An optical imaging system

Abstract

The present invention discloses an optical imaging system, which includes, in order from the object side to the image side along the optical axis: an aperture; a first lens with optical power; a second lens with negative optical power; a third lens with optical power; a fourth lens with negative optical power; a fifth lens with optical power; a sixth lens with positive optical power, whose image side surface is convex; and a seventh lens with optical power; wherein the effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy: f / EPD<1.4; the effective focal length f of the optical imaging system and the curvature radius R4 of the image side surface of the second lens satisfy: 2.5<f / R4≤3.5; and the half Semi-FOV of the maximum field of view of the optical imaging system satisfies: 10.0°<Semi-FOV<30.0°. The optical imaging system provided by the present invention has a large aperture, a long focal length, good imaging quality, and is suitable for taking clear portrait photos.

Description

Technical Field

[0001] The invention belongs to the field of optical imaging, and in particular relates to an optical imaging system comprising seven lenses. Background Art

[0002] With the rapid development of smart phones, the demand for mobile phone lenses with good imaging performance is increasing day by day, especially people's demand for taking clear portrait photos. In order to allow users to have a better photo-taking experience, mobile phone lenses need to have the characteristics of highlighting the subject and blurring the background, which requires optical imaging lenses with large aperture and long focal length.

[0003] Therefore, there is a need for a seven-element telephoto lens with an aspherical surface, which has good imaging quality and is suitable for taking clear portrait photos. Summary of the invention

[0004] The present invention aims to provide an optical imaging system composed of seven lenses, which has a large aperture, a long focal length, and good imaging quality and is suitable for taking clear portrait photos.

[0005] One aspect of the present invention provides an optical imaging system, which includes, in order from the object side to the image side along the optical axis: an aperture; a first lens with optical focal power; a second lens with negative optical focal power; a third lens with optical focal power; a fourth lens with negative optical focal power; a fifth lens with optical focal power; a sixth lens with positive optical focal power, whose image side surface is convex; and a seventh lens with optical focal power.

[0006] The effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy: f / EPD<1.4.

[0007] According to one embodiment of the present invention, the effective focal length f1 of the first lens, the curvature radius R1 of the object side of the first lens, and the effective focal length f of the optical imaging system satisfy: 1.0<(f1+R1) / f<1.6.

[0008] According to one embodiment of the present invention, the effective focal length f2 of the second lens and the curvature radius R3 of the object side surface of the second lens satisfy: -6.5<f2 / R3<-2.0.

[0009] According to one embodiment of the present invention, the effective focal length f of the optical imaging system and the curvature radius R4 of the image-side surface of the second lens satisfy: 2.5<f / R4≤3.5.

[0010] According to one embodiment of the present invention, the effective focal length f3 of the third lens and the curvature radius R5 of the object side surface of the third lens satisfy: 1.5<f3 / R5<5.0.

[0011] According to one embodiment of the present invention, the effective focal length f4 of the fourth lens, the curvature radius R8 of the image-side surface of the fourth lens, and the effective focal length f of the optical imaging system satisfy: -3.0<(f4+R8) / f<0.

[0012] According to one embodiment of the present invention, the effective focal length f6 of the sixth lens and the curvature radius R12 of the image-side surface of the sixth lens satisfy: -2.0<f6 / R12<0.

[0013] According to one embodiment of the present invention, the effective focal length f7 of the seventh lens and the curvature radius R14 of the image-side surface of the seventh lens satisfy: -9.5<f7 / R14<-2.5.

[0014] According to one embodiment of the present invention, a center thickness CT1 of the first lens on the optical axis and a center thickness CT2 of the second lens on the optical axis satisfy: 3.5<CT1 / CT2<5.0.

[0015] According to one embodiment of the present invention, a center thickness CT3 of the third lens on the optical axis and a center thickness CT5 of the fifth lens on the optical axis satisfy: 2.0<CT3 / CT5<3.5.

[0016] According to one embodiment of the present invention, the air interval T45 between the fourth lens and the fifth lens on the optical axis and the air interval T34 between the third lens and the fourth lens on the optical axis satisfy: 17.0 mm -2 <1 / (T45×T34)<27.0mm -2 .

[0017] According to one embodiment of the present invention, half of the maximum field of view Semi-FOV of the optical imaging system satisfies: 10.0°<Semi-FOV<30.0°.

[0018] According to one embodiment of the present invention, the on-axis distance TTL from the object side of the first lens to the imaging plane and half the diagonal length of the effective pixel area on the imaging plane ImgH satisfy the following: 2.5<TTL / ImgH<3.0.

[0019] Another aspect of the present invention provides an optical imaging system, which includes, in order from the object side to the image side along the optical axis: an aperture; a first lens with optical focal power; a second lens with negative optical focal power; a third lens with optical focal power; a fourth lens with negative optical focal power; a fifth lens with optical focal power; a sixth lens with positive optical focal power, whose image side surface is convex; and a seventh lens with optical focal power.

[0020] Among them, each lens is independent of each other, and there is an air gap between each lens on the optical axis; the effective focal length f of the optical imaging system and the curvature radius R4 of the image side surface of the second lens satisfy: 2.5<f / R4≤3.5.

[0021] Beneficial effects of the present invention:

[0022] The optical imaging system provided by the present invention comprises a plurality of lenses, such as the first lens to the seventh lens. The optical imaging system of the present invention has a large aperture, a long focal length, good imaging quality, and is suitable for taking clear portrait photos. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 Schematic diagram of the lens group structure of embodiment 1 of the optical imaging system of the present invention;

[0025] Figure 2a to Figure 2d They are respectively an axial chromatic aberration curve, an astigmatism curve, a distortion curve and a magnification chromatic aberration curve of the optical imaging system embodiment 1 of the present invention;

[0026] Figure 3 Schematic diagram of the lens group structure of embodiment 2 of the optical imaging system of the present invention;

[0027] Figures 4a to 4d They are respectively an axial chromatic aberration curve, an astigmatism curve, a distortion curve and a magnification chromatic aberration curve of Embodiment 2 of the optical imaging system of the present invention;

[0028] Figure 5 Schematic diagram of the lens group structure of embodiment 3 of the optical imaging system of the present invention;

[0029] Figures 6a to 6d They are respectively an axial chromatic aberration curve, an astigmatism curve, a distortion curve and a magnification chromatic aberration curve of Embodiment 3 of the optical imaging system of the present invention;

[0030] Figure 7 Schematic diagram of the lens group structure of embodiment 4 of the optical imaging system of the present invention;

[0031] Figures 8a to 8d They are respectively an axial chromatic aberration curve, an astigmatism curve, a distortion curve and a magnification chromatic aberration curve of Embodiment 4 of the optical imaging system of the present invention;

[0032] Fig. 9Schematic diagram of the lens group structure of Embodiment 5 of the optical camera lens of the present invention;

[0033] Figures 10a to 10d They are respectively an axial chromatic aberration curve, an astigmatism curve, a distortion curve and a magnification chromatic aberration curve of the optical camera lens embodiment 5 of the present invention;

[0034] Fig.11 Schematic diagram of the structure of a lens group of an optical camera lens embodiment 6 of the present invention;

[0035] Figures 12a to 12d They are respectively the axial chromatic aberration curve, the astigmatism curve, the distortion curve and the magnification chromatic aberration curve of the optical camera lens embodiment 6 of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0038] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0039] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0040] In the description of the present invention, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region. If the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object being photographed is called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens.

