A large-aperture small-volume optical imaging system and an application camera module thereof

Abstract

The application provides a large-aperture small-volume optical imaging system and an applied camera module, which are composed of eight lenses, the first lens has positive focal power, the object side is a convex surface, and the image side is a convex surface; the second lens has negative focal power, the object side is a convex surface, and the image side is a concave surface; the third lens has positive focal power, and the image side is a convex surface; the fourth lens has positive focal power, the object side is a concave surface, and the image side is a convex surface; the fifth lens has negative focal power, the object side is a concave surface; the sixth lens has positive focal power, the object side is a convex surface; the seventh lens has positive focal power, the object side is a convex surface, and the image side is a concave surface; and the eighth lens has negative focal power, the object side is a convex surface, and the image side is a concave surface. The optical lens can effectively correct aberration, has better imaging quality, larger aperture size, smaller volume and better thermal stability, and improves the overall imaging quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical imaging, in particular to a large-aperture small-volume optical imaging system and a camera module using the same. BACKGROUND

[0002] With the continuous development of science and technology and the continuous improvement of people's living standards, the application range of optical lenses is becoming more and more extensive, and electronic devices (such as aerial cameras, action cameras or handheld gimbal cameras) equipped with optical lenses also tend to be thinner and smaller, and the requirements for optical lenses are also more diversified, requiring optical lenses to have better imaging quality, larger aperture size, smaller volume and better thermal stability. However, the existing optical lenses are difficult to balance these requirements. SUMMARY

[0003] The present application aims to provide a large-aperture small-volume optical imaging system, which can effectively compress the volume of the optical system while ensuring imaging quality, a large aperture and thermal stability, and realize the miniaturization and lightweight design of the lens.

[0004] A large-aperture small-volume optical imaging system, sequentially comprising 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 along an optical axis from an object plane to an image plane;

[0005] The first lens has positive refractive power, and its object side surface is convex and its image side surface is convex.

[0006] The second lens has negative refractive power, and its object side surface is convex and its image side surface is concave.

[0007] The third lens has positive refractive power, and its image side surface is convex.

[0008] The fourth lens has positive refractive power, and its object side surface is concave and its image side surface is convex.

[0009] The fifth lens has negative refractive power, and its object side surface is concave.

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

[0011] The seventh lens has positive refractive power, and its object side surface is convex and its image side surface is concave.

[0012] The eighth lens has negative refractive power, and its object side surface is convex and its image side surface is concave.

[0013] In another aspect, the present application also provides a camera module comprising at least an optical lens, wherein the optical lens is installed with the above-mentioned large-aperture small-volume optical imaging system.

[0014] Compared with the prior art, the application has the following beneficial effects:

[0015] The application provides a large-aperture small-volume optical imaging system and an application thereof, which is composed of eight lenses, a proper number of lenses are selected, and the refractive power, surface shape, thickness and air gap of each lens are reasonably configured, so that aberration can be effectively corrected, the optical lens has better imaging quality, larger aperture size, smaller volume and better thermal stability, and the overall imaging quality is improved, the application can effectively compress the volume of the optical system under the premise of ensuring the imaging quality, large aperture and thermal stability, and realize small and light design of the lens. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed to be used will be briefly introduced as follows.

[0017] Figure 1 is a structural schematic diagram of an optical imaging system in Embodiment 1 of the application;

[0018] Figure 2 is an on-axis chromatic aberration, astigmatism and distortion curve of the optical imaging system in Embodiment 1 of the application;

[0019] Figure 3 is a structural schematic diagram of an optical imaging system in Embodiment 2 of the application;

[0020] Figure 4 is an on-axis chromatic aberration, astigmatism and distortion curve of the optical imaging system in Embodiment 2 of the application;

[0021] Figure 5 is a structural schematic diagram of an optical imaging system in Embodiment 3 of the application;

[0022] Figure 6 is an on-axis chromatic aberration, astigmatism and distortion curve of the optical imaging system in Embodiment 3 of the application;

