An optical imaging lens

Abstract

The present invention discloses an optical imaging lens, which includes a first lens, a second lens, a diaphragm, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially arranged along an optical axis from the object side to the image side. The first lens has a negative refractive power, the second lens has a positive refractive power, the third lens has a positive refractive power, the fourth lens has a positive refractive power, the fifth lens has a negative refractive power, and the sixth lens has a positive refractive power. Among them, the first lens, the second lens, the fourth lens, the fifth lens, and the sixth lens are all plastic aspherical lenses, and the third lens is a glass lens. The optical imaging lens of the present invention adopts a 1G5P glass-plastic hybrid design, with a compact overall structure, small volume, low cost, and small chromatic aberration; at the same time, it has a large aperture and high brightness, and can also have good imaging quality in a relatively dark environment; in addition, the distortion control of the lens is good, the optical distortion of the lens is within 2%, the imaging quality is good, and the difficulty of post-correction is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and more particularly, to an optical imaging lens. Background Art

[0002] With the continuous progress of science and technology and the continuous development of society, in recent years, optical imaging lenses have also developed rapidly and are widely used in various fields such as smart phones, tablet computers, video conferencing, vehicle-mounted monitoring, and security monitoring. Therefore, the requirements for optical imaging lenses are getting higher and higher.

[0003] Currently, for video conferencing lenses on the market, in order to correct chromatic aberration, an excessive number of lenses are used, resulting in a large overall volume and high cost of the lens, and it is often impossible to meet the requirements of small size and light weight at the same time; moreover, existing video conferencing lenses generally have the problem of small light transmission, resulting in insufficient brightness and poor imaging effects under relatively dark conditions; in addition, large lens distortion makes it difficult to correct imaging at the edge position, which is also a common problem of existing video conferencing lenses.

[0004] In view of this, the inventor of the present application has invented an optical imaging lens. Summary of the Invention

[0005] The purpose of the present invention is to provide an optical imaging lens with a small volume, large light transmission, and small distortion.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions: An optical imaging lens includes a first lens, a second lens, a diaphragm, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially arranged along an optical axis from the object side to the image side. Each of the first lens to the sixth lens includes an object side facing the object side and allowing imaging light to pass through, and an image side facing the image side and allowing imaging light to pass through;

[0007] The first lens has a negative refractive power, and the object side of the first lens is convex, and the image side is concave;

[0008] The second lens has a positive refractive power, and the object side of the second lens is convex, and the image side is concave;

[0009] The third lens has a positive refractive power, and the object side of the third lens is convex, and the image side is convex;

[0010] The fourth lens has a positive refractive power, and the object side of the fourth lens is concave, and the image side is convex;

[0011] The fifth lens has a negative refractive power, and the object side of the fifth lens near the optical axis is convex, and the image side is concave;

[0012] The sixth lens has a positive diopter, the object side of the sixth lens is convex, and the image side near the optical axis is convex;

[0013] Among them, the first lens, the second lens, the fourth lens, the fifth lens, and the sixth lens are all plastic aspherical lenses, and the third lens is a glass lens.

[0014] Furthermore, the lens satisfies: -10.5 < f1 < -9, 30 < f2 < 40, 7 < f3 < 9, 11 < f4 < 13, -8 < f5 < -7, 7 < f6 < 9, where f1, f2, f3, f4, f5, and f6 are the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens, respectively.

[0015] Furthermore, the lens satisfies: 1 < |(f1 / f)| < 2.5, 5 < |(f2 / f)| < 7, 1 < |(f3 / f)| < 2, 1.5 < |(f4 / f)| < 3, 1 < |(f5 / f)| < 2, 1 < |(f6 / f)| < 2, where f is the overall focal length of the lens, and f1, f2, f3, f4, f5, and f6 are the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens, respectively.

[0016] Furthermore, the first lens satisfies: f1 / R1 < -2, where f1 is the focal length of the first lens and R1 is the radius of curvature of the object side of the first lens.

[0017] Furthermore, the lens satisfies: nd2 ≥ 1.64, nd5 ≥ 1.64, where nd2 and nd5 are the refractive indices of the second lens and the fifth lens, respectively.

