A wide-angle high-resolution lens

Abstract

The application discloses a wide-angle high-resolution lens, which comprises, from an object side to an image side, a first lens with negative focal power, a second lens with positive focal power, a diaphragm, a third lens with positive focal power, a fourth lens with negative focal power, and a fifth lens with positive focal power; the first lens is a non-spherical lens and has a C type or M type, with a concave surface facing the image side; the second lens is a non-spherical lens and has a meniscus type, with a concave surface facing the object side; the third lens is a biconvex spherical lens; the fourth lens is a biconcave spherical lens; and the fifth lens is a non-spherical lens and has a biconvex type; the technical scheme balances and corrects optical aberrations at all levels by reasonably distributing the focal power of the lenses, matching the optical materials, shapes and focal lengths, so that the wide-angle high-resolution lens has the advantages of wide angle, high resolution, low distortion, high resolving power and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical lens, in particular to a wide-angle high-resolution lens. BACKGROUND

[0002] In the existing monitoring security field, active infrared light supplement occupies a large share in the monitoring security field. However, with the development of ultra-low-illumination cameras and the use in special fields, the optical lens in the existing market cannot meet the needs of ultra-low-illumination applications. Most of the products in the market are 2MP, 3MP and 5MP resolution, and have problems such as low resolution and poor resolving power. SUMMARY

[0003] The present application aims to at least solve one of the problems in the prior art. To this end, the present application provides a wide-angle high-resolution lens, which effectively solves the problems of low resolution and poor resolving power.

[0004] According to the wide-angle high-resolution lens of the embodiment of the present application, the first lens, the second lens, the stop, the third lens, the fourth lens and the fifth lens are sequentially arranged from the object side to the image side.

[0005] The first lens is a non-spherical lens and is in C type or M type, and the concave surface faces the image side. The second lens is a non-spherical lens and is in meniscus type, and the concave surface faces the object side. The third lens is a double-convex spherical lens. The fourth lens is a double-concave spherical lens. The fifth lens is a non-spherical lens and is in double-convex type.

[0006] The focal lengths of the above lenses satisfy the following relationship:

[0007] -6.0≤f1 / f≤-1.5;

[0008] 25≤f2 / f≤40;

[0009] 0.5≤f3 / f≤1.5;

[0010] -1.5≤f4 / f≤-0.5;

[0011] 0.6≤f5 / f≤1.5;

[0012] Wherein, f is the effective focal length of the wide-angle high-resolution lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, and f5 is the focal length of the fifth lens.

[0013] According to the wide-angle high-resolution lens of the embodiment of the present application, at least the following beneficial effects are achieved:

[0014] The technical scheme balances and corrects optical aberrations of all levels by reasonably distributing lens optical power, matching optical materials, shapes and focal lengths, and realizes advantages such as wide angle, high resolution, low distortion, high resolving power and the like of the lens.

[0015] According to some embodiments of the present application, the refractive index of the lens of the wide-angle high-resolution lens satisfies the following relationship:

[0016] 1.50≤Nd1≤1.65;

[0017] 1.50≤Nd2≤1.65;

[0018] 1.60≤Nd3≤1.80;

[0019] 1.75≤Nd4≤1.90;

[0020] 1.50≤Nd5≤1.65;

[0021] wherein Nd1 is the refractive index of the first lens under the helium yellow line d spectrum, Nd2 is the refractive index of the second lens under the helium yellow line d spectrum, Nd3 is the refractive index of the third lens under the helium yellow line d spectrum, Nd4 is the refractive index of the fourth lens under the helium yellow line d spectrum, and Nd5 is the refractive index of the fifth lens under the helium yellow line d spectrum.

[0022] According to some embodiments of the present application, the dispersion coefficient of the lens of the wide-angle high-resolution lens satisfies the following relationship:

[0023] 50.0≤Vd1≤70.0;

[0024] 50.0≤Vd2≤70.0;

[0025] 45.0≤Vd3≤65.0;

[0026] 18.0≤Vd4≤25.0;

[0027] 50.0≤Vd5≤70.0;

[0028] wherein Vd1 is the dispersion coefficient of the first lens, Vd2 is the dispersion coefficient of the second lens, Vd3 is the dispersion coefficient of the third lens, Vd4 is the dispersion coefficient of the fourth lens, and Vd5 is the dispersion coefficient of the fifth lens.