[0023] Figure 7 is a structural schematic diagram of an optical imaging system in Embodiment 4 of the application;

[0024] Figure 8 is an on-axis chromatic aberration, astigmatism and distortion curve of the optical imaging system in Embodiment 4 of the application;

[0025] Figure 9 is a structural schematic diagram of an optical imaging system in Embodiment 5 of the application;

[0026] Figure 10 is an on-axis chromatic aberration, astigmatism and distortion curve of the optical imaging system in Embodiment 5 of the application;

[0027] Figure 11is a structural schematic diagram of an optical imaging system of Embodiment 6 of the present application;

[0028] Figure 12 is an on-axis chromatic aberration, astigmatism and distortion curve of the optical imaging system of Embodiment 6 of the present application. DETAILED DESCRIPTION

[0029] As shown in Figures 1-12 , a large-aperture small-volume optical imaging system includes, in order from the object side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens and an infrared filter, and a diaphragm is located before the first lens or between the first lens and the second lens, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are all aspherical lenses and are all arranged with air as the separation medium, the first lens has positive refractive power, the object side surface thereof is a convex surface, and the image side surface thereof is a convex surface; the second lens has negative refractive power, the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; the third lens has positive refractive power, and the image side surface thereof is a convex surface; the fourth lens has positive refractive power, the object side surface thereof is a concave surface, and the image side surface thereof is a convex surface; the fifth lens has negative refractive power, the object side surface thereof is a concave surface; the sixth lens has positive refractive power, the object side surface thereof is a convex surface; the seventh lens has positive refractive power, the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; the eighth lens has negative refractive power, the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; the full field of view angle of the optical system is > 89°, the total length of the lens is ≤ 11.3 mm, and the effective focal length is < 7.12 mm. The optical imaging system of the embodiment of the present application is composed of eight lenses, a proper number of lenses are selected, and the refractive power, surface shape, thickness and air gap of each lens are reasonably configured, which can effectively correct aberration, so that the optical lens has better imaging quality, larger aperture size, smaller volume and better thermal stability, and the overall imaging quality is improved. The present application can effectively compress the volume of the optical system while ensuring the imaging quality, large aperture and thermal stability, and realize the small and light design of the lens.

[0030] The optical imaging system satisfies the following relationship: 1.10 ≤ FOV / TTL / ImgH ≤ 1.25, wherein FOV is the maximum field of view angle of the optical imaging system, TTL is the on-axis distance from the object side surface of the first lens to the imaging surface, and ImgH is half the diagonal length of the effective pixel area on the imaging surface. This relationship reflects the proportion of the field of view angle to the system length per unit image height, balances the field of view angle and the compactness of the lens, and at the same time avoids the difficulty in correcting aberration caused by too short TTL. This condition ensures that the system provides sufficient field of view coverage while maintaining a small volume.

[0031] The optical imaging system satisfies the following relationship: 5.40 ≤ f*tan(HFOV) / CT3 ≤ 7.65, wherein, f is an effective focal length of the optical imaging system, HFOV is a half field of view angle of the optical imaging system, and CT3 is a center thickness of the third lens on the optical axis. The relationship reflects the geometric relationship between the focal length and the field of view angle of the optical lens, and in combination with the thickness of the third lens, can be used to control the light incidence angle and the lens processing difficulty. Too thin CT3 can cause structural weakness, and too thick can increase the system weight or spherical aberration.

[0032] The optical imaging system satisfies the following relationship: 2.85 ≤ f1*fno / f ≤ 3.56, wherein, f is an effective focal length of the optical imaging system, HFOV is a half field of view angle of the optical imaging system, and CT3 is a center thickness of the third lens on the optical axis. Balancing the optical power of the first lens and the system aperture, a larger f1*fno / f value means that the first lens has weak positive optical power, which cooperates with a smaller aperture to control aberration while avoiding insufficient light intake.

