Ultra-short object distance imaging lens and electronic equipment

Abstract

The present invention discloses an ultra-short object distance imaging lens and electronic equipment, wherein the imaging lens comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens from the object side to the image side, the object side surface and the image side surface of the first lens, the second lens, the third lens, the fourth lens and the fifth lens are all aspherical surfaces, the effective focal lengths f1, f2, f3, f4, f5 of the first lens, the second lens, the third lens, the fourth lens and the fifth lens satisfy f4>f1, f4>f2, f4>f1, f4>f5; the sum of the center thicknesses ∑CT on the optical axis of each lens and the spacing distance TTL from the object side surface of the first lens to the imaging surface of the imaging lens on the optical axis satisfy 0.2<∑CT / TTL<0.5. The imaging lens and electronic equipment in the present invention realize ultra-short object distance imaging by increasing the total optical length and controlling parameters such as the center thickness of each lens and the air spacing, which can improve the resolution of the lens, reduce optical distortion, and ensure relative illumination.

Description

Technical Field

[0001] The invention belongs to the technical field of optical lenses, and in particular relates to an ultra-short object distance imaging lens and electronic equipment. Background Art

[0002] With the advancement of science and technology and the development of economy, people have higher and higher requirements for the camera function of portable electronic devices (such as tablets, iPads, smart phones, etc.). They not only require the camera module equipped with the electronic device to achieve background blur and clear night shots, but also require the camera module equipped with the electronic device to achieve optical zoom. As a camera module with strong optical zoom capability, the periscope camera module is becoming more and more popular and valued by people.

[0003] In the prior art, the object distance in the periscope camera module is relatively large, and ultra-short object distance (<20 mm) imaging cannot be achieved, and optical distortion, resolution and relative illumination cannot be effectively guaranteed.

[0004] Therefore, in view of the above technical problems, it is necessary to provide an ultra-short object distance imaging lens and electronic equipment. Summary of the invention

[0005] The object of the present invention is to provide an ultra-short object distance imaging lens and electronic equipment.

[0006] In order to achieve the above purpose, the technical solution provided by an embodiment of the present invention is as follows:

[0007] An ultra-short object distance imaging lens, the imaging lens comprising a first lens, a second lens, a third lens, a fourth lens and a fifth lens from the object side to the image side, the object side surface and the image side surface of the first lens, the second lens, the third lens, the fourth lens and the fifth lens are all aspherical surfaces, wherein:

[0008] The first lens has negative optical power, and its object side optical axis is convex, and its image side optical axis is concave;

[0009] The second lens has positive refractive power, and its object side optical axis is convex, and its image side optical axis is convex;

[0010] The third lens has negative optical power, and its object side surface is concave at the optical axis;

[0011] The fourth lens has positive refractive power;

[0012] The fifth lens has negative power, and its object side surface is convex at the optical axis, and has at least one concave surface off the axis, and its image side surface is concave at the optical axis, and has at least one convex surface off the axis;

[0013] The effective focal lengths f1, f2, f3, f4, and f5 of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens satisfy f4>f1, f4>f2, f4>f1, and f4>f5;

[0014] The sum ΣCT of the center thicknesses of the first lens, the second lens, the third lens, the fourth lens and the fifth lens on the optical axis and the spacing distance TTL from the object side surface of the first lens to the imaging surface of the imaging lens on the optical axis satisfy 0.2<ΣCT / TTL<0.5.

[0015] In one embodiment, the air interval T12 between the first lens and the second lens on the optical axis, the air interval T23 between the second lens and the third lens on the optical axis, the air interval T34 between the third lens and the fourth lens on the optical axis, the air interval T45 between the fourth lens and the fifth lens on the optical axis, and the center thickness CT3 of the third lens on the optical axis and the center thickness CT4 of the fourth lens on the optical axis satisfy 1.73<(T12+T23+T34+T45) / (CT3+CT4)<2.7.

[0016] In one embodiment, an air interval T12 between the first lens and the second lens on the optical axis, an air interval T23 between the second lens and the third lens on the optical axis, an air interval T34 between the third lens and the fourth lens on the optical axis, and an air interval T45 between the fourth lens and the fifth lens on the optical axis satisfy 0.13 mm ≤ T12 ≤ 0.47 mm, 0.21 mm ≤ T23 ≤ 0.43 mm, 1.83 mm ≤ T34 ≤ 5.11 mm, and 1.55 mm ≤ T45 ≤ 3.81 mm.

