Ultra-wide-angle lens

Abstract

The invention relates to an ultra-wide-angle lens which is arranged along an optical axis from an object side to an image side. The invention relates to a multi-lens zoom lens, which sequentially comprises a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with positive focal power, a fifth lens, a sixth lens with positive focal power, a seventh lens with positive focal power, an eighth lens with negative focal power and a ninth lens with positive focal power, the optical total length TTL, the total focal length f and the image height H under the maximum field angle of the ultra-wide-angle lens meet the following relation: TTL * f / H is more than or equal to 6.9 and less than or equal to 7.4. The ultra-wide-angle lens at least has one of the characteristics that the FOV is larger than or equal to 196 degrees, the total optical length is long, the thermal stability is good, the resolution ratio is high, a large aperture (FNO is smaller than or equal to 1.8) can be achieved, and the illumination is high.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging lenses, and in particular to an ultra-wide-angle lens having one of the characteristics of a large field of view, a large aperture, a high resolution, a high illumination, and a low cost. Background Art

[0002] With the development of optical imaging lenses, the demand for lenses in the fields of panoramic monitoring, drones, sports cameras and automotive lenses is increasing, which puts higher requirements on optical imaging lenses. The details are as follows:

[0003] 1. In order to obtain a wider target range, the optical imaging lens is required to have a large field of view;

[0004] 2. In order to obtain more light throughput, the optical imaging lens is required to have a large aperture;

[0005] 3. The existing technical lenses have the defect of not being able to achieve high resolution and high brightness at the same time, so the optical imaging lenses are required to have high resolution and high illumination;

[0006] 4. In order to ensure good thermal stability, existing technology lenses use materials with stable thermal expansion coefficients, which results in high costs and poor market competitiveness, thus putting forward low-cost requirements for optical imaging lenses.

[0007] Therefore, designing an ultra-wide-angle lens with one of the characteristics of large field of view, large aperture, high resolution, high illumination, and low cost has become a market development trend. Summary of the invention

[0008] In order to solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide an ultra-wide-angle lens having at least one of the characteristics of a large field of view FOV ≥ 196°, a short optical total length, good thermal stability, high resolution, a large aperture (FNO ≤ 1.8), and high illumination.

[0009] To achieve the above-mentioned object, the present invention provides an ultra-wide-angle lens, which includes, in order from the object side to the image side of the optical axis: a first lens with negative optical power, a second lens with negative optical power, a third lens with negative optical power, a fourth lens with positive optical power, a fifth lens, a sixth lens with positive optical power, a seventh lens with positive optical power, an eighth lens with negative optical power and a ninth lens with positive optical power,

[0010] The total optical length TTL, the total focal length f and the image height H at the maximum field of view of the ultra-wide-angle lens satisfy the following relationship: 6.9≤TTL*f / H≤7.4.

[0011] According to a technical solution of the present invention, the optical system further includes a tenth lens located on the object side of the first lens, and the tenth lens has negative optical power.

[0012] According to a technical solution of the present invention, the tenth lens is a convex-concave lens.

[0013] According to a technical solution of the present invention, the optical effective aperture D10 of the tenth lens and the effective focal length f10 of the tenth lens satisfy the following relationship: -0.3≤D10 / f10<0.

[0014] According to a technical solution of the present invention, the first lens is a convexo-concave lens, the second lens is a convexo-concave lens, and the object side surface of the third lens is a concave surface.

[0015] According to a technical solution of the present invention, the object side surface of the sixth lens is convex, the seventh lens is a convex-convex lens, the object side surface of the eighth lens is concave, and the object side surface of the ninth lens is convex.

[0016] According to a technical solution of the present invention, the third lens is glued to the fourth lens, or the fourth lens is glued to the fifth lens.

[0017] According to a technical solution of the present invention, the seventh lens and the eighth lens form a cemented lens.

[0018] According to a technical solution of the present invention, the effective focal length f1 of the first lens and the total focal length f of the ultra-wide-angle lens satisfy the following relationship: -6.3≤f1 / f≤-4.

[0019] According to a technical solution of the present invention, the combined effective focal length f12 of the first lens and the second lens and the effective focal length f of the ultra-wide-angle lens satisfy the following relationship: -1.8≤f12 / f≤-1.6.

[0020] According to a technical solution of the present invention, the effective focal length f2 of the second lens and the total focal length f of the ultra-wide-angle lens satisfy the following relationship: -4≤f2 / f≤-2.6.

[0021] According to a technical solution of the present invention, the effective focal length f2 of the second lens and the image side curvature radius R22 of the second lens satisfy the following relationship: -2.9≤f2 / R22≤-1.6.

[0022] According to a technical solution of the present invention, the effective focal length f3 of the third lens and the total focal length f of the ultra-wide-angle lens satisfy the following relationship: -6.7≤f3 / f≤-3.8.

[0023] According to a technical solution of the present invention, the effective focal length f4 of the fourth lens and the total focal length f of the ultra-wide-angle lens satisfy the following relationship: 2.1≤f4 / f≤7.

[0024] According to a technical solution of the present invention, the effective focal length f6 of the sixth lens and the effective focal length f5 of the fifth lens satisfy the following relationship: 0<|f6 / f5|≤1.2.

[0025] According to a technical solution of the present invention, the effective focal length f6 of the sixth lens and the effective focal length fb of the rear lens group satisfy the following relationship: 1.35≤f6 / fb≤3.

[0026] According to a technical solution of the present invention, the effective focal length f7 of the seventh lens and the effective focal length f8 of the eighth lens satisfy the following relationship: -1.67≤f7 / f8≤-0.8.

[0027] According to a technical solution of the present invention, the effective focal length f9 of the ninth lens and the total focal length f of the ultra wide-angle lens satisfy the following relationship: 2.7≤f9 / f≤5.