[0018] Furthermore, the lens satisfies: 8mm < CT3 + CT4 + CT5 + CT6 < 12mm, where CT3, CT4, CT5, and CT6 are the central thicknesses of the third lens, the fourth lens, the fifth lens, and the sixth lens, respectively.

[0019] Furthermore, the lens satisfies: 1 ≤ AAG / BFL ≤ 2, where AAG is the sum of the air gaps between adjacent two lenses among the first to sixth lenses on the optical axis, and BFL is the distance from the image side of the sixth lens to the imaging plane on the optical axis.

[0020] Furthermore, the lens satisfies: 0.75 ≤ IMH / EFL ≤ 1, where IMH is the image-side semi-image height of the lens and EFL is the effective focal length of the lens.

[0021] Furthermore, the effective focal length EFL of the lens satisfies: 5.0mm < EFL < 6.0mm.

[0022] Furthermore, the maximum aperture of this lens is F / NO = 1.6.

[0023] After adopting the above technical solutions, compared with the prior art, the present invention has the following advantages:

[0024] The optical imaging lens of the present invention adopts a 1G5P glass-plastic hybrid design, with a compact overall structure, small volume, low cost, and small chromatic aberration; at the same time, it has a large aperture and high brightness, and can also have good imaging quality in a relatively dark environment; in addition, the lens has good distortion control, with the optical distortion of the lens within 2%, good imaging quality, and reduced difficulty of later correction. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is the optical path diagram of Embodiment 1 of the present invention;

[0026] Figure 2 It is the MTF curve diagram of the lens in Embodiment 1 of the present invention under visible light of 435nm - 650nm;

[0027] Figure 3 It is the defocus curve diagram of the lens in Embodiment 1 of the present invention under visible light of 435nm - 650nm;

[0028] Figure 4 It is the lateral chromatic aberration curve diagram of the lens in Embodiment 1 of the present invention under visible light of 435nm - 650nm;

[0029] Figure 5 It is the longitudinal chromatic aberration curve diagram of the lens in Embodiment 1 of the present invention under visible light of 435nm - 650nm;

[0030] Figure 6 It is the field curvature and distortion diagram of the lens in Embodiment 1 of the present invention under visible light of 435nm - 650nm;

[0031] Figure 7 It is the grid distortion diagram of the lens in Embodiment 1 of the present invention under visible light of 435nm - 650nm;

[0032] Figure 8 It is the optical path diagram of Embodiment 2 of the present invention;

[0033] Figure 9 It is the MTF curve diagram of the lens in Embodiment 2 of the present invention under visible light of 435nm - 650nm;

[0034] Figure 10 It is the defocus curve diagram of the lens in Embodiment 2 of the present invention under visible light of 435nm - 650nm;

[0035] Figure 11 It is the lateral chromatic aberration curve diagram of the lens in Embodiment 2 of the present invention under visible light of 435nm - 650nm;

[0036] Figure 12 It is the longitudinal chromatic aberration curve graph of the lens in Example 2 of the present invention under visible light of 435nm - 650nm;

[0037] Figure 13 It is the field curvature and distortion graph of the lens in Example 2 of the present invention under visible light of 435nm - 650nm;

[0038] Figure 14 It is the grid distortion graph of the lens in Example 2 of the present invention under visible light of 435nm - 650nm;

[0039] Figure 15 It is the optical path diagram of Example 3 of the present invention;

[0040] Figure 16 It is the MTF curve graph of the lens in Example 3 of the present invention under visible light of 435nm - 650nm;

[0041] Figure 17 It is the defocus curve graph of the lens in Example 3 of the present invention under visible light of 435nm - 650nm;

[0042] Figure 18 It is the lateral chromatic aberration curve graph of the lens in Example 3 of the present invention under visible light of 435nm - 650nm;

[0043] Figure 19 It is the longitudinal chromatic aberration curve graph of the lens in Example 3 of the present invention under visible light of 435nm - 650nm;

[0044] Figure 20 It is the field curvature and distortion graph of the lens in Example 3 of the present invention under visible light of 435nm - 650nm;

[0045] Figure 21 It is the grid distortion graph of the lens in Example 3 of the present invention under visible light of 435nm - 650nm;

[0046] Figure 22 It is the optical path diagram of Example 4 of the present invention;

