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: a first lens with negative optical focal length; a second lens, whose image side surface is a concave surface; a third lens; a fourth lens; a fifth lens; a sixth lens; a seventh lens; and an eighth lens; wherein there is an air gap between adjacent lenses; and the maximum half field of view HFOV of the optical imaging system is greater than 90°. By reasonably matching the positive and negative optical focal lengths and surface shapes of the first to eighth lenses, various on-axis and off-axis aberrations of the lens can be effectively balanced to improve the imaging clarity of the system. By controlling HFOV>90°, it is beneficial to receive information within a larger field of view of the object side; in addition, there is an air gap between adjacent lenses to ensure the assembly of the lenses.

Description

Technical Field

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

[0002] Fisheye lenses have been widely used in the fields of drones, surveillance, and vehicles in recent years because their field of view is close to or equal to 180°, which enables the real-shot image to contain information within a larger field of view. However, current fisheye lenses still have many problems, such as severe chromatic aberration, low relative illumination, large astigmatism, poor resolution, large optical distortion, and severe edge image deformation and compression. In order to solve the above problems, the purpose of the present invention is to design an 8-piece optical imaging lens with ultra-wide angle, small chromatic aberration, small astigmatism, and high resolution. Summary of the invention

[0003] The present application aims to provide an optical imaging system composed of eight lenses, which has the characteristics of ultra-wide angle, small chromatic aberration, small astigmatism, and high resolution.

[0004] The present invention provides an optical imaging system, which comprises, in order from the object side to the image side along the optical axis:

[0005] a first lens having negative optical power;

[0006] The second lens has a concave image side surface;

[0007] The third lens;

[0008] The fourth lens;

[0009] The fifth lens;

[0010] The sixth lens;

[0011] a seventh lens; and

[0012] The eighth lens;

[0013] There is an air gap between adjacent lenses; and the maximum half field of view HFOV of the optical imaging system satisfies: HFOV>90°.

[0014] According to one embodiment of the present application, the effective focal length f3 of the third lens and the effective focal length f of the optical imaging system satisfy: 4.0 <f3 / f<6.0。

[0015] According to one embodiment of the present application, the center thickness CT1 of the first lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, and the air interval T12 between the first lens and the second lens on the optical axis satisfy: 0.1 <CT1 / (T12+CT2)<1.0。

[0016] According to one embodiment of the present application, a curvature radius R15 of the object-side surface of the eighth lens and a curvature radius R16 of the image-side surface of the eighth lens satisfy: -3.5<(R15+R16) / (R15-R16)<0.2.

[0017] According to one embodiment of the present application, the effective focal length f7 of the seventh lens and the curvature radius R11 of the object side surface of the sixth lens satisfy: 0.4<|f7 / R11|<4.0.

[0018] According to one embodiment of the present application, the effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy: 3.0<|f5 / f6|+|f5 / f7|<4.5.

[0019] According to one embodiment of the present application, the effective focal length f6 of the sixth lens and the effective focal length f of the optical imaging system satisfy: 1.5<|f6 / f|<2.5.

[0020] According to one embodiment of the present application, the center thickness CT1 of the first lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, the center thickness CT3 of the third lens on the optical axis, the air interval T12 between the first lens and the second lens on the optical axis, and the air interval T23 between the second lens and the third lens on the optical axis satisfy: 0.6<(CT1+CT2+CT3) / (T12+T23)<1.6.

[0021] According to one embodiment of the present application, the air interval T12 between the first lens and the second lens on the optical axis, the center thickness CT8 of the eighth lens on the optical axis, and the sum of the center thicknesses ΣCT of all lenses on the optical axis satisfy: 0.3<(T12+CT8) / ΣCT<0.5.

[0022] According to one embodiment of the present application, the effective focal length f of the optical imaging lens and the entrance pupil diameter EPD of the optical imaging system satisfy: f / EPD<1.3.

[0023] According to one embodiment of the present application, the axial distance TD from the object side of the first lens to the image side of the last lens and the axial distance SL from the aperture to the imaging surface satisfy: 1.0 <TD / SL<2.0。

[0024] The present application also provides an optical imaging system, which includes, in order from the object side to the image side along the optical axis:

[0025] a first lens having negative optical power;

[0026] The second lens has a concave image side surface;

[0027] The third lens;

[0028] The fourth lens;

[0029] The fifth lens;

[0030] The sixth lens;

[0031] a seventh lens; and

[0032] The eighth lens;

[0033] There is an air gap between adjacent lenses; the effective focal length f3 of the third lens and the effective focal length f of the optical imaging system satisfy: 4.0 <f3 / f<6.0。

[0034] According to one embodiment of the present application, the maximum half field of view HFOV of the optical imaging system satisfies: HFOV>90°.

[0035] According to one embodiment of the present application, the center thickness CT1 of the first lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, and the air interval T12 between the first lens and the second lens on the optical axis satisfy: 0.1 <CT1 / (T12+CT2)<1.0。

[0036] According to one embodiment of the present application, a curvature radius R15 of the object-side surface of the eighth lens and a curvature radius R16 of the image-side surface of the eighth lens satisfy: -3.5<(R15+R16) / (R15-R16)<0.2.

[0037] According to one embodiment of the present application, the effective focal length f7 of the seventh lens and the curvature radius R11 of the object side surface of the sixth lens satisfy: 0.4<|f7 / R11|<4.0.

[0038] According to one embodiment of the present application, the effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy: 3.0<|f5 / f6|+|f5 / f7|<4.5.

[0039] According to one embodiment of the present application, the effective focal length f6 of the sixth lens and the effective focal length f of the optical imaging system satisfy: 1.5<|f6 / f|<2.5.

[0040] According to one embodiment of the present application, the center thickness CT1 of the first lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, the center thickness CT3 of the third lens on the optical axis, the air interval T12 between the first lens and the second lens on the optical axis, and the air interval T23 between the second lens and the third lens on the optical axis satisfy: 0.6<(CT1+CT2+CT3) / (T12+T23)<1.6.