[0017] In one embodiment, a sum ΣCT of the center thicknesses of the first lens, the second lens, the third lens, the fourth lens and the fifth lens on the optical axis and a distance SL from the aperture to the imaging surface of the imaging lens on the optical axis satisfy 0.300≤ΣCT / SL≤0.383.

[0018] In one embodiment, a center thickness CT2 of the second lens on the optical axis and a center thickness CT3 of the third lens on the optical axis satisfy 0.3<CT2 / CT3<1.5.

[0019] In one embodiment, the center thickness CT5 of the fifth lens on the optical axis, the center thickness CT3 of the third lens on the optical axis, and half of the maximum field of view HFOV of the imaging lens satisfy 0.07<CT5 / CT3×TAN(HFOV)<0.22.

[0020] In one embodiment, an axial distance SAG11 from the intersection of the object side surface of the first lens and the optical axis to the effective half-aperture vertex of the object side surface of the first lens and a center thickness CT1 of the first lens on the optical axis satisfy 0.5<SAG11 / CT1<1.2.

[0021] In one embodiment, the distance SAG32 from the intersection of the image side surface of the third lens and the optical axis to the effective half-aperture vertex of the image side surface of the third lens on the optical axis and the distance SAG31 from the intersection of the object side surface of the third lens and the optical axis to the effective half-aperture vertex of the object side surface of the third lens on the optical axis satisfy 0.39<SAG31 / SAG32<0.54.

[0022] In one embodiment, the effective focal length f1 of the first lens and the curvature radius R1 of the object side surface of the first lens satisfy -7<f1 / R1<-1, the curvature radius R1 of the object side surface of the first lens and the total effective focal length f of the imaging lens satisfy 0.3<R1 / f<1.2, the curvature radius R3 of the object side surface of the fourth lens, the curvature radius R4 of the image side surface of the fourth lens, the curvature radius R5 of the object side surface of the fifth lens, the curvature radius R6 of the image side surface of the fifth lens, and the total effective focal length f of the imaging lens satisfy 3.5<(|R3|+|R4|+|R5|+|R6|) / f<7.5.

[0023] In one embodiment, the total effective focal length f of the imaging lens and the entrance pupil diameter EPD of the imaging lens satisfy f / EPD≤2.0, and the distance TTL from the center of the object side surface of the first lens to the imaging surface of the imaging lens on the optical axis and half the diagonal length of the effective pixel area on the imaging surface of the imaging lens ImgH satisfy 4.5. <TTL / ImgH<5.5。

[0024] In one embodiment, the imaging lens further includes:

[0025] A filter, located on the image side of the fifth lens;

[0026] A lens barrel, used for encapsulating the first lens, the second lens, the third lens, the fourth lens and the fifth lens;

[0027] A plurality of spacer rings are packaged between the first lens and the second lens, and / or the second lens and the third lens, and / or the third lens and the fourth lens, and / or the fourth lens and the fifth lens.

[0028] The technical solution provided by an embodiment of the present invention is as follows:

[0029] An electronic device is provided with at least one ultra-short object distance imaging lens as described above.

[0030] Compared with the prior art, the present invention has the following advantages:

[0031] The imaging lens and electronic device of the present invention realize ultra-short object distance imaging by increasing the total optical length and controlling parameters such as the center thickness of each lens and the air interval, which can improve the resolution of the lens, reduce optical distortion, and ensure relative illumination. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] 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 or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 is a schematic structural diagram of the imaging lens in the present invention;

[0034] Figure 2 Schematic diagram of light transmission of the imaging lens in the present invention;

[0035] Figure 3 is a resolution curve diagram of the imaging lens in the first embodiment of the present invention;

[0036] Figure 4 is a distortion curve diagram of the imaging lens in the first embodiment of the present invention;

[0037] Figure 5 FIG. 4 is a relative illumination curve diagram of the imaging lens in the first embodiment of the present invention. DETAILED DESCRIPTION

[0038] The present invention will be described in detail below in conjunction with the various embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional changes made by a person skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0039] Ginseng Figure 1 , Figure 2 As shown, the present invention discloses an ultra-short object distance imaging lens, which includes a first lens 10, a second lens 20, a third lens 30, a fourth lens 40 and a fifth lens 50 from the object side to the image side, and the object side surface and the image side surface of the first lens 10, the second lens 20, the third lens 30, the fourth lens 40 and the fifth lens 50 are all aspherical surfaces, wherein:

