An ultra-wide-angle video doorbell infrared confocal lens

Abstract

The present invention discloses an ultra-wide-angle video doorbell infrared confocal lens, comprising a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, and a sixth lens, arranged sequentially 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 negative 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. The lens satisfies the following conditions: TTL / F < 7, where TTL is the total optical length of the lens and F is the clear aperture of the lens. The ultra-wide-angle video doorbell infrared confocal lens of the present invention utilizes a design combining four plastic aspheric lenses with two glass spherical lenses, achieving excellent aberration correction and high resolution. The lens has a relative illumination (RI) greater than 50%, a high and low temperature defocus within 2 μm, and a lens f-tan (theta) distortion within 5%, controlling wide-angle distortion and excellent correction of external field distortion. The lens has confocal properties for both visible and infrared light and has a wide spectral range.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and in particular to an ultra-wide-angle visual doorbell infrared confocal lens. Background Art

[0002] With the continuous development of the economy, home security has received more and more attention from people. Among them, visual doorbell system technology has been widely used in society. Users' requirements and technical indicators are also constantly improving, pursuing larger apertures, wider fields of view, and ensuring clear imaging quality. However, the current visual doorbell lenses generally have problems such as large distortion, severe distortion of the external field of view, relatively low relative illumination (RI), and difficulty in correcting glass-plastic temperature drift.

[0003] In view of this, the inventors of the present application invented an ultra-wide-angle video doorbell infrared confocal lens. Summary of the Invention

[0004] The object of the present invention is to provide an ultra-wide-angle video doorbell infrared confocal lens with good aberration correction, high relative illumination and small distortion.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an ultra-wide-angle video doorbell infrared confocal lens, comprising a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, and a sixth lens, arranged in sequence along an optical axis from the object side to the image side, wherein the first to sixth lenses each include an object-side surface facing the object side and through which imaging light passes, and an image-side surface facing the image side and through which imaging light passes;

[0006] The first lens has a negative refractive power, and the object-side surface of the first lens is convex, and the image-side surface is concave;

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

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

[0009] The fourth lens element has positive refractive power, and the object-side surface and image-side surface of the fourth lens element are convex;

[0010] The fifth lens element has a negative refractive power, and the object-side surface of the fifth lens element is convex, and the image-side surface of the fifth lens element is concave;

[0011] The sixth lens element has positive refractive power, and the object-side surface and image-side surface of the sixth lens element are convex;

[0012] The lens satisfies: TTL / F<7, where TTL is the total optical length of the lens and F is the clear aperture of the lens.

[0013] Further, the first lens and the fourth lens are both glass spherical lenses, and the second lens, the third lens, the fifth lens, and the sixth lens are all plastic aspherical lenses.

[0014] Further, the lens satisfies: -10 < f1 < 0, -5 < f2 < 0, 0 < f3 < 10, 0 < f4 < 5, -5 < f5 < 0, 0 < f6 < 5, 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] Further, the lens satisfies: 2 < |f1 / f| < 5, 1 < |f2 / f| < 5, 3 < |f3 / f| < 5, 1 < |f4 / f| < 3, 1 < |f5 / f| < 3, 1 < |f6 / f| < 3, 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] Further, the lens satisfies: 1.7 < nd1 < 1.9, 40 < vd1 < 70, 1.5 < nd2 < 1.7, 50 < vd2 < 70, 1.5 < nd3 < 1.8, 15 < vd3 < 30, 1.7 < nd4 < 1.9, 40 < vd4 < 60, 1.5 < nd5 < 1.8, 15 < vd5 < 30, 1.5 < nd6 < 1.7, 5 < vd6 < 70, where nd1, nd2, nd3, nd4, nd5, and nd6 are the refractive indices of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens, respectively, and vd1, vd2, vd3, vd4, vd5, and vd6 are the Abbe numbers of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens, respectively.

[0017] Further, the lens satisfies: 100 < vd1 + vd2 + vd3 < 120, where vd1, vd2, and vd3 are the Abbe numbers of the first lens, the second lens, and the third lens, respectively.

[0018] Further, the lens satisfies: 6.9 ≤ TTL / AAG, where AAG is the sum of the two air gaps on the optical axis between the first lens, the second lens, and the third lens. [[ID=??]]

[0019] Further, the lens satisfies: ALT < 2.72 mm, where ALT is the sum of the central thicknesses of the first lens, the second lens, and the third lens.

