An optical imaging lens

Abstract

The present invention discloses an optical imaging lens, which includes lenses arranged in sequence from the object side to the image side: the first lens has a negative optical power, the object side is convex, and the image side is concave; the second lens has a negative optical power, the object side is convex, and the image side is concave; the third lens has a positive optical power; the fourth lens has a negative optical power; the fifth lens has a positive optical power, the object side is convex, and the image side is convex; the sixth lens has a positive optical power, the object side is convex, and the image side is convex; the seventh lens has a negative optical power, the object side is concave, and the image side is concave; the eighth lens has a positive optical power, the object side is convex, and the image side is concave; the ninth lens has a positive optical power, the object side is convex, and the image side is convex, etc. The lens of the present invention adopts a hybrid glass-plastic 9-piece design, with a combined focal length of 4.0 mm < EFL < 4.3 mm, a field of view FOV > 143°, a total system length TTL < 35.0 mm. The overall imaging field of view is large, the structure is compact, the volume is small, the installation is convenient, the light input of the lens is large, and the imaging quality is good, meeting high-definition imaging requirements, and it has strong practicability.

Description

Technical Field

[0001] This invention relates to the field of wide field-of-view lens technology, and more particularly to an optical imaging lens. Background Technology

[0002] A wide-angle lens is a photographic lens with a shorter focal length than a standard lens, a wider angle of view than a standard lens, a longer focal length than a fisheye lens, and a narrower angle of view than a fisheye lens. As CMOS / CCD sensor chips achieve increasingly higher pixel counts, the demands on wide-angle lenses, such as resolution, are also increasing. Existing wide-angle lenses suffer from the following three problems:

[0003] 1. The excessively large optical TTL and numerous lens elements result in excessively high overall lens cost and weight, and also limit its installation and use.

[0004] 2. Large distortion makes it difficult to develop subsequent algorithms;

[0005] 3. The lens has poor image quality and cannot meet the requirements for high-definition imaging;

[0006] 4. The small image area and limited light transmission result in insufficient light entering the lens, leading to poor image quality. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide an optical imaging lens that, by adopting a nine-element lens architecture and rationally allocating the optical power of each lens element, optimizing the surface shape, thickness, and distance between each lens element, enables the lens to have good imaging quality and solves at least one of the technical problems mentioned in the background art.

[0008] According to one aspect of the present invention, an optical imaging lens is provided, comprising: a first lens, a second lens, a third lens, a fourth lens, an aperture stop, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens, arranged sequentially from the object side to the image side;

[0009] The first lens has negative optical power, and its object side is convex while its image side is concave.

[0010] The second lens has negative optical power, and its object side is convex while its image side is concave.

[0011] The third lens has positive optical power;

[0012] The fourth lens has negative optical power;

[0013] The fifth lens has positive optical power, and its object-side surface is convex, as is its image-side surface.

[0014] The sixth lens has positive optical power, and its object-side surface is convex, as is its image-side surface.

[0015] The seventh lens has a negative focal power, its object side is concave, and its image side is concave;

[0016] The eighth lens has a positive focal power, its object side is convex, and its image side is concave;

[0017] The ninth lens has a positive focal power, its object side is convex, and its image side is convex;

[0018] The optical imaging lens satisfies the following conditional expressions:

[0019] 4.0mm < EFL < 4.3mm

[0020] FOV > 143°

[0021] TTL < 35.0mm

[0022] Where, EFL is the effective focal length, FOV is the field angle, and TTL is the total length of the lens.

[0023] In some embodiments, the optical imaging lens satisfies the following conditional expressions: 9 < f1 < 12, 8.5 < f2 < 14, 6 < f3 < 18, 12 < f4 < 70, 10 < f5 < 14.5, 6 < f6 < 7, 4 < f7 < 5, 20 < f8 < 60, 8 < f9 < 12, where f1, f2, f3, f4, f5, f6, f7, f8, f9 are the focal length values of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens respectively.

[0024] In some embodiments, the first lens, the third lens, the fourth lens, the sixth lens, and the seventh lens are glass lenses, and the second lens, the fifth lens, the eighth lens, and the ninth lens are composed of plastic aspherical lenses, where the sixth and seventh lenses are cemented lenses.

[0025] In some embodiments, the cemented lens has a positive focal power and satisfies 5 < f6f7 / f < 11.5, where f6f7 is the combined focal length of the sixth and seventh cemented lenses, and f is the overall focal length of the lens.