[0040] The first lens 10 has negative refractive power, and its object side optical axis is convex, and its image side optical axis is concave;

[0041] The second lens 20 has positive refractive power, and its object side optical axis is convex, and its image side optical axis is convex;

[0042] The third lens 30 has negative refractive power, and its object side surface is concave at the optical axis;

[0043] The fourth lens 40 has positive refractive power;

[0044] The fifth lens 50 has negative refractive power, with a convex surface on the object side at the optical axis and at least one concave surface on the object side off-axis, a concave surface on the image side at the optical axis and at least one convex surface on the image side off-axis.

[0045] Furthermore, the imaging lens also includes:

[0046] A filter 60, located on the image side of the fifth lens 50;

[0047] The lens barrel 70 is used to encapsulate the first lens, the second lens, the third lens, the fourth lens and the fifth lens;

[0048] A plurality of spacer rings 80 are packaged between the first lens and the second lens, and / or the second lens and the third lens, and / or the third lens and the fourth lens, and / or the fourth lens and the fifth lens.

[0049] The effective focal lengths f1, f2, f3, f4, and f5 of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens in the present invention satisfy f4>f1, f4>f2, f4>f1, and f4>f5. In the case of an ultra-short object distance, the focal length of the fourth lens is always ensured to be greater than that of the other lenses, so as to constrain and ensure that the optical parameters are within a required range.

[0050] In addition, the sum of the center thicknesses ∑CT of the first lens, the second lens, the third lens, the fourth lens and the fifth lens on the optical axis and the distance TTL between the object side of the first lens and the imaging surface of the imaging lens on the optical axis satisfy 0.2<∑CT / TTL<0.5. The ratio of the thickness of each lens to the total optical length ensures that the processing requirements can be met at ultra-short object distances, and the imaging lens has good resolution.

[0051] Preferably, the air interval T12 between the first lens and the second lens on the optical axis, the air interval T23 between the second lens and the third lens on the optical axis, the air interval T34 between the third lens and the fourth lens on the optical axis, the air interval T45 between the fourth lens and the fifth lens on the optical axis, the center thickness CT3 of the third lens on the optical axis, and the center thickness CT4 of the fourth lens on the optical axis satisfy 1.73<(T12+T23+T34+T45) / (CT3+CT4)<2.7. In this way, the difficulty of processing and assembly can be reduced, and the interval can be reasonably controlled to correct distortion and field curvature, avoiding excessive distortion and excessive field curvature.

[0052] Preferably, the air interval T12 between the first lens and the second lens on the optical axis, the air interval T23 between the second lens and the third lens on the optical axis, the air interval T34 between the third lens and the fourth lens on the optical axis, and the air interval T45 between the fourth lens and the fifth lens on the optical axis satisfy 0.13 mm ≤ T12 ≤ 0.47 mm, 0.21 mm ≤ T23 ≤ 0.43 mm, 1.83 mm ≤ T34 ≤ 5.11 mm, and 1.55 mm ≤ T45 ≤ 3.81 mm.

[0053] Preferably, the sum of the center thicknesses ∑CT of the first lens, the second lens, the third lens, the fourth lens and the fifth lens on the optical axis and the distance SL from the aperture to the imaging surface of the imaging lens on the optical axis (located at the object side of the first lens, and 14mm≤SL≤18mm) satisfy 0.300≤∑CT / SL≤0.383. The total length is reduced by controlling the sum of the center thicknesses of the entire imaging lens, and the distortion can be reduced.

[0054] Preferably, the center thickness CT2 of the second lens on the optical axis and the center thickness CT3 of the third lens on the optical axis satisfy 0.3<CT2 / CT3<1.5. By optimizing the ratio of the center thickness of the second lens and the third lens, it can be ensured that the imaging requirements can be met when the object distance is small.

[0055] Preferably, the center thickness CT5 of the fifth lens on the optical axis, the center thickness CT3 of the third lens on the optical axis and half of the maximum field of view HFOV of the imaging lens satisfy 0.07<CT5 / CT3×TAN(HFOV)<0.22. The resolution is improved and the distortion is reduced by controlling the linear relationship between the field of view angle and the thickness.