[0041] According to one embodiment of the present application, the air interval T12 between the first lens and the second lens on the optical axis, the center thickness CT8 of the eighth lens on the optical axis, and the sum of the center thicknesses ΣCT of all lenses on the optical axis satisfy: 0.3<(T12+CT8) / ΣCT<0.5.

[0042] According to one embodiment of the present application, the effective focal length f of the optical imaging lens and the entrance pupil diameter EPD of the optical imaging system satisfy: f / EPD<1.3.

[0043] According to one embodiment of the present application, the axial distance TD from the object side of the first lens to the image side of the last lens and the axial distance SL from the aperture to the imaging surface satisfy: 1.0 <TD / SL<2.0。

[0044] Beneficial effects of the present invention:

[0045] The optical imaging system provided by the present invention includes multiple lenses, such as the first lens to the eighth lens. By reasonably matching the positive and negative optical power and surface shape of the first to the eighth lenses, various on-axis and off-axis aberrations of the lens can be effectively balanced to improve the imaging clarity of the system. The first lens is constrained to have a negative optical power, which can effectively control the deflection of the incident light, which is beneficial for the system to have a large field of view; the image side of the second lens is a concave surface, which can be reasonably matched with the first lens to further collect light; by controlling HFOV>90°, it is beneficial to receive information within a larger field of view of the object; in addition, there is an air gap between adjacent lenses to ensure the assembly of each lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] 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.

[0047] Figure 1 Schematic diagram of the lens group structure of embodiment 1 of the optical imaging system of the present invention;

[0048] Figure 2a and Figure 2b They are respectively an axial chromatic aberration curve and an astigmatism curve of the optical imaging system embodiment 1 of the present invention;

[0049] Figure 3 Schematic diagram of the lens group structure of embodiment 2 of the optical imaging system of the present invention;

[0050] Figure 4a and Figure 4b They are respectively an axial chromatic aberration curve and an astigmatism curve of Embodiment 2 of the optical imaging system of the present invention;

[0051] Figure 5 Schematic diagram of the lens group structure of embodiment 3 of the optical imaging system of the present invention;

[0052] Figure 6a and Figure 6b They are respectively an axial chromatic aberration curve and an astigmatism curve of Embodiment 3 of the optical imaging system of the present invention;

[0053] Figure 7 Schematic diagram of the lens group structure of embodiment 4 of the optical imaging system of the present invention;

[0054] Figure 8a and Figure 8b They are respectively an axial chromatic aberration curve and an astigmatism curve of Embodiment 4 of the optical imaging system of the present invention;

[0055] Fig. 9 Schematic diagram of the lens group structure of embodiment 5 of the optical imaging system of the present invention;

[0056] Fig.10a and Fig.10b They are respectively an axial chromatic aberration curve and an astigmatism curve of Embodiment 5 of the optical imaging system of the present invention;

[0057] Fig.11 Schematic diagram of the lens group structure of embodiment 6 of the optical imaging system of the present invention;

[0058] Fig.12a and Figure 12b They are respectively the axial chromatic aberration curve and the astigmatism curve of Example 6 of the optical imaging system of the present invention. DETAILED DESCRIPTION

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] Exemplary Embodiments

[0067] The optical imaging system according to an exemplary embodiment of the present invention includes eight lenses, which sequentially include, from the object side to the image side along the optical axis: a first lens with negative optical power, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens. Among them, each lens is independent of each other. The image side surface of the second lens is concave, and there is an air gap between each lens on the optical axis. By reasonably matching the positive and negative optical powers and surface shapes of the first to eighth lenses, various on-axis and off-axis aberrations of the lens can be effectively balanced, and the imaging clarity of the system can be improved. Among them, the first lens is constrained to have negative optical power, which can effectively control the deflection of incident light and is beneficial to the system having the characteristic of a large field of view; the image side surface of the second lens is concave, which can be reasonably matched with the first lens to further collect light.

[0068] In this exemplary embodiment, the maximum half field of view angle HFOV of the optical imaging system satisfies: HFOV > 90°. By controlling HFOV > 90°, it is beneficial to receive information within a larger field of view range on the object side; in addition, there is an air gap between adjacent lenses, which can ensure the assembly between each lens. More specifically, the maximum half field of view angle HFOV of the optical imaging system satisfies: HFOV > 95°.

[0069] In this exemplary embodiment, the effective focal length f3 of the third lens and the effective focal length f of the optical imaging system satisfy: 4.0 < f3 / f < 6.0. By constraining the ratio of the effective focal length of the third lens to the effective focal length of the optical imaging lens within a certain range, it is beneficial to control the contribution of the third lens to the focal length of the overall optical system and correct the spherical aberration and distortion of the system. More specifically, the effective focal length f3 of the third lens and the effective focal length f of the optical imaging system satisfy: 4.40 < f3 / f < 5.95.

[0070] In this exemplary embodiment, the central thickness CT1 of the first lens on the optical axis, the central thickness CT2 of the second lens on the optical axis, and the air gap T12 between the first lens and the second lens on the optical axis satisfy: 0.1 < CT1 / (T12 + CT2) < 1.0. When the system satisfies 0.1 < CT1 / (T12 + CT2) < 1.0, it can effectively deflect incident light, meet the characteristics of the large field of view of the system, and in addition, is beneficial to the assembly between the first and second lenses and improves the assembly yield of the optical lens. More specifically, the central thickness CT1 of the first lens on the optical axis, the central thickness CT2 of the second lens on the optical axis, and the air gap T12 between the first lens and the second lens on the optical axis satisfy: 0.15 < CT1 / (T12 + CT2) < 0.9.