[0028] According to a technical solution of the present invention, the image-side surface curvature radius R92 of the ninth lens and the effective focal length f9 of the ninth lens satisfy the following relationship: 0.8≤|R92 / f9|≤2.5.

[0029] According to a technical solution of the present invention, the effective focal length fa of the front lens group and the total focal length f of the ultra-wide-angle lens satisfy the following relationship: -5.6≤fa / f≤-3.4.

[0030] According to a technical solution of the present invention, the effective focal length fb of the rear lens group and the total focal length f of the ultra-wide-angle lens satisfy the following relationship: 2.8≤fb / f≤3.2.

[0031] According to a technical solution of the present invention, the effective focal length fa of the front lens group and the effective focal length fb of the rear lens group satisfy the following relationship: -1.75≤fa / fb≤-1.2.

[0032] According to a technical solution of the present invention, the maximum field of view FOV, the image height H at the maximum field of view, and the maximum aperture D of the ultra-wide-angle lens satisfy the following relationship: 3.4≤FOV / H / D≤3.75.

[0033] According to a technical solution of the present invention, the combined effective focal length f345 of the third lens to the fifth lens and the effective focal length fa of the front lens group satisfy the following relationship: -3≤f345 / fa≤-1.3.

[0034] According to a technical solution of the present invention, the back focal length BFL of the ultra wide-angle lens and the total focal length f of the ultra wide-angle lens satisfy the following relationship: 1.3≤BFL / f≤1.5.

[0035] According to a technical solution of the present invention, the Abbe number Vd4 of the fourth lens and the Abbe number Vd5 of the fifth lens satisfy the following relationship: 1≤|Vd4-Vd5|≤15;

[0036] The lens Abbe number Vd7 of the seventh lens and the lens Abbe number Vd8 of the eighth lens satisfy the following relationship: 40≤|Vd7-Vd8|≤67.

[0037] According to a technical solution of the present invention, the image height H corresponding to the maximum field angle of the ultra-wide-angle lens is 4.5 mm to 4.7 mm.

[0038] According to a technical solution of the present invention, the ultra-wide-angle lens satisfies at least one of the following conditions:

[0039] -6.3≤f1 / f≤-4.2,

[0040] -3.9≤f2 / f≤-2.8,

[0041] -1.75≤f12 / f≤-1.6,

[0042] -2.8≤f2 / R22≤-1.8,

[0043] -6.4≤f3 / f≤-4,

[0044] 2.15≤f4 / f≤6.8,

[0045] 0.25≤|f6 / f5|≤1.05,

[0046] 1.4≤f6 / fb≤2.85,

[0047] -1.6≤f7 / f8≤-0.9,

[0048] 2.85≤f9 / f≤4.85,

[0049] 0.9≤|R92 / f9|≤2.1,

[0050] -5.4≤fa / f≤-3.75,

[0051] 2.8≤fb / f≤3.2,

[0052] -1.7≤fa / fb≤-1.25,

[0053] -3≤f345 / fa≤-1.3,

[0054] 3.4≤FOV / H / D≤3.7,

[0055] 1.3≤BFL / f≤1.45,

[0056] 6.95≤TTL*F / H≤7.4,

[0057] 1≤|Vd4-Vd5|≤14,

[0058] 43.5≤|Vd7-Vd8|≤64.5,

[0059] Wherein, f1 is the effective focal length of the first lens; f is the total focal length of the ultra-wide-angle lens; f2 is the effective focal length of the second lens; f12 is the combined effective focal length of the first lens and the second lens; R22 is the radius of curvature of the image side of the second lens; f3 is the effective focal length of the third lens; f4 is the effective focal length of the fourth lens; f6 is the effective focal length of the sixth lens; f5 is the effective focal length of the fifth lens; fb is the effective focal length of the rear lens group; f7 is the effective focal length of the seventh lens; f8 is the effective focal length of the eighth lens; f9 is the effective focal length of the ninth lens; R92 is The radius of curvature of the image side surface of the ninth lens; fa is the effective focal length of the front lens group; f345 is the combined effective focal length of the third lens to the fifth lens; FOV is the maximum field of view of the ultra-wide-angle lens; H is the image height at the maximum field of view of the ultra-wide-angle lens; D is the maximum aperture of the ultra-wide-angle lens; TTL is the total optical length of the ultra-wide-angle lens; BFL is the back focal length of the ultra-wide-angle lens; Vd4 is the Abbe number of the fourth lens; Vd5 is the Abbe number of the fifth lens; Vd7 is the Abbe number of the seventh lens; Vd8 is the Abbe number Vd8 of the eighth lens.

[0060] According to a technical solution of the present invention, the optical effective aperture D10 of the tenth lens and the effective focal length f10 of the tenth lens satisfy: -0.3≤D10 / F10≤-0.1.

[0061] According to the solution of the present invention, by setting the relationship between the number of ultra-wide-angle lenses and the optical focal length, the ultra-wide-angle lens has at least one of the characteristics of good total optical length and thermal stability, a large field of view FOV ≥ 196°, can be matched with a camera to achieve high resolution (25 million pixels), can achieve a larger aperture (FNO ≤ 1.8), and high illumination (relative illumination ≥ 63%). BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0063] Figure 1 Schematic diagram of the structure of the ultra-wide-angle lens of Embodiment 1 of the present invention;

[0064] Figure 2 Schematic diagram of the structure of the ultra-wide-angle lens of Embodiment 2 of the present invention;

[0065] Figure 3 Schematic diagram of the structure of the ultra-wide-angle lens of Embodiment 3 of the present invention;

[0066] Figure 4 Schematic diagram of the structure of the ultra-wide-angle lens of Embodiment 4 of the present invention. DETAILED DESCRIPTION

[0067] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0068] 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 application, the first lens discussed below may also be referred to as the second lens or the first lens.

[0069] 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.

