[0040] In the above structure, the object-side surface of the first lens 11 is convex, with a positive refractive power configuration, and the object-side surface of the first lens 11 is convex near the optical axis, which can effectively balance the low-order aberrations. The second lens 12 has a negative refractive power, which is beneficial to eliminating the aberrations generated by the first lens 11. The third lens 13 has a positive refractive power, the fourth lens 14 has a negative refractive power, the sixth lens 16 has a negative refractive power, and the seventh lens 17 has a positive refractive power, which can effectively correct the paraxial spherical aberration and reduce the astigmatism field curvature at the periphery at the same time. The eighth lens 18 has a negative refractive power and its image-side surface is concave near the optical axis, which helps to move the principal point of the optical imaging system away from the image-side end, thereby effectively shortening the overall length of the optical imaging system, being beneficial to the miniaturization of the system, and at the same time can correct the off-axis aberration to improve the peripheral imaging quality.

[0041] The above eight-element large-aperture high-pixel imaging lens satisfies the following relationship: ImgH / Fno > 3.55; where ImgH is half of the length of the diagonal of the effective imaging area of the eight-element large-aperture high-pixel imaging lens, and Fno is the f-number of the eight-element large-aperture high-pixel imaging lens. By controlling the ratio of ImgH to Fno, it can be ensured that the lens has a large aperture and a large image plane.

[0042] Preferably, the above eight-element large-aperture high-pixel imaging lens satisfies the relationship: TTL / ImgH < 1.58; where TTL is the distance from the object-side surface of the first lens 11 at the paraxial position to the image plane, and ImgH is half of the length of the diagonal of the effective imaging area of the eight-element large-aperture high-pixel imaging lens. Satisfying the above relationship can ensure that the lens has a large image plane and is thin.

[0043] Preferably, the above eight-element large-aperture high-pixel imaging lens satisfies the relationship: 3.43 < CT3 / T34 ≤ 6.15; where CT3 is the maximum thickness of the third lens 13 on the optical axis, and T34 is the distance between the third lens 13 and the fourth lens 14 on the optical axis. Satisfying the above relationship can appropriately distribute the distance between the lenses, reduce the total length of the camera lens, and reduce the assembly difficulty of the lens, enabling the assembly process to proceed smoothly and simply.

[0044] Preferably, the above eight-element large-aperture high-pixel imaging lens satisfies the relationship: -14.55 < f6 / f < -2.17; where f6 is the focal length of the sixth lens 16, and f is the focal length of the eight-element large-aperture high-pixel imaging lens. Satisfying the above relationship can avoid excessive optical power of the sixth lens 16, reduce the sensitivity of the lens, improve the imaging quality, and at the same time make the lens have a shorter optical length.

[0045] Preferably, the above eight-element large-aperture high-pixel imaging lens satisfies the relationship: SAG81 / CT8 ≤ 2.92; where SAG81 is the distance from the intersection of the object-side surface of the eighth lens 18 and the optical axis to the vertex of the effective semi-aperture of the object-side surface of the eighth lens 18 on the optical axis, and CT8 is the maximum thickness of the eighth lens 18 on the optical axis. Satisfying the above relationship can effectively reduce the manufacturing difficulty, reduce the total length of the camera lens, and reduce the assembly difficulty of the camera lens, enabling the assembly process to proceed smoothly and simply.

[0046] Preferably, the above eight-element large-aperture high-pixel imaging lens satisfies the relationship: -23.66 < f4 / f < -9.72; where f4 is the focal length of the fourth lens 14, and f is the focal length of the eight-element large-aperture high-pixel imaging lens. Satisfying the above relationship can avoid excessive optical power of the fourth lens 14, make the sensitivity of the optical imaging lens low and the imaging quality good, and at the same time make the lens have a shorter optical length.

[0047] Preferably, the above eight-element large-aperture high-pixel imaging lens satisfies the relationship: -2.06 < R32 / R31 < -0.24; where R31 is the radius of curvature of the object-side surface of the third lens 13, and R32 is the radius of curvature of the image-side surface of the third lens 13. Satisfying the above relationship can effectively balance astigmatism and coma, making the imaging quality of the lens better.

[0048] Preferably, the above eight-element large-aperture high-pixel imaging lens satisfies the relationship: 0.46 < R62 / R61 < 0.87; where R61 is the radius of curvature of the object-side surface of the sixth lens 16, and R62 is the radius of curvature of the image-side surface of the sixth lens 16. Satisfying the above relationship can effectively balance astigmatism and coma, making the imaging quality of the lens better.

[0049] The eight - element large - aperture high - pixel imaging lens of the present invention will be described in detail through the following specific embodiments in conjunction with the accompanying drawings.

[0050] First Embodiment

[0051] Please refer to Figure 2 and Figure 3 , in the first embodiment, the eight - element large - aperture high - pixel imaging lens satisfies Table 1 - 1, Table 1 - 2, and Table 1 - 3.

