Day and night confocal optical system and application of camera module thereof

Abstract

The application provides a day and night confocal optical system and an application camera module thereof. The optical system is sequentially composed of a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens along an optical axis from an object plane to an image plane. Through reasonable distribution of the surface shape and optical power of each lens, the lens aberration is optimized, so that the optical system has excellent resolving power, high pixels, a large aperture, no thermalization, day and night confocal, light weight and other characteristics, and has greater competitiveness in the IPC market.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical imaging, in particular to a day and night confocal optical system and an application thereof. BACKGROUND

[0002] With the progress of science and technology and the development of social economy, camera lenses are widely used in various fields, especially in the field of security monitoring. However, the previous camera lenses or optical systems have defects such as low pixel, small field of view, poor day and night effect, and small light quantity, which are difficult to meet the needs of users. SUMMARY

[0003] In order to overcome the technical problems of low pixel, small field of view, poor day and night effect, and small light quantity of the existing vehicle-mounted optical lens, the present application provides a day and night confocal optical system, which optimizes the lens aberration by reasonably distributing the surface shape and optical power of each lens, and has excellent resolving power, high pixel, large aperture, no thermalization, day and night confocal, light weight and other characteristics, and has greater competitiveness in the IPC market.

[0004] A day and night confocal optical system, which is composed of a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens in sequence from an object plane to an image plane along an optical axis.

[0005] The object plane side of the first lens is convex, and the image plane side is concave, and the optical power thereof is negative.

[0006] The object plane side of the second lens is concave, and the image plane side is convex, and the optical power thereof is positive.

[0007] The image plane side of the third lens is convex, and the optical power thereof is positive.

[0008] The object plane side and the image plane side of the fourth lens are both convex, and the optical power thereof is positive.

[0009] The object plane side and the image plane side of the fifth lens are both concave, and the optical power thereof is negative.

[0010] The object plane side and the image plane side of the sixth lens are both convex, and the optical power thereof is positive.

[0011] Preferably, each lens of the optical system satisfies the following conditions:

[0012] -1.70 < f1 / f < -1;

[0013] 9.5 < f2 / f < 12.30;

[0014] 2.0 < f3 / f < 8.9;

[0015] 1.80 < f4 / f < 3.00;

[0016] -2.1<f5 / f<-1.15;

[0017] 1.7<f6 / f<2.5;

[0018] Wherein, f is the focal length of the entire optical system, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, and f6 is the focal length of the sixth lens.

[0019] Preferably, the curvature radius R1 on the object side and the curvature radius R2 on the image side of the first lens satisfy: 5.1<(R1+R2) / R2<7.1.

[0020] Preferably, the optical system satisfies the following conditions: 0.3<f / TTL*ImagH<0.55;

[0021] Wherein, f is the effective focal length of the optical system, TTL is the on-axis distance from the object side of the first lens to the imaging surface, and ImgH is half the diagonal length of the effective pixel area on the imaging surface.

[0022] Preferably, the refractive index Nd1 and the Abbe number Vd1 of the material of the first lens satisfy: 1.70<Nd1<2.00, 45.00<Vd1<52.00;

[0023] The material refractive index Nd2 and the material Abbe number Vd2 of the second lens satisfy the following conditions: 1.55<Nd2<1.66, 21.30<Vd2<24.00;

[0024] The refractive index Nd3 and Abbe number Vd3 of the material of the third lens satisfy the following conditions: 1.51<Nd3<1.65, 53.00<Vd3<70.00;

[0025] The material refractive index Nd4 and the material Abbe number Vd4 of the fourth lens satisfy the following conditions: 1.45<Nd4<1.60, 55.00<Vd4<83.00;

[0026] The refractive index Nd5 and Abbe number Vd5 of the material of the fifth lens satisfy the following conditions: 1.55<Nd5<1.73, 20.00<Vd5<30.00;

[0027] The material refractive index Nd6 and the material Abbe number Vd6 of the sixth lens satisfy: 1.47<Nd6<1.65, 50.00<Vd6<60.00.

[0028] Preferably, the first lens is a spherical lens, the second lens, the fifth lens, and the sixth lens are aspherical lenses, and the third lens and the fourth lens are spherical or aspherical lenses.

[0029] Preferably, the optics of the optical system satisfy: 0.6<(CT5+CT6) / f<1.3;

[0030] Wherein, CT5 is the center thickness of the fifth lens on the optical axis, CT6 is the center thickness of the sixth lens on the optical axis, and f is the effective focal length of the optical imaging system.