[0020] Further, the lens satisfies: TTL < 12 mm. It seems there is a small error in the English translation of item . The correct range for vd6 should be 50 < vd6 < 70 instead of 5 < vd6 < 70 as in the original text. Also, there seems to be a mislabeled [[ID=??]] which should probably be . Please double-check these details.

[0021] Furthermore, the field of view of the lens satisfies: DFOV=180°.

[0022] After adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0023] The ultra-wide-angle video doorbell infrared confocal lens of the present invention is designed by combining four plastic aspheric lenses with two glass spherical lenses, with good aberration correction and high resolution. The relative illumination RI is greater than 50%, and the high and low temperature defocus is within 2μm. The lens f-tan (theta) distortion is within 5%, which controls wide-angle distortion and well corrects external field distortion. It has visible light and infrared light confocal characteristics and has a wide spectral range of application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a light path diagram of Example 1 of the present invention;

[0025] Figure 2 : This is an MTF curve diagram of the lens under visible light in Example 1 of the present invention;

[0026] Figure 3 : is a defocus curve diagram of the lens under visible light in Example 1 of the present invention;

[0027] Figure 4 This is a defocus curve diagram of the lens under infrared light in Example 1 of the present invention;

[0028] Figure 5 is a relative illumination curve diagram of the lens under visible light in Example 1 of the present invention;

[0029] Figure 6 Graph showing longitudinal chromatic aberration of the lens under visible light in Example 1 of the present invention;

[0030] Figure 7 Graphs showing field curvature and distortion of the lens under visible light in Example 1 of the present invention;

[0031] Figure 8 This is a light path diagram of Example 2 of the present invention;

[0032] Figure 9 This is an MTF curve diagram of the lens under visible light in Example 2 of the present invention;

[0033] Figure 10 : is a defocus curve diagram of the lens under visible light in Example 2 of the present invention;

[0034] Figure 11 This is a defocus curve diagram of the lens under infrared light in Example 2 of the present invention;

[0035] Figure 12is a relative illumination curve diagram of the lens under visible light in Example 2 of the present invention;

[0036] Figure 13 Graph showing longitudinal chromatic aberration of the lens under visible light in Example 2 of the present invention;

[0037] Figure 14 Graphs showing field curvature and distortion of the lens under visible light in Example 2 of the present invention;

[0038] Figure 15 This is a light path diagram of Example 3 of the present invention;

[0039] Figure 16 : This is an MTF curve diagram of the lens under visible light in Example 3 of the present invention;

[0040] Figure 17 : is a defocus curve diagram of the lens under visible light in Example 3 of the present invention;

[0041] Figure 18 This is a defocus curve diagram of the lens under infrared light in Example 3 of the present invention;

[0042] Figure 19 : is a relative illumination curve diagram of the lens under visible light in Example 3 of the present invention;

[0043] Figure 20 Graph showing longitudinal chromatic aberration of the lens under visible light in Example 3 of the present invention;

[0044] Figure 21 Graphs showing field curvature and distortion of the lens under visible light in Example 3 of the present invention.

[0045] Description of reference numerals:

[0046] 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Sixth lens; 7. Aperture diaphragm; 8. Protective glass & filter. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, 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 intended to limit the present invention.

[0048] Here, "a lens having a positive (or negative) refractive power" means that the lens's paraxial refractive power, calculated using Gaussian optics theory, is positive (or negative). The "object-side (or image-side) of a lens" is defined as the specific area of ​​the lens surface through which the imaging light passes. The concavity or convexity of a lens's surface can be determined using the same method commonly used by those skilled in the art: the sign of the radius of curvature (abbreviated as R value). R values ​​are commonly used in optical design software such as Zemax or CodeV. R values ​​are also commonly found in lens data sheets within optical design software. For the object-side surface, a positive R value indicates a convex surface; a negative R value indicates a concave surface. Conversely, for the image-side surface, a positive R value indicates a concave surface; a negative R value indicates a convex surface.

[0049] The invention discloses an ultra-wide-angle visual doorbell infrared confocal lens. The lens is an ultra-wide-angle lens that realizes confocality of visible light wavelengths and infrared wavelengths. When used in doorbells, it has high imaging quality.

[0050] An ultra-wide-angle video doorbell infrared confocal lens includes a first lens 1, a second lens 2, a third lens 3, an aperture 7, a fourth lens 4, a fifth lens 5, and a sixth lens 6, which are arranged in sequence along an optical axis from the object side to the image side. The first lens 1 to the sixth lens 6 each include 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.