[0033] The optical imaging system satisfies the following relationship: 4.50 ≤ |f4*f5 / f6| ≤ 9.60, wherein, f4 is an effective focal length of the fourth lens, f5 is an effective focal length of the fifth lens, and f6 is an effective focal length of the sixth lens. By constraining the optical power distribution of the fourth lens, the fifth lens and the sixth lens, it is avoided that the optical power is too concentrated on the sixth lens, and it is also helpful to constrain the surface shape of the image side of the sixth lens, to avoid excessive bending and affect the processing process of the sixth lens. In addition, by satisfying the above relationship, the correction of high-order aberration can be further enhanced on the basis of reducing the third-order aberrations such as spherical aberration, coma and field curvature, and the tolerance sensitivity of the optical lens is reduced.

[0034] The optical imaging system satisfies the following relationship: 1.80 ≤ (f7-f8) / f3 ≤ 3.45, wherein, f3 is an effective focal length of the third lens, f7 is an effective focal length of the seventh lens, and f8 is an effective focal length of the eighth lens. By constraining the optical power distribution of the third lens, the seventh lens and the eighth lens, the optical power distribution of the system can be appropriate, which can be used to compensate for axial chromatic aberration and control the optical power of the rear group, so that the sensitivity of the imaging performance of the optical lens and the eccentricity and inclination generated during the manufacture of each lens are suppressed within a good range.

[0035] The optical imaging system satisfies the following relationship: 1.30 ≤ f23 / f13 ≤ 2.55; wherein, f12 is a combined focal length of the first lens and the second lens, and f23 is a combined focal length of the second lens and the third lens. By controlling the ratio of the combined focal length of the first lens and the second lens and the combined focal length of the second lens and the third lens, the smooth transition of light is ensured, the astigmatism or distortion is avoided, and the improvement of imaging quality is facilitated.

[0036] The optical imaging system satisfies the following relationship: 1.02 ≤ f56 / f5678 ≤ 1.73, wherein f56 is the combined focal length of the fifth lens and the sixth lens, and f5678 is the combined focal length of the fifth lens, the sixth lens, the seventh lens and the eighth lens. The ratio range helps to balance aberration correction and system compactness, and improves imaging quality. Aberration control: by controlling the focal length ratio of the combined focal length of the fifth lens and the sixth lens to the combined focal length of the fifth lens, the sixth lens, the seventh lens and the eighth lens, the aberrations such as spherical aberration and chromatic aberration can be effectively reduced, which helps to correct aberration and system compactness, reduces the volume of the optical system, facilitates integration into small devices, and helps to reduce the processing difficulty and production cost of the optical lens group.

[0037] The optical imaging system satisfies the following relationship: 1.90 ≤ f2 / (R2+R3) ≤ 3.45, wherein R2 is the curvature radius of the object image side of the first lens, R3 is the curvature radius of the object side of the second lens, and f2 is the effective focal length of the second lens. By controlling the ratio of the sum of the curvature radius of the object image side of the first lens and the curvature radius of the object side of the second lens to the effective focal length of the second lens, the specific lens shape (double convex lens and meniscus) can be effectively controlled, which helps to optimize the propagation path of light, avoid excessive deflection of light during transmission between lenses, and reduce the processing difficulty of the optical lens group.

[0038] The optical imaging system satisfies the following relationship: 2.80 ≤ |R15+R16| / |R15-R16| ≤ 5.65; wherein R15 is the curvature radius of the object side of the eighth lens, and R16 is the curvature radius of the image side of the eighth lens. By controlling the curvature radius of the object side and the image side of the eighth lens, high-order aberrations can be reduced, and the incident angle of the chief ray of each field of view of the optical imaging lens on the image plane can be relatively reasonably controlled, meeting the requirements of the incident angle of the chief ray of the optical system design.

[0039] The optical imaging system satisfies the following relationship: 1.00 ≤ CT5 / T45 ≤ 3.10, wherein CT5 is the center thickness of the fifth lens on the optical axis, and T45 is the air gap of the fourth lens and the fifth lens on the optical axis. By controlling the ratio of the air gap of the fourth lens and the fifth lens on the optical axis to the thickness of the fifth lens, sufficient gap adjustment aberration (such as field curvature) is ensured, while avoiding processing difficulty caused by too thin lens.

