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 positive focal power; a second lens with focal power; a third lens with focal power; a fourth lens with focal power; a fifth lens with focal power; a sixth lens with focal power, whose object side surface is convex; and a seventh lens with positive focal 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<1.3; the axial distance TTL from the object side surface of the first lens to the imaging surface and the half of the maximum field angle Semi-FOV of the optical imaging system satisfy: 3.0mm<TTL×Tan(Semi-FOV)<4.0mm. The optical imaging system provided by the present invention has a long focal depth and a large aperture characteristic, which can better realize the small depth of field characteristics such as prominent portraits and blurred backgrounds, meet the needs of portrait photography, and the large aperture characteristic can have enough light beams passing through the imaging system, so it has good weak light imaging quality.

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] The optical imaging module is undoubtedly a revolutionary innovation in smartphones, and has become an indispensable standard configuration for smartphones at this stage. When using smartphones, taking out the phone to take pictures anytime and anywhere has become a fashion trend, which has greatly enriched the material and spiritual life of the people, and the optical imaging module is an important carrier of this trend. With the further demand for smartphones, the optical imaging module is also constantly updated and iterated, from the initial clear shooting to the current good-looking shooting, and the future easy shooting of blockbuster texture. In daily shooting applications, portrait photography is an extremely important application scenario. A portrait lens with a large aperture and small depth of field can undoubtedly achieve high-definition partial close-ups of characters and good background blur, satisfying consumers' dreams of taking blockbuster movies at will, so it has huge application prospects.

[0003] Based on this, a compact optical imaging system with a long focal depth is needed, which also has a large aperture characteristic, can better achieve small depth of field characteristics such as portrait prominence and background blur, and meet the needs of portrait photography. In addition, its large aperture characteristic can have enough light beams passing through the imaging system, so it has good low-light imaging quality and achieves good complementary performance with other camera modules. Summary of the invention

[0004] The present invention aims to provide an optical imaging system composed of seven lenses, which has a long focal depth and a large aperture characteristic, and can better achieve small depth of field characteristics such as prominent portraits and blurred backgrounds to meet the needs of portrait photography. The large aperture characteristic can allow sufficient light beams to pass through the imaging system, so it has good low-light imaging quality and achieves good complementary performance with other camera modules.

[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 positive optical power; a second lens with optical power; a third lens with optical power; a fourth lens with optical power; a fifth lens with optical power; a sixth lens with optical power, whose image side surface is convex; and a seventh lens with positive optical 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<1.3.

[0007] According to one embodiment of the present invention, the effective focal length f1 of the first lens, the curvature radius R2 of the image-side surface of the first lens, and the effective focal length f of the optical imaging system satisfy: 1.0<(f1+|R2|) / f<3.0.

[0008] According to one embodiment of the present invention, the effective focal length f3 of the third lens and the effective focal length f of the optical imaging system satisfy: -1.0<f3 / f<0.

[0009] 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: -5.0<f6 / R12<-1.0.

[0010] According to one embodiment of the present invention, the effective focal length f4 of the fourth lens and the effective focal length f5 of the fifth lens satisfy: 0<|f4 / f5|<9.0.

[0011] According to one embodiment of the present invention, a curvature radius R5 of the object-side surface of the third lens and a curvature radius R6 of the image-side surface of the third lens satisfy: 1.0<R5 / R6<2.5.

[0012] According to one embodiment of the present invention, a curvature radius R9 of the object-side surface of the fifth lens and a curvature radius R14 of the image-side surface of the seventh lens satisfy: 1.0<R9 / R14<5.0.

[0013] According to one embodiment of the present invention, a curvature radius R11 of the object side surface of the sixth lens and a curvature radius R7 of the object side surface of the fourth lens satisfy: 1.0<|R11 / R7|<5.5.

[0014] According to one embodiment of the present invention, a center thickness CT2 of the second lens on the optical axis and a center thickness CT3 of the third lens on the optical axis satisfy: 4.0<CT2 / CT3<7.5.

[0015] According to one embodiment of the present invention, an air interval T45 between the fourth lens and the fifth lens on the optical axis and a center thickness CT4 of the fourth lens on the optical axis satisfy: 3.0<T45 / CT4<8.0.

[0016] According to one embodiment of the present invention, the center thickness CT3 of the third lens on the optical axis and the center thickness CT6 of the sixth lens on the optical axis satisfy: 4.5 mm -2 <1 / (CT3×CT6)<13.5mm -2 .

[0017] According to one embodiment of the present invention, the on-axis distance TTL from the object side surface of the first lens to the imaging surface and half of the maximum field of view Semi-FOV of the optical imaging system satisfy: 3.0mm<TTL×Tan(Semi-FOV)<4.0mm.

[0018] According to one embodiment of the present invention, the refractive index N7 of the seventh lens satisfies: N7>1.6.

[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 positive optical power; a second lens with optical power; a third lens with optical power; a fourth lens with optical power; a fifth lens with optical power; a sixth lens with optical power, whose object side surface is convex; and a seventh lens with positive optical 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 on-axis distance TTL from the object side of the first lens to the imaging surface and half of the maximum field of view Semi-FOV of the optical imaging system satisfy: 3.0mm<TTL×Tan(Semi-FOV)<4.0mm.