[0041] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms (such as those defined in a common dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal manner unless expressly so defined herein.

[0042] It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention may be combined with each other. The features, principles and other aspects of the present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0043] Exemplary Embodiments

[0044] The optical imaging system according to the exemplary embodiment of the present invention includes seven lenses, which are sequentially arranged from the object side to the image side along the optical axis: a stop, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. Among them, each lens is independent of each other, and there is an air gap between each lens on the optical axis.

[0045] In this exemplary embodiment, the first lens may have a positive or negative optical power; the second lens has a negative optical power; the third lens may have a positive or negative optical power; the fourth lens has a negative optical power; the fifth lens may have a positive or negative optical power; the sixth lens has a positive optical power, and its image side surface is convex; the seventh lens may have a positive or negative optical power.

[0046] In this exemplary embodiment, the conditional formula satisfied by the effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system is: f / EPD < 1.4. By reasonably distributing the optical power of the lenses, the system has smaller aberrations; by restricting the ratio of the focal length to the entrance pupil diameter, the light flux of the system can be increased, the imaging effect in a dark environment can be enhanced, and at the same time, the aberrations of the edge field of view can be reduced. More specifically, f and EPD satisfy: 1.2 < f / EPD < 1.3. For example, 1.22 ≤ f / EPD ≤ 1.27.

[0047] In the present exemplary embodiment, the conditional formula satisfied by the effective focal length f1 of the first lens, the radius of curvature R1 of the object side surface of the first lens, and the effective focal length f of the optical imaging system is: 1.0 < (f1 + R1) / f < 1.6. By constraining the effective focal length of the first lens, the effective focal length of the optical imaging system, and the radius of curvature of the object side surface of the first lens, the light converging ability can be improved, and it is also beneficial to reduce the aberration of the optical imaging lens. More specifically, f1, R1, and f satisfy: 1.3 < (f1 + R1) / f < 1.55. For example, 1.31 ≤ (f1 + R1) / f ≤ 1.53.

[0048] In the present exemplary embodiment, the conditional formula satisfied by the effective focal length f2 of the second lens and the radius of curvature R3 of the object side surface of the second lens is: -6.5 < f2 / R3 < -2.0. By constraining the effective focal length of the second lens and the radius of curvature of the object side surface of the second lens, the deflection angle of light in the second lens can be controlled, which is beneficial to reducing the sensitivity of the system. More specifically, f2 and R3 satisfy: -6.4 < f2 / R3 < -2.1. For example, -6.33 ≤ f2 / R3 ≤ -2.13.

[0049] In the present exemplary embodiment, the conditional formula satisfied by the effective focal length f of the optical imaging system and the radius of curvature R4 of the image side surface of the second lens is: 2.5 < f / R4 ≤ 3.5. By constraining the ratio of the effective focal length of the optical imaging system to the radius of curvature of the image side surface of the second lens, it is beneficial to correct aberrations and enable the lens to have good imaging quality. More specifically, f and R4 satisfy:

[0050] 2.7 < f / R4 ≤ 3.5. For example, 2.75 ≤ f / R4 ≤ 3.50.

[0051] In the present exemplary embodiment, the conditional formula satisfied by the effective focal length f3 of the third lens and the radius of curvature R5 of the object side surface of the third lens is: 1.5 < f3 / R5 < 5.0. By constraining the effective focal length of the third lens and the radius of curvature of the object side surface of the third lens, the optical imaging lens has a better ability to balance chromatic aberration and distortion. More specifically, f3 and R5 satisfy: 1.6 < f3 / R5 < 4.6. For example, 1.68 ≤ f3 / R5 ≤ 4.53.

[0052] In the present exemplary embodiment, the conditional expression satisfied by the effective focal length f4 of the fourth lens, the radius of curvature R8 of the image side surface of the fourth lens, and the effective focal length f of the optical imaging system is: -3.0 < (f4 + R8) / f < 0. By reasonably controlling the effective focal length of the fourth lens, the effective focal length of the optical imaging system, and the radius of curvature of the image side surface of the fourth lens, the system has a smaller spherical aberration and the lens has good imaging quality. More specifically, f4, R8, and f satisfy: -2.9 < (f4 + R8) / f < -0.1. For example, -2.87 ≤ (f4 + R8) / f ≤ -0.18.

[0053] In the present exemplary embodiment, the conditional expression satisfied by the effective focal length f6 of the sixth lens and the radius of curvature R12 of the image side surface of the sixth lens is: -2.0 < f6 / R12 < 0. By restricting the effective focal length of the sixth lens and the radius of curvature of the image side surface of the sixth lens, the deflection angle of light in the sixth lens can be effectively controlled, and good processing characteristics of the system can be achieved. More specifically, f6 and R12 satisfy: -1.9 < f6 / R12 < -1. For example, -1.89 ≤ f6 / R12 ≤ -1.11.

[0054] In the present exemplary embodiment, the conditional expression satisfied by the effective focal length f7 of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens is: -9.5 < f7 / R14 < -2.5. By restricting the effective focal length of the seventh lens and the radius of curvature of the image side surface of the seventh lens, the light angle of the edge field of view can be within a reasonable range, and the sensitivity of the system can be effectively reduced. More specifically, f7 and R14 satisfy: -5 < f7 / R14 < -2.7. For example, -4.95 ≤ f7 / R14 ≤ -2.77.

[0055] In the present exemplary embodiment, the conditional expression satisfied by the central thickness CT1 of the first lens on the optical axis and the central thickness CT2 of the second lens on the optical axis is: 3.5 < CT1 / CT2 < 5.0. By reasonably controlling the ratio of the central thicknesses of the first lens and the second lens on the optical axis, the degree of freedom of lens surface variation is higher, thereby improving the ability of the optical imaging lens to correct astigmatism and field curvature. More specifically, CT1 and CT2 satisfy: 3.7 < CT1 / CT2 < 4.5. For example, 3.78 ≤ CT1 / CT2 ≤ 4.34.

[0056] In the present exemplary embodiment, the conditional expression satisfied by the central thickness CT3 of the third lens on the optical axis and the central thickness CT5 of the fifth lens on the optical axis is: 2.0 < CT3 / CT5 < 3.5. By reasonably controlling the ratio of the central thicknesses of the third lens and the fifth lens on the optical axis, the system size is effectively compressed, and the volume of the lens group of the optical imaging lens is prevented from being too large. More specifically, CT3 and CT5 satisfy: 2.5 < CT3 / CT5 < 3.1. For example, 2.59 ≤ CT3 / CT5 ≤ 3.03.

[0057] In the present exemplary embodiment, the conditional expression satisfied by the air gap T45 between the fourth lens and the fifth lens on the optical axis and the air gap T34 between the third lens and the fourth lens on the optical axis is: 17.0mm -2 <1 / (T45×T34)<27.0mm -2 。Reasonably controlling the ratio of the air gap between the third lens and the fourth lens on the optical axis to the air gap between the fourth lens and the fifth lens on the optical axis helps to control the distortion of the system and enables the system to have good distortion performance. More specifically, T45 and T34 satisfy: 17.1mm -2 <1 / (T45×T34)<26.95mm -2 ,For example, 17.20mm -2 ≤1 / (T45×T34)≤26.94mm -2 。

[0058] In the present exemplary embodiment, the conditional expression satisfied by half of the maximum field of view Semi-FOV of the optical imaging system is: 10.0°<Semi-FOV<30.0°. Reasonably controlling the maximum half field of view of the optical imaging lens enables the optical imaging lens to satisfy the telephoto characteristics and have a good ability to balance aberrations, and can reasonably control the main ray deflection angle to improve the matching degree with the chip. More specifically, Semi-FOV satisfies: 20°<Semi-FOV<22°, for example, 20.3°≤Semi-FOV≤21.3°.