[0040] The optical imaging system satisfies the following relationship: 2.50 ≤ |(DT31-DT32) / (DT21-DT22)| ≤ 4.25, where DT31 is the maximum effective radius of the object-side surface of the third lens, DT32 is the maximum effective radius of the image-side surface of the third lens, DT21 is the maximum effective radius of the object-side surface of the second lens, and DT22 is the maximum effective radius of the image-side surface of the second lens. Controlling the ratio of the rate of change of the effective radii of the third and second lenses can effectively control vignetting and the height of edge rays, reduce the aberration of the edge field of view, improve resolution, and simultaneously reduce the size of the lens, meeting the requirements for lens miniaturization.

[0041] The optical imaging system satisfies the following relationship: 12.65 ≤ DT71 / SAG13 + DT72 / SAG14 ≤ 16.55; where DT71 is the maximum effective radius of the object side of the seventh lens, DT72 is the maximum effective radius of the image side of the seventh lens, SAG13 is the distance from the point where the object side of the seventh lens has the maximum effective aperture to the point where the object side of the first lens intersects with the optical axis, and the distance from the point where the image side of the first lens intersects with the optical axis, and the distance from the point where the object side of the seventh lens has the maximum effective aperture to the point where the image side of the first lens intersects with the optical axis, and the distance from the point where the image side of the first lens intersects with the optical axis, and the distance from the point where the image side of the seventh ...

[0042] Example 1, the following is a reference Figures 1 to 2 This describes an optical imaging lens according to Embodiment 1 of this application. For example... Figure 1 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: STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, an infrared filter E9, and an imaging surface S19.

[0043] The first lens E1 has positive refractive power, the object side surface S1 is convex, and the image side surface S2 is convex. The second lens E2 has negative refractive power, the object side surface S3 is convex, and the image side surface S4 is concave. The third lens E3 has positive refractive power, the object side surface S5 is concave, and the image side surface S6 is convex. The fourth lens E4 has positive refractive power, the object side surface S7 is concave, and the image side surface S8 is convex. The fifth lens E5 has negative refractive power, the object side surface S9 is concave, and the image side surface S10 is convex. The sixth lens E6 has positive refractive power, the object side surface S11 is convex, and the image side surface S12 is concave. The seventh lens E7 has positive refractive power, the object side surface S13 is convex, and the image side surface S14 is concave. The eighth lens E8 has negative refractive power, the object side surface S15 is convex, and the image side surface S16 is concave. The filter E7 has an object side surface S17 and an image side surface S18. Light from an object passes through the surfaces S1 to S18 in sequence and is finally imaged on an imaging surface S19.

[0044] Table 1 shows the surface type, the radius of curvature, the thickness and the material of each lens of the optical imaging lens of Example 1, wherein the radius of curvature and the thickness are in millimeters (mm).

[0045] Table 1

[0046]

[0047] In Table 1, any one of the object side surface and the image side surface of the first lens E1, the second lens E2, the third lens E3, the fourth lens E4, the fifth lens E5, the sixth lens E6, the seventh lens E7 and the eighth lens E8 is a Q-type aspherical surface, and the surface type of each aspherical lens can be defined by, but not limited to, the following aspherical surface formula:

[0048]

[0049] wherein Z is the distance from a corresponding point on the aspherical surface to a plane tangent to the vertex of the surface, r is the radial coordinate of the aspherical surface, c is the curvature of the vertex of the aspherical surface, K is the conic coefficient, Am is the aspherical coefficient, r max is the maximum value of the radial radius coordinate, and u = r / r max . Table 2 shows the conic coefficient and the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28 and A30 of each aspherical surface that can be used in the first embodiment.