[0071] In this exemplary embodiment, the radius of curvature R15 of the object side of the eighth lens and the radius of curvature R16 of the image side of the eighth lens satisfy: -3.5<(R15+R16) / (R15-R16)<0.2. By controlling the radius of curvature of the object side and the image side of the eighth lens, on the one hand, the sensitivity of the lens can be reduced and the production yield can be improved. On the other hand, it is beneficial to adjust the ghost image produced by the eighth lens so that the ghost image position is as close to the light source as possible. More specifically, the radius of curvature R15 of the object side of the eighth lens and the radius of curvature R16 of the image side of the eighth lens satisfy: -3.5<(R15+R16) / (R15-R16)<0.18.

[0072] In this exemplary embodiment, the effective focal length f7 of the seventh lens and the curvature radius R11 of the object side surface of the sixth lens satisfy: 0.4<|f7 / R11|<4.0. By controlling the ratio of the effective focal length of the seventh lens to the curvature radius of the object side surface of the sixth lens, various aberrations of the system can be effectively balanced and the imaging quality of the lens can be improved. More specifically, the effective focal length f7 of the seventh lens and the curvature radius R11 of the object side surface of the sixth lens satisfy: 0.70<|f7 / R11|<3.7.

[0073] In this exemplary embodiment, the effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy: 3.0<|f5 / f6|+|f5 / f7|<4.5. The system satisfies 3.0<|f5 / f6|+|f5 / f7|<4.5, which can reasonably distribute the optical power borne by the lenses, and is conducive to correcting the field curvature and astigmatism of the system, ensuring that the system has high imaging clarity. More specifically, the effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy: 3.40<|f5 / f6|+|f5 / f7|<4.45.

[0074] In this exemplary embodiment, the effective focal length f6 of the sixth lens and the effective focal length f of the optical imaging system satisfy: 1.5<|f6 / f|<2.5. By constraining the ratio of the effective focal length of the sixth lens to the effective focal length of the optical imaging lens within a certain range, it is beneficial to balance the on-axis and off-axis aberrations of the system and to reduce the intensity of ghost images generated by the last few lenses. More specifically, the effective focal length f6 of the sixth lens and the effective focal length f of the optical imaging system satisfy: 1.70<|f6 / f|<2.30.

[0075] In this exemplary embodiment, the center thickness CT1 of the first lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, the center thickness CT3 of the third lens on the optical axis, the air interval T12 between the first lens and the second lens on the optical axis, and the air interval T23 between the second lens and the third lens on the optical axis satisfy: 0.6<(CT1+CT2+CT3) / (T12+T23)<1.6. (CT1+CT2+CT3) / (T12+T23) is between 0.6 and 1.6, which can effectively control the deflection of the edge large field of view light and improve the relative illumination of the system on the one hand, and effectively control the reasonable distribution of the first three lenses in space on the other hand, ensure that the system has better assembly and improve the production yield. More specifically, the center thickness CT1 of the first lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, the center thickness CT3 of the third lens on the optical axis, the air interval T12 between the first lens and the second lens on the optical axis, and the air interval T23 between the second lens and the third lens on the optical axis satisfy: 0.6<(CT1+CT2+CT3) / (T12+T23)<1.55.

[0076] In this exemplary embodiment, the air interval T12 between the first lens and the second lens on the optical axis, the center thickness CT8 of the eighth lens on the optical axis, and the sum of the center thicknesses ΣCT of all lenses on the optical axis satisfy: 0.3<(T12+CT8) / ΣCT<0.5. The system satisfies 0.3<(T12+CT8) / ΣCT<0.5, which is beneficial to control the spatial arrangement of each lens on the one hand, and can effectively correct the spherical aberration and coma of the system on the other hand. More specifically, the air interval T12 between the first lens and the second lens on the optical axis, the center thickness CT8 of the eighth lens on the optical axis, and the sum of the center thicknesses ΣCT of all lenses on the optical axis satisfy: 0.32<(T12+CT8) / ΣCT<0.48.

[0077] In this exemplary embodiment, the effective focal length f of the optical imaging lens and the entrance pupil diameter EPD of the optical imaging system satisfy: f / EPD<1.3. By controlling the ratio of the effective focal length of the optical imaging lens to the entrance pupil diameter, it is helpful to improve the lens's ability to receive light source energy and obtain as much object information as possible, thereby obtaining imaging information with higher brightness and resolution. More specifically, the effective focal length f of the optical imaging lens and the entrance pupil diameter EPD of the optical imaging system satisfy: f / EPD<1.28.

[0078] In the present exemplary embodiment, the on-axis distance TD from the object side surface of the first lens to the image side surface of the last lens and the on-axis distance SL from the aperture stop to the imaging surface satisfy: 1.0 < TD / SL < 2.0. By controlling the ratio of the on-axis distance from the object side surface of the first lens to the image side surface of the last lens to the on-axis distance from the aperture stop to the imaging surface, it is not only beneficial to control the spatial distribution of the lenses before and after the aperture stop, but also beneficial to reducing the tolerance sensitivity of the system and improving the production yield of the system. More specifically, the on-axis distance TD from the object side surface of the first lens to the image side surface of the last lens and the on-axis distance SL from the aperture stop to the imaging surface satisfy: 1.30 < TD / SL < 1.70.

[0079] In the present exemplary embodiment, the object side surface and the image side surface of any one of the first lens E1 to the eighth lens E8 are aspherical surfaces, and the surface profile x of each aspherical lens can be defined by, but not limited to, the following aspherical formula:

[0080]

[0081] where x is the sagitta of the distance from the vertex of the aspherical surface when the aspherical surface is at a position with a height of h along the optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1); k is the conic constant; and Ai is the correction coefficient of the i-th order of the aspherical surface.

[0082] In the present exemplary embodiment, the above optical imaging system may further include an aperture stop. The aperture stop can be set at an appropriate position as needed. For example, the aperture stop can be set between the third lens and the fourth 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.