[0047] Figure 23 It is the MTF curve graph of the lens in Example 4 of the present invention under visible light of 435nm - 650nm;

[0048] Figure 24 It is the defocus curve graph of the lens in Example 4 of the present invention under visible light of 435nm - 650nm;

[0049] Figure 25 It is the lateral chromatic aberration curve graph of the lens in Example 4 of the present invention under visible light of 435nm - 650nm;

[0050] Figure 26 This is the longitudinal chromatic aberration curve graph of the lens in Example 4 of the present invention under visible light of 435nm - 650nm;

[0051] Figure 27 This is the field curvature and distortion graph of the lens in Example 4 of the present invention under visible light of 435nm - 650nm;

[0052] Figure 28 This is the grid distortion graph of the lens in Example 4 of the present invention under visible light of 435nm - 650nm;

[0053] Figure 29 This is the optical path diagram of Example 5 of the present invention;

[0054] Figure 30 This is the MTF curve graph of the lens in Example 5 of the present invention under visible light of 435nm - 650nm;

[0055] Figure 31 This is the defocus curve graph of the lens in Example 5 of the present invention under visible light of 435nm - 650nm;

[0056] Figure 32 This is the lateral chromatic aberration curve graph of the lens in Example 5 of the present invention under visible light of 435nm - 650nm;

[0057] Figure 33 This is the longitudinal chromatic aberration curve graph of the lens in Example 5 of the present invention under visible light of 435nm - 650nm;

[0058] Figure 34 This is the field curvature and distortion graph of the lens in Example 5 of the present invention under visible light of 435nm - 650nm;

[0059] Figure 35 This is the grid distortion graph of the lens in Example 5 of the present invention under visible light of 435nm - 650nm.

[0060] Explanation of reference numerals: 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Sixth lens; 7. Diaphragm; 8. Protective sheet. Detailed implementation manners

[0061] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0062] When it is said that "a lens has a positive refractive power (or negative refractive power)", it means that the paraxial refractive power of the lens calculated by Gaussian optical theory is positive (or negative). The "object side (or image side) of the lens" is defined as a specific range through which imaging light passes through the lens surface. The concavity and convexity of the lens surface can be judged in the same way as those of an ordinary person in this field, that is, by the positive and negative signs of the radius of curvature (abbreviated as R value) to judge the concavity and convexity of the lens surface. The R value is commonly used in optical design software, such as Zemax or CodeV. The R value is also commonly found in the lens data sheet of optical design software. Taking the object side as an example, when the R value is positive, it is determined that the object side is a convex surface; when the R value is negative, it is determined that the object side is a concave surface. On the contrary, taking the image side as an example, when the R value is positive, it is determined that the image side is a concave surface; when the R value is negative, it is determined that the image side is a convex surface.

[0063] The present invention discloses an optical imaging lens, especially an optical imaging lens suitable for video conferencing, which includes a first lens 1, a second lens 2, a diaphragm 7, a third lens 3, a fourth lens 4, a fifth lens 5, and a sixth lens 6 arranged in sequence along an optical axis from the object side to the image side. The first lens 1 to the second lens are the front group of the lens, and the third to the sixth lens 6 are the rear group of the lens. Each of the first lens 1 to the sixth lens 6 includes an object side facing the object side and through which imaging light passes and an image side facing the image side and through which imaging light passes;

[0064] The first lens 1 has a negative diopter, and the object side of the first lens 1 is a convex surface, and the image side is a concave surface; the second lens 2 has a positive diopter, and the object side of the second lens 2 is a convex surface, and the image side is a concave surface;

[0065] The third lens 3 has a positive diopter, and the object side of the third lens 3 is a convex surface, and the image side is a convex surface; the fourth lens 4 has a positive diopter, and the object side of the fourth lens 4 is a concave surface, and the image side is a convex surface; the fifth lens 5 has a negative diopter, and the object side of the fifth lens 5 near the optical axis is a convex surface, and the image side is a concave surface; the sixth lens 6 has a positive diopter, and the object side of the sixth lens 6 is a convex surface, and the image side near the optical axis is a convex surface;

[0066] Among them, the first lens 1, the second lens 2, the fourth lens 4, the fifth lens 5, and the sixth lens 6 are all plastic aspherical lenses, and the third lens 3 is a glass lens. The lens adopts a design combining one glass lens and five plastic aspherical lenses, which is beneficial to correcting secondary spectrum and higher-order aberrations.