[0050] Table 2

[0051]

[0052] Example 2, which is described below Figures 3 to 4An optical imaging lens according to Embodiment Two of the present application is described. As shown in Figure 3 The optical imaging lens according to the exemplary embodiments of the present application comprises, in order from the object side to the image side along the optical axis, an STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, an infrared filter E9, and an imaging surface S19.

[0053] The first lens E1 has positive refractive power, the object side surface S1 is convex, and the image side surface S2 is convex. The second lens E2 has negative refractive power, the object side surface S3 is convex, and the image side surface S4 is concave. The third lens E3 has positive refractive power, the object side surface S5 is convex, and the image side surface S6 is convex. The fourth lens E4 has positive refractive power, the object side surface S7 is concave, and the image side surface S8 is convex. The fifth lens E5 has negative refractive power, the object side surface S9 is concave, and the image side surface S10 is convex. The sixth lens E6 has positive refractive power, the object side surface S11 is convex, and the image side surface S12 is convex. The seventh lens E7 has positive refractive power, the object side surface S13 is convex, and the image side surface S14 is concave. The eighth lens E8 has negative refractive power, the object side surface S15 is convex, and the image side surface S16 is concave. The filter E7 has an object side surface S17 and an image side surface S18. Light from an object passes through the surfaces S1 to S18 in order and is finally imaged on the imaging surface S19.

[0054] Table 3 shows the surface type, the radius of curvature, the thickness, and the material of each lens of the optical imaging lens of Embodiment Two, wherein the units of the radius of curvature and the thickness are millimeters (mm).

[0055] Table 3

[0056]

[0057] In Table 3, the object side surface and the image side surface of each of the first lens E1, the second lens E2, the third lens E3, the fourth lens E4, the fifth lens E5, the sixth lens E6, the seventh lens E7, and the eighth lens E8 are Q-type aspheric surfaces, and the surface type of each aspheric lens can be defined by, but is not limited to, the following aspheric surface formula:

[0058]

[0059] wherein Z is the distance from a corresponding point on the aspheric surface to a plane tangent to the vertex of the surface, r is the radial coordinate of the aspheric surface, c is the curvature of the vertex of the aspheric surface, K is the conic coefficient, Am is the aspheric coefficient, r max is the maximum value of the radial radius coordinate, and u = r / r maxTable 4 provides the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28 and A30 for each aspherical surface that can be used in the second embodiment.

[0060] Table 4

[0061]

[0062] Example 3, the following is a reference Figures 5 to 6 Describes an optical imaging lens according to Embodiment 3 of this application. For example... 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: STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, an infrared filter E9, and an imaging surface S19.

[0063] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens E2 has negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has positive optical power, with its object-side surface S7 being concave and its image-side surface S8 being convex. The fifth lens E5 has negative optical power, with its object-side surface S9 being concave and its image-side surface S10 being convex. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being convex. The seventh lens E7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being concave. The eighth lens E8 has negative optical power, with its object-side surface S15 being convex and its image-side surface S16 being concave. The filter E7 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.

[0064] Table 5 shows the surface type, radius of curvature, thickness, and material of each lens in the optical imaging lens of Embodiment 3, wherein the units for radius of curvature and thickness are millimeters (mm).

[0065] Table 5

[0066]

[0067] In Table 6, the object-side surface and image-side surface of any one of the lenses E1, E2, E3, E4, E5, E6, E7, and E8 are Q-type aspherical surfaces. The surface shape of each aspherical lens can be limited by, but is not limited to, the following aspherical formulas:

[0068]

[0069] Where Z is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, r is the radial coordinate of the aspherical surface, c is the curvature of the vertex of the aspherical surface, K is the conic coefficient, Am is the aspherical coefficient, and r max The maximum value of the radial radius coordinate is u = r / r max Table 6 provides the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28 and A30 for each aspherical surface that can be used in the third embodiment.

[0070] Table 6

[0071]

[0072] Example 4, the following reference Figures 7 to 8 Describes an optical imaging lens according to Embodiment 4 of this application. For example... Figure 7 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: STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, an infrared filter E9, and an imaging surface S19.