[0021] Beneficial effects of the present invention:

[0022] The optical imaging system provided by the present invention includes multiple lenses, such as the first lens to the seventh lens. The optical imaging system of the present invention has a long focal depth and a large aperture characteristic, which can well achieve small depth of field characteristics such as prominent portraits and blurred backgrounds, meet the needs of portrait photography, and the large aperture characteristic can have sufficient light beams passing through the imaging system, so it has good low-light imaging quality and achieves good complementary performance with other camera modules. 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 3Schematic 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. 9 Schematic 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 is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

[0041] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal way unless explicitly defined in this article.

[0042] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can 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 drawings and in combination with the embodiments.

[0043] Exemplary Embodiments

[0044] The optical imaging system of an exemplary embodiment of the present invention includes seven lenses, which include, in order from the object side to the image side along the optical axis: an aperture, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens, wherein each lens is independent of each other and has an air gap on the optical axis.

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

[0046] In the present 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 < 1.3. By controlling the ratio of the effective focal length of the imaging system to the entrance pupil diameter, while optimizing the wide-angle characteristics of the system, the lens can obtain sufficient light intensity to ensure that there is sufficient light beam at the image plane, and optimize the imaging quality in the evening or in a weak light environment. More specifically, f and EPD satisfy: 1 < f / EPD < 1.25. For example, 1.18 ≤ f / EPD ≤ 1.23.

[0047] In the present exemplary embodiment, the conditional formula satisfied by the effective focal length f1 of the first lens, the radius of curvature R2 of the image side of the first lens, and the effective focal length f of the optical imaging system is: 1.0 < (f1 + |R2|) / f < 3.0. By controlling the ratio of the sum of the focal length of the first lens and the radius of curvature of the image side of the first lens to the value of the effective focal length of the optical imaging system, the values of the radius of curvature and the optical power of the first lens can be effectively controlled, thereby reducing the sensitivity of the lens and avoiding overly strict tolerance requirements. Controlling this value can also cooperate with the entire system through cross-distribution to better complement and eliminate positive and negative spherical aberrations and chromatic aberrations of magnification in different fields of view, thereby improving the resolution level of the entire system. More specifically, f1, R2, and f satisfy: 1.1 < (f1 + |R2|) / f < 2.8. For example, 1.18 ≤ (f1 + |R2|) / f ≤ 2.79.

[0048] In the present exemplary embodiment, the conditional formula satisfied by the effective focal length f3 of the third lens and the effective focal length f of the optical imaging system is: -1.0 < f3 / f < 0. Reasonably configuring the effective focal length of the third lens can effectively reduce the sensitivity of the lens, avoid overly strict tolerance requirements for addition, and balance the spherical aberration, chromatic aberration, and astigmatism generated by the third lens. More specifically, f3 and f satisfy: -0.8 < f3 / f < -0.6. For example, -0.75 ≤ f3 / f ≤ -0.64.

[0049] 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: -5.0 < f6 / R12 < -1.0. Reasonably distributing the radius of curvature of the image side surface of the sixth lens can ensure that the radius of curvature of the optical surface of the image side of the sixth lens does not exceed the tolerance, control the sagitta height of the lens within a reasonable range, slow down the deflection of light in the sixth lens, effectively reduce the sensitivity of the lens, and at the same time facilitate the convergence of light, avoiding total internal reflection on the lens surface and the generation of ghost images. More specifically, f6 and R12 satisfy: -4.9 < f6 / R12 < -1.3. For example, -4.80 ≤ f6 / R12 ≤ -1.37.

[0050] In the present exemplary embodiment, the conditional expression satisfied by the effective focal length f4 of the fourth lens and the effective focal length f5 of the fifth lens is: 0 < |f4 / f5| < 9.0. Reasonably distributing the effective focal length values of the fourth and fifth lenses can better balance problems such as distortion and astigmatism of the entire system. In addition, a larger image plane can be obtained by controlling this ratio, matching a larger imaging image plane, and achieving higher imaging quality. More specifically, f4 and f5 satisfy: 1.3 < |f4 / f5| < 8.8. For example, 1.32 ≤ |f4 / f5| ≤ 8.78.

[0051] In the present exemplary embodiment, the conditional expression satisfied by the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens is: 1.0 < R5 / R6 < 2.5. Reasonably controlling the numerical values of the radius of curvature of the object side surface and the image side surface of the third lens can ensure that the light passing through the third lens has good convergence ability, slow down the refraction angle of light, and reduce sensitivity. Ensure that the lens has a large light transmission amount, and avoid excessive tilt angle of the lens surface shape caused by overly steep light, thereby causing process problems in actual processing and forming. More specifically, R5 and R6 satisfy: 2 < R5 / R6 < 2.4. For example, 2.07 ≤ R5 / R6 ≤ 2.36.