[0070] In this article, 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.

[0071] 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.

[0072] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as those 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 sense unless explicitly defined in this article.

[0073] It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following examples only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for those of ordinary skill in the art, without departing from the concept of the present application, several variations and improvements can also be made, which all belong to the protection scope of the present application.

[0074] like Figures 1 to 4 As shown, an embodiment of the present invention provides an ultra-wide-angle lens, which includes, in order from the object side to the image side of the optical axis: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, an aperture STO, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9 and a protective plate glass CG. The first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 form a front lens group, and the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9 form a rear lens group.

[0075] The first lens L1 is a convex-concave lens with negative optical power, which can effectively converge light with a large field angle, reduce the incident angle of light on the object side of the second lens L2, effectively avoid the subsequent optical lens from generating high-order aberrations due to excessively large incident angles, and improve the resolution performance of the lens.

[0076] The second lens L2 is a convex-concave lens with negative optical power, which is beneficial to controlling the trend of light, making the light transition smoothly, and is beneficial to better correcting the aberration of the central field of view area and improving the resolution of the lens.

[0077] The third lens L3 has negative focal power, and its object side surface is concave. The fourth lens L4 has positive focal power, and preferably a glass lens can be used. The third lens L3 with negative focal power cooperates with the fourth lens L4 with positive focal power, which is conducive to better correcting the spherical aberration of the optical system and improving the resolution performance of the lens. The fourth lens L4 cooperates with the fifth lens L5, which is conducive to better correcting the spherical aberration of the optical system, can effectively correct the axial chromatic aberration, and can also effectively reduce the tolerance sensitivity of the lens and improve the production yield of the lens.

[0078] The fifth lens L5 can preferably be a glass lens, and the object side surface of the sixth lens L6 is a convex surface with positive focal power. Through the cooperation between the fifth lens L5 and the sixth lens L6, the axial chromatic aberration can be effectively corrected, and the trend of light before and after the aperture can be controlled, so that a larger aperture can be achieved, and the aperture FNO≤1.8 can be made, effectively improving the illumination. The sixth lens L6 is a spherical lens or an aspherical lens. When the sixth lens L6 is an aspherical lens, it is beneficial to correct the residual astigmatism and axial chromatic aberration of the front group; when the sixth lens L6 is a spherical lens, it is preferred to use a material with stable thermal expansion to help achieve thermal compensation of the optical lens.

[0079] The aperture STO is located between the fifth lens L5 and the sixth lens L6. By providing an aperture for limiting the light beam between the fifth lens L5 and the sixth lens L6, the imaging quality of the optical lens can be further improved, which is beneficial to focusing the light entering the optical system, reducing the rear port diameter of the optical system, and reducing the assembly sensitivity of the system.

[0080] The seventh lens L7 is a convex-convex lens with positive focal length, and the eighth lens L8 has negative focal length, and its object side is concave. The seventh lens L7 and the eighth lens L8 are combined into a double cemented lens, which is conducive to the smooth transmission of light, reduces the tolerance sensitivity of the lens, and can effectively improve the production yield of the lens; at the same time, the eighth lens L8 can also effectively correct the vertical axis chromatic aberration and improve the imaging quality. The seventh lens L7 adopts a material with low refractive index and high Abbe number, which effectively corrects the vertical axis chromatic aberration of the optical system and improves the imaging quality of the lens.

[0081] The ninth lens L9 has positive refractive power, and its object side surface is convex, which can effectively control the direction of light, effectively lower the exit angle of light passing through the ninth lens L9, and reduce the main light angle, so as to better match the chip and the chip CRA curve requirements.

[0082] In some embodiments of the present invention, the combined effective focal length f345 of the third lens L3 to the fifth lens L5 and the effective focal length fa of the front lens group satisfy the following relationship: -3≤f345 / fa≤-1.3. By reasonably controlling the ratio of the combined effective focal length of the third lens L3 to the fifth lens L5 to the effective focal length of the front lens group of the ultra-wide-angle lens, the trend of light can be effectively controlled, which is conducive to better correction of the spherical aberration of the optical system, and can also effectively correct the axial chromatic aberration; it is conducive to the smooth transition of light, which can effectively reduce the tolerance sensitivity of the lens and improve the production yield of the lens.

[0083] In some embodiments of the present invention, a tenth lens L10 is further included, which is located on the object-side surface of the first lens L1. The tenth lens L10 is a convex-concave lens with negative optical power, which is beneficial to reducing the incident angle of the incident light on the object-side surface of the first lens L1, so that the light enters the rear optical system smoothly, and effectively corrects the aberration of the rear group of the optical system. The lens material of the tenth lens L10 is glass, which can be used as a protective cover to achieve the effect of protecting the lens.

[0084] In some embodiments of the present invention, the optical effective aperture D10 of the tenth lens L10 and the effective focal length f10 of the tenth lens L10 satisfy the following relationship: -0.3≤D10 / f10<0, preferably -0.3≤D10 / F10≤-0.1. Reasonable configuration of the ratio of the optical effective aperture D10 of the tenth lens L10 to the effective focal length f10 of the tenth lens L10 is conducive to large-angle incident light entering the optical system, effectively expanding the field of view of the optical system, so that the field of view FOV ≥ 196°, and can also effectively avoid the generation of aberrations.

[0085] In some embodiments of the present invention, the effective focal length f1 of the first lens L1 and the total focal length f of the ultra-wide-angle lens satisfy the following relationship: -6.3≤f1 / f≤-4, preferably -6.3≤f1 / f≤-4.2. Reasonable control of the effective focal length f1 of the first lens L1 can effectively collect light with a large field angle, reduce the incident angle of the light on the object side of the second lens L2, and effectively avoid the subsequent optical lens from generating high-order aberrations due to excessively large incident angles, thereby facilitating the improvement of the resolution performance of the lens.