[0056] Preferably, an axial distance SAG11 from the intersection of the object side surface of the first lens and the optical axis to the effective half-aperture vertex of the object side surface of the first lens and a center thickness CT1 of the first lens on the optical axis satisfy 0.5<SAG11 / CT1<1.2.

[0057] Preferably, the distance SAG32 from the intersection of the image side surface of the third lens and the optical axis to the effective half-aperture vertex of the image side surface of the third lens on the optical axis and the distance SAG31 from the intersection of the object side surface of the third lens and the optical axis to the effective half-aperture vertex of the object side surface of the third lens on the optical axis satisfy 0.39<SAG31 / SAG32<0.54. By controlling the effective aperture, the incident angle of light is reduced and the relative illumination is increased.

[0058] Preferably, the effective focal length f1 of the first lens and the curvature radius R1 of the object side surface of the first lens satisfy -7<f1 / R1<-1, the curvature radius R1 of the object side surface of the first lens and the total effective focal length f of the imaging lens satisfy 0.3<R1 / f<1.2, the curvature radius R3 of the object side surface of the fourth lens, the curvature radius R4 of the image side surface of the fourth lens, the curvature radius R5 of the object side surface of the fifth lens, the curvature radius R6 of the image side surface of the fifth lens, and the total effective focal length f of the imaging lens satisfy 3.5<(|R3|+|R4|+|R5|+|R6|) / f<7.5. By controlling the ratio of the Y radius to the focal length, light deflection is avoided, aberrations are reduced, and imaging quality is guaranteed.

[0059] Preferably, the total effective focal length f of the imaging lens and the entrance pupil diameter EPD of the imaging lens satisfy f / EPD≤2.0, and the distance TTL from the center of the object side surface of the first lens to the imaging surface of the imaging lens on the optical axis and half the diagonal length of the effective pixel area on the imaging surface of the imaging lens ImgH satisfy 4.5 <TTL / ImgH<5.5。

[0060] The invention also discloses an electronic device, in which at least one ultra-short object distance imaging lens is provided.

[0061] The present invention is further described below in conjunction with specific embodiments.

[0062] Embodiment 1:

[0063] In this embodiment, the total effective focal length of the imaging lens is f=3.815 mm, and the first lens 10, the second lens 20, the third lens 30, the fourth lens 40 and the fifth lens 50 are all resin lenses, the center is a lens, and the edges are corroded and matted. The parameters of the material, refractive index, effective focal length, etc. are as follows:

[0064] The first lens 10 is made of K26R, has a refractive index of 1.531, an effective focal length f1=-5.676 mm, an effective aperture of 3.63 mm on the object side, and an effective aperture of 3.69 mm on the image side;

[0065] The second lens 20 is made of K26R, has a refractive index of 1.531, an effective focal length f2=2.144 mm, an effective aperture of 3.81 mm on the object side, and an effective aperture of 3.79 mm on the image side;

[0066] The third lens 30 is made of EP6000, has a refractive index of 1.635, an effective focal length f3=-6.124mm, an effective aperture of 3.76mm on the object side, and an effective aperture of 4.02mm on the image side;

[0067] The fourth lens 40 is made of K26R, has a refractive index of 1.531, an effective focal length f4=10.301 mm, an effective aperture on the object side is 5.42 mm, and an effective aperture on the image side is 4.69 mm;

[0068] The fifth lens 50 is made of K26R, has a refractive index of 1.531, an effective focal length f5=-5.324 mm, an effective aperture on the object side is 4.58 mm, and an effective aperture on the image side is 5.28 mm.

[0069] The air interval T12 between the first lens and the second lens on the optical axis is 0.136 mm, the air interval T23 between the second lens and the third lens on the optical axis is 0.429 mm, the air interval T34 between the third lens and the fourth lens on the optical axis is 5.110 mm, and the air interval T45 between the fourth lens and the fifth lens on the optical axis is 1.585 mm.

[0070] The center thicknesses of the first lens, the second lens, the third lens, the fourth lens and the fifth lens on the optical axis are CT1=0.479 mm, CT2=1.103 mm, CT3=0.982 mm, CT4=1.712 mm, CT5=0.421 mm, respectively, and the sum of the center thicknesses ∑CT=4.696 mm.