[0051] 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;

[0052] The second lens element 2 has a negative refractive power, and the object side surface of the second lens element 2 is convex, and the image side surface is concave;

[0053] The third lens element 3 has positive refractive power, and the object side surface of the third lens element 3 is convex, and the image side surface is concave;

[0054] The fourth lens element 4 has positive refractive power, and the object-side surface and image-side surface of the fourth lens element 4 are convex.

[0055] The fifth lens element 5 has a negative refractive power, and the object-side surface of the fifth lens element 5 is convex, and the image-side surface is concave;

[0056] The sixth lens element 6 has positive refractive power, and the object-side surface and the image-side surface of the sixth lens element 6 are convex.

[0057] The aperture stop 7 is located between the third lens 3 and the fourth lens 4. The first to third lenses 3 form the front lens group of the lens, and the fourth to sixth lenses 6 form the rear lens group of the lens. Among them, the first lens 1 and the fourth lens 4 are both glass spherical lenses, and the second lens 2, the third lens 3, the fifth lens 5, and the sixth lens 6 are all plastic aspherical lenses. The lens adopts a glass-plastic hybrid design, which can better improve the imaging quality, correct the temperature drift, and also improve the relative illumination well.

[0058] This lens satisfies: TTL / F < 7, where TTL is the overall optical length of the lens and F is the aperture diameter of the lens. The lens arrangement is reasonable, the sensitivity is low, and the lens has a confocal characteristic at visible light wavelengths and infrared light wavelengths.

[0059] This lens satisfies: -10 < f1 < 0, -5 < f2 < 0, 0 < f3 < 10, 0 < f4 < 5, -5 < f5 < 0, 0 < f6 < 5, where f1, f2, f3, f4, f5, and f6 are the focal length values 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. The optical power distribution of this lens is reasonable and uniform, the spherical aberration and off-axis aberration are corrected significantly, and the deviation of the defocus curve at high and low temperatures is less than 2um.

[0060] This lens satisfies: 2 < |f1 / f| < 5, 1 < |f2 / f| < 5, 3 < |f3 / f| < 5, 1 < |f4 / f| < 3, 1 < |f5 / f| < 3, 1 < |f6 / f| < 3, where f is the overall focal length value of the lens, and f1, f2, f3, f4, f5, and f6 are the focal length values 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.

[0061] This lens satisfies: 1.7 < nd1 < 1.9, 40 < vd1 < 70, 1.5 < nd2 < 1.7, 50 < vd2 < 70, 1.5 < nd3 < 1.8, 15 < vd3 < 30, 1.7 < nd4 < 1.9, 40 < vd4 < 60, 1.5 < nd5 < 1.8, 15 < vd5 < 30, 1.5 < nd6 < 1.7, 50 < vd6 < 70, where nd1, nd2, nd3, nd4, nd5, and nd6 are the refractive indices 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, and vd1, vd2, vd3, vd4, vd5, and vd6 are the Abbe numbers 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. Among them, the second lens 2 and the sixth lens 6 both use materials with low refractive index and high Abbe number, which can effectively correct astigmatism and off-axis lateral chromatic aberration of large wide-angle, improve the image quality, the lens shape is gentle, and the processability is high.

[0062] The lens satisfies: 100 < vd1 + vd2 + vd3 < 120, where vd1, vd2, and vd3 are the Abbe numbers of the first lens 1, the second lens 2, and the third lens 3 respectively. By satisfying this relationship, the axial chromatic aberration of the lens can be well corrected.

[0063] The lens satisfies: 6.9 ≤ TTL / AAG, where AAG is the sum of the two air gaps on the optical axis between the first lens 1, the second lens 2, and the third lens 3 (the two air gaps are the air gap between the first lens 1 and the second lens 2, and the air gap between the second lens 2 and the third lens 3). By satisfying this relationship, the lens structure is more compact and has a smaller volume.

[0064] The lens satisfies: ALT < 2.72 mm, where ALT is the sum of the central thicknesses of the three lenses, the first lens 1, the second lens 2, and the third lens 3.

[0065] The overall optical length TTL of the lens satisfies: TTL < 12 mm. The lens has a compact structure, high resolution, low lens sensitivity, and a stable system.

[0066] The field angle of the lens satisfies: DFOV = 180°, achieving a large wide-angle of the lens.