[0052] Table 1 - 1 shows the basic parameters of the eight - element large - aperture high - pixel imaging lens in the first embodiment:

[0053]

[0054]

[0055] Table 1 - 2 shows the aspherical coefficients of each lens in the first embodiment:

[0056]

[0057] Table 1 - 3 shows the values of each conditional expression in the first embodiment:

[0058]

[0059]

[0060] Second Embodiment

[0061] Please refer to Figures 4 to 6 . The eight - element large - aperture high - pixel imaging lens in this embodiment includes, in order from the object side to the image side, a first lens 21, a second lens 22, a third lens 23, a fourth lens 24, a fifth lens 25, a sixth lens 26, a seventh lens 27, and an eighth lens 28. Specifically, a diaphragm 20 is provided on the object - side surface of the first lens 21, and a filter 29 is provided on the image - side of the eighth lens 28.

[0062] It should be understood that the eight - element large - aperture high - pixel imaging lens in the second embodiment satisfies the bending force, surface concavity and convexity, and each expression in the above - mentioned first embodiment, which will not be elaborated here.

[0063] In the second embodiment, the eight - element large - aperture high - pixel imaging lens satisfies Table 2 - 1, Table 2 - 2, and Table 2 - 3.

[0064] Table 2 - 1 shows the basic parameters of the eight - element large - aperture high - pixel imaging lens in the second embodiment:

[0065]

[0066] Table 2-2 shows the aspherical coefficients of each lens in the second embodiment:

[0067]

[0068]

[0069] Table 2-3 shows the values of each conditional expression in the second embodiment:

[0070]

[0071] Third Embodiment

[0072] Please refer to Figures 4 to 6 , the eight-element large-aperture high-pixel imaging lens of this embodiment includes, in order from the object side to the image side, a first lens 31, a second lens 32, a third lens 33, a fourth lens 34, a fifth lens 35, a sixth lens 36, a seventh lens 37, and an eighth lens 38. Specifically, a diaphragm 30 is provided on the object-side surface of the first lens 31, and a filter 39 is provided on the image side of the eighth lens 38.

[0073] It should be understood that the eight-element large-aperture high-pixel imaging lens in the third embodiment satisfies the bending force, surface concavity and convexity, and each expression in the above first embodiment, which will not be elaborated here.

[0074] In the third embodiment, the eight-element large-aperture high-pixel imaging lens satisfies Table 3-1, Table 3-2, and Table 3-3.

[0075] Table 3-1 shows the basic parameters of the eight-element large-aperture high-pixel imaging lens in the third embodiment:

[0076]

[0077]

[0078] Table 3-2 shows the aspherical coefficients of each lens in the third embodiment:

[0079]

[0080] Table 3-3 shows the values of each conditional expression in the third embodiment:

[0081]

[0082] Fourth Embodiment

[0083] Fourth Embodiment

[0084] Please refer to Figures 10 to 12, the eight - element large - aperture high - pixel imaging lens of this embodiment sequentially includes a first lens 41, a second lens 42, a third lens 43, a fourth lens 44, a fifth lens 45, a sixth lens 46, a seventh lens 47, and an eighth lens 48 from the object side to the image side. Specifically, when implemented, a diaphragm 40 is provided on the object - side surface of the first lens 41, and a filter 49 is provided on the image - side of the eighth lens 48.

[0085] It should be understood that the eight - element large - aperture high - pixel imaging lens in the fourth embodiment satisfies the bending force, surface unevenness, and each expression in the above - mentioned first embodiment, and will not be elaborated here.

[0086] In the fourth embodiment, the eight - element large - aperture high - pixel imaging lens satisfies Table 4 - 1, Table 4 - 2, and Table 4 - 3.

[0087] Table 4 - 1 shows the basic parameters of the eight - element large - aperture high - pixel imaging lens in the fourth embodiment:

[0088]

[0089] Table 4 - 2 shows the aspherical coefficients of each lens in the fourth embodiment:

[0090]

[0091]

[0092] Table 4 - 3 shows the values of each conditional expression in the fourth embodiment:

[0093]

[0094] The Fifth Embodiment

[0095] Please combine Figures 13 to 15 , the eight - element large - aperture high - pixel imaging lens of this embodiment sequentially includes a first lens 51, a second lens 52, a third lens 53, a fourth lens 54, a fifth lens 55, a sixth lens 56, a seventh lens 57, and an eighth lens 58 from the object side to the image side. Specifically, when implemented, a diaphragm 50 is provided on the object - side surface of the first lens 51, and a filter 59 is provided on the image - side of the eighth lens 58.

[0096] It should be understood that the eight - element large - aperture high - pixel imaging lens in the fifth embodiment satisfies the bending force, surface unevenness, and each expression in the above - mentioned first embodiment, and will not be elaborated here.

[0097] In the fifth embodiment, the eight - element large - aperture high - pixel imaging lens satisfies Table 5 - 1, Table 5 - 2, and Table 5 - 3.