[0083] The optical imaging system according to the above embodiment of the present invention may employ multiple lenses, such as the eight lenses described above. By reasonably allocating the optical power, surface profile, central thickness of each lens, and the on-axis spacing between each lens, etc., the optical imaging system has a large imaging image plane, has the characteristics of a wide imaging range and high imaging quality, and ensures the ultra-thinness of the mobile phone.

[0084] 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 eighth 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, the seventh lens and the eighth 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, the seventh lens and the eighth lens are all aspherical mirror surfaces.

[0085] 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 eight lenses are used as an example in the embodiments, the optical imaging system is not limited to including eight lenses, and the optical imaging system may also include other numbers of lenses if necessary.

[0086] 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

[0088] 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: a first lens E1, a second lens E2, a third lens E3, an aperture STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, a filter E9 and an imaging surface S19.

[0089] The first lens E1 has negative 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 concave, 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 positive focal power, and its object side surface S7 is concave, and its image side surface S8 is convex. 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 concave, and its image side surface S12 is convex. The seventh lens E7 has positive focal power, and its object side surface S13 is convex, and its image side surface S14 is convex. The eighth lens E8 has positive focal power, and its object side surface S15 is convex, and its image side surface S16 is concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes through each of the surfaces S1 to S18 in sequence and is finally imaged on the imaging surface S19.

[0090] 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 in millimeters (mm). Among them, the first lens E1 is preferably but not limited to glass material, which can eliminate temperature drift and increase hardness. The refractive index and Abbe number range of the material are wider than those of plastic, which is more conducive to optimization. The fourth lens E4 or the fifth lens E5 is preferably but not limited to GM material (molded glass), which has the characteristics of glass material. It is also easy to manufacture aspheric lenses, which is more conducive to optimization.

[0091]

[0092]

[0093] Table 1

[0094] As shown in Table 2, in Example 1, the total effective focal length f of the optical imaging system is 1.43 mm, the distance TTL on the optical axis from the object side surface S1 of the first lens E1 to the imaging surface S19 of the optical imaging system is 12.50 mm, and half of the diagonal length of the effective pixel area on the imaging surface S19 is ImgH=2.75 mm. Half of the maximum field of view of the optical imaging system is HFOV=107.00°. The aperture value Fno of the optical imaging system is 1.10.

[0095]

[0096] Table 2

[0097] The optical imaging system in Example 1 satisfies:

[0098] f3 / f=4.41; wherein f3 is the effective focal length f3 of the third lens, and f is the effective focal length of the optical imaging system.

[0099] CT1 / (T12+CT2)=0.20; wherein CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, and T12 is the air interval between the first lens and the second lens on the optical axis.

[0100] (R15+R16) / (R15-R16)=-3.48; wherein R15 is the radius of curvature of the object side of the eighth lens, and R16 is the radius of curvature of the image side of the eighth lens.

[0101] |f7 / R11|=2.53; wherein f7 is the effective focal length of the seventh lens, and R11 is the radius of curvature of the object side of the sixth lens.

[0102] |f5 / f6|+|f5 / f7|=3.51; wherein f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, and f7 is the effective focal length of the seventh lens.

[0103] |f6 / f|=2.05; wherein f6 is the effective focal length of the sixth lens, and f is the effective focal length f of the optical imaging system.

[0104] (CT1+CT2+CT3) / (T12+T23)=0.64; wherein CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third lens on the optical axis, T12 is the air spacing between the first lens and the second lens on the optical axis, and T23 is the air spacing between the second lens and the third lens on the optical axis.

[0105] (T12+CT8) / ΣC=0.45; wherein T12 is the air interval between the first lens and the second lens on the optical axis, CT8 is the center thickness of the eighth lens on the optical axis, and ΣCT is the sum of the center thicknesses of all lenses on the optical axis.

[0106] f / EPD=1.10; wherein f is the effective focal length f of the optical imaging lens, and EPD is the entrance pupil diameter of the optical imaging system.

[0107] TD / SL=1.51; wherein TD is the axial distance from the object side of the first lens to the image side of the last lens, and SL is the axial distance from the aperture to the imaging surface.

[0108] In Example 1, the object side surface and the image side surface of any lens from the first lens E1 to the eighth lens E8 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 , A18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30 .

[0109]

[0110]

[0111] Table 3

[0112] 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 FIG. 1 shows the astigmatism curve of the optical imaging system of Example 1, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 2a to Figure 2b It can be seen from the figure that the optical imaging system provided in Example 1 can achieve good imaging quality. Specific embodiment 2

[0114] 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: a first lens E1, a second lens E2, a third lens E3, an aperture STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, a filter E9 and an imaging surface S19.

[0115] The first lens E1 has negative 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 concave, and its image side surface S6 is convex. The fourth lens E4 has negative focal power, and its object side surface S7 is concave, and its image side surface S8 is convex. The fifth lens E5 has positive focal power, and its object side surface S9 is a convex-concave surface, and its image side surface S10 is convex. 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 concave, and its image side surface S14 is concave. The eighth lens E8 has positive focal power, and its object side surface S15 is convex, and its image side surface S16 is convex. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes through each of the surfaces S1 to S18 in sequence and is finally imaged on the imaging surface S19.

[0116] 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 in millimeters (mm). Among them, the first lens E1 is preferably but not limited to glass material, which can eliminate temperature drift and increase hardness. The refractive index and Abbe number range of the material are wider than those of plastic, which is more conducive to optimization. The fourth lens E4 or the fifth lens E5 is preferably but not limited to GM material (molded glass), which has the characteristics of glass material. It is also easy to manufacture aspheric lenses, which is more conducive to optimization.

[0117]

[0118]

[0119] Table 4

[0120] As shown in Table 5, in Example 2, the total effective focal length f of the optical imaging system is 1.46 mm, the distance TTL on the optical axis from the object side surface S1 of the first lens E1 to the imaging surface S19 of the optical imaging system is 12.20 mm, and half of the diagonal length of the effective pixel area on the imaging surface S19 is ImgH=2.81 mm. Half of the maximum field angle HFOV of the optical imaging system is 107.00°. The aperture value Fno of the optical imaging system is 1.26.