[0052] In the present exemplary embodiment, the conditional expression satisfied by the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R14 of the image side surface of the seventh lens is: 1.0 < R9 / R14 < 5.0. Reasonably controlling the ratio of the radius of curvature of the object side surface of the fifth lens and the image side surface of the seventh lens can avoid the processing difficulty caused by excessive mirror surface tilt angle, and at the same time reduce the process sensitivity of the fifth lens, avoiding strict tolerance limits and demanding processing processes, and effectively buffering the coma and field curvature of the lens. More specifically, R9 and R14 satisfy: 1.0 < R9 / R14 < 4.6. For example, 1.03 ≤ R9 / R14 ≤ 4.50.

[0053] In this exemplary embodiment, the conditional expression satisfied by the radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R7 of the object side surface of the fourth lens is: 1.0 < |R11 / R7| < 5.5. Reasonably controlling the ratio of the radius of curvature of the object side surface of the fourth lens to that of the sixth lens can avoid the processing difficulty caused by an excessive mirror surface inclination angle, and at the same time can reduce the process sensitivity of the fifth lens. Cooperating with the third lens of the optical system can ensure better convergence of external light and effectively balance the spherical aberration and field curvature of the optical system. More specifically, R11 and R7 satisfy: 1.1 < |R11 / R7| < 5.2. For example, 1.16 ≤ |R11 / R7| ≤ 5.12.

[0054] In this exemplary embodiment, the conditional expression satisfied by the central thickness CT2 of the second lens on the optical axis and the central thickness CT3 of the third lens on the optical axis is: 4.0 mm -2 <(CT2 × CT3)<7.5 mm -2 。Reasonably distributing the ratio range of the central thickness of the second lens to the central thickness of the third lens can achieve an orderly combination of the thicknesses of these two lenses. This combination mode has a good canceling effect on positive and negative spherical aberrations, positive and negative astigmatisms, positive and negative distortions, and axial chromatic aberrations to a certain extent, and has a good complementary buffering effect on the performance under different temperature environments, showing better temperature drift performance. More specifically, CT2 and CT3 satisfy: 4.3 mm -2 <(CT2 × CT3) < 6 mm -2 ,For example, 4.32 mm -2 ≤(CT2 × CT3) ≤ 5.72 mm -2 。

[0055] In this 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 central thickness CT4 of the fourth lens on the optical axis is: 3.0 < T45 / CT4 < 8.0. Reasonably adjusting the central thickness of the fourth lens on the optical axis and the size of the air gap between the fourth lens and the fifth lens on the optical axis, and cooperatively controlling the ratio range of the two can better balance the distortion of the system. Through this cooperative control, the ghost image energy between the fourth lens and the fifth lens can be appropriately reduced, and better imaging quality of the system can be ensured. More specifically, T45 and CT4 satisfy: 3.2 < T45 / CT4 < 5. For example, 3.26 ≤ T45 / CT4 ≤ 4.39.

[0056] In this exemplary embodiment, the conditional expression satisfied by the central thickness CT3 of the third lens on the optical axis and the central thickness CT6 of the sixth lens on the optical axis is: 4.5 < 1 / CT3 / CT6 < 13.5. By reasonably allocating the combination of the central thicknesses of the third lens and the sixth lens on the optical axis and jointly constraining them in the form of the reciprocal of the product, it is possible to avoid the processing difficulties caused by too thin central thickness of the lens, cooperate with the fourth lens of the optical system to effectively reduce the coma of the system, and at the same time have a good improvement in the ghost image and the MTF design value. More specifically, CT3 and CT6 satisfy: 4.9 < 1 / CT3 / CT6 < 13.5. For example, 4.95 ≤ 1 / CT3 / CT6 ≤ 13.49.

[0057] In this 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 maximum field of view Semi-FOV of the optical imaging system is: 3.0 mm < TTL × Tan(Semi-FOV) < 4.0 mm. By controlling the product of the total length dimension of the optical system and the maximum half field of view angle of the optical system to satisfy the above constraint conditions, while ensuring that the optical system has a smaller size, the maximum half field of view angle of the lens can be increased as much as possible to obtain object surface information within a larger angular range. By controlling this value, the miniaturization and portability of the system can be promoted, and the compact structure is also beneficial to resist torsion, high-altitude drop, drum test, and achieve a wider range of applications. More specifically, TTL and Semi-FOV satisfy: 3.2 mm < TTL × Tan(Semi-FOV) < 3.9 mm. For example, 3.25 mm ≤ TTL × Tan(Semi-FOV) ≤ 3.81 mm.

[0058] In this exemplary embodiment, the conditional expression satisfied by the refractive index N7 of the seventh lens is: N7 > 1.6. More specifically, N7 satisfies: N7 > 1.65. For example, N7 = 1.68.

[0059] In this exemplary embodiment, the above optical imaging system may further include a diaphragm. The diaphragm can be set at an appropriate position as needed. 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.

[0060] The optical imaging system according to the above embodiment of the present invention may employ multiple lenses, such as the above seven lenses. By reasonably allocating the optical power, surface shape, central thickness of each lens, and the on-axis spacing between each lens, etc., the optical imaging system has a large imaging image surface, has the characteristics of a wide imaging range and high imaging quality, and ensures the ultra-thinness of the mobile phone.

[0061] 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.

[0062] 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.

[0063] 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

[0065] 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.