[0026] In some embodiments, the optical imaging lens satisfies the following relational values: 2 < |f1 / f| < 3, 2 < |f2 / f| < 3.5, 1 < |f3 / f| < 4.5, 2.5 < |f4 / f| < 16.5, 2 < |f5 / f| < 3, 1 < |f6 / f| < 2,

[0027] 0.5 < |f7 / f| < 1.5, 5 < |f8 / f| < 14, 2 < |f9 / f| < 3, where f is the overall focal length of the lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, f8 is the focal length of the eighth lens, and f9 is the focal length of the ninth lens.

[0028] In some embodiments, the optical imaging lens satisfies 0.1 <T 45 / AAG<0.35, where T 45 AAG is the air gap between the fourth and fifth lenses on the optical axis, i.e., the air gap at the aperture stop; AAG is the sum of the air gaps between the first and ninth lenses on the optical axis.

[0029] In some embodiments, the optical imaging lens satisfies f / EPD < 1.65, where f is the effective focal length of the lens and EPD is the entrance pupil diameter of the lens.

[0030] In some implementations, the optical imaging lens satisfies the following condition values:

[0031] The first lens has a side surface curvature radius of 90–214 mm and a thickness of 0.9–1.2 mm.

[0032] The first lens has a side surface curvature radius of 5.4–6.5 mm and a thickness of 1.6–2.9 mm.

[0033] The second lens has a side surface curvature radius of 4.7–6.7 mm and a thickness of 1.2–1.4 mm.

[0034] The second lens has a side surface curvature radius of 2.5–2.7 mm and a thickness of 1.2–2.4 mm.

[0035] The third lens has a side surface curvature radius of 8.3–10.8 mm and a thickness of 1.7–4.7 mm.

[0036] The radius of curvature of the side surface of the third lens is -17.3 to 30.3 mm, and the thickness is 0.5 to 1.5 mm.

[0037] The fourth lens has a side surface curvature radius of -7.6 to -8.0 mm and a thickness of 4.0 to 4.1 mm.

[0038] The radius of curvature of the side surface of the fourth lens is -11.3 to 53.1 mm, and the thickness is 0.9 to 4.3 mm.

[0039] The thickness of the aperture is -1.1 to 0 mm;

[0040] The fifth lens has a side surface curvature radius of 6.9–10.4 mm and a thickness of 2.1–3.7 mm.

[0041] The fifth lens has a side surface curvature radius of -24.1 to -26.1 mm and a thickness of 0 to 0.8 mm.

[0042] The sixth lens has a side surface curvature radius of 7.0–10.3 mm and a thickness of 2.9–3.6 mm.

[0043] The seventh lens has a side surface curvature radius of -5.6 to -5.9 mm and a thickness of 0.8 to 1.0 mm.

[0044] The seventh lens has a side surface curvature radius of 7.8–17.1 mm and a thickness of 0–0.7 mm.

[0045] The eighth lens has a side surface curvature radius of 7.8–9.1 mm and a thickness of 1.6–1.7 mm.

[0046] The radius of curvature of the side surface of the eighth lens is 9.1–21.1 mm, and the thickness is 1.2–1.6 mm.

[0047] The ninth lens has a side surface curvature radius of 5.9–9.0 mm and a thickness of 2.4–3.4 mm.

[0048] The ninth lens has a side surface curvature radius of -17.5 to -19.5 mm and a thickness of 0.9 to 1.1 mm.

[0049] The sign of the curvature value indicates the direction: positive means curving towards the object side, and negative means curving towards the image side. A negative value for the aperture stop indicates that the aperture stop plane is behind the object side of the next lens; the aperture stop is a light-blocking position.

[0050] In some embodiments, the optical imaging lens satisfies the following condition:

[0051] 1.5 <nd1<1.7,60<vd1<69

[0052] 1.5 <nd2<1.6,55<vd2<56

[0053] 1.9 <nd3<2.0,35<vd3<36

[0054] 1.5 <nd4<1.9,40<vd4<56

[0055] 1.5 <nd5<1.6,55<vd5<56

[0056] 1.5 <nd6<1.6,71<vd6<72

[0057] 1.7 < nd7 < 1.9, 25 < vd7 < 26

[0058] 1.6 < nd8 < 1.7, 20 < vd8 < 21

[0059] 1.5 < nd9 < 1.6, 55 < vd9 < 57

[0060] Among them, nd1, nd2, nd3, nd4, nd5, nd6, nd7, nd8, and nd9 are the refractive indices of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, eighth lens, and ninth lens respectively, and vd1, vd2, vd3, vd4, vd5, vd6, vd7, vd8, and vd9 are the Abbe numbers of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, eighth lens, and ninth lens respectively.