[0121]

[0122] Table 5

[0123] The optical imaging system in Example 2 satisfies:

[0124] f3 / f=5.93; wherein f3 is the effective focal length of the third lens, and f is the effective focal length of the optical imaging system.

[0125] CT1 / (T12+CT2)=0.22; wherein CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, and T12 is the air interval between the first lens and the second lens on the optical axis.

[0126] (R15+R16) / (R15-R16)=0.17; wherein R15 is the radius of curvature of the object side surface of the eighth lens, and R16 is the radius of curvature of the image side surface of the eighth lens.

[0127] |f7 / R11|=0.79; wherein f7 is the effective focal length of the seventh lens, and R11 is the radius of curvature of the object side of the sixth lens.

[0128] |f5 / f6|+|f5 / f7|=4.41; wherein f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, and f7 is the effective focal length of the seventh lens.

[0129] |f6 / f|=1.73; wherein f6 is the effective focal length of the sixth lens, and f is the effective focal length f of the optical imaging system.

[0130] (CT1+CT2+CT3) / (T12+T23)=0.85; wherein CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third lens on the optical axis, T12 is the air spacing between the first lens and the second lens on the optical axis, and T23 is the air spacing between the second lens and the third lens on the optical axis.

[0131] (T12+CT8) / ΣC=0.42; wherein T12 is the air interval between the first lens and the second lens on the optical axis, CT8 is the center thickness of the eighth lens on the optical axis, and ΣCT is the sum of the center thicknesses of all lenses on the optical axis.

[0132] f / EPD=1.26; wherein f is the effective focal length f of the optical imaging lens, and EPD is the entrance pupil diameter of the optical imaging system.

[0133] TD / SL=1.48; wherein TD is the axial distance from the object side of the first lens to the image side of the last lens, and SL is the axial distance from the aperture to the imaging surface.

[0134] In Example 2, the object side surface and the image side surface of any one of the first lens E1 to the eighth lens E8 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 and A 20 .

[0135] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S3 3.8686E-02 -3.6947E-02 1.6510E-02 -4.9108E-03 1.0179E-03 -1.4353E-04 1.3108E-05 -7.0050E-07 1.6712E-08 S4 6.7169E-02 3.0011E-02 -1.8324E-01 3.0439E-01 -2.9582E-01 1.8025E-01 -6.7140E-02 1.3908E-02 -1.2189E-03 S5 -4.4668E-03 6.7181E-03 -3.5830E-02 6.4955E-02 -7.1534E-02 4.7842E-02 -1.9142E-02 4.2267E-03 -3.9616E-04 S6 1.6320E-03 1.8277E-02 -7.7741E-02 1.4800E-01 -1.6851E-01 1.1920E-01 -5.0807E-02 1.1933E-02 -1.1799E-03 S7 3.9116E-02 -5.2172E-02 9.1508E-02 -1.4787E-01 1.5399E-01 -9.7772E-02 3.7241E-02 -7.7825E-03 6.8446E-04 S8 2.0924E-03 -8.2721E-02 2.1644E-01 -4.2433E-01 4.4004E-01 -2.5971E-01 9.0110E-02 -1.7357E-02 1.4502E-03 S9 7.9747E-02 -1.1673E-01 2.6260E-01 -4.1766E-01 3.6974E-01 -1.8356E-01 5.0041E-02 -6.6698E-03 2.8882E-04 S10 3.3998E-02 -2.2234E-03 4.0477E-02 -6.8169E-02 6.2409E-02 -3.3409E-02 1.0075E-02 -1.5747E-03 9.6949E-05 S11 -4.2982E-02 3.2893E-02 -3.3271E-02 2.4533E-02 -1.2329E-02 3.9207E-03 -7.3162E-04 6.6608E-05 -1.5909E-06 S12 -2.2694E-01 4.3633E-01 -4.4417E-01 2.8630E-01 -1.2107E-01 3.3148E-02 -5.5699E-03 5.0772E-04 -1.8100E-05 S13 -1.1140E-01 3.4917E-01 -4.1846E-01 3.0178E-01 -1.4148E-01 4.3417E-02 -8.3954E-03 9.2570E-04 -4.4228E-05 S14 3.8948E-03 1.6152E-02 -2.6864E-02 2.0284E-02 -9.1671E-03 2.6410E-03 -4.7861E-04 4.9952E-05 -2.3014E-06 S15 -6.2892E-02 3.9021E-02 -1.3262E-02 2.3885E-03 -1.8508E-04 6.2114E-05 -3.8214E-05 8.4247E-06 -6.3442E-07 S16 2.2760E-02 -1.3655E-02 1.3784E-02 -9.0824E-03 4.1098E-03 -1.2250E-03 2.2885E-04 -2.4351E-05 1.1323E-06

[0136] Table 6

[0137] 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 FIG. 2 shows the astigmatism curve of the optical imaging system of Example 2, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 4a to Figure 4b It can be seen from the figure that the optical imaging system provided in Example 2 can achieve good imaging quality. Specific embodiment 3

[0139] Figure 5Schematic 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: a first lens E1, a second lens E2, a third lens E3, an aperture STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, a filter E9 and an imaging surface S19.

[0140] The first lens E1 has negative 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 concave, 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 positive focal power, and its object side surface S7 is concave, and its image side surface S8 is convex. 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 concave, and its image side surface S12 is convex. 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 eighth lens E8 has positive focal power, and its object side surface S15 is convex, and its image side surface S16 is concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes through each of the surfaces S1 to S18 in sequence and is finally imaged on the imaging surface S19.