[0073] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens E2 has negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has positive optical power, with its object-side surface S7 being concave and its image-side surface S8 being convex. The fifth lens E5 has negative optical power, with its object-side surface S9 being concave and its image-side surface S10 being convex. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being convex. The seventh lens E7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being concave. The eighth lens E8 has negative optical power, with its object-side surface S15 being convex and its image-side surface S16 being concave. The filter E7 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.

[0074] Table 7 shows the surface type, radius of curvature, thickness, and material of each lens in the optical imaging lens of Embodiment 4, wherein the units for radius of curvature and thickness are millimeters (mm).

[0075] Table 7

[0076]

[0077] In Table 8, the object-side surface and image-side surface of any one of the lenses E1, E2, E3, E4, E5, E6, E7, and E8 are Q-type aspherical surfaces. The surface shape of each aspherical lens can be limited by, but is not limited to, the following aspherical formulas:

[0078]

[0079] Where Z is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, r is the radial coordinate of the aspherical surface, c is the curvature of the vertex of the aspherical surface, K is the conic coefficient, Am is the aspherical coefficient, and r max The maximum value of the radial radius coordinate is u = r / r max Table 8 provides the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28 and A30 for each aspherical surface that can be used in the fourth embodiment.

[0080] Table 8

[0081]

[0082] Example 5, the following reference Figures 9 to 10 This describes an optical imaging lens according to Embodiment 5 of this application. For example... Figure 9 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 STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, an infrared filter E9, and an imaging surface S19.

[0083] The first lens E1 has positive refractive power, the object side surface S1 is convex, and the image side surface S2 is convex. The second lens E2 has negative refractive power, the object side surface S3 is convex, and the image side surface S4 is concave. The third lens E3 has positive refractive power, the object side surface S5 is convex, and the image side surface S6 is convex. The fourth lens E4 has positive refractive power, the object side surface S7 is concave, and the image side surface S8 is convex. The fifth lens E5 has negative refractive power, the object side surface S9 is concave, and the image side surface S10 is convex. The sixth lens E6 has positive refractive power, the object side surface S11 is convex, and the image side surface S12 is convex. The seventh lens E7 has positive refractive power, the object side surface S13 is convex, and the image side surface S14 is concave. The eighth lens E8 has negative refractive power, the object side surface S15 is convex, and the image side surface S16 is concave. The filter E7 has an object side surface S17 and an image side surface S18. Light from an object passes through the surfaces S1 to S18 in sequence and is finally imaged on an imaging surface S19.

[0084] Table 9 shows the surface type, the radius of curvature, the thickness and the material of each lens of the optical imaging lens of Example Five, wherein the units of the radius of curvature and the thickness are millimeter (mm).

[0085] Table 9

[0086]

[0087] In Table 10, the object side surface and the image side surface of each lens of the first lens E1, the second lens E2, the third lens E3, the fourth lens E4, the fifth lens E5, the sixth lens E6, the seventh lens E7 and the eighth lens E8 are Q type aspheric surfaces, and the surface type of each aspheric lens can be defined by, but not limited to, the following aspheric surface formula:

[0088]

[0089] wherein Z is the distance from a corresponding point on the aspheric surface to a plane tangent to the vertex of the surface, r is the radial coordinate of the aspheric surface, c is the curvature of the vertex of the aspheric surface, K is the conic coefficient, Am is the aspheric coefficient, r max is the maximum value of the radial radius coordinate, and u = r / r max Table 8 shows the conic coefficient and the high order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28 and A30 of each aspheric surface that can be used in the fifth embodiment.

[0090] Table 10

[0091]

[0092] Example Six, the following refers toFigures 11 to 12 An optical imaging lens according to Embodiment Six of the present application is described. As shown in Figure 11 The optical imaging lens according to the exemplary embodiments of the present application comprises, in order from the object side to the image side along the optical axis, a first lens E1, an STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, an infrared filter E9, and an imaging surface S19.