[0029] According to some embodiments of the present application, the curve driving equation of the aspheric lens is as follows:

[0030]

[0031] In the formula, c is the aspheric curvature, r is the radial coordinate, k is the conic coefficient of the quadratic surface, and Ar4-20 is the aspheric coefficient of each order.

[0032] According to some embodiments of the present application, the aspherical lens is organic optical glass or inorganic optical glass.

[0033] According to some embodiments of the present application, further comprising an image sensor disposed on the image side.

[0034] According to some embodiments of the present application, a filter set is disposed between the fifth lens and the image sensor.

[0035] According to some embodiments of the present application, a protective glass is disposed between the filter set and the image sensor.

[0036] According to some embodiments of the present application, the effective focal length of the wide-angle high-resolution lens is f=4.46mm, the aperture value Fno=2.0, and the field of view angle ω=75.0°.

[0037] According to some embodiments of the present application, the effective focal length of the wide-angle high-resolution lens is f=4.7mm, the aperture value Fno=2.0, and the field of view angle ω=71.5°.

[0038] Additional aspects and advantages of the present application will be given in part in the following description, become apparent from the following description, or be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0039] The present application will be further described below in conjunction with the accompanying drawings and embodiments, wherein:

[0040] Figure 1 It is a structural schematic diagram of the wide-angle high-resolution lens of the embodiment 1 of the present application;

[0041] Figure 2 It is a chromatic aberration, astigmatic field curve, distortion diagram of the embodiment 1 of the present application;

[0042] Figure 3 It is a ray aberration diagram of the embodiment 1 of the present application;

[0043] Figure 4 It is an MTF diagram of the wide-angle high-resolution lens of the embodiment 1 of the present application;

[0044] Figure 5 It is a structural schematic diagram of the wide-angle high-resolution lens of the embodiment 2 of the present application;

[0045] Figure 6 It is a chromatic aberration, astigmatic field curve, distortion diagram of the embodiment 2 of the present application;

[0046] Figure 7 It is a ray aberration diagram of the embodiment 2 of the present application;

[0047] Figure 8 MTF chart of the wide-angle high-resolution lens of Embodiment 2 of the present application.

[0048] Reference Signs:

[0049] First lens L1, second lens L2, stop STO, third lens L3, fourth lens L4, fifth lens L5, image sensor IMG, filter set IR, cover glass CG. DETAILED DESCRIPTION

[0050] Embodiments of the present application are described in detail below with reference to the accompanying drawings, in which the same or similar components have the same or similar reference numbers throughout the several views. The embodiments described below are exemplary, and are merely intended to explain the present application, and are not to be understood as limiting the present application.

[0051] In the description of the present application, it should be understood that, in relation to the orientation description, for example, the orientation or position relationship indicated by up, down, etc. is based on the orientation or position relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0052] In the description of the present application, plural means two or more. If there is a description of first, second, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the sequence of technical features indicated.

[0053] In the description of the present application, unless otherwise explicitly limited, the words such as arrangement, installation, connection, etc. should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0054] Referring to Figure 1 As shown in the figure, the wide-angle high-resolution lens of Embodiment 1 of the present application comprises, arranged in order from the object side to the image side: a first lens L1 with negative refractive power, a second lens L2 with positive refractive power, a stop STO, a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, and a fifth lens L5 with positive refractive power; the object plane is moved in the optical axis direction through the entire lens at different distances (i.e. the optical back focus of the lens is changed), thereby achieving the focusing effect.

[0055] The first lens L1 is a non-spherical lens and is in a C type or M type, with a concave surface facing the image side, for increasing the field angle and balancing the correction of off-axis aberrations; the second lens L2 is a non-spherical lens and is in a meniscus type, with a concave surface facing the object side, for balancing the correction of field curvature and astigmatism; the third lens L3 is a biconvex spherical lens, for balancing the correction of coma and astigmatism; the fourth lens L4 is a biconcave spherical lens, for correcting distortion; and the fifth lens L5 is a non-spherical lens and is in a biconvex type, for balancing off-axis aberrations.