[0067] The maximum aperture F / NO of the lens is 2.0, increasing the light input of the lens and improving the imaging brightness.

[0068] The relative illumination of the lens is greater than 50%, with uniform imaging and no vignetting at the edges; the f - tan(theta) distortion of the lens is within 5%, and the distortion correction of the outer field of view is good.

[0069] The applicable spectral range of the lens is 435 nm - 850 nm.

[0070] In this lens, the second lens 2, the third lens 3, the fifth lens 5, and the sixth lens 6 are all plastic aspherical lenses, and both surfaces of the aspherical lens are aspherical. The equation of the surface curve of the aspherical lens is expressed as follows:

[0071]

[0072] Among them,

[0073] 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);

[0074] c: the curvature of the aspherical vertex (the vertex curvature);

[0075] K: Conic Constant;

[0076] , radial distance;

[0077] rn: normalization radius (NRADIUS);

[0078] u: r / rn;

[0079] am: the mth Qcon coefficient (is the mth Qcon coefficient);

[0080] Qmcon: the mth Qcon polynomial.

[0081] The ultra-wide-angle video doorbell infrared confocal lens of the present invention will be described in detail with reference to specific embodiments below.

[0082] Example 1

[0083] Reference Figure 1 As shown, the present invention discloses an ultra-wide-angle visual doorbell infrared confocal lens, comprising a first lens 1, a second lens 2, a third lens 3, an aperture 7, a fourth lens 4, a fifth lens 5, and a sixth lens 6, which are arranged in sequence along an optical axis from the object side to the image side. The first lens 1 to the sixth lens 6 each include 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.

[0084] 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;

[0085] The second lens element 2 has a negative refractive power, and the object side surface of the second lens element 2 is convex, and the image side surface is concave;

[0086] The third lens element 3 has positive refractive power, and the object side surface of the third lens element 3 is convex, and the image side surface is concave;

[0087] The fourth lens element 4 has positive refractive power, and the object-side surface and image-side surface of the fourth lens element 4 are convex.

[0088] The fifth lens element 5 has a negative refractive power, and the object-side surface of the fifth lens element 5 is convex, and the image-side surface is concave;

[0089] The sixth lens element 6 has positive refractive power, and the object-side surface and the image-side surface of the sixth lens element 6 are convex.

[0090] The detailed optical data of this specific embodiment are shown in Table 1-1.

[0091] Table 1-1 Detailed optical data of Example 1

[0092] surface type Caliber size (diameter) Radius of curvature thickness Material Refractive index dispersion coefficient focal length 0 Infinity Infinity Infinity 1 17.541 15.000 2.000 2 First lens 8.558 11.308 1.022 1.8160,46.5561 1.82 46.56 -5.221 3 4.851 2.977 0.694 4 Second lens 4.533 1.991 0.755 1.5445,56.0033 1.55 56.00 -3.622 5 2.766 0.859 1.364 6 The third lens 2.430 3.390 0.818 1.6713,19.2758 1.68 19.28 7.674 7 1.806 8.803 0.314 8 STO 1.515 Infinity 0.099 9 Fourth lens 3.200 10.724 1.630 1.7550,52.3221 1.76 52.32 2.310 10 3.200 -1.955 0.099 11 Fifth lens 2.725 40.1608 0.493 1.6713,19.2758 1.68 19.28 -2.518 12 3.293 1.627 0.134 13 Sixth lens 3.627 2.455 2.034 1.5350,55.7107 1.54 55.71 2.670 14 4.130 -2.448 1.000 15 Protective glass & filters 4.409 Infinity 0.510 H-K9L 1.52 64.20 Infinity 16 4.4885 Infinity 1.038 17 4.7517 Infinity 0

[0093] The aspheric surface data of this embodiment is shown in Table 1-2.