[0093] The first lens E1 has positive refractive power, the object side surface S1 is convex, and the image side surface S2 is convex. The second lens E2 has negative refractive power, the object side surface S3 is convex, and the image side surface S4 is concave. The third lens E3 has positive refractive power, the object side surface S5 is convex, and the image side surface S6 is convex. The fourth lens E4 has positive refractive power, the object side surface S7 is concave, and the image side surface S8 is convex. The fifth lens E5 has negative refractive power, the object side surface S9 is concave, and the image side surface S10 is convex. The sixth lens E6 has positive refractive power, the object side surface S11 is convex, and the image side surface S12 is convex. The seventh lens E7 has positive refractive power, the object side surface S13 is convex, and the image side surface S14 is concave. The eighth lens E8 has negative refractive power, the object side surface S15 is convex, and the image side surface S16 is concave. The filter E7 has an object side surface S17 and an image side surface S18. Light from an object passes through the surfaces S1 to S18 in order and is finally imaged on the imaging surface S19.

[0094] Table 11 shows the surface type, the radius of curvature, the thickness, and the material of each lens of the optical imaging lens of Embodiment Six, wherein the units of the radius of curvature and the thickness are millimeters (mm).

[0095] Table 11

[0096]

[0097] In Table 12, the object side surface and the image side surface of each of the first lens E1, the second lens E2, the third lens E3, the fourth lens E4, the fifth lens E5, the sixth lens E6, the seventh lens E7, and the eighth lens E8 are Q-type aspheric surfaces, and the surface type of each aspheric lens can be defined by, but is not limited to, the following aspheric surface formula:

[0098]

[0099] wherein Z is the distance from a corresponding point on the aspheric surface to a plane tangent to the vertex of the surface, r is the radial coordinate of the aspheric surface, c is the curvature of the vertex of the aspheric surface, K is the conic coefficient, Am is the aspheric coefficient, r max is the maximum value of the radial radius coordinate, and u = r / r maxThe conic coefficients and the higher order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28 and A30 of each aspherical surface used in the sixth embodiment are given in Table 8.

[0100] Table 12

[0101]

[0102] In the embodiments 1-6, the basic data are as follows:

[0103] Table 13

[0104]

[0105] In the embodiments 1-6, each conditional expression satisfies the conditions of the following table:

[0106] Table 14

[0107]

[0108] A camera module at least includes an optical lens, and the optical lens is installed with the above-mentioned large-aperture small-volume optical imaging system. The camera module selects a proper number of lenses and reasonably configures the refractive power, surface shape, thickness and air gap of each lens, so as to effectively correct aberration, so that the optical lens has better imaging quality, larger aperture size, smaller volume and better thermal stability, and improves the overall imaging quality.

[0109] The above description is one or more embodiments provided in combination with specific content, and does not mean that the specific implementation of the present application is limited to these descriptions. Any approximation, similarity or replacement of the method and structure of the present application, or any technical deduction or replacement under the premise of the concept of the present application, should be considered as the protection scope of the present application.

Claims

1. A large-aperture, small-volume optical imaging system, characterized in that: Along the optical axis from the object plane to the image plane, it consists of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens in sequence; The first lens has positive optical power, and its object side is convex, and its image side is convex. The second lens has negative optical power, its object side is convex, and its image side is concave. The third lens has positive optical power and its image-side surface is convex. The fourth lens has positive optical power, its object side is concave, and its image side is convex. The fifth lens has negative optical power and its object side is concave. The sixth lens has positive optical power and its object-side surface is convex. The seventh lens has positive optical power, its object side is convex, and its image side is concave. The eighth lens has negative optical power, its object side is convex, and its image side is concave. The following relationship must be satisfied: 4.50 ≤ |f4*f5 / f6| ≤ 9.60; 1.80 ≤ (f7-f8) / f3 ≤ 3.45; 1.30 ≤ f23 / f13 ≤ 2.55; 1.02 ≤ f56 / f5678 ≤ 1.73; Wherein, f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, f7 is the effective focal length of the seventh lens, f8 is the effective focal length of the eighth lens, f12 is the combined focal length of the first and second lenses, f23 is the combined focal length of the second and third lenses, f56 is the combined focal length of the fifth and sixth lenses, and f5678 is the combined focal length of the fifth, sixth, seventh, and eighth lenses.