[0061] Advantages of this application: The present invention adopts a nine-piece lens structure. By reasonably distributing the optical power of each lens, optimizing the surface shape, thickness of each lens, and the distance between lenses, the lens has good imaging quality.

[0062] 1. Adopting a hybrid plastic and glass nine-piece design, the combined focal length of the lens is 4.0 mm < EFL < 4.3 mm, the field of view FOV > 143°, the total system length TTL < 35.0 mm. The overall imaging field of view is large, the structure is compact, the overall volume of the lens is small, it is convenient to install and use, and has strong practicability;

[0063] 2. Adopting a design of four plastic aspherical lenses plus five glass lenses is beneficial to correcting secondary spectrum and higher-order aberrations; at the same time, reasonably distributing the arrangement of glass lenses and plastic lenses can better optimize the optical structure while facilitating the lens structure design and reducing the lens cost;

[0064] 3. The f-theta distortion of the lens is within 5%, which can greatly reduce the difficulty of post-processing algorithm correction;

[0065] 4. At 85 l p / mm, the MTF of the full field of view is greater than 0.5, which can meet high-definition imaging;

[0066] 5. A cemented lens with positive optical power is adopted in the lens, and at the same time, 5 < f6f7 / f < 11.5 is satisfied, so as to more effectively reduce chromatic aberration and make the lens have better color reproducibility;

[0067] 6. The lens has a large light-gathering capacity and can be paired with a 1 / 1.6″ large image sensor, with an MTF of 85 l p / mm>0.5 from the center to the edge; this allows the lens to have greater light intake and better image quality, greatly improving the lens's image quality, meeting the requirements of high-definition imaging, and enhancing its practicality. Attached Figure Description

[0068] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0069] Figure 1 This is a schematic diagram of the structure of a lens in one embodiment of the optical imaging lens of the present invention;

[0070] Figure 2 The MTF curve of a lens in one embodiment of the optical imaging lens of this application in the visible light range of 435nm to 650nm;

[0071] Figure 3 The defocusing curve of a lens in the visible light range of 435nm to 650nm, which is one of the embodiments of the optical imaging lens of this application;

[0072] Figure 4 This is a defocus curve of a lens in one embodiment of the optical imaging lens of this application under infrared light at 850nm.

[0073] Figure 5 The lateral chromatic aberration curve of a lens in one embodiment of the optical imaging lens of this application in the visible light range of 435nm to 650nm.

[0074] Figure 6 The longitudinal chromatic aberration curve of a lens in one embodiment of the optical imaging lens of this application in the visible light range of 435nm to 650nm;

[0075] Figure 7 Field curvature and distortion of a lens according to one embodiment of the optical imaging lens of this application in the visible light range of 435nm to 650nm;

[0076] Figure 8 This is a schematic diagram of the lens structure of a second embodiment of the optical imaging lens of the present invention;

[0077] Figure 9 This is an MTF curve of the lens in the visible light range of 435nm to 650nm, which is the second embodiment of the optical imaging lens of this application.

[0078] Figure 10 This is a defocus curve of the lens in the visible light range of 435nm to 650nm, which is a second embodiment of the optical imaging lens of this application.

[0079] Figure 11 This is a defocus curve of the lens in the second embodiment of the optical imaging lens of this application under infrared light at 850nm.

[0080] Figure 12 This is a lateral chromatic aberration curve of the lens in the visible light range of 435nm to 650nm, according to a second embodiment of the optical imaging lens of this application.

[0081] Figure 13 This is a longitudinal chromatic aberration curve of the lens in the visible light range of 435nm to 650nm, according to the second embodiment of the optical imaging lens of this application.

[0082] Figure 14 The field curvature and distortion diagram of the lens in the second embodiment of the optical imaging lens of this application in the visible light range of 435nm to 650nm;

[0083] Figure 15 This is a schematic diagram of the structure of a lens in one embodiment of the optical imaging lens of the present invention;

[0084] Figure 16 This is an MTF curve of the lens in the visible light range of 435nm to 650nm, which is the third embodiment of the optical imaging lens of this application.

[0085] Figure 17 This is a defocus curve of the lens in the visible light range of 435nm to 650nm, which is the third embodiment of the optical imaging lens of this application.

[0086] Figure 18 This is a defocus curve of the lens in the third embodiment of the optical imaging lens of this application under infrared light at 850nm.