[0086] In some embodiments of the present invention, the combined effective focal length f12 of the first lens L1 and the second lens L2 satisfies the following relationship with the effective focal length f of the ultra-wide-angle lens: -1.8≤f12 / f≤-1.6, preferably -1.75≤f12 / f≤-1.6. Reasonable configuration of the combined effective focal length f12 of the first lens L1 and the second lens L2 can effectively control the trend of light, so that the light has a divergent effect, which is conducive to allowing as much large-angle light as possible to enter the rear of the optical system, thereby improving the relative illumination of the lens.

[0087] In some embodiments of the present invention, the effective focal length f2 of the second lens L2 and the total focal length f of the ultra-wide-angle lens satisfy the following relationship: -4≤f2 / f≤-2.6, preferably -3.9≤f2 / f≤-2.8. The effective focal length f2 of the second lens L2 is reasonably configured to effectively control the trend of light, so that the light has a divergent effect, which is conducive to allowing as much large-angle light as possible to enter the rear of the optical system and improve the relative illumination of the lens.

[0088] In some embodiments of the present invention, the effective focal length f2 of the second lens L2 and the image side curvature radius R22 of the second lens L2 satisfy the following relationship: -2.9≤f2 / R22≤-1.6, preferably -2.8≤f2 / R22≤-1.8. Reasonable configuration of the ratio of the effective focal length f2 of the second lens L2 to the image side curvature radius R22 is conducive to controlling the trend of light, making the light smoothly incident on the object side of the third lens L3, helping to reduce the tolerance sensitivity of the optical lens, and at the same time helping to better correct the aberration of the central field of view area and improve the resolution of the lens.

[0089] In some embodiments of the present invention, the effective focal length f3 of the third lens L3 and the total focal length f of the ultra-wide-angle lens satisfy the following relationship: -6.7≤f3 / f≤-3.8, preferably -6.4≤f3 / f≤-4. Reasonable configuration of the effective focal length f3 of the third lens L3 is conducive to correcting the spherical aberration of the optical system and improving the resolution of the lens.

[0090] In some embodiments of the present invention, the effective focal length f4 of the fourth lens L4 and the total focal length f of the ultra-wide-angle lens satisfy the following relationship: 2.1≤f4 / f≤7, preferably 2.15≤f4 / f≤6.8. Reasonable configuration of the effective focal length f4 of the fourth lens L4 is conducive to correcting the spherical aberration and axial chromatic aberration of the optical system and improving the resolution of the lens.

[0091] In some embodiments of the present invention, the effective focal length f6 of the sixth lens L6 and the effective focal length f5 of the fifth lens L5 satisfy the following relationship: 0<|f6 / f5|≤1.2, preferably 0.25≤|f6 / f5|≤1.05. Reasonable allocation of the focal lengths of the fifth lens L5 and the sixth lens L6 can effectively correct spherical aberration and axial chromatic aberration, improve the resolution of the lens; and at the same time, it can also control the trend of light before and after the aperture, which is helpful to achieve a larger aperture, so that the aperture FNO≤1.8, effectively improve the illumination; and it can also better realize the characteristic of eliminating temperature drift, which is helpful to achieve thermal compensation of the optical lens, so that the optical lens has good temperature performance.

[0092] In some embodiments of the present invention, the effective focal length f6 of the sixth lens L6 and the effective focal length fb of the rear lens group satisfy the following relationship: 1.35≤f6 / fb≤3, preferably 1.4≤f6 / fb≤2.85. Reasonable configuration of the ratio of the effective focal length f6 of the sixth lens L6 to the effective focal length fb of the rear lens group of the optical system is conducive to smooth transmission of light, reducing the tolerance sensitivity of the lens, and effectively improving the production yield of the lens.

[0093] In some embodiments of the present invention, the effective focal length f7 of the seventh lens L7 and the effective focal length f8 of the eighth lens L8 satisfy the following relationship: -1.67≤f7 / f8≤-0.8, preferably -1.6≤f7 / f8≤-0.9. The focal length ratio of the seventh lens L7 and the eighth lens L8 is reasonably configured, and the seventh lens L7 and the eighth lens L8 are matched in the form of positive and negative optical power, which is conducive to balancing the astigmatism generated by the lens group after the aperture, thereby improving the resolution performance.

[0094] In some embodiments of the present invention, the effective focal length f9 of the ninth lens L9 and the total focal length f of the ultra-wide-angle lens satisfy the following relationship: 2.7≤f9 / f≤5, preferably 2.85≤f9 / f≤4.85. Reasonable allocation of the effective focal length f9 of the ninth lens L9 can effectively control the light trend, fold the maximum field of view main light emitted by the eighth lens L8, and ensure better matching with chip requirements.

[0095] In some embodiments of the present invention, the image side surface curvature radius R92 of the ninth lens L9 and the effective focal length f9 of the ninth lens L9 satisfy the following relationship: 0.8≤|R92 / f9|≤2.5, preferably 0.9≤|R92 / f9|≤2.1. Reasonable control of the ratio of the image side surface curvature radius R92 of the ninth lens L9 to its effective focal length f9 can effectively reduce the exit angle of light passing through L9, reduce the main light angle, so as to better match the chip and the chip CRA curve requirements, and make the lens have strong tolerance and manufacturability.

[0096] In some embodiments of the present invention, the effective focal length fa of the front lens group and the total focal length f of the ultra-wide-angle lens satisfy the following relationship: -5.6≤fa / f≤-3.4, preferably -5.4≤fa / f≤-3.75. Reasonable setting of the effective focal length fa of the front lens group can make the main plane of the image side of the entire optical system closer to the imaging surface, achieve the effect of reverse telephoto of the optical system, effectively increase the back focal length of the optical lens, and facilitate the assembly of the optical lens module. At the same time, lengthening the back focal length can also help reduce the energy of the ghost image generated by the central reflection of the lens and the color filter, and improve the quality of the lens.