[0059] In the present exemplary embodiment, the conditional expression satisfied by the on-axis distance TTL from the object side of the first lens to the imaging surface and half of the diagonal length ImgH of the effective pixel region on the imaging surface is: 2.5<TTL / ImgH<3.0. Reasonably restricting the ratio of the total system length to the image height is beneficial to the miniaturization of the optical imaging lens. More specifically, TTL and ImgH satisfy: 2.7<TTL / ImgH<3.0, for example, 2.80≤TTL / ImgH≤2.99.

[0060] In the present exemplary embodiment, the above optical imaging system may further include a diaphragm. The diaphragm can be set at an appropriate position according to needs. For example, the diaphragm can be set between the object side and the first lens. Optionally, the above optical imaging system may further include a filter for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface.

[0061] The optical imaging system according to the above embodiment of the present invention can use multiple lenses, such as the above seven lenses. By reasonably allocating the focal length, surface shape, center thickness of each lens, and axial spacing between lenses, the optical imaging system has a larger imaging surface, a wide imaging range, and high imaging quality, and ensures the ultra-thinness of the mobile phone.

[0062] In an exemplary embodiment, at least one of the mirror surfaces of each lens is an aspherical mirror surface, that is, at least one of the mirror surfaces from the object side of the first lens to the image side of the seventh lens is an aspherical mirror surface. The characteristics of the aspherical lens are: the curvature changes continuously from the center of the lens to the periphery of the lens. Unlike the spherical lens with a constant curvature from the center of the lens to the periphery of the lens, the aspherical lens has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving astigmatism aberration. After adopting the aspherical lens, the aberration that occurs during imaging can be eliminated as much as possible, thereby improving the imaging quality. Optionally, at least one of the object side and image side of each lens in the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens is an aspherical mirror surface. Optionally, the object side and image side of each lens in the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all aspherical mirror surfaces.

[0063] However, those skilled in the art should understand that, without departing from the technical solution claimed in the present application, the number of lenses constituting the optical imaging system can be changed to obtain the various results and advantages described in this specification. For example, although seven lenses are used as an example in the embodiment, the optical imaging system is not limited to including seven lenses, and the optical imaging system may also include other numbers of lenses if necessary.

[0064] Specific embodiments of the optical imaging system applicable to the above embodiments are further described below with reference to the accompanying drawings. Specific embodiment 1

[0066] Figure 1 Schematic diagram of the lens group structure of embodiment 1 of the optical imaging system of the present invention. The optical imaging system includes, in order from the object side to the image side along the optical axis: an aperture 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, a filter E8 and an imaging surface S17.

[0067] The first lens E1 has positive focal power, and its object side surface S1 is convex, and its image side surface S2 is concave. The second lens E2 has negative focal power, and its object side surface S3 is convex, and its image side surface S4 is concave. The third lens E3 has positive focal power, and its object side surface S5 is convex, and its image side surface S6 is concave. The fourth lens E4 has negative focal power, and its object side surface S7 is convex, and its image side surface S8 is concave. The fifth lens E5 has positive focal power, and its object side surface S9 is convex, and its image side surface S10 is concave. The sixth lens E6 has positive focal power, and its object side surface S11 is convex, and its image side surface S12 is convex. The seventh lens E7 has negative focal power, and its object side surface S13 is convex, and its image side surface S14 is concave. The filter E8 has an object side surface S15 and an image side surface S16. The light from the object passes through each surface of the surfaces S1 to S16 in sequence and is finally imaged on the imaging surface S17.

[0068] As shown in Table 1, it is a basic parameter table of the optical imaging system of Example 1, wherein the units of the radius of curvature, thickness, and focal length are all millimeters (mm).

[0069] Face number Surface type Radius of curvature Thickness / distance focal length Refractive Index Dispersion coefficient Cone coefficient OBJ Spherical endless endless STO Spherical endless -1.5000 S1 Aspheric 3.8729 2.0833 7.69 1.55 56.1 -1.0194 S2 Aspheric 40.5971 0.1000 -0.0370 S3 Aspheric 4.1500 0.4800 -10.08 1.68 19.2 0.0017 S4 Aspheric 2.4602 0.1569 -1.0425 S5 Aspheric 3.2752 1.4033 13.86 1.55 56.1 -0.0044 S6 Aspheric 4.8998 0.0993 -0.0497 S7 Aspheric 4.8238 0.4800 -28.40 1.68 19.2 0.1275 S8 Aspheric 3.7012 0.5692 0.1233 S9 Aspheric 4.3808 0.4800 174.97 1.68 19.2 0.2166 S10 Aspheric 4.3478 0.7636 0.2557 S11 Aspheric 1465.8210 0.8825 19.79 1.68 19.2 -99.0000 S12 Aspheric -13.5144 0.6216 23.9047 S13 Aspheric 12.3878 0.4800 -10.71 1.54 55.7 -69.0042 S14 Aspheric 3.8718 0.1004 -0.2627 S15 Spherical endless 0.2100 1.52 64.2 S16 Spherical endless 0.5900 S17 Spherical endless

[0070] Table 1

[0071] As shown in Table 2, in Example 1, the total effective focal length of the optical imaging system is f=8.60 mm, the distance TTL on the optical axis from the object-side surface S1 of the first lens E1 to the imaging surface S17 is 9.50 mm, half of the diagonal length of the effective pixel area on the imaging surface S17 is ImgH=3.39 mm, and half of the maximum field of view of the optical imaging system is Semi-FOV=20.6°.

[0072]

[0073]

[0074] Table 2

[0075] The optical imaging system in Example 1 satisfies:

[0076] f / EPD=1.23, where f is the effective focal length of the optical imaging system, and EPD is the entrance pupil diameter of the optical imaging system;

[0077] (f1+R1) / f=1.34, where f1 is the effective focal length of the first lens, R1 is the radius of curvature of the object side of the first lens, and f is the effective focal length of the optical imaging system;

[0078] f2 / R3=-2.43, where f2 is the effective focal length of the second lens, and R3 is the radius of curvature of the object side of the second lens;

[0079] f / R4=3.50, where f is the effective focal length of the optical imaging system, and R4 is the radius of curvature of the image side of the second lens;

[0080] f3 / R5=4.23, where f3 is the effective focal length of the third lens, and R5 is the radius of curvature of the object side of the third lens;

[0081] (f4+R8) / f=-2.87, where f4 is the effective focal length of the fourth lens element, R8 is the radius of curvature of the image side of the fourth lens element, and f is the effective focal length of the optical imaging system;

[0082] f6 / R12=-1.46, where f6 is the effective focal length of the sixth lens, and R12 is the radius of curvature of the image side of the sixth lens;

[0083] f7 / R14=-2.77, where f7 is the effective focal length of the seventh lens, and R14 is the radius of curvature of the image side of the seventh lens;

[0084] CT1 / CT2=4.34, where CT1 is the center thickness of the first lens on the optical axis, and CT2 is the center thickness of the second lens on the optical axis;

[0085] CT3 / CT5=2.92, where CT3 is the center thickness of the third lens on the optical axis, and CT5 is the center thickness of the fifth lens on the optical axis;

[0086] 1 / (T45×T34)=17.69mm -2 , wherein T45 is the air interval between the fourth lens and the fifth lens on the optical axis, and T34 is the air interval between the third lens and the fourth lens on the optical axis;

[0087] Semi-FOV = 20.6°, where Semi-FOV is half of the maximum field of view of the optical imaging system;

[0088] TTL / ImgH=2.80, where TTL is the axial distance from the object side of the first lens to the imaging plane, and ImgH is half of the diagonal length of the effective pixel area on the imaging plane.