[0067] Among them, the refractive indices of the second lens 2 and the fifth lens 5 satisfy: nd2≥1.64, nd5≥1.64, where nd2 and nd5 are the refractive indices of the second lens 2 and the fifth lens 5 respectively. The second lens 2 and the fifth lens 5 are made of materials with high refractive indices, which can better optimize the optical structure, facilitate the lens structure design, and reduce the lens cost.

[0068] This lens satisfies: -10.5 < f1 < -9, 30 < f2 < 40, 7 < f3 < 9, 11 < f4 < 13, -8 < f5 < -7, 7 < f6 < 9, where f1, f2, f3, f4, f5, and f6 are the focal lengths of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, and the sixth lens 6 respectively.

[0069] This lens satisfies: 1 < |(f1 / f)| < 2.5, 5 < |(f2 / f)| < 7, 1 < |(f3 / f)| < 2, 1.5 < |(f4 / f)| < 3, 1 < |(f5 / f)| < 2, 1 < |(f6 / f)| < 2, where f is the overall focal length of the lens, and f1, f2, f3, f4, f5, and f6 are the focal lengths of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, and the sixth lens 6 respectively.

[0070] The first lens 1 satisfies: f1 / R1 < -2, where f1 is the focal length of the first lens 1, and R1 is the curvature radius of the object side surface of the first lens 1. In this way, the bending direction of the first lens faces the diaphragm side, which can better control the lens distortion and make the lens achieve the effect of low distortion.

[0071] This lens satisfies: 8mm < CT3 + CT4 + CT5 + CT6 < 12mm, where CT3, CT4, CT5, and CT6 are the central thicknesses of the third lens 3, the fourth lens 4, the fifth lens 5, and the sixth lens 6 respectively. By controlling the combined length of the rear group of lenses (the third lens 3 to the sixth lens 6), it can not only better balance the rear group optical power and improve the imaging quality, but also effectively control the overall length of the lens, which is more conducive to the miniaturization of the lens.

[0072] This lens satisfies: 1 ≤ AAG / BFL ≤ 2, where AAG is the sum of the air gaps between adjacent two lenses among the first to sixth lenses 6 on the optical axis, and BFL is the distance from the image side surface of the sixth lens 6 to the imaging surface on the optical axis. By controlling the ratio of the air gap between each lens and the back focal length (BFL), the optical power between each lens can be better distributed, and at the same time, the system field curvature can be controlled, which can effectively improve the overall imaging quality of the lens.

[0073] The lens satisfies: 0.75 ≤ IMH / EFL ≤ 1, where IMH is the semi-image height on the image side of the lens and EFL is the effective focal length of the lens. Among them, the effective focal length EFL of the lens satisfies: 5.0 mm < EFL < 6.0 mm. By controlling the ratio of the image height to the focal length, the distortion of the system can be made smaller, thereby effectively improving the imaging quality of the lens.

[0074] The maximum aperture F / NO of the lens is 1.6. It effectively improves the illumination at the image edge and enhances the imaging brightness.

[0075] The lens is paired with a 1 / 2.8" sensor, and the grid distortion (TV Dist) satisfies ≤ 2%.

[0076] The field of view angle of the lens satisfies: FOV = 78°, and the total optical length TTL satisfies: TTL < 30 mm. The lens is small in size, easy to install, and highly practical.

[0077] Hereinafter, the optical imaging lens of the present invention will be described in detail with specific embodiments.

[0078] Embodiment 1

[0079] Referring to Figure 1 As shown, the present invention discloses an optical imaging lens, which includes a first lens 1, a second lens 2, a diaphragm 7, a third lens 3, a fourth lens 4, a fifth lens 5, and a sixth lens 6 sequentially arranged along an optical axis from the object side to the image side. Each of the first lens 1 to the sixth lens 6 includes an object side surface facing the object side and allowing imaging light to pass through, and an image side surface facing the image side and allowing imaging light to pass through;

[0080] The first lens 1 has a negative refractive power, and the object side surface of the first lens 1 is convex, and the image side surface is concave; the second lens 2 has a positive refractive power, and the object side surface of the second lens 2 is convex, and the image side surface is concave;

[0081] The third lens 3 has a positive refractive power, and the object side surface of the third lens 3 is convex, and the image side surface is convex; the fourth lens 4 has a positive refractive power, and the object side surface of the fourth lens 4 is concave, and the image side surface is convex; the fifth lens 5 has a negative refractive power, and the object side surface of the fifth lens 5 near the optical axis is convex, and the image side surface is concave; the sixth lens 6 has a positive refractive power, and the object side surface of the sixth lens 6 is convex, and the image side surface near the optical axis is convex.