[0056] The focal lengths of the lenses satisfy the following relationship:

[0057] -6.0≤f1 / f≤-1.5;

[0058] 25≤f2 / f≤40;

[0059] 0.5≤f3 / f≤1.5;

[0060] -1.5≤f4 / f≤-0.5;

[0061] 0.6≤f5 / f≤1.5;

[0062] wherein f is the effective focal length of the wide-angle high-resolution lens, f1 is the focal length of the first lens L1, f2 is the focal length of the second lens L2, f3 is the focal length of the third lens L3, f4 is the focal length of the fourth lens L4, and f5 is the focal length of the fifth lens L5.

[0063] As described above, it can be seen that the technical solution balances and corrects optical aberrations of various levels by reasonably distributing the refractive power of the lenses, matching the optical materials, shapes and focal lengths, and realizes the advantages of wide angle, high resolution, low distortion, high resolving power and the like of the lens. Moreover, the optical path architecture of the technical solution has the advantages of simple structure, low cost and good imaging performance, and has great market application value.

[0064] In some embodiments of the present application, the refractive indices of the lenses of the wide-angle high-resolution lens of the present embodiment satisfy the following relationship:

[0065] 1.50≤Nd1≤1.65;

[0066] 1.50≤Nd2≤1.65;

[0067] 1.60≤Nd3≤1.80;

[0068] 1.75≤Nd4≤1.90;

[0069] 1.50≤Nd5≤1.65;

[0070] Wherein, Nd1 is the refractive index of the first lens L1 under the helium yellow line d spectrum, Nd2 is the refractive index of the second lens L2 under the helium yellow line d spectrum, Nd3 is the refractive index of the third lens L3 under the helium yellow line d spectrum, Nd4 is the refractive index of the fourth lens L4 under the helium yellow line d spectrum, and Nd5 is the refractive index of the fifth lens L5 under the helium yellow line d spectrum. In the embodiment, the lens combination structure satisfying the above refractive index relationship is beneficial to realize reasonable distribution of optical power, and can better balance spherical aberration, coma, field curvature and chromatic aberration, thereby generating a high-quality imaging picture with high resolution and color fidelity.

[0071] In some embodiments of the present application, the lens dispersion coefficient of the wide-angle high-resolution lens satisfies the following relationship:

[0072] 50.0≤Vd1≤70.0;

[0073] 50.0≤Vd2≤70.0;

[0074] 45.0≤Vd3≤65.0;

[0075] 18.0≤Vd4≤25.0;

[0076] 50.0≤Vd5≤70.0;

[0077] Wherein, Vd1 is the dispersion coefficient of the first lens L1, Vd2 is the dispersion coefficient of the second lens L2, Vd3 is the dispersion coefficient of the third lens L3, Vd4 is the dispersion coefficient of the fourth lens L4, and Vd5 is the dispersion coefficient of the fifth lens L5. Since the off-axis light beam has a large incidence height on the first lens, it is easy to produce a large off-axis chromatic aberration, and therefore the first lens L1 is selected from a material with a low dispersion coefficient to reduce the off-axis chromatic aberration; the dispersion becomes serious after the light propagates through a long distance before and after the stop STO, and therefore the fourth lens L4 and the fifth lens L5 are matched with high and low dispersion coefficients to reduce the influence of chromatic aberration through a large difference in the dispersion coefficient.

[0078] In the embodiment, the optical back focus of the lens is continuously reduced in the process of gradually increasing the projection distance during the focusing process.

[0079] In some embodiments of the present application, the curve driving equation of the aspheric lens is as follows:

[0080] In the formula, c is the aspheric curvature, r is the radial coordinate, k is the conic coefficient of the quadratic surface, and Ar4-20 is the aspheric surface of each order.

[0081]

[0082] coefficient.

[0083] In some embodiments of the present application, the aspheric lens is organic optical glass or inorganic optical glass.

[0084] In some embodiments of the present application, an image sensor IMG is arranged on the image side for capturing an imaging signal. If a 1 / 2.5 inch sensor is selected, the display resolution is 3840x2160, and the total number of pixels is 8 million. It should be noted that the sensor is not limited to a specific type (image sensor, such as COMS, CCD, etc.).