[0097] In some embodiments of the present invention, the effective focal length fb of the rear lens group and the total focal length f of the ultra-wide-angle lens satisfy the following relationship: 2.8≤fb / f≤3.2. Reasonable setting of the effective focal length fb of the rear lens group can help achieve a larger aperture, making the aperture FNO≤1.8.

[0098] In some embodiments of the present invention, the effective focal length fa of the front lens group and the effective focal length fb of the rear lens group satisfy the following relationship: -1.75≤fa / fb≤-1.2, preferably -1.7≤fa / fb≤-1.25. Reasonable allocation of the effective focal lengths of the front lens group and the rear lens group is conducive to controlling the overall light trend of the optical system, making the light transition smoother, reducing the sensitivity of the system, and improving the imaging quality of the system.

[0099] In some embodiments of the present invention, the maximum field of view FOV, the image height H at the maximum field of view, and the maximum aperture D of the ultra-wide-angle lens satisfy the following relationship: 3.4≤FOV / H / D≤3.75, preferably 3.4≤FOV / H / D≤3.7. By controlling the ratio range of the maximum field of view FOV, the image height H at the maximum field of view, and the maximum aperture D of the ultra-wide-angle lens, the viewpoint position can be effectively controlled to ensure that the aperture meets the design requirements. When the image height is fixed, the shorter the focal length, the larger the field of view, and vice versa. By controlling the ratio range between the field of view, focal length, and image height, the lens can have a reasonable field of view when corresponding to different sensors.

[0100] In some embodiments of the present invention, the total optical length TTL, the total focal length f and the image height H at the maximum field angle of the ultra-wide-angle lens satisfy the following relationship: 6.9≤TTL*f / H≤7.4, preferably 6.95≤TTL*F / H≤7.4. By rationally adjusting the total optical length TTL of the optical lens, the total focal length f of the system and the image height H, it is helpful to make the entire optical lens more compact and miniaturized.

[0101] In some embodiments of the present invention, the back focal length BFL of the ultra-wide-angle lens and the total focal length f of the ultra-wide-angle lens satisfy the following relationship: 1.3≤BFL / f≤1.5, preferably 1.3≤BFL / f≤1.45. On the basis of achieving miniaturization, by controlling the optical back focal length BFL of the system, the back focal length of the lens is made longer, which helps to reserve space for the installation of optical elements, facilitates the assembly of the optical lens, avoids interference, and improves the assembly yield of the optical lens.

[0102] In some embodiments of the present invention, the lens Abbe number Vd4 of the fourth lens L4 and the lens Abbe number Vd5 of the fifth lens L5 satisfy the following relationship: 1≤|Vd4-Vd5|≤15, preferably 1≤|Vd4-Vd5|≤14;

[0103] The Abbe number Vd7 of the seventh lens L7 and the Abbe number Vd8 of the eighth lens L8 satisfy the following relationship: 40≤|Vd7-Vd8|≤67, preferably 43.5≤|Vd7-Vd8|≤64.5. By properly selecting the lens materials of the fourth lens L4 and the fifth lens L5, the seventh lens L7 and the eighth lens L8, the fourth lens L4, the fifth lens L5, the seventh lens L7 and the eighth lens L8 use glass lenses, which can effectively correct the vertical axis chromatic aberration of the optical system, avoid the generation of purple fringing of the lens, and improve the imaging quality of the lens; at the same time, it can also suppress the deviation of the back focus of the optical system caused by temperature changes, so as to improve the stability of the system and help improve the quality of the lens.

[0104] In some embodiments of the present invention, the image height H corresponding to the maximum field angle of the ultra-wide-angle lens is 4.5 mm to 4.7 mm. Further, the image height H corresponding to the maximum field angle of the ultra-wide-angle lens may be 4.6 mm.

[0105] In some embodiments of the present invention, at least the ninth lens L9 among the first lens L1 to the ninth lens L9 is an aspherical lens, and the aspherical surface has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving aberration. The use of an aspherical surface can eliminate aberrations that occur during imaging as much as possible, thereby improving the resolution of the fixed-focus lens.

[0106] In some embodiments of the present invention, the first lens to the ninth lens may adopt glass-plastic hybrid lenses, or all of them may adopt glass lenses. The use of glass lenses can effectively suppress the deviation of the back focal length of the fixed-focus lens caused by temperature changes, and improve the stability of the fixed-focus lens; at the same time, the glass lens can effectively avoid the problem of blurred imaging caused by high temperature or low temperature environments, ensure the normal use of the fixed-focus lens, and better correct the system chromatic aberration, and improve the resolution ability of the fixed-focus lens. The use of plastic lenses can effectively reduce the production cost. In addition, the temperature range of the optical lens with an all-glass design is wider, and it can maintain stable optical performance in the range of -40°C to 85°C.

[0107] Specifically, when focusing on resolution quality and reliability, the first to ninth lenses can all be glass lenses; when taking production costs into consideration, the first to ninth lenses can be made of a glass-plastic hybrid.

[0108] Four groups of specific implementations are given below according to the above-mentioned configuration of the present invention to specifically illustrate the ultra-wide-angle lens according to the present invention. The ultra-wide-angle lens according to the present invention has a total of ten lenses, and each cemented surface of the cemented lens is recorded as a surface, plus the aperture STO, the protective glass CG and the image surface IMA, a total of 21 surfaces. Among them, the aperture STO is set between the fifth lens L5 and the sixth lens L6. For the convenience of description, each lens surface, the aperture STO and the protective glass CG are numbered S1, S2 to S21. And the aspheric surface satisfies the following formula:

[0109]

[0110] In the above formula, z is the axial distance from the surface to the vertex at a height y perpendicular to the optical axis along the optical axis; c represents the curvature at the vertex of the aspheric surface; k is the cone coefficient; A4, A6, A8, A 10 , A 12 , A 14 , A 16 ···represent the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, sixteenth-order···aspheric coefficients respectively.