[0089] In Example 1, the object side surface and the image side surface of any lens among the first lens E1 to the seventh lens E7 are both aspherical surfaces, and the surface shape x of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0090]

[0091] Wherein, x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 1); k is the cone coefficient; Ai is the correction coefficient of the i-th order aspheric surface.

[0092] In Example 1, the object side surface and the image side surface of any one of the first lens E1 to the seventh lens E7 are aspherical surfaces. Table 3 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A51, A52, A53, A54, A55, A56, A57, A58, A5 10 , A 12 , A 14 , A 16 , A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30 .

[0093] Face number A4 A6 A8 A10 A12 A14 A16 S1 2.7313E-01 1.3924E-02 -6.9798E-04 -2.0495E-03 -1.0159E-03 -8.7140E-04 -2.7264E-04 S2 1.4986E-01 -1.3083E-02 1.0912E-03 -3.0562E-03 -1.0568E-03 -7.4243E-05 -1.3774E-04 S3 -2.4520E-01 -8.0467E-04 8.5581E-03 -2.1604E-03 -2.0733E-03 -5.2782E-04 1.6147E-04 S4 1.0756E-01 1.3156E-02 5.9038E-03 -8.0442E-04 -1.1175E-03 -1.6006E-03 1.8635E-04 S5 1.2750E-01 4.3286E-02 7.3338E-03 -2.2457E-03 9.3128E-05 -1.2300E-03 2.0963E-04 S6 -1.1626E-01 1.1227E-02 -3.8562E-03 -7.3267E-03 7.4200E-04 1.1052E-04 -2.1205E-04 S7 -8.1483E-02 -1.2415E-02 5.4465E-03 -2.7659E-03 -3.0099E-05 -3.0352E-04 -3.5629E-04 S8 1.4425E-02 1.7167E-02 1.4554E-02 7.9512E-03 2.6783E-03 1.1057E-03 2.9233E-04 S9 -3.6639E-01 1.6351E-02 3.8030E-03 1.3452E-03 -8.0222E-04 -6.1187E-04 -2.7493E-04 S10 -3.9003E-01 4.9977E-02 8.2077E-03 -2.4601E-03 -3.6824E-03 -1.3989E-03 -6.5685E-05 S11 -5.5371E-01 -4.9822E-02 1.0403E-02 7.5344E-03 1.9229E-03 1.2086E-04 -4.9728E-04 S12 -6.3680E-01 -2.6369E-02 9.3531E-03 1.1781E-02 5.5238E-03 4.8038E-03 1.6304E-03 S13 -1.5458E+00 2.1366E-01 -3.8575E-02 4.2532E-02 4.8074E-03 6.4732E-03 -4.2123E-03 S14 -2.5803E+00 2.1617E-01 -1.2480E-01 2.6864E-02 -9.0301E-03 9.9961E-03 -5.7548E-04 Face number A18 A20 A22 A24 A26 A28 A30 S1 -1.8596E-04 4.2876E-05 -3.6403E-05 4.4527E-05 -2.3372E-05 1.2323E-05 -2.3440E-05 S2 2.2277E-04 -8.3095E-05 4.6480E-05 2.2244E-05 -4.5700E-05 4.4845E-05 -3.1955E-05 S3 1.8726E-05 9.6929E-05 -1.2164E-04 1.6723E-04 -1.2550E-04 7.8945E-05 -3.2688E-05 S4 -2.0547E-04 7.9299E-05 -2.6017E-04 2.3591E-04 -6.5874E-05 2.5574E-06 -6.7301E-06 S5 -3.1869E-04 -1.4752E-05 -3.3621E-04 1.3572E-04 -5.7362E-05 -3.8242E-07 -3.7881E-05 S6 -9.1476E-05 8.9727E-05 -4.5544E-07 5.7712E-06 -1.3705E-05 -6.0715E-06 6.2345E-06 S7 -7.6204E-05 1.1576E-04 5.8346E-06 4.6675E-06 -1.6271E-05 -2.1506E-06 6.4262E-06 S8 1.7197E-04 1.0361E-04 1.0023E-04 5.0299E-05 4.3046E-05 1.1468E-05 1.5105E-05 S9 2.9541E-05 9.0152E-05 1.0123E-04 5.3681E-05 3.8132E-05 1.9895E-05 1.3360E-05 S10 3.8368E-04 2.3503E-04 5.4505E-05 -6.4145E-05 -5.5042E-05 -3.2894E-05 -2.6960E-06 S11 -3.9351E-04 -1.1669E-04 5.0869E-05 1.1382E-04 6.8935E-05 3.5502E-05 5.2521E-06 S12 5.8410E-04 1.8246E-05 -5.2403E-05 -8.7292E-05 -6.8484E-05 -5.1238E-05 -2.8301E-05 S13 -2.2474E-03 -8.0102E-04 3.3405E-04 2.5211E-04 9.9062E-05 3.0894E-05 -4.1448E-05 S14 1.6526E-03 -1.2391E-04 4.8493E-04 -9.9725E-06 1.2883E-04 5.1817E-06 -4.2227E-05

[0094] Table 3

[0095] Figure 2a The axial chromatic aberration curve of the optical imaging system of Example 1 is shown, which indicates that light of different wavelengths deviates from the focal point behind the lens. Figure 2b The astigmatism curve of the optical imaging lens of Example 1 is shown, which indicates the meridional field curvature and the sagittal field curvature. Figure 2c The distortion curve of the optical imaging system of Example 1 is shown, which represents the distortion magnitude values ​​corresponding to different image heights. Figure 2d The magnification chromatic aberration curve of the optical imaging system of Example 1 is shown, which represents the deviation of different image heights on the imaging surface after the light passes through the lens. Figure 2a to Figure 2d It can be seen from the figure that the optical imaging system provided in Example 1 can achieve good imaging quality. Specific embodiment 2

[0097] Figure 3 Schematic diagram of the lens group structure of embodiment 2 of the optical imaging system of the present invention. The optical imaging system includes, in order from the object side to the image side along the optical axis: an aperture 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, a filter E8 and an imaging surface S17.

[0098] The first lens E1 has positive power, and its object side surface S1 is convex, and its image side surface S2 is convex. The second lens E2 has negative power, and its object side surface S3 is convex, and its image side surface S4 is concave. The third lens E3 has positive power, and its object side surface S5 is convex, and its image side surface S6 is concave. The fourth lens E4 has negative power, and its object side surface S7 is convex, and its image side surface S8 is concave. The fifth lens E5 has positive power, and its object side surface S9 is convex, and its image side surface S10 is concave. The sixth lens E6 has positive power, and its object side surface S11 is convex, and its image side surface S12 is convex. The seventh lens E7 has negative power, and its object side surface S13 is convex, and its image side surface S14 is concave. The filter E8 has an object side surface S15 and an image side surface S16. The light from the object passes through each surface of the surfaces S1 to S16 in sequence and is finally imaged on the imaging surface S17.

[0099] As shown in Table 4, it is a basic parameter table of the optical imaging system of Example 2, wherein the units of the radius of curvature, thickness, and focal length are all millimeters (mm).