[0085] In some embodiments of the present application, an optical filter set IR is arranged between the fifth lens L5 and the image sensor IMG. The optical filter set IR is a parallel flat plate with a certain thickness, and the optical surface is coated with different bandwidth films according to day and night. The optical filter set IR can use an infrared cutoff or absorption filter, or a full-spectrum filter, which can filter out interfering light to achieve the best imaging effect of the image sensor IMG.

[0086] Further, in some embodiments of the present application, a protective glass CG is arranged between the optical filter set IR and the image sensor IMG, which can protect the image sensor IMG from direct damage by external forces.

[0087] In embodiment 1 of the present application, the effective focal length of the wide-angle high-resolution lens is f=4.46mm, the aperture value Fno=2.0, and the field of view angle ω=75.0°. The following table shows the specific parameters of embodiment 1:

[0088]

[0089]

[0090] Table 1

[0091] Table 2 shows the aspheric data of embodiment 1:

[0092] Surface ASP S1 ASP S2 ASP S3 ASP S4 ASP S10 ASP S11 Radius 1.65 1.224 -3.74 -4.15 7.1 -4.24 K -2.4804806 -0.81 0 0 0 0 A 4.6385e-2 1.0909e-2 2.47994e-3 4.308716e-3 6.58942e-3 1.19393088e-2 B -5.62235922e-3 1.448117e-3 4.4139e-4 4.741495e-4 7.8295621e-5 2.98565285e-4 C 4.33692e-5 -1.537234e-3 1.8537657e-5 -2.921391e-5 -1.6741685e-5 2.6795544e-4 D -2.98183173e-5 2.3664351e-4 -3.0047063e-6 6.7813605e-6 1.02257e-5 -2.52452827e05 E 8.62799e-7 -2.07618316e-5 - - - -

[0093] The corresponding conditions of embodiment 1 are as follows:

[0094] (1) f1 / f=-3.904, (2) f2 / f=32.543, (3) f3 / f=0.972, (4) -f4 / f=-0.931, (5) f5 / f=1.177;

[0095] (6) Nd1=1.54, (7) Nd2=1.54, (8) Nd3=1.77, (9) Nd4=1.81, (10) Nd5=1.54;

[0096] (11) Vd1=55.7, (12) Vd2=55.7, (13) Vd3=49.6, (14) Vd4=22.8, (15) Vd5=55.7.

[0097] In Embodiment 2 of the present invention, the effective focal length of the wide-angle high-resolution lens is f = 4.7mm, the aperture value Fno = 2.0, and the field of view ω = 71.5°. The specific parameters of this embodiment are given in the table below:

[0098]

[0099]

[0100] Table 3

[0101] Table 4 provides the aspherical data for this embodiment:

[0102]

[0103] Table 4

[0104] The corresponding conditional expressions for Example 1 are as follows:

[0105] (1)f1 / f=-3.703, (2)f2 / f=30.867, (3)f3 / f=0.965, (4)-f4 / f=-0.945, (5)f5 / f=1.213;

[0106] (6)Nd1=1.54, (7)Nd2=1.54, (8)Nd3=1.77, (9)Nd4=1.81, (10)Nd5=1.54;

[0107] (11) Vd1=55.7, (12) Vd2=55.7, (13) Vd3=49.6, (14) Vd4=22.8, (15) Vd5=55.7.

[0108] Figures 1 to 8 This is an optical evaluation diagram of an embodiment of the present invention. Figure 2 , Figure 6 The image shown is a spherical aberration field curve according to an embodiment of the present invention. It can be seen that the chromatic aberration along the red and green light axes is small, the focal point difference of each band is small, the optical distortion is less than 1.5%, and the degree of image distortion is small. Figure 3 , Figure 7 The light aberration diagram of this embodiment of the invention shows that the aberrations are well balanced and corrected. Slight vignetting at the edge of the field of view blocks the edge light, thereby improving the image quality of the edge field of view. The chromatic aberration is small, and the chromatic aberration effect in the actual shooting image is good. Figure 4 , Figure 8For the MTF diagram of the embodiment of the present application, the central field MTF at 220 lp / mm under F2.0 large aperture can be greater than 0.3, and the average MTF of the edge field at 220 lp / mm can be greater than 0.2.