[0031] Preferably, the full field of view FOV of the optical system satisfies: 150°≤FOV≤160°.

[0032] Preferably, the refractive index Nd6 and the Abbe number Vd6 of the sixth lens, and the refractive index Nd5 and the Abbe number Vd5 of the fifth lens satisfy: 0.85<Nd5 / Nd6<1.15, 0.35<Vd5 / Vd6<0.55.

[0033] Preferably, the fourth lens and the fifth lens constitute a cemented lens.

[0034] On the other hand, an embodiment of the present application further provides a camera module, which includes at least an optical lens, in which the above-mentioned day and night confocal optical system is installed.

[0035] Compared with the prior art, the present invention has the following advantages:

[0036] The present invention provides a day-night confocal optical system and a camera module using the same. The optical system comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, arranged in sequence along the optical axis from the object plane to the image plane. By rationally allocating the surface shape and optical power of each lens and optimizing lens aberrations, the system has the characteristics of excellent resolution, high pixel count, large aperture, athermalization, day-night confocality, and light weight, making it more competitive in the IPC market. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments.

[0038] Figure 1 Schematic diagram of the structure of the optical system or camera lens in Example 1 of the present application;

[0039] Figure 2 is a graph of field curvature and distortion of the optical system or camera lens in Example 1 of the present application;

[0040] Figure 3 is an MTF curve diagram of the optical system or camera lens of Example 1 of the present application;

[0041] Figure 4 2 is a schematic structural diagram of an optical system or camera lens according to embodiment 2 of the present application;

[0042] Figure 5 It is a structural diagram of the optical system or camera lens of Example 3 of the present application. DETAILED DESCRIPTION

[0043] The present application provides a day and night confocal wide-angle optical system, which is composed of a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, and a sixth lens E6 in order from the object plane to the image plane along the optical axis;

[0044] The object side of the first lens E1 is convex, the image side is concave, and its optical power is negative;

[0045] The object side of the second lens E2 is concave, the image side is convex, and its optical power is positive;

[0046] The image side of the third lens E3 is convex and has positive refractive power;

[0047] The fourth lens element E4 has convex surfaces on both the object side and the image side, and has positive refractive power;

[0048] The object side and image side of the fifth lens E5 are both concave, and its optical power is negative;

[0049] The object side and image side of the sixth lens E6 are both convex, and its optical power is positive;

[0050] The optical system of the embodiment of the present application is composed of a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens in sequence along the optical axis from the object plane to the image plane. By rationally allocating the surface shape and optical power of each lens, lens aberrations are optimized, resulting in excellent resolution, high pixel count, large aperture, athermalization, day and night confocality, and light weight, making the system more competitive in the IPC market.

[0051] Furthermore, as a preferred embodiment of the present invention but not limiting, each lens of the optical system satisfies the following conditions:

[0052] -1.70<f1 / f<-1.0, by constraining the effective focal length ratio of the first lens E1 to the optical system within a reasonable range, the distortion of the system is controlled, and the imaging center has a higher angular resolution;

[0053] 9.50<f2 / f<12.30; by constraining the effective focal length ratio of the second lens E2 to the optical system within a reasonable range, lens aberrations are optimized and imaging quality is improved;

[0054] 2.0<f3 / f<8.90; By constraining the effective focal length ratio of the third lens E3 to the optical system within a reasonable range, the spherical aberration of the system is fine-tuned and controlled, thereby effectively improving the imaging quality of the system;

[0055] 1.80<f4 / f<3.00; by reasonably controlling the ratio range of the fourth lens E4 and the effective focal length of the optical system, the imaging quality of the system is effectively improved;

[0056] -2.1<f5 / f<-1.15; by constraining the ratio of the fifth lens E5 focal length to the effective focal length of the optical system to a reasonable range, the imaging quality is improved;

[0057] 1.7<f6 / f<2.5; By constraining the effective focal length ratio of the sixth lens E6 to the optical system within a reasonable range, lens aberrations are optimized and analytical performance is improved;

[0058] Wherein, f is the focal length of the entire optical system, f1 is the focal length of the first lens E1, f2 is the focal length of the second lens E2, f3 is the focal length of the third lens E3, f4 is the focal length of the fourth lens E4, f5 is the focal length of the fifth lens E5, and f6 is the focal length of the sixth lens E6.