[0071] The distance between the object side of the first lens and the imaging surface of the imaging lens on the optical axis is TTL=15.000 mm;

[0072] The distance SL from the aperture to the imaging surface of the imaging lens on the optical axis is 14.763 mm;

[0073] Half of the maximum field of view of the imaging lens HFOV = 14.595°;

[0074] The axial distance from the intersection of the object side surface of the first lens and the optical axis to the effective half-aperture vertex of the object side surface of the first lens SAG11=0.358mm, the distance from the intersection of the image side surface of the third lens and the optical axis to the effective half-aperture vertex of the image side surface of the third lens on the optical axis SAG32=0.472mm, the distance from the intersection of the object side surface of the third lens and the optical axis to the effective half-aperture vertex of the object side surface of the third lens on the optical axis SAG31=0.253mm;

[0075] The entrance pupil diameter of the imaging lens EPD = 3.522 mm;

[0076] Half of the diagonal length of the effective pixel area on the imaging surface of the imaging lens is ImgH = 3.304mm;

[0077] The curvature radius of the object side surface of the first lens is R1 = 3.821 mm, the curvature radius of the object side surface of the fourth lens is R3 = -2.027 mm, the curvature radius of the image side surface of the fourth lens is R4 = -4.957 mm, the curvature radius of the object side surface of the fifth lens is R5 = 4.264 mm, and the curvature radius of the image side surface of the fifth lens is R6 = 16.063 mm.

[0078] In this embodiment, the ultra-short object distance imaging lens satisfies:

[0079] ∑CT / TTL=0.313;

[0080] (T12+T23+T34+T45) / (CT3+CT4)=2.230;

[0081] ∑CT / SL=0.318;

[0082] CT2 / CT3=1.123;

[0083] CT5 / CT3×TAN(HFOV)=0.112;

[0084] f1 / R1=-1.485;

[0085] R1 / f=1.000;

[0086] (|R3|+|R4|+|R5|+|R6|) / f=7.159;

[0087] f / EPD=1.083;

[0088] TTL / ImgH=4.540.

[0089] The surface of each lens is aspherical and satisfies the aspherical formula:

[0090]

[0091] Among them, Z is the aspheric curve, C=1 / r (r is the paraxial spherical radius), Y is the radius of curvature, K is the cone constant (quadratic surface constant), and a, b, c, d, e... are high-order coefficients (4th order, 6th order, 8th order, 10th order, 12th order...).

[0092] The object side surface and image side surface of the first lens 10 are S1 and S2 respectively, the object side surface and image side surface of the second lens 20 are S3 and S4 respectively, the object side surface and image side surface of the third lens 30 are S5 and S6 respectively, the object side surface and image side surface of the fourth lens 40 are S7 and S8 respectively, the object side surface and image side surface of the fifth lens 50 are S9 and S10 respectively, and S1-SAG to S10-SAG are the sag heights of each surface (at 0.2mm, 0.4mm, 1.0mm, and 2.5mm). The specific surface parameters are shown in Tables 1 and 2.

[0093] Table 1: Lens surface parameters Table 1

[0094]

[0095] Table 2: Lens surface parameters Table 2

[0096]

[0097]

[0098] In this embodiment, the object distance is 10 mm, the optical length is 15 mm, and the magnification is 15 times.

[0099] Ginseng Figure 3 The graph of image height (Real Image Height)-resolution (MTF) in this embodiment is shown, and from top to bottom are the resolution curves of the meridian direction (S) and arc loss direction (T) when the spatial frequency is 0% (0lp / mm), the meridian direction (S) and arc loss direction (T) when the spatial frequency is 33% (33lp / mm), the meridian direction (S) and arc loss direction (T) when the spatial frequency is 66% (66lp / mm), and the meridian direction (S) and arc loss direction (T) when the spatial frequency is 132% (132lp / mm). It can be seen that the imaging lens in this embodiment has good resolution at high frequencies and the overall trend is smooth.

[0100] Ginseng Figure 4 FIG. 1 is a distortion curve diagram of this embodiment. It can be seen that the distortion of the imaging lens in this embodiment is relatively small, less than 2.0%. Figure 5 The graph shown is a curve of relative field height (Relative Field Height)-relative illumination (Relative Illumination) in this embodiment. It can be seen that the relative illumination of the imaging lens in this embodiment is greater than 80%.