[0082] The detailed optical data of this specific embodiment are shown in Table 1-1.

[0083] Table 1-1 Detailed Optical Data of Embodiment 1

[0084]

[0085]

[0086] In this embodiment, the specific values of the parameters of the lens part are shown in Table 1-2.

[0087] Table 1-2 Partial lens parameters of Embodiment 1

[0088] Parameter CT3 + CT4 + CT5 + CT6 11.7 AAG / BFL 1.41 IMH / EFL 0.8 f1 / R1 -2.44

[0089] In this embodiment, the first lens 1, the second lens 2, the fourth lens 4, the fifth lens 5, and the sixth lens 6 are all plastic aspherical lenses. The equation of the surface curve of the aspherical lens is expressed as follows:

[0090]

[0091] Among them,

[0092] z: The depth of the aspherical surface (the vertical distance between a point on the aspherical surface at a distance y from the optical axis and the tangent plane at the vertex of the aspherical surface on the optical axis);

[0093] c: The curvature of the aspherical vertex (the vertex curvature);

[0094] K: The conic constant (Conic Constant);

[0095] Radial distance;

[0096] r n : Normalization radius (normalization radius (NRADIUS));

[0097] u: r / r n ;

[0098] a m : The m-th order Q con coefficient (is the m th Q con coefficient);

[0099] Q m con : The m-th order Q con polynomial (the m th Q con polynomial).

[0100] The aspherical data in this embodiment is shown in Table 1-3.

[0101] Table 1-3 Aspherical data of Embodiment 1

[0102]

[0103]

[0104] In this embodiment, for the MTF curve graph of the lens under visible light of 435nm - 650nm, please refer to Figure 2 , it can be seen from the figure that when the spatial frequency of this lens reaches 200 lp / mm, the MTF value is greater than 0.3, the imaging quality is excellent, and the resolution of the lens is high. For the defocus curve graph of the lens under visible light of 435nm - 650nm, please refer to Figure 3 , it can be seen from the figure that the defocus curves of each field of view of this lens under visible light are relatively concentrated and the defocus amount is small. For the lateral chromatic aberration curve graph of the lens under visible light of 435nm - 650nm, please refer to Figure 4 , it can be seen from the figure that the chromatic aberration is less than 11um, the chromatic aberration is small, and it has a high image color reducibility.

[0105] For the longitudinal chromatic aberration curve graph of the lens under visible light of 435nm - 650nm, please refer to Figure 5 , it can be seen from the figure that the axial chromatic aberration is less than ±0.03mm, the color reduction is good, the color chromatic aberration is small, and the blue-violet edge phenomenon is not obvious. For the field curvature and distortion graph of the lens under visible light of 435nm - 650nm, please refer to Figure 6 , it can be seen from the figure that the field curvatures of each wavelength basically coincide, the chromatic aberration is small, and at the same time, the optical distortion of the system <|2%|, the distortion is small, the wide-angle distortion is controlled, the image quality is improved, and there is no need for post-image algorithm to correct the distortion, which is convenient for application. For the grid distortion graph of the lens under visible light of 435nm - 650nm, please refer to Figure 7 , the grid distortion (TV Dist) of this lens ≤ |-2%|.

[0106] Embodiment 2

[0107] As Figure 8 shown, compared with Embodiment 1, this embodiment is mainly characterized in that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0108] The detailed optical data of this specific embodiment are shown in Table 2-1.

[0109] Table 2-1 Detailed optical data of Embodiment 2

[0110]

[0111] In this embodiment, the specific values of some parameters of the lens are shown in Table 2-2.