[0098] Table 5 - 1 shows the basic parameters of the eight - element large - aperture high - pixel imaging lens in the fifth embodiment:

[0099]

[0100]

[0101] Table 5-2 shows the aspherical coefficients of each lens in the fifth embodiment:

[0102]

[0103] Table 5-3 shows the values of each conditional expression in the fifth embodiment:

[0104]

[0105] To facilitate the comparison of the above five embodiments, the following table summarizes the values obtained by each expression under the corresponding conditions of each embodiment:

[0106]

[0107]

[0108] The eight-piece large-aperture high-pixel imaging lens in the above embodiments adopts an eight-piece lens combination. Through reasonable matching of the bending forces, while ensuring high imaging quality of the lens, the overall length of the lens is effectively shortened, so that the lens meets the requirement of being thin. The reasonable parameter matching between each lens makes the lens have the characteristics of a large aperture and meets the shooting requirements of people in low-light environments.

[0109] In the description of the present invention, it should be understood that terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0110] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0111] Although the description of the present invention is made in conjunction with the above specific embodiments, it is obvious that those skilled in the art can make many substitutions, modifications and variations based on the above content. Therefore, all such substitutions, improvements and variations are included within the spirit and scope of the appended claims.

Claims

1. An eight-piece large-aperture high-pixel imaging lens, characterized in that, From the object side to the image side, it includes in sequence: The first lens, which has a positive refractive power. The object-side surface of the first lens is convex near the optical axis, and the image-side surface is concave near the optical axis. The second lens, which has a negative refractive power. The object-side surface of the second lens is convex near the optical axis, and the image-side surface is concave near the optical axis. The third lens, which has a positive refractive power. The object-side surface of the third lens is convex near the optical axis, and the image-side surface is convex near the optical axis. The fourth lens, which has a negative refractive power. The image-side surface of the fourth lens is concave near the optical axis. The fifth lens, whose object-side surface is concave near the optical axis and whose image-side surface is convex near the optical axis. The sixth lens, which has a negative refractive power. The object-side surface of the sixth lens is convex near the optical axis, and the image-side surface is concave near the optical axis. The seventh lens, which has a positive refractive power. The object-side surface of the seventh lens is convex near the optical axis, and the image-side surface is concave near the optical axis. The eighth lens, which has a negative refractive power. The object-side surface of the eighth lens is concave near the optical axis, and the image-side surface is concave near the optical axis. The eight-element large-aperture high-pixel imaging lens satisfies the following relational expressions: 3.55 < ImgH / Fno ≤ 3.733; where ImgH is half of the length of the diagonal of the effective imaging area of the eight-element large-aperture high-pixel imaging lens, and Fno is the f-number of the eight-element large-aperture high-pixel imaging lens. 3.43 < CT3 / T34 ≤ 6.15; where CT3 is the maximum thickness of the third lens on the optical axis, and T34 is the distance between the third lens and the fourth lens on the optical axis.

2. The eight-piece large-aperture high-pixel imaging lens according to claim 1, wherein The eight-element large-aperture high-pixel imaging lens satisfies the relational expression: 1.563 ≤ TTL / ImgH < 1.58; where TTL is the distance from the object-side surface of the first lens at the paraxial region to the image plane, and ImgH is half of the length of the diagonal of the effective imaging area of the eight-element large-aperture high-pixel imaging lens.

3. The eight-piece large-aperture high-pixel imaging lens according to claim 1, characterized in that, The eight-element large-aperture high-pixel imaging lens satisfies the relational expression: -14.55 < f6 / f < -2.17; where f6 is the focal length of the sixth lens, and f is the focal length of the eight-element large-aperture high-pixel imaging lens.

4. The eight-piece large-aperture high-pixel imaging lens according to claim 1, wherein The eight-element large-aperture high-pixel imaging lens satisfies the relational expression: 2 ≤ SAG81 / CT8 ≤ 2.92; where SAG81 is the distance from the intersection of the object-side surface of the eighth lens and the optical axis to the vertex of the effective semi-aperture of the object-side surface of the eighth lens on the optical axis, and CT8 is the maximum thickness of the eighth lens on the optical axis.

5. The eight-piece large-aperture high-pixel imaging lens according to claim 1, characterized in that, The eight-element large-aperture high-pixel imaging lens satisfies the relational expression: -23.66 < f4 / f < -9.72; where f4 is the focal length of the fourth lens, and f is the focal length of the eight-element large-aperture high-pixel imaging lens.

6. The eight-piece large-aperture high-pixel imaging lens according to claim 1, wherein, The eight-element large-aperture high-pixel imaging lens satisfies the relational expression: -2.06 < R32 / R31 < -0.24; where R31 is the radius of curvature of the object-side surface of the third lens, and R32 is the radius of curvature of the image-side surface of the third lens.

7. The eight-piece large-aperture high-pixel imaging lens according to claim 1, characterized in that, The eight-piece large-aperture high-pixel imaging lens satisfies the relation: 0.46 < R62 / R61 < 0.87; where R61 is the radius of curvature of the object-side surface of the sixth lens, and R62 is the radius of curvature of the image-side surface of the sixth lens.

Images