[0100] Face number Surface type Radius of curvature Thickness / distance focal length Refractive Index Dispersion coefficient Cone coefficient OBJ Spherical endless endless STO Spherical endless -1.5000 S1 Aspheric 3.9409 2.1266 7.18 1.55 56.1 -1.0397 S2 Aspheric -549.9446 0.1981 -95.7730 S3 Aspheric 4.5778 0.5046 -9.77 1.68 19.2 0.0446 S4 Aspheric 2.5844 0.1327 -1.0817 S5 Aspheric 3.4679 1.3877 15.72 1.55 56.1 0.0032 S6 Aspheric 4.9982 0.1063 0.2543 S7 Aspheric 4.9345 0.4649 -22.21 1.68 19.2 0.3933 S8 Aspheric 3.5739 0.5469 0.1675 S9 Aspheric 5.0629 0.4815 140.77 1.68 19.2 0.5888 S10 Aspheric 5.1417 0.7613 0.9165 S11 Aspheric 483.4549 0.9295 19.18 1.68 19.2 99.0000 S12 Aspheric -13.3318 0.5717 25.5624 S13 Aspheric 7.3702 0.4899 -14.39 1.54 55.7 -34.3546 S14 Aspheric 3.6836 0.1698 -0.2425 S15 Spherical endless 0.2100 1.52 64.2 S16 Spherical endless 0.5900 S17 Spherical endless

[0101] Table 4

[0102] As shown in Table 5, in Example 2, the total effective focal length of the optical imaging system is f=8.47 mm, the distance TTL from the object side surface S1 of the first lens E1 to the imaging surface S17 on the optical axis is 9.67 mm, half of the diagonal length of the effective pixel area on the imaging surface S17 is ImgH=3.39 mm, and half of the maximum field angle of the optical imaging system is Semi-FOV=20.3°. The parameters of each relational expression are as explained in the first embodiment, and the values ​​of each relational expression are listed in the following table.

[0103]

[0104] Table 5

[0105] In Example 2, the object side surface and the image side surface of any one of the first lens E1 to the seventh lens E7 are aspherical surfaces. Table 6 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A51, A52, A53, A54, A55, A56, A57, A58, A5 10 , A 12 , A 14 , A 16 , A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30 .

[0106] Face number A4 A6 A8 A10 A12 A14 A16 S1 2.0917E-01 8.1604E-03 1.0651E-03 6.3923E-04 2.5606E-04 -4.6146E-05 -2.7840E-05 S2 1.3726E-01 -1.4651E-02 5.7915E-03 -1.1530E-03 9.0136E-05 -3.6936E-04 2.6466E-04 S3 -1.8587E-01 1.4937E-03 4.6467E-03 -9.3548E-04 -4.7707E-04 -4.8842E-04 5.3944E-04 S4 5.9016E-02 5.3669E-03 4.0561E-03 -5.1986E-04 -5.7623E-04 -9.7816E-04 5.4404E-04 S5 7.8625E-02 1.9721E-02 6.6369E-03 -2.9229E-04 -3.6280E-04 -8.4224E-04 8.4993E-05 S6 -7.0864E-02 1.0858E-02 2.2519E-04 -8.4843E-04 -1.3497E-03 4.6696E-04 -1.4851E-04 S7 -3.4353E-02 -5.0076E-03 -1.8321E-04 4.3579E-04 -1.5069E-03 3.9033E-04 -9.8445E-05 S8 2.9993E-03 3.3699E-03 4.0129E-03 3.1444E-03 -1.8310E-04 1.0082E-04 -1.6155E-04 S9 -3.2364E-01 1.5925E-02 6.1599E-03 3.9981E-03 5.4021E-04 7.5768E-05 -2.9632E-05 S10 -3.4259E-01 4.7132E-02 1.5186E-02 4.3885E-03 -3.4140E-04 -7.2905E-04 -6.8765E-04 S11 -4.6122E-01 -4.0606E-02 7.7796E-03 5.7015E-03 2.1151E-03 1.2493E-03 8.5515E-04 S12 -6.2876E-01 -3.2974E-02 7.4007E-03 6.2875E-03 2.8805E-03 4.2132E-03 2.7633E-03 S13 -1.5572E+00 2.0333E-01 2.3408E-03 4.0605E-02 1.1533E-02 8.1324E-03 -3.3750E-03 S14 -2.6240E+00 1.6241E-01 -7.4537E-02 3.0931E-02 8.5382E-03 1.8991E-02 1.0644E-02 Face number A18 A20 A22 A24 A26 A28 A30 S1 -6.9014E-06 2.0104E-05 1.2118E-05 1.4415E-05 9.7135E-06 8.7766E-06 -1.0060E-06 S2 -1.5893E-04 8.4023E-05 -6.4235E-05 1.4164E-05 -2.8653E-05 -4.3871E-06 -1.0406E-05 S3 -1.1226E-04 9.0456E-05 -4.4191E-05 -2.5038E-06 -2.4495E-05 -1.0792E-05 -4.0641E-06 S4 3.6703E-04 3.6432E-04 2.3708E-04 1.6988E-04 6.6316E-05 -9.6889E-06 -2.1056E-05 S5 1.1379E-04 1.7461E-04 1.5425E-04 1.5329E-04 8.4433E-05 1.1059E-05 -1.6178E-05 S6 -1.2360E-04 -1.9819E-05 -2.2983E-05 3.9304E-06 -1.5505E-06 7.7194E-06 1.1609E-06 S7 -1.0087E-04 -1.2899E-05 -1.5414E-05 3.7673E-06 -4.1313E-06 3.5298E-06 -2.7972E-07 S8 -9.6733E-05 -2.1793E-06 2.8949E-05 3.2320E-05 2.0254E-05 1.1180E-05 3.0806E-06 S9 -1.2319E-05 8.9163E-06 3.5319E-05 3.5595E-05 3.0078E-05 1.4925E-05 7.0686E-06 S10 -5.6742E-04 -4.1122E-04 -2.5244E-04 -1.3270E-04 -5.8562E-05 -2.1897E-05 -5.0327E-06 S11 4.4256E-04 1.0370E-04 -6.2585E-05 -8.9746E-05 -6.7533E-05 -3.7310E-05 -1.6613E-05 S12 1.5510E-03 5.8620E-04 1.8207E-04 4.6957E-06 -2.2772E-05 -2.2835E-05 -5.3756E-06 S13 -4.6110E-03 -2.4453E-03 -2.0004E-04 3.6759E-04 4.5013E-04 2.8521E-04 1.7544E-04 S14 7.8196E-03 4.6854E-03 3.2891E-03 1.8852E-03 1.0616E-03 4.3674E-04 2.1375E-04

[0107] Table 6

[0108] Figure 4a The axial chromatic aberration curve of the optical imaging system of Example 2 is shown, which indicates that light of different wavelengths deviates from the focal point behind the lens. Figure 4b The astigmatism curve of the optical imaging lens of Example 2 is shown, which indicates the meridional field curvature and the sagittal field curvature. Figure 4c The distortion curve of the optical imaging system of Example 2 is shown, which represents the distortion magnitude values ​​corresponding to different image heights. Figure 4d The magnification chromatic aberration curve of the optical imaging system of Example 2 is shown, which represents the deviation of different image heights on the imaging surface after the light passes through the lens. Figures 4a to 4d It can be seen from the figure that the optical imaging system provided in Example 2 can achieve good imaging quality. Specific embodiment 3

[0110] Figure 5 Schematic diagram of the lens group structure of embodiment 3 of the optical imaging system of the present invention. The optical imaging system includes, in order from the object side to the image side along the optical axis: an aperture 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, a filter E8 and an imaging surface S17.