[0112] Table 2-2 Some lens parameters of Embodiment 2

[0113]

[0114]

[0115] In this embodiment, the first lens 1, the second lens 2, the fourth lens 4, the fifth lens 5, and the sixth lens 6 are all plastic aspherical lenses. The aspherical data in this embodiment is shown in Table 2-3.

[0116] Table 2-3 Aspherical Data of Embodiment 2

[0117]

[0118] In this embodiment, for the MTF curve graph of the lens under visible light of 435 nm - 650 nm, please refer to Figure 9 , and it can be seen from the figure that when the spatial frequency of this lens reaches 200 lp / mm, the MTF value is greater than 0.25, the imaging quality is excellent, and the resolution of the lens is high. For the defocus curve graph of the lens under visible light of 435 nm - 650 nm, please refer to Figure 10 , and it can be seen from the figure that the defocus curves of each field of view of this lens under visible light are relatively concentrated and the defocus amount is small. For the lateral chromatic aberration curve graph of the lens under visible light of 435 nm - 650 nm, please refer to Figure 11 , and it can be seen from the figure that the chromatic aberration is less than 8 um, the chromatic aberration is small, and the image color reducibility is high.

[0119] For the longitudinal chromatic aberration curve graph of the lens under visible light of 435 nm - 650 nm, please refer to Figure 12 , and it can be seen from the figure that the axial chromatic aberration is less than ±0.03 mm, the color reduction is good, the color chromatic aberration is small, and the blue-violet edge phenomenon is not obvious. For the field curvature and distortion graph of the lens under visible light of 435 nm - 650 nm, please refer to Figure 13 , and it can be seen from the figure that the field curvatures of each wavelength basically coincide, the chromatic aberration is small, and at the same time, the optical distortion of the system <|2%, the distortion is small, the wide-angle distortion is controlled, the image quality is improved, and there is no need for post-image algorithm to correct the distortion, which is convenient for application. For the grid distortion graph of the lens under visible light of 435 nm - 650 nm, please refer to Figure 14 , and the grid distortion (TV Dist) of this lens ≤ |-1.55%|.

[0120] Embodiment 3

[0121] As Figure 15 shown, compared with Embodiment 1, this embodiment is mainly characterized in that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0122] The detailed optical data of this specific embodiment is shown in Table 3-1.

[0123] Table 3-1 Detailed Optical Data of Example 3

[0124]

[0125]

[0126] In this embodiment, the specific values of the lens part parameters are shown in Table 3-2.

[0127] Table 3-2 Partial Lens Parameters of Example 3

[0128] Parameter CT3 + CT4 + CT5 + CT6 8.4 AAG / BFL 1.42 IMH / EFL 0.81 f1 / R1 -10

[0129] In this embodiment, the first lens 1, the second lens 2, the fourth lens 4, the fifth lens 5, and the sixth lens 6 are all plastic aspherical lenses. The aspherical data in this embodiment is shown in Table 3-3.

[0130] Table 3-3 Aspherical Data of Example 3

[0131]

[0132] In this embodiment, for the MTF curve graph of the lens under visible light of 435nm - 650nm, please refer to Figure 16 , it can be seen from the figure that when the spatial frequency of this lens reaches 200 lp / mm, the MTF value is greater than 0.2, the imaging quality is excellent, and the resolution of the lens is high. For the defocus curve graph of the lens under visible light of 435nm - 650nm, please refer to Figure 17 , it can be seen from the figure that the defocus curves of each field of view of this lens under visible light are relatively concentrated and the defocus amount is small. For the lateral chromatic aberration curve graph of the lens under visible light of 435nm - 650nm, please refer to Figure 18 , it can be seen from the figure that the chromatic aberration is less than 7um, the chromatic aberration is small, and it has high image color reducibility.

[0133] For the longitudinal chromatic aberration curve graph of the lens under visible light of 435nm - 650nm, please refer to Figure 19 , it can be seen from the figure that the axial chromatic aberration is less than ±0.03mm, the color reduction is good, the color chromatic aberration is small, and the blue-violet edge phenomenon is not obvious. For the field curvature and distortion graph of the lens under visible light of 435nm - 650nm, please refer to Figure 20 , it can be seen from the figure that the field curvatures of each wavelength basically coincide, the chromatic aberration is small, and at the same time, the optical distortion of the system <|2%|, the distortion is small, the wide-angle distortion is controlled, the image quality is improved, and there is no need for post-image algorithm to correct the distortion, which is convenient to apply. For the grid distortion graph of the lens under visible light of 435nm - 650nm, please refer to Figure 21 , the grid distortion (TV Dist) of this lens ≤|-1.1%|.