[0111] Four sets of example data are shown in Table 1 below:

[0112] Conditional expression Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 -0.3≤D10 / F10<0 -0.22 -0.11 -0.11 -0.11 -6.3≤f1 / f≤-4 -6.28 -4.51 -4.25 -4.60 -4≤f2 / f≤-2.6 -2.82 -3.60 -3.75 -3.85 -1.8≤f12 / f≤-1.6 -1.63 -1.67 -1.65 -1.72 -2.9≤f2 / R22≤-1.6 -2.37 -2.00 -1.81 -2.76 -6.7≤f3 / f≤-3.8 -6.34 -4.66 -5.19 -4.09 2.1≤f4 / f≤7 2.18 4.89 6.75 2.62 0<|f6 / f5|≤1.2 1.02 0.30 0.60 0.87 1.35≤f6 / fb≤3 1.56 1.41 1.91 2.81 -1.67≤f7 / f8≤-0.8 -1.56 -1.57 -1.32 -0.94 2.7≤f9 / f≤5 2.89 3.08 3.06 4.82 0.8≤|R92 / f9|≤2.5 1.14 1.29 0.94 2.07 -5.6≤fa / f≤-3.4 -5.32 -4.32 -4.36 -3.78 2.8≤fb / f≤3.2 3.16 2.86 2.91 2.89 -1.75≤fa / fb≤-1.2 -1.68 -1.51 -1.50 -1.30 -3≤f345 / fa≤-1.3 -1.36 -1.92 -1.96 -2.89 3.4≤FOV / H / D≤3.75 3.65 3.47 3.44 3.44 1.3≤BFL / f≤1.5 1.43 1.36 1.35 1.40 6.9≤TTL*F / H≤7.4 6.99 7.34 7.24 7.09 1≤|Vd4-Vd5|≤15 1.02 13.82 13.74 1.02 40≤|Vd7-Vd8|≤67 43.57 64.47 43.57 43.57

[0113] Table 1

[0114] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments cannot be described one by one here, but the embodiments of the present invention are not therefore limited to the following embodiments.

[0115] Embodiment 1

[0116] Figure 1 Schematic diagram of the structure of the ultra-wide-angle lens of Example 1 of the present invention.

[0117] In Embodiment 1, the tenth lens L10 is a convexo-concave lens with negative power, the first lens L1 is a convexo-concave lens with negative power, the second lens L2 is a convexo-concave lens with negative power, the third lens L3 is a convexo-concave lens with negative power, the fourth lens L4 is a convexo-convex lens with positive power, the fifth lens L5 is a convexo-convex lens with negative power, the sixth lens L6 is a convexo-convex lens with positive power, the seventh lens L7 is a convexo-convex lens with positive power, the eighth lens L8 is a convexo-concave lens with negative power, and the ninth lens L9 is a convexo-convex lens with positive power.

[0118] The second lens L2, the third lens L3, the sixth lens L6 and the ninth lens L9 are aspherical lenses; the aperture STO is arranged between the fifth lens L5 and the sixth lens L6. The fourth lens L4 and the fifth lens L5, the seventh lens L7 and the eighth lens L8 form a cemented lens.

[0119] Table 2 lists the relevant parameters of each lens in the ultra-wide-angle lens of this embodiment, including: surface type, curvature radius R, thickness d, refractive index Nd and Abbe number Vd of the material.

[0120]

[0121] Table 2

[0122] Table 3 lists the aspheric coefficients of the aspheric lenses of the ultra-wide-angle lens of this embodiment, including: the quadratic surface constant K, the fourth-order aspheric coefficient A4, the sixth-order aspheric coefficient A6, the eighth-order aspheric coefficient A8, the tenth-order aspheric coefficient A 10 , 12th-order aspheric coefficient A 12 , Fourteenth-order aspheric coefficient A 14 and the sixteenth-order aspheric coefficient A 16 .

[0123]

[0124]

[0125] Table 3

[0126] Combination Figure 1 As shown in Tables 1 to 3 above, in Embodiment 1, the total focal length f of the ultra-wide-angle lens is 1.42, the FNO is 1.8, and the relative illumination RI ≥ 75%.

[0127] The first embodiment of the present invention is an ultra-wide-angle lens having at least one of the following characteristics: short total optical length and good thermal stability, a large field of view FOV ≥ 196°, high resolution (25 million pixels) that can be matched with a camera, a large aperture (FNO ≤ 1.8), and high illumination (relative illumination ≥ 63%).

[0128] Embodiment 2

[0129] Figure 2 Schematic diagram of the structure of the ultra-wide-angle lens of Embodiment 2 of the present invention.

[0130] In Embodiment 2, the tenth lens L10 is a convexo-concave lens with negative power, the first lens L1 is a convexo-concave lens with negative power, the second lens L2 is a convexo-concave lens with negative power, the third lens L3 is a convexo-concave lens with negative power, the fourth lens L4 is a convexo-concave lens with positive power, the fifth lens L5 is a convexo-concave lens with positive power, the sixth lens L6 is a convexo-convex lens with positive power, the seventh lens L7 is a convexo-convex lens with positive power, the eighth lens L8 is a convexo-concave lens with negative power, and the ninth lens L9 is a convexo-convex lens with positive power.

[0131] The fifth lens L5, the sixth lens L6 and the ninth lens L9 are aspherical lenses; the aperture STO is arranged between the fifth lens L5 and the sixth lens L6; the third lens L3, the fourth lens L4, the seventh lens L7 and the eighth lens L8 form a cemented lens.

[0132] Table 4 lists the relevant parameters of each lens in the ultra-wide-angle lens of this embodiment, including: surface type, curvature radius R, thickness d, refractive index Nd and Abbe number Vd of the material.