[0094] Table 1-2 Aspheric surface data of Example 1

[0095] Surface number K A4 A6 A8 A10 A12 A14 A16 7 -3.15E-01 -2.59E-02 5.03E-03 -1.19E-02 5.87E-03 -1.43E-03 1.81E-04 -9.77E-06 8 -6.36E-01 -5.93E-02 2.10E-01 -5.44E-01 6.85E-01 -5.15E-01 2.13E-01 -3.77E-02 9 2.89E+00 4.36E-02 3.47E-02 -6.47E-02 1.15E-01 -1.13E-01 6.46E-02 -1.56E-02 10 0 7.42E-02 -1.08E-02 4.18E-01 -1.56E+00 2.91E+00 -2.57E+00 8.82E-01 14 0 -1.66E-01 1.57E-01 -1.82E-01 1.71E-01 -1.05E-01 3.51E-02 -4.82E-03 15 -9.37E-02 -2.41E-01 1.93E-01 -1.72E-01 1.24E-01 -6.03E-02 1.61E-02 -1.81E-03 16 -5.46E-01 -6.33E-02 1.22E-02 1.12E-02 -5.64E-03 -3.88E-05 4.72E-04 -7.65E-05 17 -4.68E-01 1.38E-02 -8.56E-03 7.69E-03 -3.64E-03 8.98E-04 -5.87E-05 -5.40E-06

[0096] In this embodiment, please refer to the MTF curve of the lens under visible light. Figure 2 As can be seen from the figure, when the spatial frequency of this lens reaches 50lp / mm, the MTF is around 0.7, the imaging quality is excellent, and the resolution of the lens is high.

[0097] For the defocus curve of the lens under visible light and infrared light, please refer to Figure 3 、 Figure 4 As can be seen from the figure, the defocus curves of each field of view of the lens under visible light and infrared light are relatively concentrated, and the defocus amount is small, achieving visible light and infrared confocality.

[0098] For the relative illumination curve of the lens under visible light, please refer to Figure 5 ,As can be seen from the figure, the relative illumination of the ,lens is greater than 50%, the lens imaging is uniform, and there is no ,vignetting at the edge of the image.

[0099] For the longitudinal chromatic aberration curve of the lens under visible light, please refer to Figure 6 As can be seen from the figure, the axial chromatic aberration is less than ±0.04mm, the color reproduction is good and the color difference is small.

[0100] For the field curvature and distortion diagram of the lens under visible light, please refer to Figure 7 As can be seen from the figure, the optical distortion of the system is <|-3%|, the distortion is small, the wide-angle distortion is controlled, the image quality is improved, and there is no need for post-processing image algorithms to correct the distortion, which is convenient for application.

[0101] Example 2

[0102] like Figure 8 As shown, the present embodiment is different from the embodiment 1 mainly in optical parameters such as the curvature radius of each lens surface and the lens thickness.

[0103] The detailed optical data of this specific embodiment are shown in Table 2-1.

[0104] Table 2-1 Detailed optical data of Example 2

[0105] surface type Caliber size (diameter) Radius of curvature thickness Material Refractive index dispersion coefficient focal length 0 Infinity Infinity Infinity 4 17.687 15.000 2.000 5 First lens 8.842 11.386 1.000 1.7725,49.5990 1.78 49.60 -5.332 6 4.906 2.917 0.825 7 Second lens 4.473 1.991 0.729 1.5445,56.0033 1.55 56.00 -3.575 8 2.745 0.858 1.368 9 The third lens 2.387 3.450 0.774 1.6713,19.2758 1.68 19.28 7.931 10 1.787 8.776 0.302 11 STO 1.504 Infinity 0.100 12 Fourth lens 3.200 10.751 1.646 1.7550,52.3221 1.76 52.32 2.314 13 3.200 -1.956 0.100 14 Fifth lens 2.732 32.9603 0.492 1.6713,19.2758 1.68 19.28 -2.545 15 3.300 1.627 0.135 16 Sixth lens 3.654 2.464 1.992 1.5350,55.7107 1.54 55.71 2.665 17 4.189 -2.448 1.000 18 Protective glass & filters 4.431 Infinity 0.510 H-K9L 1.52 64.20 Infinity 19 4.5191 Infinity 1.028 20 4.7504 Infinity 0

[0106] The aspheric surface data in this embodiment is shown in Table 2-2.

[0107] Table 2-2 Aspheric surface data of Example 2

[0108] Surface number K A4 A6 A8 A10 A12 A14 A16 7 -3.15E-01 -2.57E-02 0.005036482 -0.011944031 0.005868863 -0.001432011 0.000181092 -9.76516E-06 8 -6.37E-01 -5.95E-02 0.208866408 -0.543750827 0.685119506 -0.514589572 0.212467658 -0.037676469 9 3.06E+00 4.48E-02 0.034757088 -0.064790988 0.115211096 -0.112785566 0.064634027 -0.015630217 10 0 7.38E-02 -0.009456215 0.420599947 -1.558597132 2.913007469 -2.566081189 0.884982448 14 0 -1.66E-01 0.157098021 -0.181687165 0.170731435 -0.10476893 0.035084463 -0.00482275 15 -9.36E-02 -2.42E-01 0.192594568 -0.172361191 0.124238734 -0.060326988 0.016114679 -0.001809073 16 -5.68E-01 -6.36E-02 0.012117112 0.011154306 -0.00563525 -3.86695E-05 0.000472522 -7.63252E-05 17 -4.96E-01 1.41E-02 -0.008623347 0.007675827 -0.003648003 0.000898235 -5.86992E-05 -5.36154E-06