2. The large-aperture, small-volume optical imaging system according to claim 1, characterized in that, The following relationship must be satisfied: 1.90 ≤ f2 / (R2+R3) ≤ 3.45; 2.80 ≤ |R15+R16| / |R15-R16| ≤ 5.65; Where f2 is the effective focal length of the second lens, R2 is the radius of curvature of the image side of the first lens, R3 is the radius of curvature of the object side of the second lens, R15 is the radius of curvature of the object side of the eighth lens, and R16 is the radius of curvature of the image side of the eighth lens.

3. The large-aperture, small-volume optical imaging system according to claim 1, characterized in that, The following relationship must be satisfied: 1.00 ≤ CT5 / T45 ≤ 3.10; 2.50 ≤ |(DT31-DT32) / (DT21-DT22)| ≤ 4.25; 12.65 ≤ DT71 / SAG13+DT72 / SAG14 ≤ 16.55; Wherein, CT5 is the center thickness of the fifth lens on the optical axis, T45 is the air gap between the fourth and fifth lenses on the optical axis, DT31 is the maximum effective radius of the object side of the third lens, DT32 is the maximum effective radius of the image side of the third lens, DT21 is the maximum effective radius of the object side of the second lens, DT22 is the maximum effective radius of the image side of the second lens, DT71 is the maximum effective radius of the object side of the seventh lens, DT52 is the maximum effective radius of the image side of the seventh lens, SAG13 is the distance from the maximum effective aperture of the object side of the seventh lens to the intersection of the object side of the first lens with the optical axis—the distance parallel to the optical axis on the image side of the first lens, and SAG14 is the distance from the maximum effective aperture of the image side of the seventh lens to the intersection of the object side of the first lens with the optical axis—the distance parallel to the optical axis.

4. The large-aperture, small-volume optical imaging system according to any one of claims 1-3, characterized in that, The following relationship must be satisfied: 1.10 ≤ FOV / TTL / IamgH ≤ 1.25; Wherein, FOV is the maximum field of view of the optical imaging system, TTL is the on-axis distance from the object side of the first lens to the imaging surface, and ImgH is half the diagonal length of the effective pixel area on the imaging surface.

5. The large-aperture, small-volume optical imaging system according to any one of claims 1-3, characterized in that, The following relationship must be satisfied: 5.40 ≤ f*tan(HFOV) / CT3 ≤ 7.65; Where f is the effective focal length of the optical imaging system, HFOV is the half field of view of the optical imaging system, and CT3 is the center thickness of the third lens on the optical axis.

6. The large-aperture, small-volume optical imaging system according to any one of claims 1-3, characterized in that, The following relationship must be satisfied: 2.85 ≤ f1*fno / f ≤ 3.56; Where f is the effective focal length of the optical imaging system, fno is the F-number of the optical imaging system, and f1 is the effective focal length of the first lens.

7. The large-aperture, small-volume optical imaging system according to any one of claims 1-3, characterized in that: The large aperture, small volume optical imaging system described above has a field of view of >89°, a total lens length of ≤11.3 mm, and an effective focal length of <7.12 mm.

8. The large-aperture, small-volume optical imaging system according to any one of claims 1-3, characterized in that: The aperture stop is located in front of the first lens or between the first lens and the second lens.

9. The large-aperture, small-volume optical imaging system according to any one of claims 1-3, characterized in that: The first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens are all aspherical lenses, and are all separated by air gaps.

10. A camera module, comprising at least an optical lens, characterized in that: The optical lens is equipped with a large-aperture, small-volume optical imaging system as described in any one of claims 1-9.

Images