[0134] Example 4

[0135] As Figure 22 shown, compared with Example 1, this example mainly differs in the optical parameters such as the curvature radius of each lens surface and the lens thickness.

[0136] The detailed optical data of this specific example are shown in Table 4-1.

[0137] Table 4-1 Detailed Optical Data of Example 4

[0138]

[0139] In this example, the specific values of some lens parameters are shown in Table 4-2.

[0140] Table 4-2 Some Lens Parameters of Example 4

[0141] Parameter CT3 + CT4 + CT5 + CT6 11.87 AAG / BFL 1.73 IMH / EFL 0.8 f1 / R1 -2.48

[0142] In this example, the first lens 1, the second lens 2, the fourth lens 4, the fifth lens 5, and the sixth lens 6 are all plastic aspherical lenses. The aspherical data in this example are shown in Table 4-3.

[0143] Table 4-3 Aspherical Data of Example 4

[0144]

[0145]

[0146] In this example, for the MTF curve graph of the lens under visible light of 435nm - 650nm, please refer to Figure 23 , it can be seen from the figure that when the spatial frequency of this lens reaches 200lp / mm, the MTF value is greater than 0.3, the imaging quality is excellent, and the resolution of the lens is high. For the defocus curve graph of the lens under visible light of 435nm - 650nm, please refer to Figure 24 , it can be seen from the figure that the defocus curves of each field of view of this lens under visible light are relatively concentrated and the defocus amount is small. For the lateral chromatic aberration curve graph of the lens under visible light of 435nm - 650nm, please refer to Figure 25 , it can be seen from the figure that the chromatic aberration is less than 9um, the chromatic aberration is small, and it has a high image color reducibility.

[0147] For the longitudinal chromatic aberration curve graph of the lens under visible light of 435nm - 650nm, please refer to Figure 26 , it can be seen from the figure that the axial chromatic aberration is less than ±0.03mm, the color reduction is good, the color chromatic aberration is small, and the blue-violet edge phenomenon is not obvious. For the field curvature and distortion graph of the lens under visible light of 435nm - 650nm, please refer to Figure 27, as can be seen from the figure, the field curvatures of each wavelength basically coincide, the chromatic aberration is small, and at the same time, the optical distortion of the system <|2%, with small distortion, controls the wide-angle distortion, improves the image quality, and does not require post-image algorithm to correct the distortion, which is convenient to use. For the grid distortion map of the lens at visible light of 435nm - 650nm, please refer to Figure 28 , the grid distortion (TV Dist) of this lens ≤|-1.45%|.

[0148] Embodiment 5

[0149] As Figure 29 shown, compared with Embodiment 1, this embodiment is mainly characterized in that the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0150] The detailed optical data of this specific embodiment are shown in Table 5-1.

[0151] Table 5-1 Detailed Optical Data of Embodiment 5

[0152]

[0153] In this embodiment, the specific values of some parameters of the lens are shown in Table 5-2.

[0154] Table 5-2 Some Lens Parameters of Embodiment 5

[0155]

[0156]

[0157] In this embodiment, the first lens 1, the second lens 2, the fourth lens 4, the fifth lens 5, and the sixth lens 6 are all plastic aspherical lenses. The aspherical data in this embodiment are shown in Table 5-3.

[0158] Table 5-3 Aspherical Data of Embodiment 5

[0159]

[0160] In this embodiment, for the MTF curve graph of the lens at visible light of 435nm - 650nm, please refer to Figure 30 , as can be seen from the figure, when the spatial frequency of this lens reaches 200lp / mm, the MTF value is greater than 0.2, the imaging quality is excellent, and the resolution of the lens is high. For the defocus curve graph of the lens at visible light of 435nm - 650nm, please refer to Figure 31 , as can be seen from the figure, the defocus curves of each field of view of this lens at visible light are relatively concentrated, and the defocus amount is small. For the lateral chromatic aberration curve graph of the lens at visible light of 435nm - 650nm, please refer to Figure 32, as can be seen from the figure, the color difference is less than 9um, with a small color difference and high image color reducibility.