[0109] In this embodiment, please refer to the MTF curve of the lens under visible light. Figure 9 As can be seen from the figure, when the spatial frequency of this lens reaches 50lp / mm, the MTF is around 0.7, the imaging quality is excellent, and the resolution of the lens is high.

[0110] For the defocus curve of the lens under visible light and infrared light, please refer to Figure 10 、 Figure 11 As can be seen from the figure, the defocus curves of each field of view of the lens under visible light and infrared light are relatively concentrated, and the defocus amount is small, achieving visible light and infrared confocality.

[0111] For the relative illumination curve of the lens under visible light, please refer to Figure 12 ,As can be seen from the figure, the relative illumination of the ,lens is greater than 50%, the lens imaging is uniform, and there is no ,vignetting at the edge of the image.

[0112] For the longitudinal chromatic aberration curve of the lens under visible light, please refer to Figure 13 As can be seen from the figure, the axial chromatic aberration is less than ±0.04mm, the color reproduction is good and the color difference is small.

[0113] For the field curvature and distortion diagram of the lens under visible light, please refer to Figure 14 As can be seen from the figure, the optical distortion of the system is <|4%|, the distortion is small, the wide-angle distortion is controlled, the image quality is improved, and there is no need for post-processing image algorithms to correct the distortion, which is convenient for application.

[0114] Example 3

[0115] like Figure 15 As shown, the present embodiment is different from the embodiment 1 mainly in optical parameters such as the curvature radius of each lens surface and the lens thickness.

[0116] The detailed optical data of this specific embodiment are shown in Table 3-1.

[0117] Table 3-1 Detailed optical data of Example 3

[0118] surface type Caliber size (diameter) Radius of curvature thickness Material Refractive index Dispersion coefficient focal length 0 Infinity Infinity Infinity 4 17.769 15.000 2.000 5 First lens 8.856 11.075 1.078 1.7880,47.4917 1.79 47.49 -5.352 6 4.866 2.931 0.773 7 Second lens 4.519 1.989 0.829 1.5350,55.7107 1.54 55.71 -3.759 8 2.722 0.856 1.265 9 The third lens 2.405 3.494 0.797 1.6613,20.3815 1.67 20.38 7.960 10 1.791 9.300 0.318 11 STO 1.476 Infinity 0.100 12 Fourth lens 3.200 11.130 1.590 1.7550,52.3221 1.76 52.32 2.398 13 3.200 -2.038 0.100 14 Fifth lens 2.756 14.426 0.497 1.6713,19.2758 1.68 19.28 -2.770 15 3.277 1.637 0.154 16 Sixth lens 3.646 2.698 1.945 1.5445,56.0033 1.55 56.00 2.667 17 4.135 -2.356 1.000 18 Protective glass & filters 4.4198 Infinity 0.510 H-K9L 1.5183 64.1987 Infinity 19 4.4975 Infinity 1.0443 20 4.721 Infinity 0

[0119] The aspheric surface data in this embodiment is shown in Table 3-2.

[0120] Table 3-2 Aspheric surface data of Example 3

[0121] Surface number K A4 A6 A8 A10 A12 A14 A16 7 -3.18E-01 -2.62E-02 4.93E-03 -1.20E-02 5.86E-03 -1.43E-03 1.81E-04 -9.74661E-06 8 -6.32E-01 -5.61E-02 1.95E-01 -5.35E-01 6.83E-01 -5.13E-01 2.11E-01 -0.037793698 9 3.56E+00 4.63E-02 3.43E-02 -6.39E-02 1.15E-01 -1.13E-01 6.44E-02 -0.015410673 10 0 7.15E-02 -9.63E-03 4.24E-01 -1.55E+00 2.87E+00 -2.52E+00 0.870209019 14 0 -1.60E-01 1.56E-01 -1.81E-01 1.71E-01 -1.05E-01 3.51E-02 -0.004813589 15 -8.10E-02 -2.39E-01 1.93E-01 -1.73E-01 1.24E-01 -6.03E-02 1.61E-02 -0.001811636 16 -4.74E-01 -5.94E-02 1.20E-02 1.13E-02 -5.65E-03 -5.67E-05 4.69E-04 -7.37778E-05 17 -4.88E-01 1.45E-02 -8.68E-03 7.78E-03 -3.64E-03 8.91E-04 -5.89E-05 -5.2062E-06