[0111] The first lens E1 has positive focal power, and its object side surface S1 is convex, and its image side surface S2 is concave. The second lens E2 has negative focal power, and its object side surface S3 is convex, and its image side surface S4 is concave. The third lens E3 has positive focal power, and its object side surface S5 is convex, and its image side surface S6 is concave. The fourth lens E4 has negative focal power, and its object side surface S7 is convex, and its image side surface S8 is concave. The fifth lens E5 has negative focal power, and its object side surface S9 is convex, and its image side surface S10 is concave. The sixth lens E6 has positive focal power, and its object side surface S11 is convex, and its image side surface S12 is convex. The seventh lens E7 has negative focal power, and its object side surface S13 is convex, and its image side surface S14 is concave. The filter E8 has an object side surface S15 and an image side surface S16. The light from the object passes through each surface of the surfaces S1 to S16 in sequence and is finally imaged on the imaging surface S17.

[0112] As shown in Table 7, it is a basic parameter table of the optical imaging system of Example 3, wherein the units of the radius of curvature, thickness, and focal length are all millimeters (mm).

[0113]

[0114]

[0115] Table 7

[0116] As shown in Table 8, in Example 3, the total effective focal length f of the optical imaging system is 8.45 mm, the distance TTL from the object side surface S1 of the first lens E1 to the imaging surface S17 on the optical axis is 9.59 mm, half of the diagonal length of the effective pixel area on the imaging surface S17 is ImgH=3.39 mm, and half of the maximum field angle Semi-FOV of the optical imaging system is 20.5°. The parameters of each relational expression are as explained in the first embodiment, and the values ​​of each relational expression are listed in the following table.

[0117]

[0118] Table 8

[0119] In Example 3, the object side surface and the image side surface of any one of the first lens E1 to the seventh lens E7 are aspherical surfaces. Table 9 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A51, A52, A53, A54, A55, A56, A57, A58, A59, A60, A61, A71, A72, A73, A74, A75 10 , A 12 , A 14 , A 16 , A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30 .

[0120]

[0121]

[0122] Table 9

[0123] Figure 6a The axial chromatic aberration curve of the optical imaging system of Example 3 is shown, which indicates that light of different wavelengths deviates from the focal point behind the lens. Figure 6b The astigmatism curve of the optical imaging lens of Example 3 is shown, which indicates the meridional field curvature and the sagittal field curvature. Figure 6c The distortion curve of the optical imaging system of Example 3 is shown, which represents the distortion magnitude values ​​corresponding to different image heights. Figure 6d The magnification chromatic aberration curve of the optical imaging system of Example 3 is shown, which represents the deviation of different image heights on the imaging surface after the light passes through the lens. Figures 6a to 6d It can be seen from the figure that the optical imaging system provided in Example 3 can achieve good imaging quality. Specific embodiment 4

[0125] Figure 7Schematic diagram of the lens group structure of embodiment 4 of the optical imaging system of the present invention. The optical imaging system includes, in order from the object side to the image side along the optical axis: an aperture 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, a filter E8 and an imaging surface S17.

[0126] The first lens E1 has positive power, and its object side surface S1 is convex, and its image side surface S2 is concave. The second lens E2 has negative power, and its object side surface S3 is convex, and its image side surface S4 is concave. The third lens E3 has positive power, and its object side surface S5 is convex, and its image side surface S6 is concave. The fourth lens E4 has negative power, and its object side surface S7 is concave, and its image side surface S8 is concave. The fifth lens E5 has positive power, and its object side surface S9 is convex, and its image side surface S10 is concave. The sixth lens E6 has positive power, and its object side surface S11 is convex, and its image side surface S12 is convex. The seventh lens E7 has negative power, and its object side surface S13 is convex, and its image side surface S14 is concave. The filter E8 has an object side surface S15 and an image side surface S16. The light from the object passes through each surface of the surfaces S1 to S16 in sequence and is finally imaged on the imaging surface S17.

[0127] As shown in Table 10, it is a basic parameter table of the optical imaging system of Example 4, wherein the units of the radius of curvature, thickness, and focal length are all millimeters (mm).

[0128]

[0129]

[0130] Table 10

[0131] As shown in Table 11, in Example 4, the total effective focal length f of the optical imaging system is 8.26 mm, the distance TTL from the object side surface S1 of the first lens E1 to the imaging surface S17 on the optical axis is 10.04 mm, half of the diagonal length of the effective pixel area on the imaging surface S17 is ImgH=3.39 mm, and half of the maximum field angle Semi-FOV of the optical imaging system is 21.2°. The parameters of each relational expression are as explained in the first embodiment, and the values ​​of each relational expression are listed in the following table.

[0132]

[0133] Table 11

[0134] In Example 4, the object side surface and the image side surface of any one of the first lens E1 to the seventh lens E7 are aspherical surfaces. Table 12 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A51, A52, A53, A54, A55, A56, A57, A58, A 10 , A12 , A 14 , A 16 , A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30 .

[0135]

[0136]

[0137] Table 12

[0138] Figure 8a The axial chromatic aberration curve of the optical imaging system of Example 4 is shown, which indicates that light of different wavelengths deviates from the focal point behind the lens. Figure 8b The astigmatism curve of the optical imaging lens of Example 4 is shown, which indicates the meridional field curvature and the sagittal field curvature. Figure 8c The distortion curve of the optical imaging system of Example 4 is shown, which represents the distortion magnitude values ​​corresponding to different image heights. Figure 8d The magnification chromatic aberration curve of the optical imaging system of Example 4 is shown, which represents the deviation of different image heights on the imaging surface after the light passes through the lens. Figures 8a to 8d It can be seen from the figure that the optical imaging system provided in Example 4 can achieve good imaging quality. Specific embodiment 5

[0140] Fig. 9 Schematic diagram of the lens group structure of embodiment 5 of the optical imaging system of the present invention. The optical imaging system includes, in order from the object side to the image side along the optical axis: an aperture 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, a filter E8 and an imaging surface S17.

[0141] The first lens E1 has positive focal power, and its object side surface S1 is convex, and its image side surface S2 is concave. The second lens E2 has negative focal power, and its object side surface S3 is convex, and its image side surface S4 is concave. The third lens E3 has positive focal power, and its object side surface S5 is convex, and its image side surface S6 is convex. The fourth lens E4 has negative focal power, and its object side surface S7 is convex, and its image side surface S8 is concave. The fifth lens E5 has positive focal power, and its object side surface S9 is convex, and its image side surface S10 is concave. The sixth lens E6 has positive focal power, and its object side surface S11 is convex, and its image side surface S12 is convex. The seventh lens E7 has negative focal power, and its object side surface S13 is convex, and its image side surface S14 is concave. The filter E8 has an object side surface S15 and an image side surface S16. The light from the object passes through each surface of the surfaces S1 to S16 in sequence and is finally imaged on the imaging surface S17.

[0142] As shown in Table 13, it is a basic parameter table of the optical imaging system of Example 5, wherein the units of the radius of curvature, thickness, and focal length are all millimeters (mm).