[0087] Figure 19 This is a lateral chromatic aberration curve of the lens in the visible light range of 435nm to 650nm, according to the third embodiment of the optical imaging lens of this application.

[0088] Figure 20 This is a longitudinal chromatic aberration curve of the lens in the visible light range of 435nm to 650nm, according to the third embodiment of the optical imaging lens of this application.

[0089] Figure 21 The image shows the field curvature and distortion of the lens in the visible light range of 435nm to 650nm, according to Embodiment 3 of the optical imaging lens of this application. Detailed Implementation

[0090] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are for illustrative purposes only and do not limit the scope of the invention. Similarly, the following embodiments are only some, not all, embodiments of the present invention, and all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0091] The present invention provides an optical imaging lens that can solve at least one of the technical problems mentioned in the background art.

[0092] An optical imaging lens includes, in order from the object side to the image side, a first lens, a second lens, a third lens, a fourth lens, an aperture stop, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens. The first lens has negative optical power, its object side is convex, and its image side is concave; the second lens has negative optical power, its object side is convex, and its image side is concave; the third lens has positive optical power; the fourth lens has negative optical power; the fifth lens has positive optical power, its object side is convex, and its image side is convex; the ninth lens... The sixth lens has positive optical power, with both its object-side and image-side surfaces being convex. The seventh lens has negative optical power, with both its object-side and image-side surfaces being concave. The eighth lens has positive optical power, with both its object-side and image-side surfaces being convex. The ninth lens also has positive optical power, with both its object-side and image-side surfaces being convex. A combination of five glass spherical lenses and four plastic aspherical lenses is used. Lenses one through four form the front group of the lens, and lenses five through nine form the rear group. The aperture stop is located between the fourth and fifth lenses. This effectively shortens the lens length while maintaining good system performance. The lens is paired with a 1 / 1.6″ sensor, achieving an MTF of 5 l p / mm > 0.5 from center to edge, significantly improving the lens's high image quality, meeting high-definition imaging requirements, and enhancing practicality.

[0093] The optical imaging lens satisfies the following condition: 4.0mm <EFL<4.3mm,FOV> 143°, TTL < 35.0mm, where EFL is the effective focal length, FOV is the field of view, and TTL is the total lens length. The optical TTL is less than 35mm, employing a hybrid glass-plastic 9-element design, resulting in a compact overall lens size and extremely convenient installation and use. The lens's f-theta distortion is within 5%, significantly reducing the difficulty of post-processing correction. At 85lp / mm, the MTF across the entire field of view is greater than 0.5, meeting high-definition imaging requirements. With large light throughput, it can be paired with a 1 / 1.6″ large image sensor, enabling greater light intake and better image quality. The overall imaging field of view is large, the structure is compact, and it is highly practical.

[0094] In some embodiments, the optical imaging lens satisfies the following conditional expressions: 9 < f1 < 12, 8.5 < f2 < 14, 6 < f3 < 18, 12 < f4 < 70, 10 < f5 < 14.5, 6 < f6 < 7, 4 < f7 < 5, 20 < f8 < 60, 8 < f9 < 12, where f1, f2, f3, f4, f5, f6, f7, f8, and f9 are the focal length values of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, eighth lens, and ninth lens, respectively. By reasonably distributing the optical power of each lens, the aberration of the lens can be effectively balanced and controlled, enabling the system to obtain better imaging quality.

[0095] In some embodiments, the first lens, third lens, fourth lens, sixth lens, and seventh lens are glass lenses, and the second lens, fifth lens, eighth lens, and ninth lens are composed of plastic aspherical lenses. The sixth and seventh lenses are cemented lenses; the design of using four plastic aspherical lenses plus five glass lenses is beneficial for correcting secondary spectrum and higher-order aberrations; at the same time, reasonably distributing the arrangement of glass lenses and plastic lenses can optimize the optical structure well while facilitating the lens structure design and reducing the lens cost. The design of using a glass-plastic hybrid structure can well correct the temperature drift of the lens and can well ensure the working state under different temperature conditions.

[0096] In some embodiments, the cemented lens has positive optical power and satisfies 5 < f6f7 / f < 11.5, where f6f7 is the combined focal length of the sixth and seventh cemented lenses, and f is the overall focal length of the lens. The sixth lens is a biconvex lens with positive optical power, and the seventh lens is a biconcave lens with negative optical power. The two lenses are cemented into one cemented lens, and this cemented lens has positive optical power; at the same time, it satisfies 5 < f6f7 / f < 11.5, where f6f7 is the combined focal length of the sixth and seventh cemented lenses, and f is the overall focal length of the lens. Meeting the above conditions can more effectively reduce chromatic aberration and enable the lens to have better color reproducibility.