[0161] Please refer to the longitudinal chromatic aberration curve diagram of the lens under visible light of 435nm - 650nm Figure 33 , as can be seen from the figure, the axial chromatic aberration is less than ±0.02mm, with good color reduction, small color difference of colors, and no obvious blue-violet edge phenomenon. Please refer to the field curvature and distortion diagram of the lens under visible light of 435nm - 650nm Figure 34 , as can be seen from the figure, the field curvature of each wavelength basically coincides, with a small chromatic aberration. At the same time, the optical distortion of the system <|2%|, with a small distortion, controlling the wide-angle distortion, improving the image quality, and no need for post-image algorithm to correct the distortion, which is convenient for application. Please refer to the grid distortion diagram of the lens under visible light of 435nm - 650nm Figure 35 , the grid distortion (TV Dist) of this lens ≤|0.86%|.

[0162] As mentioned above, it is only the preferred specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An optical imaging lens, characterized in that: It includes a first lens, a second lens, a diaphragm, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially arranged along an optical axis from the object side to the image side. Each of the first lens to the sixth lens includes an object side facing the object side through which imaging light passes and an image side facing the image side through which imaging light passes. The first lens has a negative refractive power, and the object side of the first lens is convex and the image side is concave. The second lens has a positive refractive power, and the object side of the second lens is convex and the image side is concave. The third lens has a positive refractive power, and the object side of the third lens is convex and the image side is convex. The fourth lens has a positive refractive power, and the object side of the fourth lens is concave and the image side is convex. The fifth lens has a negative refractive power, and the object side of the fifth lens near the optical axis is convex and the image side is concave. The sixth lens has a positive refractive power, and the object side of the sixth lens is convex and the image side near the optical axis is convex. Among them, the first lens, the second lens, the fourth lens, the fifth lens, and the sixth lens are all plastic aspherical lenses, and the third lens is a glass lens; this optical imaging lens satisfies: -10.5 < f1 < -9, 30 < f2 < 40, 7 < f3 < 9, 11 < f4 < 13, -8 < f5 < -7, 7 < f6 < 9, where f1, f2, f3, f4, f5, f6 are the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens respectively.

2. The optical imaging lens according to claim 1, wherein: This lens satisfies: 1 < |(f1 / f)| < 2.5, 5 < |(f2 / f)| < 7, 1 < |(f3 / f)| < 2, 1.5 < |(f4 / f)| < 3, 1 < |(f5 / f)| < 2, 1 < |(f6 / f)| < 2, where f is the overall focal length of the lens, and f1, f2, f3, f4, f5, f6 are the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens respectively.

3. An optical imaging lens according to claim 1, characterized in that: The first lens satisfies: f1 / R1 < -2, where f1 is the focal length of the first lens and R1 is the radius of curvature of the object side of the first lens.

4. An optical imaging lens according to claim 1, characterized in that: This lens satisfies: nd2 ≥ 1.64, nd5 ≥ 1.64, where nd2 and nd5 are the refractive indices of the second lens and the fifth lens respectively.

5. An optical imaging lens according to claim 1, characterized in that: This lens satisfies: 8mm < CT3 + CT4 + CT5 + CT6 < 12mm, where CT3, CT4, CT5, and CT6 are the central thicknesses of the third lens, the fourth lens, the fifth lens, and the sixth lens respectively.

6. An optical imaging lens according to claim 1, wherein: This lens satisfies: 1 ≤ AAG / BFL ≤ 2, where AAG is the sum of the air gaps between adjacent two lenses among the first to sixth lenses on the optical axis, and BFL is the distance from the image side of the sixth lens to the imaging plane on the optical axis.

7. An optical imaging lens according to claim 1, characterized in that: This lens satisfies: 0.75 ≤ IMH / EFL ≤ 1, where IMH is the semi-image height on the image side of the lens and EFL is the effective focal length of the lens.

8. An optical imaging lens according to claim 1 or 7, characterized in that: The effective focal length EFL of this lens satisfies: 5.0mm < EFL < 6.0mm.

9. An optical imaging lens according to claim 1, characterized in that: The maximum aperture F / NO of this lens is 1.6.

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