[0133]

[0134]

[0135] Table 4

[0136] Table 5 lists the aspheric coefficients of the aspheric lenses of the ultra-wide-angle lens of this embodiment, including: the quadratic surface constant K, the fourth-order aspheric coefficient A4, the sixth-order aspheric coefficient A6, the eighth-order aspheric coefficient A8, the tenth-order aspheric coefficient A 10 , 12th-order aspheric coefficient A 12 , Fourteenth-order aspheric coefficient A 14 and the sixteenth-order aspheric coefficient A 16 .

[0137] Surface number K A4 A6 A8 A10 A12 A14 A16 S10 -3.29 1.17E-02 -1.13E-04 1.10E-05 -4.32E-05 6.32E-07 -1.13E-06 0.00E+00 S11 3.64 3.26E-03 7.15E-04 -2.16E-04 -2.21E-04 -4.23E-05 -8.14E-06 0.00E+00 S13 -21890.45 7.04E-04 -2.24E-03 2.44E-04 -7.35E-05 -8.21E-05 -6.89E-06 0.00E+00 S14 -4.54 -1.51E-02 2.97E-04 -4.30E-04 6.53E-05 -8.21E-06 -4.35E-06 0.00E+00 S18 0.54 -8.78E-03 1.13E-03 -7.09E-04 3.12E-04 -8.90E-05 1.27E-05 -7.59E-07 S19 -3.03 6.02E-03 -7.38E-05 1.32E-04 -1.77E-06 -9.06E-06 1.47E-06 -9.66E-08

[0138] Table 5

[0139] Combination Figure 2 As shown in Tables 1, 4 and 5 above, in Example 2, the total focal length f of the ultra wide-angle lens is 1.48, the FNO is 1.8, and the relative illumination RI ≥ 75%.

[0140] This embodiment 2 is an ultra-wide-angle lens having at least one of the following characteristics: short total optical length and good thermal stability, a large field of view FOV ≥ 196°, the ability to be matched with a camera to achieve high resolution (25 million pixels), a large aperture (FNO ≤ 1.8), and high illumination (relative illumination ≥ 63%).

[0141] Embodiment 3

[0142] Figure 3 Schematic diagram of the structure of the ultra-wide-angle lens of Embodiment 3 of the present invention.

[0143] In embodiment 3, the tenth lens L10 is a convexo-concave lens with negative power, the first lens L1 is a convexo-concave lens with negative power, the second lens L2 is a convexo-concave lens with negative power, the third lens L3 is a convexo-concave lens with negative power, the fourth lens L4 is a convexo-concave lens with positive power, the fifth lens L5 is a convexo-concave lens with positive power, the sixth lens L6 is a convexo-convex lens with positive power, the seventh lens L7 is a convexo-convex lens with positive power, the eighth lens L8 is a convexo-concave lens with negative power, and the ninth lens L9 is a convexo-convex lens with positive power.

[0144] The second lens L2 and the ninth lens L9 are aspherical lenses; the aperture STO is arranged between the fifth lens L5 and the sixth lens L6. The third lens L3 and the fourth lens L4, the seventh lens L7 and the eighth lens L8 form a cemented lens.

[0145] Table 6 lists the relevant parameters of each lens in the ultra-wide-angle lens of this embodiment, including: surface type, curvature radius R, thickness d, refractive index Nd and Abbe number Vd of the material.

[0146]

[0147] Table 6

[0148] Table 7 lists the aspheric coefficients of the aspheric lenses of the ultra-wide-angle lens of this embodiment, including: the quadratic surface constant K, the fourth-order aspheric coefficient A4, the sixth-order aspheric coefficient A6, the eighth-order aspheric coefficient A8, the tenth-order aspheric coefficient A 10 , 12th-order aspheric coefficient A 12 , Fourteenth-order aspheric coefficient A 14 and the sixteenth-order aspheric coefficient A 16 .

[0149] Surface number K <![CDATA[A4]]> <![CDATA[A6]]> <![CDATA[A8]]> <![CDATA[A 10 ]]> <![CDATA[A 12 ]]> <![CDATA[A 14 ]]> <![CDATA[A 16 ]]> S5 0.00 1.30E-02 -2.98E-03 4.46E-04 -3.79E-05 9.70E-07 8.98E-08 -5.27E-09 S6 -0.68 2.27E-02 -4.71E-03 3.09E-03 -2.18E-03 1.02E-03 -2.38E-04 2.24E-05 S18 0.78 -1.23E-02 -7.09E-05 -3.85E-04 2.05E-04 -8.02E-05 1.32E-05 -7.67E-07 S19 -0.33 8.07E-03 -1.99E-03 1.72E-04 1.13E-05 -1.47E-05 2.53E-06 -1.34E-07

[0150] Table 7

[0151] Combination Figure 3 As shown in Table 1, Table 6 and Table 7 above, in Example 3, the total focal length f of the ultra-wide-angle lens is 1.48, the FNO is 1.8, and the relative illumination RI ≥ 73%.

[0152] The third embodiment of the present invention is an ultra-wide-angle lens having at least one of the following characteristics: short total optical length and good thermal stability, a large field of view FOV ≥ 196°, the ability to be matched with a camera to achieve high resolution (25 million pixels), the ability to achieve a large aperture (FNO ≤ 1.8), and high illumination (relative illumination ≥ 63%).

[0153] Embodiment 4

[0154] Figure 4 Schematic diagram of the structure of the ultra-wide-angle lens of Embodiment 4 of the present invention.