[0097] In some embodiments, the optical imaging lens satisfies the following relational values: 2 < |f1 / f| < 3, 2 < |f2 / f| < 3.5, 1 < |f3 / f| < 4.5, 2.5 < |f4 / f| < 16.5, 2 < |f5 / f| < 3, 1 < |f6 / f| < 2,

[0098] 0.5 < |f7 / f| < 1.5, 5 < |f8 / f| < 14, 2 < |f9 / f| < 3, where f is the overall focal length of the lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, f8 is the focal length of the eighth lens, and f9 is the focal length of the ninth lens. Satisfying the above formula better eliminates advanced aberrations, improves lens performance, and also reduces tolerance sensitivity issues such as tilting / eccentricity of lens elements during assembly.

[0099] In some embodiments, the optical imaging lens satisfies 0.1 <T 45 / AAG<0.35, where T 45 AAG is the air gap between the fourth and fifth lenses on the optical axis, i.e., the air gap at the aperture stop; AAG is the sum of the air gaps between the first to ninth lenses on the optical axis. Satisfying the above formula can better constrain the field curvature and distortion of the lens, resulting in better image quality.

[0100] In some implementations, the optical imaging lens satisfies f / EPD < 1.65, where f is the effective focal length of the lens and EPD is the entrance pupil diameter of the lens. Satisfying this equation allows the lens to have a large light transmission capacity, increasing the amount of light transmitted and enhancing the lens's detail capture.

[0101] In some embodiments, the optical imaging lens satisfies the following conditions: the first lens has an object-side radius of curvature of 90–214 mm and a thickness of 0.9–1.2 mm; the first lens has an image-side radius of curvature of 5.4–6.5 mm and a thickness of 1.6–2.9 mm; the second lens has an object-side radius of curvature of 4.7–6.7 mm and a thickness of 1.2–1.4 mm; and the second lens has an image-side radius of curvature of 2.5–2.7 mm and a thickness of 1.2–2.4 mm. The third lens has an object-side radius of curvature of 8.3–10.8 mm and a thickness of 1.7–4.7 mm; the third lens has an image-side radius of curvature of -17.3–30.3 mm and a thickness of 0.5–1.5 mm; the fourth lens has an object-side radius of curvature of -7.6–-8.0 mm and a thickness of 4.0–4.1 mm; the fourth lens has an image-side radius of curvature of -11.3–53.1 mm and a thickness of 0.9–4.3 mm; and the aperture stop has a thickness of -1.1–0 mm. The fifth lens has an object-side radius of curvature of 6.9–10.4 mm and a thickness of 2.1–3.7 mm; its image-side radius of curvature is -24.1–-26.1 mm and a thickness of 0–0.8 mm. The sixth lens has an object-side radius of curvature of 7.0–10.3 mm and a thickness of 2.9–3.6 mm. The seventh lens has an object-side radius of curvature of -5.6–-5.9 mm and a thickness of 0.8–1.0 mm; its image-side radius of curvature is 7.8 mm. The eighth lens has an object-side radius of curvature of 7.8–9.1 mm and a thickness of 1.6–1.7 mm, while the image-side radius of curvature of the eighth lens is 9.1–21.1 mm and a thickness of 1.2–1.6 mm. The ninth lens has an object-side radius of curvature of 5.9–9.0 mm and a thickness of 2.4–3.4 mm, while the image-side radius of curvature of the ninth lens is -17.5–-19.5 mm and a thickness of 0.9–1.1 mm. This is to achieve low distortion.

[0102] In some embodiments, the optical imaging lens satisfies the following conditional expressions: 1.5 < nd1 < 1.7, 60 < vd1 < 69, 1.5 < nd2 < 1.6, 55 < vd2 < 56, 1.9 < nd3 < 2.0, 35 < vd3 < 36, 1.5 < nd4 < 1.9, 40 < vd4 < 56, 1.5 < nd5 < 1.6, 55 < vd5 < 56, 1.5 < nd6 < 1.6, 71 < vd6 < 72, 1.7 < nd7 < 1.9, 25 < vd7 < 26, 1.6 < nd8 < 1.7, 20 < vd8 < 21, 1.5 < nd9 < 1.6, 55 < vd9 < 57; where nd1, nd2, nd3, nd4, nd5, nd6, nd7, nd8, nd9 are the refractive indices of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens respectively, and vd1, vd2, vd3, vd4, vd5, vd6, vd7, vd8, vd9 are the Abbe numbers of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens respectively. This helps to eliminate the influence of chromatic aberration, reduce field curvature, and correct coma aberration.