[0141] As shown in Table 7, it is a basic parameter table of the optical imaging system of Example 3, where the units of the radius of curvature, thickness, and focal length are all in millimeters (mm). Among them, the first lens E1 is preferably but not limited to glass material, which can eliminate temperature drift and increase hardness. The refractive index and Abbe number range of the material are wider than those of plastic, which is more conducive to optimization. The fourth lens E4 or the fifth lens E5 is preferably but not limited to GM material (molded glass), which has the characteristics of glass material. It is also easy to manufacture aspheric lenses, which is more conducive to optimization.

[0142]

[0143] Table 7

[0144] As shown in Table 8, in Example 3, the total effective focal length f of the optical imaging system is 1.41 mm, the distance TTL on the optical axis from the object side surface S1 of the first lens E1 to the imaging surface S19 of the optical imaging system is 13.49 mm, and half of the diagonal length of the effective pixel area on the imaging surface S19 is ImgH=2.76 mm. Half of the maximum field of view of the optical imaging system is HFOV=101.00°. The aperture value Fno of the optical imaging system is 1.15.

[0145]

[0146] Table 8

[0147] The optical imaging system in Example 3 satisfies:

[0148] f3 / f=4.61; wherein f3 is the effective focal length f3 of the third lens, and f is the effective focal length of the optical imaging system.

[0149] CT1 / (T12+CT2)=0.26; wherein CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, and T12 is the air interval between the first lens and the second lens on the optical axis.

[0150] (R15+R16) / (R15-R16)=-2.25; wherein R15 is the radius of curvature of the object side of the eighth lens, and R16 is the radius of curvature of the image side of the eighth lens.

[0151] |f7 / R11|=3.63; wherein f7 is the effective focal length of the seventh lens, and R11 is the radius of curvature of the object side of the sixth lens.

[0152] |f5 / f6|+|f5 / f7|=3.49; wherein f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, and f7 is the effective focal length of the seventh lens.

[0153] |f6 / f|=2.23; wherein f6 is the effective focal length of the sixth lens, and f is the effective focal length f of the optical imaging system.

[0154] (CT1+CT2+CT3) / (T12+T23)=0.77; wherein CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third lens on the optical axis, T12 is the air spacing between the first lens and the second lens on the optical axis, and T23 is the air spacing between the second lens and the third lens on the optical axis.

[0155] (T12+CT8) / ΣC=0.42; wherein T12 is the air interval between the first lens and the second lens on the optical axis, CT8 is the center thickness of the eighth lens on the optical axis, and ΣCT is the sum of the center thicknesses of all lenses on the optical axis.

[0156] f / EPD=1.15; where f is the effective focal length of the optical imaging lens, and EPD is the entrance pupil diameter of the optical imaging system.

[0157] TD / SL=1.44; wherein TD is the axial distance from the object side of the first lens to the image side of the last lens, and SL is the axial distance from the aperture to the imaging surface.

[0158] In Example 3, the object side surface and the image side surface of any one of the first lens E1 to the eighth lens E8 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, A5 10 , A 12 , A 14 , A 16 , A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30 .

[0159]

[0160]

[0161] Table 9

[0162] 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 FIG. 3 shows the astigmatism curve of the optical imaging system of Example 3, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 6a to Figure 6b It can be seen from the figure that the optical imaging system provided in Example 3 can achieve good imaging quality. Specific embodiment 4

[0164] 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: a first lens E1, a second lens E2, a third lens E3, an aperture STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, a filter E9 and an imaging surface S19.

[0165] The first lens E1 has negative 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 concave, 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 positive focal power, and its object side surface S7 is convex, and its image side surface S8 is convex. 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 concave, and its image side surface S12 is convex. 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 eighth lens E8 has positive focal power, and its object side surface S15 is convex, and its image side surface S16 is concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes through each of the surfaces S1 to S18 in sequence and is finally imaged on the imaging surface S19.

[0166] 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 in millimeters (mm). Among them, the first lens E1 is preferably but not limited to glass material, which can eliminate temperature drift and increase hardness. The refractive index and Abbe number range of the material are wider than those of plastic, which is more conducive to optimization. The fourth lens E4 or the fifth lens E5 is preferably but not limited to GM material (molded glass), which has the characteristics of glass material. It is also easy to manufacture aspheric lenses, which is more conducive to optimization.

[0167]

[0168] Table 10

[0169] As shown in Table 11, in Example 4, the total effective focal length f of the optical imaging system is 1.34 mm, the distance TTL on the optical axis from the object side surface S1 of the first lens E1 to the imaging surface S19 of the optical imaging system is 15.00 mm, and half of the diagonal length of the effective pixel area on the imaging surface S19 is ImgH=2.55 mm. Half of the maximum field angle HFOV of the optical imaging system is 100.00°. The aperture value Fno of the optical imaging system is 1.15.

[0170]

[0171]

[0172] Table 11

[0173] The optical imaging system in Example 4 satisfies:

[0174] f3 / f=5.17; wherein f3 is the effective focal length f3 of the third lens, and f is the effective focal length of the optical imaging system.

[0175] CT1 / (T12+CT2)=0.88; wherein CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, and T12 is the air interval between the first lens and the second lens on the optical axis.

[0176] (R15+R16) / (R15-R16)=-2.29; wherein R15 is the radius of curvature of the object side of the eighth lens, and R16 is the radius of curvature of the image side of the eighth lens.

[0177] |f7 / R11|=3.56; wherein f7 is the effective focal length of the seventh lens, and R11 is the radius of curvature of the object side of the sixth lens.

[0178] |f5 / f6|+|f5 / f7|=3.86; wherein f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, and f7 is the effective focal length of the seventh lens.

[0179] |f6 / f|=2.21; wherein f6 is the effective focal length of the sixth lens, and f is the effective focal length f of the optical imaging system.

[0180] (CT1+CT2+CT3) / (T12+T23)=1.53; wherein CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third lens on the optical axis, T12 is the air spacing between the first lens and the second lens on the optical axis, and T23 is the air spacing between the second lens and the third lens on the optical axis.