[0101] Embodiment 2:

[0102] In this embodiment, the total effective focal length of the imaging lens is f=3.729 mm, and the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are all resin lenses, with the center being a lens and the edges being subjected to corrosion and matting treatment. The materials, refractive indices, and effective focal lengths thereof are as follows:

[0103] The first lens is made of K26R, with a refractive index of 1.531 and an effective focal length of f1 = -20.013 mm;

[0104] The second lens is made of K26R, with a refractive index of 1.531 and an effective focal length of f2 = 3.160 mm;

[0105] The third lens is made of EP6000, with a refractive index of 1.635 and an effective focal length of f3 = -7.734mm;

[0106] The fourth lens is made of K26R, with a refractive index of 1.531 and an effective focal length of f4 = 12.787 mm;

[0107] The fifth lens is made of K26R, has a refractive index of 1.531, and an effective focal length of f5 = -6.061 mm.

[0108] The air interval on the optical axis between the first lens and the second lens is T12=0.462mm, the air interval on the optical axis between the second lens and the third lens is T23=0.294mm, the air interval on the optical axis between the third lens and the fourth lens is T34=1.832mm, and the air interval on the optical axis between the fourth lens and the fifth lens is T45=3.744mm.

[0109] The center thicknesses of the first lens, the second lens, the third lens, the fourth lens and the fifth lens on the optical axis are CT1=0.300 mm, CT2=0.822 mm, CT3=1.987 mm, CT4=1.676 mm, CT5=0.853 mm, respectively, and the sum of the center thicknesses ∑CT=5.638 mm.

[0110] The distance between the object side of the first lens and the imaging surface of the imaging lens on the optical axis is TTL=15.000 mm;

[0111] The distance SL from the aperture to the imaging surface of the imaging lens on the optical axis is 14.763 mm;

[0112] Half of the maximum field of view of the imaging lens HFOV = 14.715°;

[0113] The axial distance from the intersection of the object side surface of the first lens and the optical axis to the effective half-aperture vertex of the object side surface of the first lens SAG11=0.367mm, the distance from the intersection of the image side surface of the third lens and the optical axis to the effective half-aperture vertex of the image side surface of the third lens on the optical axis SAG32=0.487mm, the distance from the intersection of the object side surface of the third lens and the optical axis to the effective half-aperture vertex of the object side surface of the third lens on the optical axis SAG31=0.224mm;

[0114] The entrance pupil diameter of the imaging lens EPD = 3.341 mm;

[0115] Half of the diagonal length of the effective pixel area on the imaging surface of the imaging lens is ImgH = 3.330 mm;

[0116] The curvature radius of the object side surface of the first lens is R1 = 2.985 mm, the curvature radius of the object side surface of the fourth lens is R3 = -3.406 mm, the curvature radius of the image side surface of the fourth lens is R4 = -13.193 mm, the curvature radius of the object side surface of the fifth lens is R5 = 8.241 mm, and the curvature radius of the image side surface of the fifth lens is R6 = -34.388 mm.

[0117] In this embodiment, the ultra-short object distance imaging lens satisfies:

[0118] ∑CT / TTL=0.376;

[0119] (T12+T23+T34+T45) / (CT3+CT4)=1.737;

[0120] ∑CT / SL=0.382;

[0121] CT2 / CT3=0.414;

[0122] CT5 / CT3×TAN(HFOV)=0.113;

[0123] f1 / R1=-6.704;

[0124] R1 / f=0.80;

[0125] (|R3|+|R4|+|R5|+|R6|) / f=15.931;

[0126] f / EPD=1.116;

[0127] TTL / ImgH=4.505.

[0128] The imaging lens in this embodiment has good resolution at high frequencies and a smooth overall trend; the distortion is small, less than 1.8%; and the relative illumination is greater than 74%.

[0129] Embodiment three:

[0130] In this embodiment, the total effective focal length of the imaging lens is f=6.139 mm, and the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are all resin lenses, with the center being a lens and the edges being subjected to corrosion and matte treatment. The materials, refractive indices, and effective focal lengths thereof are as follows:

[0131] The first lens is made of K26R, with a refractive index of 1.531 and an effective focal length of f1 = -11.748 mm;

[0132] The second lens is made of K26R, with a refractive index of 1.531 and an effective focal length of f2 = 2.838 mm;

[0133] The third lens is made of EP6000, with a refractive index of 1.635 and an effective focal length of f3 = -5.694mm;

[0134] The fourth lens is made of K26R, with a refractive index of 1.531 and an effective focal length of f4 = 11.160 mm;

[0135] The fifth lens is made of K26R, has a refractive index of 1.531, and an effective focal length of f5 = -23.089 mm.