[0155] In Embodiment 4, the tenth lens L10 is a convexo-concave lens with negative power, the first lens L1 is a convexo-concave lens with negative power, the second lens L2 is a convexo-concave lens with negative power, the third lens L3 is a convexo-concave lens with negative power, the fourth lens L4 is a convexo-convex lens with positive power, the fifth lens L5 is a convexo-convex lens with negative power, the sixth lens L6 is a convexo-concave lens with positive power, the seventh lens L7 is a convexo-convex lens with positive power, the eighth lens L8 is a convexo-convex lens with negative power, and the ninth lens L9 is a convexo-concave lens with positive power.

[0156] The second lens L2, the third lens L3, the sixth lens L6 and the ninth lens L9 are aspherical lenses; the aperture STO is arranged between the fifth lens L5 and the sixth lens L6. The fourth lens L4 and the fifth lens L5, the seventh lens L7 and the eighth lens L8 form a cemented lens.

[0157] Table 8 lists the relevant parameters of each lens in the ultra-wide-angle lens of this embodiment, including: surface type, curvature radius R, thickness d, refractive index Nd and Abbe number Vd of the material.

[0158]

[0159]

[0160] Table 8

[0161] Table 9 lists the aspheric coefficients of the aspheric lenses of the ultra-wide-angle lens of this embodiment, including: the quadratic surface constant K, the fourth-order aspheric coefficient A4, the sixth-order aspheric coefficient A6, the eighth-order aspheric coefficient A8, the tenth-order aspheric coefficient A 10 , 12th-order aspheric coefficient A 12 , Fourteenth-order aspheric coefficient A 14 and the sixteenth-order aspheric coefficient A 16 .

[0162] Surface number K A4 A6 A8 A10 A12 A14 A16 S5 -2.76 8.72E-03 -2.17E-03 2.58E-04 -3.40E-05 2.73E-06 -8.02E-08 0.00E+00 S6 -0.53 2.08E-02 1.78E-03 -2.50E-03 1.21E-03 -2.01E-04 -1.31E-05 3.87E-06 S7 -6.12 2.76E-02 -3.75E-03 5.44E-04 -4.76E-05 2.67E-05 -1.13E-05 1.03E-06 S8 14.46 2.59E-02 -4.79E-03 5.09E-04 -1.44E-05 -6.81E-05 2.01E-05 -2.12E-06 S13 1.23 1.16E-02 2.07E-03 -8.25E-04 4.45E-04 -1.19E-04 2.17E-05 -1.96E-06 S14 0.00 1.23E-02 1.29E-04 1.73E-03 -8.35E-04 2.86E-04 -4.57E-05 4.65E-06 S18 -3.04 1.38E-02 -1.72E-03 3.77E-04 -1.06E-04 1.38E-05 -1.04E-06 0.00E+00 S19 0.00 1.58E-02 -9.03E-04 1.22E-04 -9.69E-05 6.21E-06 2.17E-07 -1.30E-08

[0163] Table 9

[0164] Combination Figure 4 As shown in Table 1, Table 8 and Table 9 above, in Example 4, the total focal length f of the ultra-wide-angle lens is 1.44, the FNO is 1.8, and the relative illumination RI ≥ 80%.

[0165] The fourth embodiment of the present invention is an ultra-wide-angle lens having one of the following characteristics: a short total optical length and good thermal stability, a large field of view FOV ≥ 196°, the ability to be matched with a camera to achieve high resolution (25 million pixels), a large aperture (FNO ≤ 1.8), and high illumination (relative illumination ≥ 63%).

[0166] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other.

Claims

1. An ultra-wide-angle lens, comprising, in order from the object side to the image side along the optical axis: A first lens (L1) with negative optical power, a second lens (L2) with negative optical power, a third lens (L3) with negative optical power, a fourth lens (L4) with positive optical power, a fifth lens (L5), a sixth lens (L6) with positive optical power, a seventh lens (L7) with positive optical power, an eighth lens (L8) with negative optical power, and a ninth lens (L9) with positive optical power, characterized in that: The total optical length TTL, the total focal length f and the image height H at the maximum field of view of the ultra-wide-angle lens satisfy the following relationship: 6.9≤TTL*f / H≤7.

4.

2. The ultra-wide-angle lens according to claim 1, characterized in that: The optical system further comprises a tenth lens (L10) located on the object side of the first lens (L1), wherein the tenth lens (L10) has negative optical power.

3. The ultra-wide-angle lens according to claim 2, characterized in that: The tenth lens (L10) is a convex-concave lens.

4. The ultra-wide-angle lens according to claim 2, characterized in that: The optical effective aperture D10 of the tenth lens (L10) and the effective focal length f10 of the tenth lens (L10) satisfy the following relationship: -0.3≤D10 / f10<0.

5. The ultra-wide-angle lens according to claim 1, characterized in that: The first lens (L1) is a convexo-concave lens, the second lens (L2) is a convexo-concave lens, and the object side surface of the third lens (L3) is a concave surface.

6. The ultra-wide-angle lens according to claim 1, characterized in that: The object side surface of the sixth lens (L6) is a convex surface, the seventh lens (L7) is a convex-convex lens, the object side surface of the eighth lens (L8) is a concave surface, and the object side surface of the ninth lens (L9) is a convex surface.

7. The ultra-wide-angle lens according to any one of claims 1 to 6, characterized in that: The third lens is cemented with the fourth lens, or the fourth lens is cemented with the fifth lens.

8. The ultra-wide-angle lens according to any one of claims 1 to 6, characterized in that: The seventh lens and the eighth lens form a cemented lens.

9. The ultra-wide-angle lens according to any one of claims 1 to 6, characterized in that: The effective focal length f1 of the first lens (L1) and the total focal length f of the ultra wide-angle lens satisfy the following relationship: -6.3≤f1 / f≤-4.

10. The ultra-wide-angle lens according to any one of claims 1 to 6, characterized in that: The combined effective focal length f12 of the first lens (L1) and the second lens (L2) and the effective focal length f of the ultra wide-angle lens satisfy the following relationship: -1.8≤f12 / f≤-1.6.

Images