[0059] Furthermore, the refractive index Nd1 and Abbe number Vd1 of the first lens element E1 satisfy the following conditions: 1.70<Nd1<2.00, 45.00<Vd1<52.00. This design can effectively reduce chromatic aberration, optimize lens aberrations, and thereby effectively improve the imaging quality of the system.

[0060] Furthermore, the refractive index Nd2 and Abbe number Vd2 of the second lens element E2 satisfy the following conditions: 1.55<Nd2<1.66, 21.30<Vd2<24.00. This design can effectively reduce chromatic aberration, optimize lens aberrations, and thus effectively improve the imaging quality of the system.

[0061] Furthermore, the refractive index Nd3 and Abbe number Vd3 of the third lens element E3 satisfy the following conditions: 1.51<Nd3<1.65, 53.00<Vd3<70.00. This design can effectively reduce chromatic aberration, optimize lens aberrations, and thus effectively improve the imaging quality of the system.

[0062] Furthermore, the refractive index Nd4 and Abbe number Vd4 of the fourth lens element E4 satisfy the following conditions: 1.45<Nd4<1.60, 55.00<Vd4<83.00. This design can effectively improve distortion and field curvature, eliminate dispersion, ensure good optical performance, and enhance the resolving power and imaging quality of the lens.

[0063] Furthermore, the refractive index Nd5 and Abbe number Vd5 of the fifth lens element E5 satisfy the following conditions: 1.55<Nd5<1.73, 20.00<Vd5<30.00. This design can effectively reduce chromatic aberration, optimize lens aberrations, and thus effectively improve the imaging quality of the system.

[0064] Furthermore, the refractive index Nd6 and Abbe number Vd6 of the sixth lens element E6 satisfy the following conditions: 1.47<Nd6<1.65, 50.00<Vd6<60.00. This design can effectively improve distortion and field curvature, ensure good optical performance, and enhance the resolving power of the lens.

[0065] Furthermore, as a preferred embodiment of the present invention but not a limitation, the first lens E1 and the fourth lens E4 are spherical lenses, and the second lens E2, the third lens E3, the fifth lens E5, and the sixth lens E6 are aspherical lenses. By rationally distributing lens surface shapes and optimizing lens aberrations, the lens has excellent resolving power, high pixel count, large aperture, day and night parfocality, and other characteristics.

[0066] Furthermore, as a preferred embodiment of the present invention but not a limitation thereof, the curvature radius R1 on the object side and the curvature radius R2 on the image side of the first lens E1 satisfy the following relationship: 5.1<(R1+R2) / R2<7.1. By controlling the curvature radii on the object side and the image side of the first lens E1, the total deflection angles of the object side and the image side of the first lens E1 at the edge of the field of view can be reasonably controlled to be within a reasonable range, thereby effectively reducing the sensitivity of the system.

[0067] Furthermore, as a preferred embodiment of the present invention but not a limitation, the optical system satisfies the following conditions: 0.3<f / TTL*ImagH<0.55; wherein f is the effective focal length of the optical system, TTL is the on-axis distance from the object side of the first lens to the imaging plane, and ImgH is half of the diagonal length of the effective pixel area on the imaging plane. This relationship reflects the constraints of the optical lens in terms of field angle and thinness. When the above relationship is met, the demand for thinness of the optical lens can be achieved on the basis of meeting the requirements of the optical lens.

[0068] Furthermore, as a preferred embodiment of the present invention, but not a limitation, the optical system satisfies the following relationship: 0.6 < (CT5 + CT6) / f < 1.3, where CT5 is the center thickness of the fifth lens element along the optical axis, CT6 is the center thickness of the sixth lens element along the optical axis, and f is the effective focal length of the optical imaging system. This relationship allows for optimal adjustment of the center thicknesses of the fifth and sixth lenses, effectively regulating the refractive power of the fifth and sixth lenses, and effectively suppressing the phenomenon of significant expansion of the incident light beam due to divergence through the sixth lens.

[0069] Furthermore, as a preferred embodiment of the present invention but not a limitation, the full field of view FOV of the optical system satisfies: 150°≤FOV≤160°. The design satisfies the large field of view of the lens and has the advantages of compact structure and easy processing and installation.

[0070] Furthermore, as a preferred embodiment of the present invention but not a limitation thereof, the refractive index Nd6 and Abbe number Vd6 of the sixth lens element E6, as well as the refractive index Nd5 and Abbe number Vd5 of the fifth lens element E5, satisfy the following conditions: 0.85<Nd5 / Nd6<1.15, 0.35<Vd5 / Vd6<0.55. Proper matching of the refractive indices and material Abbe numbers of the fifth and sixth lenses can further reduce system chromatic aberration and improve system imaging quality.