[0103] The present invention will be further described below with multiple embodiments. In each embodiment, the aperture size, curvature radius, thickness, material selection, refractive index, dispersion coefficient, and focal length of each lens in the wide-angle lens are partially different. For specific differences, refer to the parameter tables of each embodiment. It should be noted that in the table, surfaces 0 to 22 represent the surfaces through which light enters and exits from the object side to the image side. Those skilled in the art can understand the positions represented by each surface number through the relevant parameter tables and lens structure diagrams, which will not be elaborated here. In the figure, A represents the object side surface, B represents the image side surface, ST represents the aperture stop, the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, the ninth lens 9, and the filter 10. The meanings in the structure diagrams of each of the following embodiments are the same and will not be repeated. The following embodiments are only the preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following embodiments. Any other changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be regarded as equivalent replacement methods and are included in the protection scope of the present invention.

[0104] Embodiment 1

[0105] For the relevant parameters of each lens provided in this embodiment, please refer to Table 1 and Table 2, and for the lens structure, please refer to Figure 1 .

[0106] Table 1 Relevant Parameters of the Lens in Embodiment 1

[0107]

[0108] Table 2. Aspheric coefficient parameter table for one of the embodiments.

[0109]

[0110] Please see Figures 2-7 , Figure 2 The image shows the MTF curve of the lens in Example 1 under visible light (435nm-650nm). It can be seen that the MTF is greater than 0.8 at the center and greater than 0.7 at the edge at 85 l p / mm, indicating excellent image quality and high lens resolution. Figure 3 The figure shows the defocus curves of the lens in Example 1 under visible light (435nm-650nm). It can be seen from the figure that the defocus curves of the lens in each field of view under visible light are relatively concentrated and the defocus amount is small. Figure 4 The image shows the defocus curve of the lens in Example 1 under infrared light at 850nm. It can be seen that the defocus curves of the lens in each field of view under visible light are relatively concentrated, with the center defocus amount being less than 10um, indicating good confocal performance. Figure 5 The image shows the lateral chromatic aberration curve of the lens in Example 1 under visible light (435nm-650nm). It can be seen that the lens chromatic aberration is within 5µm, exhibiting high color fidelity and good correction of blue-purple fringing under night vision confocal conditions. Figure 6 The image shows the longitudinal chromatic aberration curve of the lens in Example 1 under visible light from 435nm to 650nm. It can be seen that the chromatic aberration on the lens axis is small, the color reproduction is good, the color difference is small, and the blue-purple fringing phenomenon is not obvious. Figure 7 The image shows the field curvature and distortion of the lens in Example 1 under visible light from 435nm to 650nm. It can be seen that the lens has good control over field curvature and distortion at various wavelengths, which effectively improves image quality and facilitates subsequent image correction.

[0111] Example 2

[0112] Please refer to Tables 3 and 4 for the relevant parameters of each lens provided in this embodiment, and refer to [Table 4 for lens structure]. Figure 8 .

[0113] Table 3 Lens-related parameters in Example 2

[0114] Table 4. Aspheric coefficient parameter table for Example 2

[0115]

[0116] Please see Figures 9-14 , Figure 9 The image shows the MTF curve of the lens in Example 2 under visible light (435nm-650nm). It can be seen that the MTF is greater than 0.8 at the center and greater than 0.55 at the edge at 85 l p / mm, indicating excellent image quality and high lens resolution. Figure 10 The image shows the defocus curves of the lens in Example 2 under visible light (435nm-650nm). It can be seen that the defocus curves of the lens in each field of view under visible light are relatively concentrated, and the defocus amount is small. Figure 11 The image shows the defocus curve of the lens in Example 2 under infrared light at 850nm. It can be seen that the defocus curves of the lens in each field of view under visible light are relatively concentrated, and the defocus amount at the infrared center is less than 10um, indicating good confocal performance. Figure 12 The image shows the lateral chromatic aberration curve of the lens in Example 2 under visible light 435nm~650nm. It can be seen that the lens chromatic aberration is within 5um, which has high color reproduction and good correction of blue-purple fringing under night vision confocal conditions. Figure 13 The image shows the longitudinal chromatic aberration curve of the lens in Example 2 under visible light 435nm~650nm. It can be seen that the chromatic aberration on the lens axis is small, the color reproduction is good, the color difference is small, and the blue-purple fringing phenomenon is not obvious. Figure 14 The image shows the field curvature and distortion of the lens in Example 2 under visible light (435nm–650nm). It can be seen that the lens has good control over field curvature and distortion at various wavelengths, effectively improving image quality and facilitating subsequent image correction.