[0181] (T12+CT8) / ΣC=0.33; wherein T12 is the air interval between the first lens and the second lens on the optical axis, CT8 is the center thickness of the eighth lens on the optical axis, and ΣCT is the sum of the center thicknesses of all lenses on the optical axis.

[0182] f / EPD=1.15; where f is the effective focal length of the optical imaging lens, and EPD is the entrance pupil diameter of the optical imaging system.

[0183] TD / SL=1.69; wherein TD is the axial distance from the object side of the first lens to the image side of the last lens, and SL is the axial distance from the aperture to the imaging surface.

[0184] In Example 4, the object side surface and the image side surface of any lens from the first lens E1 to the eighth lens E8 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 , A 12 , A 14 , A 16, A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30 .

[0185]

[0186]

[0187] Table 12

[0188] 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 system of Example 4 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 8a to Figure 8b It can be seen from the figure that the optical imaging system provided in Example 4 can achieve good imaging quality. Specific embodiment 5

[0190] 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: a first lens E1, a second lens E2, a third lens E3, an aperture STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, a filter E9 and an imaging surface S19.

[0191] The first lens E1 has negative 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 concave, 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 positive focal power, and its object side surface S7 is concave, and its image side surface S8 is convex. 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 concave, and its image side surface S12 is convex. 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 eighth lens E8 has positive focal power, and its object side surface S15 is convex, and its image side surface S16 is concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes through each of the surfaces S1 to S18 in sequence and is finally imaged on the imaging surface S19.

[0192] As shown in Table 13, it is a basic parameter table of the optical imaging system of Example 5, where the units of the radius of curvature, thickness, and focal length are all in millimeters (mm). Among them, the first lens E1 is preferably but not limited to glass material, which can eliminate temperature drift and increase hardness. The refractive index and Abbe number range of the material are wider than those of plastic, which is more conducive to optimization. The fourth lens E4 or the fifth lens E5 is preferably but not limited to GM material (molded glass), which has the characteristics of glass material. It is also easy to manufacture aspheric lenses, which is more conducive to optimization.

[0193]

[0194] Table 13

[0195] As shown in Table 14, in Example 5, the total effective focal length f of the optical imaging system is 1.36 mm, the distance TTL on the optical axis from the object side surface S1 of the first lens E1 to the imaging surface S19 of the optical imaging system is 14.01 mm, and half of the diagonal length of the effective pixel area on the imaging surface S19 is ImgH=2.60 mm. Half of the maximum field angle HFOV of the optical imaging system is 101.50°. The aperture value Fno of the optical imaging system is 1.15.

[0196]

[0197]

[0198] Table 14

[0199] The optical imaging system in Example 5 satisfies:

[0200] f3 / f=4.61; wherein f3 is the effective focal length f3 of the third lens, and f is the effective focal length of the optical imaging system.

[0201] CT1 / (T12+CT2)=0.42; wherein CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, and T12 is the air interval between the first lens and the second lens on the optical axis.

[0202] (R15+R16) / (R15-R16)=-2.24; wherein R15 is the radius of curvature of the object side of the eighth lens, and R16 is the radius of curvature of the image side of the eighth lens.

[0203] |f7 / R11|=3.51; wherein f7 is the effective focal length of the seventh lens, and R11 is the radius of curvature of the object side of the sixth lens.

[0204] |f5 / f6|+|f5 / f7|=3.42; wherein f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, and f7 is the effective focal length of the seventh lens.

[0205] |f6 / f|=2.26; wherein f6 is the effective focal length of the sixth lens, and f is the effective focal length f of the optical imaging system.

[0206] (CT1+CT2+CT3) / (T12+T23)=0.97; wherein CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third lens on the optical axis, T12 is the air spacing between the first lens and the second lens on the optical axis, and T23 is the air spacing between the second lens and the third lens on the optical axis.

[0207] (T12+CT8) / ΣC=0.38; wherein T12 is the air interval between the first lens and the second lens on the optical axis, CT8 is the center thickness of the eighth lens on the optical axis, and ΣCT is the sum of the center thicknesses of all lenses on the optical axis.

[0208] f / EPD=1.15; where f is the effective focal length of the optical imaging lens, and EPD is the entrance pupil diameter of the optical imaging system.

[0209] TD / SL=1.50; wherein TD is the axial distance from the object side of the first lens to the image side of the last lens, and SL is the axial distance from the aperture to the imaging surface.

[0210] In Example 5, the object side surface and the image side surface of any one of the first lens E1 to the eighth lens E8 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, 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 .

[0211]

[0212]

[0213] Table 15

[0214] 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.10bThe astigmatism curve of the optical imaging system of Example 5 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 10a to Figure 10b It can be seen from the figure that the optical imaging system provided in Example 5 can achieve good imaging quality. Specific embodiment 6

[0216] 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: a first lens E1, a second lens E2, a third lens E3, an aperture STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, a filter E9 and an imaging surface S19.

[0217] The first lens E1 has negative 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 concave, 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 positive focal power, and its object side surface S7 is concave, and its image side surface S8 is convex. 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 concave, and its image side surface S12 is convex. 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 eighth lens E8 has positive focal power, and its object side surface S15 is convex, and its image side surface S16 is concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes through each of the surfaces S1 to S18 in sequence and is finally imaged on the imaging surface S19.

[0218] As shown in Table 16, it is a basic parameter table of the optical imaging system of Example 6, where the units of the radius of curvature, thickness, and focal length are all in millimeters (mm). Among them, the first lens E1 is preferably but not limited to glass material, which can eliminate temperature drift and increase hardness. The refractive index and Abbe number range of the material are wider than those of plastic, which is more conducive to optimization. The fourth lens E4 or the fifth lens E5 is preferably but not limited to GM material (molded glass), which has the characteristics of glass material. It is also easy to manufacture aspheric lenses, which is more conducive to optimization.