[0066] 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 positive focal power, and its object side surface S3 is convex, and its image side surface S4 is convex. The third lens E3 has negative 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 negative focal power, and its object side surface S11 is convex, and its image side surface S12 is concave. The seventh lens E7 has positive 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.

[0067] 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).

[0068] Face number Surface type Radius of curvature Thickness / distance focal length Refractive Index Dispersion coefficient Cone coefficient OBJ Spherical endless endless STO Spherical endless -1.6000 S1 Aspheric 3.9356 1.6464 9.52 1.55 56.0 0.0000 S2 Aspheric 13.8714 0.0200 0.0000 S3 Aspheric 4.9262 1.7150 8.12 1.55 56.0 0.0000 S4 Aspheric -38.4341 0.0200 36.5801 S5 Aspheric 5.1849 0.3000 -5.87 1.68 19.2 0.0000 S6 Aspheric 2.1965 0.5478 0.0000 S7 Aspheric 3.7958 0.3000 -26.22 1.68 19.2 0.0000 S8 Aspheric 3.0274 1.3174 0.0000 S9 Aspheric 10.6348 0.7321 15.76 1.68 19.2 0.0000 S10 Aspheric 2985.7615 0.6884 0.0000 S11 Aspheric 4.3989 0.4000 -12.36 1.55 56.0 0.0000 S12 Aspheric 2.5760 0.4173 -1.0000 S13 Aspheric 10.3307 0.6293 617.95 1.68 19.2 0.0000 S14 Aspheric 10.3318 0.0365 0.0000 S15 Spherical endless 0.2100 1.52 64.2 S16 Spherical endless 0.5397 S17 Spherical endless

[0069] Table 1

[0070] As shown in Table 2, in Example 1, the total effective focal length of the optical imaging system is f=8.90 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 9.52 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°.

[0071]

[0072] Table 2

[0073] The optical imaging system in Example 1 satisfies:

[0074] 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;

[0075] (f1+|R2|) / f=2.63, where f1 is the effective focal length of the first lens, R2 is the radius of curvature of the image side of the first lens, and f is the effective focal length of the optical imaging system;

[0076] f3 / f=-0.66, where f3 is the effective focal length of the third lens and f is the effective focal length of the optical imaging system;

[0077] f6 / R12=-4.80, 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;

[0078] |f4 / f5|=1.66, where f4 is the effective focal length of the fourth lens, and f5 is the effective focal length of the fifth lens;

[0079] R5 / R6=2.36, where R5 is the radius of curvature of the object side of the third lens, and R6 is the radius of curvature of the image side of the third lens;

[0080] R9 / R14=1.03, where R9 is the radius of curvature of the object side of the fifth lens, and R14 is the radius of curvature of the image side of the seventh lens;

[0081] |R11 / R7|=1.16, where R11 is the radius of curvature of the object side of the sixth lens, and R7 is the radius of curvature of the object side of the fourth lens;

[0082] CT2 / CT3=5.72, where CT2 is the center thickness of the second lens on the optical axis, and CT3 is the center thickness of the third lens on the optical axis;

[0083] T45 / CT4=4.39, where T45 is the air spacing between the fourth lens and the fifth lens on the optical axis, and CT4 is the center thickness of the fourth lens on the optical axis;

[0084] 1 / (CT3×CT6)=8.33mm -2 , wherein CT3 is the center thickness of the third lens on the optical axis, and CT6 is the center thickness of the sixth lens on the optical axis;

[0085] TTL×Tan(Semi-FOV)=3.58mm, where TTL is the axial distance from the object side of the first lens to the imaging surface, and Semi-FOV is half of the maximum field of view of the optical imaging system;

[0086] N7=1.68, where N7 is the refractive index of the seventh lens element.

[0087] 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:

[0088]

[0089] 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.

[0090] 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 A of the aspherical mirror surfaces S1-S14 that can be used in Example 1. 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 , A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30 .

[0091]

[0092]

[0093] Table 3

[0094] 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

[0096] 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.

[0097] 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 concave, and its image side surface S4 is convex. The third lens E3 has negative 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 negative power, and its object side surface S11 is convex, and its image side surface S12 is concave. The seventh lens E7 has positive 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.

[0098] 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).

[0099] Face number Surface type Radius of curvature Thickness / distance focal length Refractive Index Dispersion coefficient Cone coefficient OBJ Spherical endless endless STO Spherical endless -1.6000 S1 Aspheric 4.2557 1.8241 4.78 1.55 56.0 0.0000 S2 Aspheric -5.7174 0.0849 0.0000 S3 Aspheric -22.0780 1.5140 -70.67 1.55 56.0 0.0000 S4 Aspheric -52.9620 0.1057 -17.3373 S5 Aspheric 4.6826 0.3509 -5.72 1.68 19.2 0.0000 S6 Aspheric 2.0554 0.4685 -1.0000 S7 Aspheric 4.2113 0.3909 -67.00 1.68 19.2 0.0000 S8 Aspheric 3.7091 1.3812 0.0000 S9 Aspheric 12.6454 1.0635 19.63 1.68 19.2 0.0000 S10 Aspheric 251.4891 0.5476 0.0000 S11 Aspheric 21.5584 0.5753 -21.32 1.55 56.0 0.0000 S12 Aspheric 7.4809 0.0468 0.0000 S13 Aspheric 4.1286 0.5000 576.78 1.68 19.2 0.0000 S14 Aspheric 3.9687 0.2167 0.0000 S15 Spherical endless 0.2100 1.52 64.2 S16 Spherical endless 0.7198 S17 Spherical endless

[0100] Table 4

[0101] As shown in Table 5, in Example 2, the total effective focal length of the optical imaging system is f=8.90 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 10.00 mm, half of the diagonal length of the effective pixel area on the imaging surface S17 is ImgH=3.27 mm, and half of the maximum field angle of the optical imaging system is Semi-FOV=20.1°. 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.