[0117] Example 3

[0118] Please refer to Tables 5 and 6 for the relevant parameters of each lens provided in this embodiment, and refer to [Table 6 for lens structure]. Figure 15 .

[0119] Table 5. Parameters related to the three lenses in the embodiment.

[0120]

[0121] Table 6. Lens-related parameters in Example 3

[0122]

[0123] Please see Figures 16-21 , Figure 16 The image shows the MTF curve of the lens in Example 3 under visible light (435nm-650nm). The image shows that the MTF is greater than 0.8 at the center and greater than 0.6 at the edge at 85 l p / mm, indicating excellent image quality and high lens resolution. Figure 17 The image shows the defocus curves of the lens in Example 3 under visible light (435nm~650nm). It can be seen that the defocus curves of the lens in each field of view under visible light are relatively concentrated, and the defocus amount is small. Figure 18 The image shows the defocus curve of the lens in Example 3 under infrared light at 850nm. It can be seen that the defocus curves of the lens in each field of view under visible light are relatively concentrated, and the defocus amount at the infrared center is less than 10um, indicating good confocal performance. Figure 19The image shows the lateral chromatic aberration curve of the lens in Example 3 under visible light (435nm-650nm). It can be seen that the lens chromatic aberration is within 5µm, which indicates high color fidelity. Under night vision confocal conditions, the blue-purple fringing phenomenon is well corrected. Figure 20 The image shows the longitudinal chromatic aberration curve of the lens in Example 3 under visible light (435nm-650nm). It can be seen that the chromatic aberration on the lens axis is small, the color reproduction is good, the color difference is small, and the blue-purple fringing phenomenon is not obvious. Figure 21 The image shows the field curvature and distortion of the lens in Example 3 under visible light from 435nm to 650nm. It can be seen that the lens has good control over field curvature and distortion at various wavelengths, which effectively improves image quality and facilitates subsequent image correction.

[0124] The above description is only a part of the embodiments of the present invention and does not limit the scope of protection of the present invention. Any equivalent device or equivalent process transformation made based on the content of the present invention specification and drawings, or direct or indirect application in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An optical imaging lens, characterized in that, Including: From the object side to the image side, there are, in sequence, a first lens, a second lens, a third lens, a fourth lens, an aperture stop, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens; The first lens has a negative focal power, its object side is convex, and its image side is concave; The second lens has a negative focal power, its object side is convex, and its image side is concave; The third lens has a positive focal power; The fourth lens has a negative focal power; The fifth lens has a positive focal power, its object side is convex, and its image side is convex; The sixth lens has a positive focal power, its object side is convex, and its image side is convex; The seventh lens has a negative focal power, its object side is concave, and its image side is concave; The eighth lens has a positive focal power, its object side is convex, and its image side is concave; The ninth lens has a positive focal power, its object side is convex, and its image side is convex; The optical imaging lens satisfies the following conditional expressions: 4.0mm < EFL < 4.3mm FOV > 143° TTL < 35.0mm Where, EFL is the effective focal length, FOV is the field angle, and TTL is the total length of the lens.

2. The optical imaging lens as described in claim 1, characterized in that, The optical imaging lens satisfies the following conditional expressions: 9 < f1 < 12, 8.5 < f2 < 14, 6 < f3 < 18, 12 < f4 < 70, 10 < f5 < 14.5, 6 < f6 < 7, 4 < f7 < 5, 20 < f8 < 60, 8 < f9 < 12, where f1, f2, f3, f4, f5, f6, f7, f8, f9 are the focal length values of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens respectively.

3. An optical imaging lens as described in claim 1 or 2, characterized in that, The first lens, the third lens, the fourth lens, the sixth lens, and the seventh lens are glass lenses, and the second lens, the fifth lens, the eighth lens, and the ninth lens are composed of plastic aspherical lenses, Among them, the sixth and seventh lenses are cemented lenses.