[0219]

[0220] Table 16

[0221] As shown in Table 17, in Example 6, the total effective focal length f of the optical imaging system is 1.43 mm, the distance TTL on the optical axis from the object side surface S1 of the first lens E1 to the imaging surface S19 of the optical imaging system is 13.00 mm, and half of the diagonal length of the effective pixel area on the imaging surface S19 is ImgH=2.77 mm. Half of the maximum field angle HFOV of the optical imaging system is 108.00°. The aperture value Fno of the optical imaging system is 1.10.

[0222]

[0223] Table 17

[0224] The optical imaging system in Example 6 satisfies:

[0225] f3 / f=4.52; wherein f3 is the effective focal length of the third lens, and f is the effective focal length of the optical imaging system.

[0226] CT1 / (T12+CT2)=0.20; wherein CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, and T12 is the air interval between the first lens and the second lens on the optical axis.

[0227] (R15+R16) / (R15-R16)=-2.29; wherein R15 is the radius of curvature of the object side of the eighth lens, and R16 is the radius of curvature of the image side of the eighth lens.

[0228] |f7 / R11|=3.45; wherein f7 is the effective focal length of the seventh lens, and R11 is the radius of curvature of the object side of the sixth lens.

[0229] |f5 / f6|+|f5 / f7|=3.464; wherein f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, and f7 is the effective focal length of the seventh lens.

[0230] |f6 / f|=2.07; wherein f6 is the effective focal length of the sixth lens, and f is the effective focal length f of the optical imaging system.

[0231] (CT1+CT2+CT3) / (T12+T23)=0.66; wherein CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third lens on the optical axis, T12 is the air spacing between the first lens and the second lens on the optical axis, and T23 is the air spacing between the second lens and the third lens on the optical axis.

[0232] (T12+CT8) / ΣC=0.39; wherein T12 is the air interval between the first lens and the second lens on the optical axis, CT8 is the center thickness of the eighth lens on the optical axis, and ΣCT is the sum of the center thicknesses of all lenses on the optical axis.

[0233] f / EPD=1.10; wherein f is the effective focal length f of the optical imaging lens, and EPD is the entrance pupil diameter of the optical imaging system.

[0234] TD / SL=1.39; wherein TD is the axial distance from the object side of the first lens to the image side of the last lens, and SL is the axial distance from the aperture to the imaging surface.

[0235] In Example 6, the object side surface and the image side surface of any one of the first lens E1 to the eighth lens E8 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 .

[0236]

[0237]

[0238] Table 18

[0239] 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 The astigmatism curve of the optical imaging system of Example 6 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 12a to Figure 12b It can be seen from the figure that the optical imaging system provided in Example 6 can achieve good imaging quality.

[0240] 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 eight lenses with optical power, and the optical imaging system includes, in order from the object side to the image side along the optical axis: The first lens has a negative optical power, and its object side surface is convex and its image side surface is concave; A second lens having negative optical power, whose image side surface is concave; a third lens having positive refractive power; The fourth lens has a convex image-side surface; a fifth lens element having positive refractive power and having a convex image-side surface; A sixth lens having an image side surface which is convex; a seventh lens; and an eighth lens having positive refractive power and a convex object-side surface; The fourth lens has positive power, the sixth lens has negative power, and the seventh lens has positive power, or the fourth lens has negative power, the sixth lens has positive power, and the seventh lens has negative power; There is an air gap between adjacent lenses; the maximum half field of view HFOV of the optical imaging system satisfies: 100°≤HFOV≤108°; The effective focal length f3 of the third lens and the effective focal length f of the optical imaging system satisfy: 4.41≤f3 / f≤5.

93.

2. The optical imaging system according to claim 1, characterized in that: The center thickness CT1 of the first lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, and the air interval T12 between the first lens and the second lens on the optical axis satisfy: 0.2≤CT1 / (T12+CT2)≤0.

88.

3. The optical imaging system according to claim 1, characterized in that: A curvature radius R15 of the object-side surface of the eighth lens and a curvature radius R16 of the image-side surface of the eighth lens satisfy: -3.5<(R15+R16) / (R15-R16)<0.

2.

4. The optical imaging system according to claim 1, characterized in that: The effective focal length f7 of the seventh lens and the curvature radius R11 of the object side surface of the sixth lens satisfy: 0.79≤|f7 / R11|≤3.

63.

5. The optical imaging system according to claim 1, characterized in that: The effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens and the effective focal length f7 of the seventh lens satisfy: 3.42≤|f5 / f6|+|f5 / f7|≤4.

41.

6. The optical imaging system according to claim 1, characterized in that: The effective focal length f6 of the sixth lens and the effective focal length f of the optical imaging system satisfy: 1.73≤|f6 / f|≤2.

26.

7. The optical imaging system according to claim 1, characterized in that: The center thickness CT1 of the first lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, the center thickness CT3 of the third lens on the optical axis, the air interval T12 between the first lens and the second lens on the optical axis, and the air interval T23 between the second lens and the third lens on the optical axis satisfy: 0.6<(CT1+CT2+CT3) / (T12+T23)≤1.

53.

8. The optical imaging system according to claim 1, characterized in that: An air interval T12 between the first lens and the second lens on the optical axis, a center thickness CT8 of the eighth lens on the optical axis, and a sum ΣCT of center thicknesses of all lenses on the optical axis satisfy: 0.3<(T12+CT8) / ΣCT<0.

5.

9. The optical imaging system according to claim 1, characterized in that: The effective focal length f of the optical imaging lens and the entrance pupil diameter EPD of the optical imaging system satisfy: 1.1≤f / EPD<1.

3.

10. The optical imaging system according to claim 1, characterized in that: The axial distance TD from the object side of the first lens to the image side of the last lens and the axial distance SL from the aperture to the imaging surface satisfy: 1.39≤TD / SL≤1.69.

Images