[0122] In this embodiment, please refer to the MTF curve of the lens under visible light. Figure 16 As can be seen from the figure, when the spatial frequency of this lens reaches 50lp / mm, the MTF is around 0.7, the imaging quality is excellent, and the resolution of the lens is high.

[0123] For the defocus curve of the lens under visible light and infrared light, please refer to Figure 17 、 Figure 18 As can be seen from the figure, the defocus curves of each field of view of the lens under visible light and infrared light are relatively concentrated, and the defocus amount is small, achieving visible light and infrared confocality.

[0124] For the relative illumination curve of the lens under visible light, please refer to Figure 19 ,As can be seen from the figure, the relative illumination of the ,lens is greater than 50%, the lens imaging is uniform, and there is no ,vignetting at the edge of the image.

[0125] For the longitudinal chromatic aberration curve of the lens under visible light, please refer to Figure 20 As can be seen from the figure, the axial chromatic aberration is less than ±0.03mm, the color reproduction is good and the color difference is small.

[0126] For the field curvature and distortion diagram of the lens under visible light, please refer to Figure 21 As can be seen from the figure, the optical distortion of the system is <|3%|, the distortion is small, the wide-angle distortion is controlled, the image quality is improved, and there is no need for post-processing image algorithms to correct the distortion, which is convenient for application.

[0127] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An ultra-wide-angle video doorbell infrared confocal lens, characterized by: It includes a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, and a sixth lens that are 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 negative 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 concave; The fourth lens has a positive refractive power, and the object side of the fourth lens is convex and the image side is convex; The fifth lens has a negative refractive power, and the object side of the fifth lens 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 is convex; This lens satisfies: TTL / F < 7, where TTL is the overall optical length of the lens and F is the clear aperture of the lens.

2. The ultra-wide-angle video doorbell infrared confocal lens according to claim 1, characterized in that: The first lens and the fourth lens are both glass spherical lenses, and the second lens, the third lens, the fifth lens, and the sixth lens are all plastic aspherical lenses.

3. The ultra-wide-angle video doorbell infrared confocal lens according to claim 1, characterized in that: This lens satisfies: -10mm < f1 < 0mm, -5mm < f2 < 0mm, 0mm < f3 < 10mm, 0mm < f4 < 5mm, -5mm < f5 < 0mm, 0mm < f6 < 5mm, where f1, f2, f3, f4, f5, and f6 are the focal length values of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens respectively.

4. The ultra-wide-angle video doorbell infrared confocal lens according to claim 1 or 3, characterized in that: This lens satisfies: 2 < |f1 / f| < 5, 1 < |f2 / f| < 5, 3 < |f3 / f| < 5, 1 < |f4 / f| < 3, 1 < |f5 / f| < 3, 1 < |f6 / f| < 3, where f is the overall focal length value of the lens, and f1, f2, f3, f4, f5, and f6 are the focal length values of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens respectively.

5. The ultra-wide-angle video doorbell infrared confocal lens according to claim 1, characterized in that: This lens satisfies:

6. The ultra-wide-angle video doorbell infrared confocal lens according to claim 1, characterized in that: ​ 7. The ultra-wide-angle video doorbell infrared confocal lens according to claim 1, characterized in that: The lens satisfies: 6.9≤TTL / AAG, where AAG is the sum of two air gaps between the first lens, the second lens, and the third lens on the optical axis.

8. The ultra-wide-angle video doorbell infrared confocal lens according to claim 1, characterized in that: The lens satisfies: ALT<2.72mm, where ALT is the sum of the center thicknesses of the first lens, the second lens, and the third lens.

9. The ultra-wide-angle video doorbell infrared confocal lens according to claim 1, characterized in that: This lens meets the following requirements: TTL<12mm.

10. The ultra-wide-angle video doorbell infrared confocal lens according to claim 1, characterized in that: The field of view of the lens satisfies: DFOV = 180°.

Images