[0102]

[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 A of the aspherical mirror surfaces S1-S14 that can be used in Example 2. 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 , A 18 , A 20 , A 22 , A 24 , A26 , A 28 and A 30 .

[0106] Face number A4 A6 A8 A10 A12 A14 A16 S1 -3.1062E-01 -8.4847E-02 -1.4834E-02 1.1694E-04 7.0861E-04 2.4273E-04 -7.7088E-05 S2 1.8344E+00 -4.5518E-01 1.7331E-01 -6.6319E-02 2.9964E-02 -1.3894E-02 6.8138E-03 S3 2.0732E+00 -4.0753E-01 1.6938E-01 -6.6560E-02 2.1448E-02 -1.5568E-02 4.9127E-03 S4 2.1459E-01 -6.0134E-02 1.6148E-02 -7.5193E-03 4.3023E-04 -2.5342E-03 -4.6035E-04 S5 -5.9182E-01 1.1554E-01 -2.2967E-02 6.7710E-03 1.7585E-04 4.3319E-04 3.8324E-04 S6 -1.8057E-01 7.5080E-02 -3.8586E-03 4.8597E-03 1.1559E-03 6.9275E-04 -9.5494E-05 S7 -1.1335E-01 -1.3995E-02 1.1124E-02 6.3104E-04 4.8921E-05 5.9082E-05 -1.3420E-04 S8 -6.0824E-02 1.0159E-02 1.0336E-02 2.0741E-03 4.3908E-04 1.3723E-04 -3.3303E-05 S9 -4.6276E-01 -6.8317E-02 5.8398E-04 7.7390E-03 4.7777E-03 1.7847E-03 2.6275E-04 S10 -8.3160E-01 -1.3735E-02 2.0058E-02 9.0354E-03 5.3130E-03 1.3055E-03 -2.8262E-05 S11 -1.1195E+00 2.4562E-01 3.9096E-02 -3.3255E-02 1.0098E-02 -7.8824E-03 -1.1775E-03 S12 -1.5748E+00 4.7613E-03 9.6097E-02 -2.2347E-02 1.7224E-02 -5.2766E-03 3.9011E-03 S13 -2.4294E+00 1.7519E-01 3.0053E-02 3.4891E-02 -8.4093E-03 1.9796E-03 7.3065E-03 S14 -2.7410E+00 2.0172E-01 -6.6224E-02 5.0731E-02 -1.3226E-02 7.5588E-03 6.2290E-03 Face number A18 A20 A22 A24 A26 A28 A30 S1 -4.8035E-05 -4.0042E-05 -7.7150E-06 -1.4604E-05 -1.3339E-05 -1.5230E-05 -8.6287E-06 S2 -3.4650E-03 1.7263E-03 -9.4078E-04 4.1993E-04 -2.7034E-04 9.1019E-05 -6.5491E-05 S3 -3.8067E-03 1.1833E-03 -9.2283E-04 4.4309E-04 -1.1508E-04 1.5181E-04 -2.6565E-05 S4 -1.3196E-03 -3.8702E-04 -5.7494E-04 -1.5875E-04 -1.9849E-04 -4.2054E-05 -4.0572E-05 S5 -3.9416E-05 4.8609E-05 -1.1677E-04 -3.8806E-05 -7.8723E-05 -2.9606E-05 -1.4548E-05 S6 -9.0615E-05 -5.4665E-05 4.0882E-05 7.9130E-05 5.8296E-05 2.4232E-05 4.6782E-06 S7 -1.2091E-04 -1.0271E-04 -5.6090E-05 -1.5912E-05 0.0000E+00 0.0000E+00 0.0000E+00 S8 -4.5252E-05 -4.4385E-05 -2.9431E-05 -1.4311E-05 0.0000E+00 0.0000E+00 0.0000E+00 S9 -2.6841E-04 -2.6476E-04 -1.3216E-04 -3.5912E-05 -2.6762E-07 0.0000E+00 0.0000E+00 S10 -7.3088E-04 -4.6967E-04 -2.2532E-04 -6.1205E-05 -2.7305E-06 -1.5982E-07 0.0000E+00 S11 1.2757E-04 1.2517E-03 7.5376E-05 -2.0142E-06 1.6805E-04 2.5011E-04 1.1131E-04 S12 -2.0364E-03 9.8336E-05 2.4674E-05 3.4092E-04 -4.5291E-04 -4.6278E-05 3.6839E-05 S13 -1.2078E-03 -2.3887E-03 -1.3728E-03 -2.2546E-04 -3.0090E-04 2.0024E-04 8.6574E-05 S14 3.0487E-03 4.7389E-04 4.2938E-04 1.5373E-04 2.2427E-04 1.6326E-04 8.1902E-05