[0109] The above describes the embodiment of the present application in detail in combination with the drawings, but the present application is not limited to the above-described embodiment, and various changes can be made within the knowledge range possessed by those skilled in the art without departing from the purpose of the present application.

Claims

1. A wide-angle high-resolution lens characterized by, The wide-angle high-resolution lens comprises, from the object side to the image side, in sequence: a first lens (L1) with negative focal power, a second lens (L2) with positive focal power, a stop (STO), a third lens (L3) with positive focal power, a fourth lens (L4) with negative focal power, and a fifth lens (L5) with positive focal power. The first lens (L1) is a non-spherical lens and is in the shape of C or M, with the concave surface facing the image side; the second lens (L2) is a non-spherical lens and is in the shape of a crescent, with the concave surface facing the object side; the third lens (L3) is a double-convex spherical lens; the fourth lens (L4) is a double-concave spherical lens; and the fifth lens (L5) is a non-spherical lens and is in the shape of double convex. The focal lengths of the lenses satisfy the following relationships: -6.0≤f1 / f≤-1.5; 25≤f2 / f≤40; 0.5≤f3 / f≤1.5; -1.5≤f4 / f≤-0.5; 0.6≤f5 / f≤1.5; wherein f is the effective focal length of the wide-angle high-resolution lens, f1 is the focal length of the first lens (L1), f2 is the focal length of the second lens (L2), f3 is the focal length of the third lens (L3), f4 is the focal length of the fourth lens (L4), and f5 is the focal length of the fifth lens (L5). The refractive indices of the lenses of the wide-angle high-resolution lens satisfy the following relationships: 1.50≤Nd1≤1.65; 1.50≤Nd2≤1.65; 1.60≤Nd3≤1.80; 1.75≤Nd4≤1.90; 1.50≤Nd5≤1.65; wherein Nd1 is the refractive index of the first lens (L1) at the helium yellow d spectral line, Nd2 is the refractive index of the second lens (L2) at the helium yellow d spectral line, Nd3 is the refractive index of the third lens (L3) at the helium yellow d spectral line, Nd4 is the refractive index of the fourth lens (L4) at the helium yellow d spectral line, and Nd5 is the refractive index of the fifth lens (L5) at the helium yellow d spectral line. The dispersion coefficients of the lenses of the wide-angle high-resolution lens satisfy the following relationships: 50.0≤Vd1≤70.0; 50.0≤Vd2≤70.0; 45.0≤Vd3≤65.0; 18.0≤Vd4≤25.0; 50.0≤Vd5≤70.0; wherein Vd1 is the dispersion coefficient of the first lens (L1), Vd2 is the dispersion coefficient of the second lens (L2), Vd3 is the dispersion coefficient of the third lens (L3), Vd4 is the dispersion coefficient of the fourth lens (L4), and Vd5 is the dispersion coefficient of the fifth lens (L5).

2. The wide-angle high-resolution lens according to claim 1, characterized in that: The non-spherical lenses are organic optical glass or inorganic optical glass.

3. The wide-angle high-resolution lens of claim 1, wherein: An image sensor (IMG) is further arranged on the image side.

4. The wide-angle high-resolution lens of claim 3, wherein: A filter group (IR) is arranged between the fifth lens (L5) and the image sensor (IMG).

5. The wide-angle high-resolution lens of claim 4, wherein: A protective glass (CG) is arranged between the filter group (IR) and the image sensor (IMG).

6. The wide-angle high-resolution lens of claim 1, wherein: The effective focal length of the wide-angle high-resolution lens is f = 4.46 mm, the aperture value is Fno = 2.0, and the field of view is ω = 75.0°.

7. The wide-angle high-resolution lens of claim 1, wherein: The effective focal length of the wide-angle high-resolution lens: f = 4.7 mm, aperture value Fno = 2.0, field angle ω = 71.5°. The effective focal length of the wide-angle high-resolution lens: f = 4.7 mm, aperture value Fno = 2.0, field angle ω = 71.5°.

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