[0136] The air interval on the optical axis between the first lens and the second lens is T12=0.420mm, the air interval on the optical axis between the second lens and the third lens is T23=0.212mm, the air interval on the optical axis between the third lens and the fourth lens is T34=2.805mm, and the air interval on the optical axis between the fourth lens and the fifth lens is T45=1.676mm.

[0137] The center thicknesses of the first lens, the second lens, the third lens, the fourth lens and the fifth lens on the optical axis are CT1=0.711mm, CT2=1.280mm, CT3=1.344mm, CT4=1.166mm, CT5=1.000mm respectively, and the sum of the center thicknesses ∑CT=5.500mm.

[0138] The distance between the object side of the first lens and the imaging surface of the imaging lens on the optical axis is TTL=17.980 mm;

[0139] The distance SL from the aperture to the imaging surface of the imaging lens on the optical axis is 17.680 mm;

[0140] Half of the maximum field of view of the imaging lens HFOV = 14.768°;

[0141] The axial distance from the intersection of the object side surface of the first lens and the optical axis to the effective half-aperture vertex of the object side surface of the first lens SAG11=0.376mm, the distance from the intersection of the image side surface of the third lens and the optical axis to the effective half-aperture vertex of the image side surface of the third lens on the optical axis SAG32=0.468mm, the distance from the intersection of the object side surface of the third lens and the optical axis to the effective half-aperture vertex of the object side surface of the third lens on the optical axis SAG31=0.250mm;

[0142] The entrance pupil diameter of the imaging lens EPD = 3.341 mm;

[0143] Half of the diagonal length of the effective pixel area on the imaging surface of the imaging lens is ImgH = 3.330 mm;

[0144] The curvature radius of the object side surface of the first lens is R1 = 2.959 mm, the curvature radius of the object side surface of the fourth lens is R3 = -6.170 mm, the curvature radius of the image side surface of the fourth lens is R4 = 9.843 mm, the curvature radius of the object side surface of the fifth lens is R5 = -3.375 mm, and the curvature radius of the image side surface of the fifth lens is R6 = -2.418 mm.

[0145] In this embodiment, the ultra-short object distance imaging lens satisfies:

[0146] ∑CT / TTL=0.306;

[0147] (T12+T23+T34+T45) / (CT3+CT4)=2.221;

[0148] ∑CT / SL=0.311;

[0149] CT2 / CT3=0.952;

[0150] CT5 / CT3×TAN(HFOV)=0.196;

[0151] f1 / R1=-3.970;

[0152] R1 / f=0.482;

[0153] (|R3|+|R4|+|R5|+|R6|) / f=3.552;

[0154] f / EPD=1.838;

[0155] TTL / ImgH=5.400.

[0156] The imaging lens in this embodiment has good resolution at high frequencies and a smooth overall trend; the distortion is small, less than -5%; and the relative illumination is greater than 78%.

[0157] It can be seen from the above technical solutions that the present invention has the following beneficial effects:

[0158] The imaging lens and electronic device of the present invention realize ultra-short object distance imaging by increasing the total optical length and controlling parameters such as the center thickness of each lens and the air interval, which can improve the resolution of the lens, reduce optical distortion, and ensure relative illumination.

[0159] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0160] In addition, it should be understood that although the present specification is described according to embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that those skilled in the art can understand.