[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 power, and its object side surface S1 is convex, and its image side surface S2 is convex. The second lens E2 has positive power, and its object side surface S3 is convex, and its image side surface S4 is convex. The third lens E3 has negative 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 negative power, and its object side surface S9 is convex, and its image side surface S10 is concave. The sixth lens E6 has negative power, and its object side surface S11 is convex, and its image side surface S12 is concave. The seventh lens E7 has positive 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] Face number Surface type Radius of curvature Thickness / distance focal length Refractive Index Dispersion coefficient Cone coefficient OBJ Spherical endless endless STO Spherical endless -1.6000 S1 Aspheric 4.2480 1.8113 5.64 1.55 56.0 0.0000 S2 Aspheric -9.4431 0.1212 0.0000 S3 Aspheric 39.8100 1.4930 43.43 1.55 56.0 0.0000 S4 Aspheric -57.6421 0.0295 94.2310 S5 Aspheric 4.7327 0.3292 -5.79 1.68 19.2 0.0000 S6 Aspheric 2.0843 0.4104 -1.0000 S7 Aspheric 3.0170 0.4474 -1480.76 1.68 19.2 0.0000 S8 Aspheric 2.8279 1.4579 0.0000 S9 Aspheric 12.7266 1.1187 -168.73 1.68 19.2 0.0000 S10 Aspheric 11.0445 0.3750 0.0000 S11 Aspheric 4.6609 0.5688 -5.87 1.55 56.0 0.0000 S12 Aspheric 1.8162 0.0300 -1.0000 S13 Aspheric 2.0606 0.5622 5.06 1.68 19.2 -1.0000 S14 Aspheric 4.6067 0.1912 0.0000 S15 Spherical endless 0.2100 1.52 64.2 S16 Spherical endless 0.6944 S17 Spherical endless

[0114] Table 7

[0115] As shown in Table 8, in Example 3, the total effective focal length of the optical imaging system is f=8.60 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 9.85 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=21.1°. 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.

[0116]

[0117] Table 8

[0118] 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 A of the aspherical mirror surfaces S1-S14 that can be used in Example 3. 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 , A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30 .

[0119]

[0120]

[0121] Table 9

[0122] 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

[0124] Figure 7 Schematic 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.

[0125] The first lens E1 has positive focal power, and its object side surface S1 is convex, and its image side surface S2 is convex. The second lens E2 has positive focal power, and its object side surface S3 is convex, and its image side surface S4 is concave. The third lens E3 has negative 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 negative focal power, and its object side surface S11 is convex, and its image side surface S12 is concave. The seventh lens E7 has positive 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.

[0126] 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).

[0127]

[0128]

[0129] Table 10

[0130] As shown in Table 11, in Example 4, the total effective focal length f of the optical imaging system is 8.64 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 9.80 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.

[0131]

[0132] Table 11

[0133] 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 A of the aspherical mirror surfaces S1 to S14 that can be used in Example 4. 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 , A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30 .

[0134]

[0135]

[0136] Table 12

[0137] 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

[0139] 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.

[0140] 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 positive focal power, and its object side surface S3 is convex, and its image side surface S4 is convex. The third lens E3 has negative 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 convex. The sixth lens E6 has negative focal power, and its object side surface S11 is convex, and its image side surface S12 is concave. The seventh lens E7 has positive 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.

[0141] 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).

[0142] Face number Surface type Radius of curvature Thickness / distance focal length Refractive Index Dispersion coefficient Cone coefficient OBJ Spherical endless endless STO Spherical endless -1.6000 S1 Aspheric 4.0880 1.5050 9.84 1.55 56.0 0.0000 S2 Aspheric 14.9696 0.0300 0.0000 S3 Aspheric 4.5176 1.6193 8.26 1.55 56.0 0.0000 S4 Aspheric -1078.1640 0.0517 -99.0000 S5 Aspheric 4.4651 0.3000 -6.51 1.68 19.2 0.0000 S6 Aspheric 2.1572 0.9521 0.0000 S7 Aspheric 11.5247 0.3000 -12.33 1.68 19.2 0.0000 S8 Aspheric 4.7903 1.1734 0.0000 S9 Aspheric 6.9555 0.7000 9.35 1.68 19.2 0.0000 S10 Aspheric -67.0975 0.7352 0.0000 S11 Aspheric 35.1237 0.3059 -12.63 1.55 56.0 0.0000 S12 Aspheric 5.7398 0.0984 0.0000 S13 Aspheric 4.6063 0.5217 1999.97 1.68 19.2 0.0000 S14 Aspheric 4.4107 0.2570 0.0000 S15 Spherical endless 0.2100 1.52 64.2 S16 Spherical endless 0.7602 S17 Spherical endless

[0143] Table 13

[0144] As shown in Table 14, in Example 5, the total effective focal length f of the optical imaging system is 8.90 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 9.52 mm, half of the diagonal length of the effective pixel area on the imaging surface S17 is ImgH=3.10 mm, and half of the maximum field angle Semi-FOV of the optical imaging system is 18.9°. 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.