4. An optical imaging lens as described in claim 3, characterized in that, The cemented lens has a positive focal power and satisfies 5 < f6f7 / f < 11.5, where f6f7 is the combined focal length of the sixth and seventh cemented lenses, and f is the overall focal length of the lens.

5. An optical imaging lens as described in claim 1, characterized in that, The optical imaging lens satisfies the following relational values: 2 < |f1 / f| < 3, 2 < |f2 / f| < 3.5, 1 < |f3 / f| < 4.5, 2.5 < |f4 / f| < 16.5, 2 < |f5 / f| < 3, 1 < |f6 / f| < 2, 0.5 < |f7 / f| < 1.5, 5 < |f8 / f| < 14, 2 < |f9 / f| < 3, where f is the overall focal length of the lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, f8 is the focal length of the eighth lens, and f9 is the focal length of the ninth lens.

6. An optical imaging lens as described in claim 1, characterized in that, The optical imaging lens satisfies 0.1 <T 45 / AAG<0.35, where T 45 AAG is the air gap between the fourth and fifth lenses on the optical axis, i.e., the air gap at the aperture stop; AAG is the sum of the air gaps between the first and ninth lenses on the optical axis.

7. An optical imaging lens as described in claim 1, characterized in that, The optical imaging lens satisfies f / EPD < 1.65, where f is the effective focal length of the lens and EPD is the entrance pupil diameter of the lens.

8. An optical imaging lens as described in claim 1, characterized in that, The optical imaging lens satisfies the following conditional values: The curvature radius of the object side of the first lens is 90 - 214mm, and the thickness is 0.9 - 1.2mm; The first lens has a side surface curvature radius of 5.4–6.5 mm and a thickness of 1.6–2.9 mm. The second lens has a side surface curvature radius of 4.7–6.7 mm and a thickness of 1.2–1.4 mm. The second lens has a side surface curvature radius of 2.5–2.7 mm and a thickness of 1.2–2.4 mm. The third lens has a side surface curvature radius of 8.3–10.8 mm and a thickness of 1.7–4.7 mm. The radius of curvature of the side surface of the third lens is -17.3 to 30.3 mm, and the thickness is 0.5 to 1.5 mm. The fourth lens has a side surface curvature radius of -7.6 to -8.0 mm and a thickness of 4.0 to 4.1 mm. The radius of curvature of the side surface of the fourth lens is -11.3 to 53.1 mm, and the thickness is 0.9 to 4.3 mm. The thickness of the aperture is -1.1 to 0 mm; The fifth lens has a side surface curvature radius of 6.9–10.4 mm and a thickness of 2.1–3.7 mm. The fifth lens has a side surface curvature radius of -24.1 to -26.1 mm and a thickness of 0 to 0.8 mm. The sixth lens has a side surface curvature radius of 7.0–10.3 mm and a thickness of 2.9–3.6 mm. The seventh lens has a side surface curvature radius of -5.6 to -5.9 mm and a thickness of 0.8 to 1.0 mm. The seventh lens has a side surface curvature radius of 7.8–17.1 mm and a thickness of 0–0.7 mm. The eighth lens has a side surface curvature radius of 7.8–9.1 mm and a thickness of 1.6–1.7 mm. The radius of curvature of the side surface of the eighth lens is 9.1–21.1 mm, and the thickness is 1.2–1.6 mm. The ninth lens has a side surface curvature radius of 5.9–9.0 mm and a thickness of 2.4–3.4 mm. The ninth lens has a side surface curvature radius of -17.5 to -19.5 mm and a thickness of 0.9 to 1.1 mm.

9. An optical imaging lens as described in claim 1, characterized in that, The optical imaging lens satisfies the following condition: 1.5 <nd1<1.7,60<vd1<69 1.5 <nd2<1.6,55<vd2<56 1.9 <nd3<2.0,35<vd3<36 1.5 <nd4<1.9,40<vd4<56 1.5 <nd5<1.6,55<vd5<56 1.5 <nd6<1.6,71<vd6<72 1.7 <nd7<1.9,25<vd7<26 1.6 <nd8<1.7,20<vd8<21 1.5 <nd9<1.6,55<vd9<57 Wherein, nd1, nd2, nd3, nd4, nd5, nd6, nd7, nd8, and nd9 are the refractive indices of the first, second, third, fourth, fifth, sixth, seventh, eighth, and ninth lenses, respectively, and vd1, vd2, vd3, vd4, vd5, vd6, vd7, vd8, and vd9 are the Abbe numbers of the first, second, third, fourth, fifth, sixth, seventh, eighth, and ninth lenses, respectively.

Images