[0143] Face number Surface type Radius of curvature Thickness / distance focal length Refractive Index Dispersion coefficient Cone coefficient OBJ Spherical endless endless STO Spherical endless -1.5000 S1 Aspheric 4.0980 2.0281 8.13 1.55 56.1 -0.9926 S2 Aspheric 43.7879 0.1035 3.3036 S3 Aspheric 3.9894 0.5280 -24.96 1.68 19.2 0.0609 S4 Aspheric 3.0551 0.4418 -1.1423 S5 Aspheric 5.3528 1.4326 9.00 1.55 56.1 -0.1526 S6 Aspheric -54.1332 0.1000 -93.1417 S7 Aspheric 265.3639 0.5382 -5.73 1.68 19.2 99.0000 S8 Aspheric 3.8180 0.3712 0.0220 S9 Aspheric 4.5018 0.5454 52.39 1.68 19.2 1.3217 S10 Aspheric 4.9041 0.5109 0.7616 S11 Aspheric 52.4741 1.1390 19.58 1.68 19.2 99.0000 S12 Aspheric -17.5745 0.4090 40.6580 S13 Aspheric 8.7034 1.0517 -16.07 1.54 55.7 -38.7732 S14 Aspheric 4.1488 0.1180 0.5748 S15 Spherical endless 0.2100 1.52 64.2 S16 Spherical endless 0.5900 S17 Spherical endless

[0144] Table 13

[0145] As shown in Table 14, in Example 5, the total effective focal length f of the optical imaging system is 8.39 mm, the distance TTL from the object side surface S1 of the first lens E1 to the imaging surface S17 on the optical axis is 10.12 mm, half of the diagonal length of the effective pixel area on the imaging surface S17 is ImgH=3.39 mm, and half of the maximum field angle of the optical imaging system is Semi-FOV=21.3°. The parameters of each relational expression are as explained in the first embodiment, and the values ​​of each relational expression are listed in the following table.

[0146]

[0147]

[0148] Table 14

[0149] In Example 5, the object side surface and the image side surface of any one of the first lens E1 to the seventh lens E7 are aspherical surfaces. Table 15 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A 10 , A 12 , A 14 , A 16 , A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A30 .

[0150] Face number A4 A6 A8 A10 A12 A14 A16 S1 2.6624E-01 1.2440E-02 -3.6620E-03 -2.7182E-03 -1.9711E-03 -1.5235E-03 -8.8899E-04 S2 1.4270E-01 -6.7279E-03 -2.5931E-03 -3.5193E-03 -3.3096E-03 -1.4476E-03 9.3750E-05 S3 -1.9923E-01 2.8831E-03 1.0452E-02 -4.5430E-04 -2.6296E-03 -2.5135E-03 -3.6664E-04 S4 9.1639E-02 2.0075E-02 1.3021E-02 -1.4448E-03 -1.9347E-03 -2.5746E-03 -1.4466E-03 S5 1.1483E-01 3.0449E-02 7.6172E-03 -2.8056E-03 -1.0257E-03 -1.3468E-03 -1.1591E-03 S6 -6.6763E-02 1.4033E-02 -1.0128E-03 -2.0549E-03 2.0300E-04 -3.7814E-04 -2.0196E-04 S7 -6.6330E-02 -1.1149E-02 2.2166E-03 -1.0473E-03 -2.6052E-04 -5.4903E-05 -1.9299E-04 S8 5.8022E-03 -6.1747E-03 2.3791E-03 2.7431E-03 5.0548E-04 9.2316E-04 4.1547E-04 S9 -3.2024E-01 1.5420E-02 3.5692E-04 3.1921E-03 2.6283E-05 4.7493E-04 2.9068E-04 S10 -3.4969E-01 3.9692E-02 9.0626E-03 3.3605E-03 -1.4939E-03 -6.2906E-04 -3.9109E-04 S11 -3.2568E-01 -1.0803E-02 5.7102E-03 2.4909E-03 -1.7165E-03 -1.1913E-03 -7.3068E-04 S12 -5.6028E-01 3.3637E-02 -8.3214E-03 6.1627E-03 -1.2216E-03 7.9170E-04 2.0357E-04 S13 -1.1725E+00 1.2674E-01 -2.9777E-02 1.0154E-02 -2.0057E-04 2.0245E-03 6.6865E-04 S14 -2.4146E+00 1.7564E-02 -8.0192E-02 5.9154E-03 -6.8155E-03 -2.0511E-04 -2.2309E-04 Face number A18 A20 A22 A24 A26 A28 A30 S1 -4.5000E-04 -2.1941E-04 -8.6267E-05 -3.0482E-05 -1.4467E-05 -6.9668E-07 -9.8617E-06 S2 -2.0118E-04 1.7873E-04 2.7409E-05 -1.8379E-05 2.6783E-05 -2.5483E-05 5.8358E-06 S3 -3.1825E-04 -5.5545E-05 7.2228E-05 -9.1665E-05 3.3803E-06 -2.1230E-05 -1.1209E-05 S4 -6.5715E-04 -5.4701E-05 2.2714E-04 8.4868E-05 3.4779E-05 2.8303E-06 -1.6940E-05 S5 -4.9967E-04 -2.0841E-06 1.4262E-04 5.8576E-05 1.3644E-05 -6.4040E-06 -1.2511E-05 S6 1.4044E-04 -1.8690E-05 1.3529E-05 3.4332E-06 -2.7308E-06 5.0413E-06 -4.1032E-06 S7 1.3233E-04 -3.3644E-05 3.8274E-06 3.2245E-06 1.2169E-06 4.3675E-07 -4.5004E-06 S8 2.8349E-04 4.1156E-05 -1.3754E-05 -1.1776E-05 -2.3137E-08 1.2221E-05 4.5887E-06 S9 2.3892E-04 6.7116E-05 -1.0873E-05 -3.1687E-05 -1.8571E-05 -1.0527E-05 -4.6775E-07 S10 -1.4895E-04 -1.6172E-04 -1.1680E-04 -8.7050E-05 -3.1812E-05 -1.3195E-05 2.2487E-06 S11 -4.7363E-04 -4.1651E-04 -3.2916E-04 -2.3856E-04 -1.5122E-04 -8.4986E-05 -3.9313E-05 S12 2.5803E-04 1.9861E-05 2.9415E-05 -2.6557E-05 -8.4915E-06 -1.4510E-05 1.3881E-05 S13 2.1565E-04 -1.1918E-04 -2.2017E-06 -3.9320E-05 2.4466E-06 -4.2120E-05 2.1436E-05 S14 -7.2420E-05 -1.0894E-04 -4.2044E-05 -2.2763E-06 3.0075E-05 2.2850E-05 -5.3717E-06

[0151] Table 15

[0152] Fig.10a The axial chromatic aberration curve of the optical imaging system of Example 5 is shown, which indicates that light of different wavelengths deviates from the focal point behind the lens. Fig.10b An astigmatism curve of the optical imaging system of Example 5 is shown, which indicates meridional field curvature and sagittal field curvature. Fig.10c The distortion curve of the optical imaging system of Example 5 is shown, which represents the distortion magnitude values ​​corresponding to different image heights. Fig.10d The magnification chromatic aberration curve of the optical imaging system of Example 5 is shown, which represents the deviation of different image heights on the imaging surface after the light passes through the lens. Figures 10a to 10d It can be seen from the figure that the optical imaging system provided in Example 5 can achieve good imaging quality. Specific embodiment 6

[0154] Fig.11 Schematic diagram of the lens group structure of embodiment 6 of the optical imaging system of the present invention. The optical imaging system includes, in order from the object side to the image side along the optical axis: an aperture 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, a filter E8 and an imaging surface S17.