[0145]

[0146] Table 14

[0147] 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 A of the aspherical mirror surfaces S1 to S14 that can be used in Example 5. 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 , A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30.

[0148] Face number A4 A6 A8 A10 A12 A14 A16 S1 -3.4957E-01 -7.8351E-02 -1.2646E-02 -1.1536E-03 7.3756E-05 2.3919E-04 1.8020E-04 S2 -3.0061E-02 -2.9036E-02 1.5144E-02 -4.0118E-03 3.4013E-03 -7.7981E-04 6.6883E-04 S3 3.4903E-01 3.0885E-02 1.1560E-02 -8.2955E-03 -1.6561E-03 -2.4290E-03 -8.6547E-04 S4 2.2572E-01 -4.6507E-02 8.2223E-03 -7.3369E-03 3.4360E-03 -2.9743E-03 1.3173E-03 S5 -4.3436E-01 9.0157E-02 -5.9761E-03 -2.1883E-03 2.3692E-03 -1.8340E-03 1.0935E-03 S6 -3.9476E-01 9.3008E-03 -2.0035E-03 1.4978E-04 6.5199E-04 -2.5157E-05 5.3312E-05 S7 -1.8034E-01 1.9008E-02 3.3644E-03 -1.7003E-04 3.2000E-05 -1.1065E-05 3.7569E-07 S8 -1.1951E-01 3.3666E-02 3.6643E-03 -3.1020E-04 -8.3950E-05 -6.5334E-05 -1.5596E-05 S9 -3.4206E-01 -6.4066E-02 -7.3228E-04 5.6756E-03 3.9721E-03 1.3685E-03 1.6580E-05 S10 -5.2825E-01 -3.1280E-02 1.4976E-02 1.4259E-02 7.6041E-03 2.0813E-03 -4.2447E-04 S11 -1.5069E+00 3.0684E-01 2.4248E-02 -2.2182E-02 1.0776E-03 -7.9924E-03 1.7966E-03 S12 -2.1324E+00 1.1712E-01 -1.9477E-05 -1.7426E-02 6.5649E-03 2.5757E-03 4.1735E-03 S13 -2.4294E+00 4.0450E-02 1.2380E-02 6.0288E-02 1.0222E-02 1.5519E-02 8.1961E-04 S14 -2.9719E+00 1.1106E-01 -4.1873E-02 6.0983E-02 6.5645E-04 1.5199E-02 5.4955E-04 Face number A18 A20 A22 A24 A26 A28 A30 S1 8.5802E-05 3.0934E-05 9.0963E-06 -8.8584E-07 -9.3828E-06 -9.3276E-06 -8.7452E-06 S2 -3.1756E-04 1.1511E-04 -1.1079E-04 -2.0704E-05 -3.4423E-05 -2.2494E-05 -6.9619E-06 S3 -9.7693E-04 -5.0515E-04 -3.5546E-04 -1.9530E-04 -9.6971E-05 -3.8018E-05 -1.6881E-05 S4 -9.2342E-04 4.9069E-04 -2.7917E-04 1.6032E-04 -7.0644E-05 3.0006E-05 -1.3676E-05 S5 -3.8755E-04 2.8660E-04 -4.5334E-05 6.7617E-05 2.4695E-05 1.1396E-05 1.0346E-05 S6 1.0060E-05 -8.8579E-06 8.7024E-06 -3.7144E-06 7.3720E-07 -3.3914E-07 -2.2092E-07 S7 -9.3671E-07 2.2073E-06 -1.0436E-06 -8.0100E-08 0.0000E+00 0.0000E+00 0.0000E+00 S8 -4.9544E-06 1.7100E-06 -4.7576E-07 5.0114E-08 0.0000E+00 0.0000E+00 0.0000E+00 S9 -2.8513E-04 -9.7069E-05 7.5566E-06 1.3695E-05 4.7370E-08 0.0000E+00 0.0000E+00 S10 -1.0367E-03 -5.6188E-04 -1.7415E-04 -3.0360E-05 -4.7795E-07 8.9362E-09 0.0000E+00 S11 6.8446E-04 -1.1998E-04 -5.4901E-04 -2.9601E-04 4.5524E-04 4.3187E-04 1.7666E-04 S12 1.8155E-03 6.6139E-05 9.6918E-04 -6.3605E-04 -2.8881E-04 -1.9071E-04 -1.1723E-05 S13 -2.3359E-03 -3.0082E-03 6.8483E-04 4.5123E-05 -3.3954E-04 -5.2731E-04 -2.6370E-04 S14 -4.8106E-04 -1.2856E-04 1.3239E-03 4.7105E-04 -1.1734E-04 -3.6184E-04 -1.6301E-04

[0149] Table 15

[0150] 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

[0152] 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.

[0153] 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 positive power, and its object side surface S3 is convex, and its image side surface S4 is convex. The third lens E3 has negative 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 convex. The sixth lens E6 has negative power, and its object side surface S11 is concave, and its image side surface S12 is concave. The seventh lens E7 has positive 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.

[0154] 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).