Claims

1. An ultra-short object distance imaging lens, characterized in that: The imaging lens is composed of a first lens, a second lens, a third lens, a fourth lens and a fifth lens from the object side to the image side, and the object side surface and the image side surface of the first lens, the second lens, the third lens, the fourth lens and the fifth lens are all aspherical surfaces, wherein: The first lens has negative optical power, and its object side optical axis is convex, and its image side optical axis is concave; The second lens has positive refractive power, and its object side optical axis is convex, and its image side optical axis is convex; The third lens has negative optical power, and its object side surface is concave at the optical axis; The fourth lens has positive refractive power; The fifth lens has negative power, and its object side surface is convex at the optical axis, and has at least one concave surface off the axis, and its image side surface is concave at the optical axis, and has at least one convex surface off the axis; The effective focal lengths f1, f2, f3, f4, and f5 of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens satisfy f4>f1, f4>f2, f4>f1, and f4>f5; The sum of the center thicknesses ∑CT of the first lens, the second lens, the third lens, the fourth lens and the fifth lens on the optical axis and the distance TTL between the object side surface of the first lens and the imaging surface of the imaging lens on the optical axis satisfy 0.2<∑CT / TTL<0.5; The air interval T12 between the first lens and the second lens on the optical axis, the air interval T23 between the second lens and the third lens on the optical axis, the air interval T34 between the third lens and the fourth lens on the optical axis, the air interval T45 between the fourth lens and the fifth lens on the optical axis, the center thickness CT3 of the third lens on the optical axis, and the center thickness CT4 of the fourth lens on the optical axis satisfy 1.73<(T12+T23+T34+T45) / (CT3+CT4)<2.7; The air interval T12 between the first lens and the second lens on the optical axis, the air interval T23 between the second lens and the third lens on the optical axis, the air interval T34 between the third lens and the fourth lens on the optical axis, and the air interval T45 between the fourth lens and the fifth lens on the optical axis satisfy 0.13 mm ≤ T12 ≤ 0.47 mm, 0.21 mm ≤ T23 ≤ 0.43 mm, 1.83 mm ≤ T34 ≤ 5.11 mm, and 1.55 mm ≤ T45 ≤ 3.81 mm; The sum of the center thicknesses ∑CT of the first lens, the second lens, the third lens, the fourth lens and the fifth lens on the optical axis and the distance SL from the aperture to the imaging surface of the imaging lens on the optical axis satisfy 0.300≤∑CT / SL≤0.383; The center thickness CT2 of the second lens on the optical axis and the center thickness CT3 of the third lens on the optical axis satisfy 0.3<CT2 / CT3<1.5; The center thickness CT5 of the fifth lens on the optical axis, the center thickness CT3 of the third lens on the optical axis, and half of the maximum field of view HFOV of the imaging lens satisfy 0.07<CT5 / CT3×TAN(HFOV)<0.22; An axial distance SAG11 from an intersection of the object side surface of the first lens and the optical axis to an effective half-aperture vertex of the object side surface of the first lens and a center thickness CT1 of the first lens on the optical axis satisfy 0.5<SAG11 / CT1<1.2; The distance SAG32 from the intersection of the image side surface of the third lens and the optical axis to the effective half-aperture vertex of the image side surface of the third lens on the optical axis and the distance SAG31 from the intersection of the object side surface of the third lens and the optical axis to the effective half-aperture vertex of the object side surface of the third lens on the optical axis satisfy 0.39<SAG31 / SAG32<0.54; The effective focal length f1 of the first lens and the curvature radius R1 of the object side surface of the first lens satisfy -7<f1 / R1<-1, the curvature radius R1 of the object side surface of the first lens and the total effective focal length f of the imaging lens satisfy 0.3<R1 / f<1.2, the curvature radius R3 of the object side surface of the fourth lens, the curvature radius R4 of the image side surface of the fourth lens, the curvature radius R5 of the object side surface of the fifth lens, the curvature radius R6 of the image side surface of the fifth lens, and the total effective focal length f of the imaging lens satisfy 3.5<(|R3|+|R4|+|R5|+|R6|) / f<7.

5.

2. The ultra-short object distance imaging lens according to claim 1, characterized in that: The total effective focal length f of the imaging lens and the entrance pupil diameter EPD of the imaging lens satisfy f / EPD≤2.0, and the distance TTL from the center of the object side surface of the first lens to the imaging surface of the imaging lens on the optical axis and half of the diagonal length of the effective pixel area on the imaging surface of the imaging lens ImgH satisfy 4.5 <TTL / ImgH<5.5。 3. The ultra-short object distance imaging lens according to claim 1, characterized in that: The imaging lens further comprises: A filter, located on the image side of the fifth lens; A lens barrel, used for encapsulating the first lens, the second lens, the third lens, the fourth lens and the fifth lens; A plurality of spacer rings are packaged between the first lens and the second lens, and / or the second lens and the third lens, and / or the third lens and the fourth lens, and / or the fourth lens and the fifth lens.

4. An electronic device, characterized in that: The electronic device is provided with at least one ultra-short object distance imaging lens according to any one of claims 1 to 3.

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