[0155] The first lens E1 has positive focal power, and its object side surface S1 is convex, and its image side surface S2 is concave. The second lens E2 has negative focal power, and its object side surface S3 is convex, and its image side surface S4 is concave. The third lens E3 has positive focal power, and its object side surface S5 is convex, and its image side surface S6 is concave. The fourth lens E4 has negative focal power, and its object side surface S7 is convex, and its image side surface S8 is concave. The fifth lens E5 has positive focal power, and its object side surface S9 is convex, and its image side surface S10 is concave. The sixth lens E6 has positive focal power, and its object side surface S11 is concave, and its image side surface S12 is convex. The seventh lens E7 has negative focal power, and its object side surface S13 is convex, and its image side surface S14 is concave. The filter E8 has an object side surface S15 and an image side surface S16. The light from the object passes through each surface of the surfaces S1 to S16 in sequence and is finally imaged on the imaging surface S17.

[0156] As shown in Table 16, it is a basic parameter table of the optical imaging system of Example 6, wherein the units of the radius of curvature, thickness, and focal length are all millimeters (mm).

[0157] Face number Surface type Radius of curvature Thickness / distance focal length Refractive Index Dispersion coefficient Cone coefficient OBJ Spherical endless endless STO Spherical endless -1.5000 S1 Aspheric 3.8676 2.0821 7.73 1.55 56.1 -1.0241 S2 Aspheric 37.7731 0.1079 6.1984 S3 Aspheric 4.1264 0.4814 -10.25 1.68 19.2 0.0011 S4 Aspheric 2.4653 0.1938 -1.0410 S5 Aspheric 3.2766 1.4018 13.10 1.55 56.1 -0.0047 S6 Aspheric 5.1335 0.1000 -0.0602 S7 Aspheric 5.0690 0.4800 -25.15 1.68 19.2 0.1564 S8 Aspheric 3.7567 0.5576 0.0949 S9 Aspheric 4.5579 0.5095 91.25 1.68 19.2 0.2003 S10 Aspheric 4.6990 0.7721 0.3860 S11 Aspheric -55.5937 0.8966 23.49 1.68 19.2 59.4569 S12 Aspheric -12.4454 0.6058 23.0479 S13 Aspheric 10.9740 0.4863 -11.35 1.54 55.7 -69.3238 S14 Aspheric 3.8562 0.1124 -0.2397 S15 Spherical endless 0.2100 1.52 64.2 S16 Spherical endless 0.5900 S17 Spherical endless

[0158] Table 16

[0159] As shown in Table 17, in Example 6, the total effective focal length f of the optical imaging system is 8.48 mm, the distance TTL from the object side surface S1 of the first lens E1 to the imaging surface S17 on the optical axis is 9.59 mm, half of the diagonal length of the effective pixel area on the imaging surface S17 is ImgH=3.39 mm, and half of the maximum field angle Semi-FOV of the optical imaging system is 20.5°. The parameters of each relational expression are as explained in the first embodiment, and the values ​​of each relational expression are listed in the following table.

[0160]

[0161] Table 17

[0162] In Example 6, the object side surface and the image side surface of any one of the first lens E1 to the seventh lens E7 are aspherical surfaces. Table 18 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A51, A52, A53, A54, A55, A56, A57, A58, A 10 , A 12 , A 14 , A 16 , A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30 .

[0163]

[0164]

[0165] Table 18

[0166] Fig.12a The axial chromatic aberration curve of the optical imaging system of Example 6 is shown, which indicates that light of different wavelengths deviates from the focal point behind the lens. Figure 12b An astigmatism curve of the optical imaging system of Example 6 is shown, which indicates meridional field curvature and sagittal field curvature. Fig.12c The distortion curve of the optical imaging system of Example 6 is shown, which represents the distortion magnitude values ​​corresponding to different image heights. Fig.12d The magnification chromatic aberration curve of the optical imaging system of Example 6 is shown, which represents the deviation of different image heights on the imaging surface after the light passes through the lens. Figures 12a to 12d It can be seen from the figure that the optical imaging system provided in Example 6 can achieve good imaging quality.

[0167] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, improvements, equivalent substitutions, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An optical imaging system, characterized in that: The optical imaging system has seven lenses with optical power, and the seven lenses include, in order from the object side to the image side along the optical axis: Aperture; A first lens having positive optical power, whose object side surface is convex; The second lens has a negative optical power, and its object side surface is convex and its image side surface is concave; a third lens having optical power and having a convex object-side surface; The fourth lens element has negative power and its image side surface is concave; a fifth lens having optical power, wherein the object side surface is convex and the image side surface is concave; a sixth lens element having positive refractive power and having a convex image-side surface; The seventh lens element has a negative optical power, and its object side surface is convex and its image side surface is concave; The effective focal length f of the optical imaging system and the curvature radius R4 of the image side surface of the second lens satisfy: 2.75≤f / R4≤3.5; The effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy: 1.22≤f / EPD≤1.

27.

2. The optical imaging system according to claim 1, characterized in that: The effective focal length f1 of the first lens, the curvature radius R1 of the object side of the first lens, and the effective focal length f of the optical imaging system satisfy: 1.31≤(f1+R1) / f≤1.

53.

3. The optical imaging system according to claim 1, characterized in that: The effective focal length f2 of the second lens and the curvature radius R3 of the object side surface of the second lens satisfy: -6.33≤f2 / R3≤-2.

13.

4. The optical imaging system according to claim 1, characterized in that: The effective focal length f3 of the third lens and the curvature radius R5 of the object side surface of the third lens satisfy: 1.68≤f3 / R5≤4.

53.

5. The optical imaging system according to claim 1, characterized in that: The effective focal length f4 of the fourth lens, the curvature radius R8 of the image side surface of the fourth lens and the effective focal length f of the optical imaging system satisfy: -2.87≤(f4+R8) / f≤-0.

18.

6. The optical imaging system according to claim 1, characterized in that: The effective focal length f6 of the sixth lens and the curvature radius R12 of the image-side surface of the sixth lens satisfy: -1.89≤f6 / R12≤-1.

11.

7. The optical imaging system according to claim 1, characterized in that: The effective focal length f7 of the seventh lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: -4.95≤f7 / R14≤-2.

77.

8. The optical imaging system according to claim 1, characterized in that: A center thickness CT1 of the first lens on the optical axis and a center thickness CT2 of the second lens on the optical axis satisfy: 3.78≤CT1 / CT2≤4.

34.

9. The optical imaging system according to claim 1, characterized in that: A center thickness CT3 of the third lens on the optical axis and a center thickness CT5 of the fifth lens on the optical axis satisfy: 2.59≤CT3 / CT5≤3.

03.

10. The optical imaging system according to claim 1, characterized in that: The air interval T45 between the fourth lens and the fifth lens on the optical axis and the air interval T34 between the third lens and the fourth lens on the optical axis meet the following conditions: 17.20 mm -2 ≤1 / (T45×T34)≤26.94mm -2 .

11. The optical imaging system according to claim 1, characterized in that: Half of the maximum field of view Semi-FOV of the optical imaging system satisfies: 20.3°≤Semi-FOV≤21.3°.

12. The optical imaging system according to claim 1, characterized in that: The axial distance TTL from the object side of the first lens to the imaging plane and half the diagonal length of the effective pixel area on the imaging plane ImgH satisfy the following: 2.80≤TTL / ImgH≤2.99.

Images