[0155] Face number Surface type Radius of curvature Thickness / distance focal length Refractive Index Dispersion coefficient Cone coefficient OBJ Spherical endless endless STO Spherical endless -1.6000 S1 Aspheric 4.0736 1.4977 10.11 1.55 56.0 0.0000 S2 Aspheric 13.5892 0.0300 0.0000 S3 Aspheric 4.4115 1.6279 8.01 1.55 56.0 0.0000 S4 Aspheric -397.4394 0.0505 99.0000 S5 Aspheric 4.3940 0.3000 -6.41 1.68 19.2 0.0000 S6 Aspheric 2.1226 0.9554 0.0000 S7 Aspheric 10.0946 0.3000 -12.98 1.68 19.2 0.0000 S8 Aspheric 4.6408 1.1659 0.0000 S9 Aspheric 8.9492 0.8015 9.04 1.68 19.2 0.0000 S10 Aspheric -18.6699 0.6862 0.0000 S11 Aspheric -26.1965 0.2471 -12.17 1.55 56.0 0.0000 S12 Aspheric 8.9169 0.1470 0.0000 S13 Aspheric 3.1959 0.4054 1989.12 1.68 19.2 0.0000 S14 Aspheric 3.0395 0.2862 -1.0000 S15 Spherical endless 0.2100 1.52 64.2 S16 Spherical endless 0.7894 S17 Spherical endless

[0156] Table 16

[0157] As shown in Table 17, in Example 6, the total effective focal length f of the optical imaging system is 8.90 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=3.10 mm, and half of the maximum field angle Semi-FOV of the optical imaging system is 18.9°. 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.

[0158]

[0159] Table 17

[0160] 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 A of the aspherical mirror surfaces S1 to S14 that can be used in Example 6. 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 , A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30 .

[0161]

[0162]

[0163] Table 18

[0164] 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.

[0165] 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 optical imaging system includes, 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; Second lens; The third lens has a negative optical power, and its object side surface is convex and its image side surface is concave; a fourth lens element having negative optical power, whose object side surface is convex and whose image side surface is concave; The fifth lens has a convex object side surface; a sixth lens element having negative optical power, whose image side surface is concave; The seventh lens has positive refractive power, and its object side surface is convex and its image side surface is concave; The axial distance TTL from the object side of the first lens to the imaging surface and half of the maximum field of view Semi-FOV of the optical imaging system satisfy: 3.25mm≤TTL×Tan(Semi-FOV)≤3.81mm; The effective focal length f1 of the first lens, the curvature radius R2 of the image side surface of the first lens, and the effective focal length f of the optical imaging system satisfy: 1.18≤(f1+|R2|) / f≤2.79; The second lens has positive refractive power and the fifth lens has positive refractive power, or the second lens has positive refractive power and the fifth lens has negative refractive power, or the second lens has negative refractive power and the fifth lens has positive refractive power.

2. The optical imaging system according to claim 1, characterized in that: The effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy: 1.18≤f / EPD≤1.

23.

3. The optical imaging system according to claim 1, characterized in that: The effective focal length f3 of the third lens and the effective focal length f of the optical imaging system satisfy: -0.75≤f3 / f≤-0.

64.

4. 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: -4.8≤f6 / R12≤-1.

37.

5. The optical imaging system according to claim 1, characterized in that: The effective focal length f4 of the fourth lens and the effective focal length f5 of the fifth lens satisfy: 1.32≤|f4 / f5|≤8.

78.

6. The optical imaging system according to claim 1, characterized in that: A curvature radius R5 of the object side surface of the third lens and a curvature radius R6 of the image side surface of the third lens satisfy: 2.07≤R5 / R6≤2.

36.

7. The optical imaging system according to claim 1, characterized in that: A curvature radius R9 of the object side surface of the fifth lens and a curvature radius R14 of the image side surface of the seventh lens satisfy: 1.0<R9 / R14≤4.

5.

8. The optical imaging system according to claim 1, characterized in that: A curvature radius R11 of the object side surface of the sixth lens and a curvature radius R7 of the object side surface of the fourth lens satisfy: 1.16≤|R11 / R7|≤5.

12.

9. The optical imaging system according to claim 1, characterized in that: A center thickness CT2 of the second lens on the optical axis and a center thickness CT3 of the third lens on the optical axis satisfy: 4.32≤CT2 / CT3≤5.

72.

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 center thickness CT4 of the fourth lens on the optical axis satisfy: 3.0 mm -2 <(T45×CT4)<8.0mm -2 .

11. 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 CT6 of the sixth lens on the optical axis satisfy: 4.5<1 / CT3 / CT6<13.

5.

12. The optical imaging system according to claim 1, characterized in that: The refractive index N7 of the seventh lens satisfies: N7=1.

68.

13. The optical imaging system according to claim 1, characterized in that: The center thickness CT3 of the third lens on the optical axis and the center thickness CT6 of the sixth lens on the optical axis satisfy: 4.95 mm -2 ≤1 / (CT3×CT6)<13.5mm -2 .

14. The optical imaging system according to claim 1, wherein: An air interval T45 between the fourth lens and the fifth lens on the optical axis and a center thickness CT4 of the fourth lens on the optical axis satisfy: 3.26≤T45 / CT4≤4.39.

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