[0071] Furthermore, as a preferred embodiment of the present invention but not a limitation, the fourth lens and the fifth lens form a cemented lens. This design increases the difference between the refractive index and the Abbe number of the lens, which can effectively reduce chromatic aberration. The present application adopts a hybrid optical system composed of glass and plastic lenses, which has excellent resolution, high pixels, large aperture, athermalization, day and night confocality, light weight, etc., and has greater competitiveness in the IPC market.

[0072] Specifically, as a preferred embodiment of the present invention but not limiting, Figure 1 FIG. 1 shows a schematic structural diagram of an optical imaging lens according to Example 1 of the present application. Figure 1 As shown, the first lens E1 has negative focal power, its object-side surface S1 is convex, and its image-side surface S2 is concave. The second lens E2 has positive focal power, its object-side surface S3 is concave, and its image-side surface S4 is convex. The third lens E3 has positive focal power, its object-side surface S5 is concave, and its image-side surface S6 is convex. The fourth lens E4 has positive focal power, its object-side surface S8 is convex, and its image-side surface S9 is convex. The fifth lens E5 has negative focal power, its object-side surface S10 is concave, and its image-side surface S11 is concave. The sixth lens E6 has positive focal power, its object-side surface S12 is convex, and its image-side surface S13 is convex. The filter E7 has an object-side surface S14 and an image-side surface S15. Light from the object passes through each surface S1 to S15 in sequence and is ultimately imaged on the imaging surface S16.

[0073] Table 1 shows the surface type, curvature radius, thickness, and material of each lens of the optical imaging lens of Example 1, where the units of curvature radius and thickness are both millimeters (mm):

[0074] Table 1: Basic parameters of the optical system of Example 1

[0075] Table 1: Basic parameters of the optical system of Example 1

[0076] Face number Surface type Curvature radius (mm) Thickness (mm) Material OBJ spherical surface endless endless S1 spherical surface 12.24 2.04 1.80，46.57 S2 spherical surface 2.38 1.97 S3 Aspheric -4.54 1.99 1.64，23.55 S4 Aspheric -4.19 0.53 S5 Aspheric -5.44 1.49 1.53，55.63 S6 Aspheric -4.05 0.48 STOP spherical surface endless 0.86 S8 spherical surface 4.38 2.36 1.49,81.61 S9 spherical surface -4.38 0.09 S10 Aspheric -18.54 0.64 1.64,23.53 S11 Aspheric 3.28 0.08 S12 Aspheric 3.21 1.25 1.53,55.63 S13 Aspheric -16.93 2.39 S14 spherical surface endless 0.70 1.52,64.20 S15 spherical surface endless 1.06 S16 spherical surface endless

[0077] In Table 1 above, any one of the object side and image side of the second lens E2, the fourth lens E4, and the fifth lens E5 to the sixth lens E6 is aspherical. The surface shape of each aspherical lens can be defined by, but not limited to, the following aspherical formula:

[0078]

[0079] Where x is the distance from the corresponding point on the aspheric surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the aspheric vertex, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspheric surface shape formula. Table 2 shows the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, A16, and A20 for various aspheric surfaces that can be used in Example 1.

[0080] Table 2: Aspheric surface related values ​​of the lens surface of Example 1

[0081] Face number K A4 A6 A8 A10 3 5.10E-01 -6.75E-04 1.47E-03 -7.90E-04 3.15E-04 4 -1.21E+00 3.58E-03 3.12E-04 -1.05E-03 7.61E-04 5 3.74E+00 1.83E-03 -5.66E-03 5.77E-03 -5.85E-03 6 2.43E-02 -3.95E-03 -3.65E-03 3.53E-03 -2.54E-03 10 1.39E+01 -1.41E-02 -1.27E-03 6.34E-04 1.13E-03 11 -5.26E+00 1.35E-02 -2.57E-02 1.98E-02 -9.17E-03 12 -3.85E+00 1.65E-02 -2.38E-02 1.66E-02 -7.16E-03 13 -9.43E+01 -3.21E-03 -4.27E-04 5.90E-04 -3.00E-04 Face number A12 A14 A16 A18 A20 3 -7.57E-05 1.11E-05 -8.92E-07 2.99E-08 2.62E-11 4 -3.08E-04 7.54E-05 -1.08E-05 8.25E-07 -2.51E-08 5 3.76E-03 -1.50E-03 3.55E-04 -4.58E-05 2.44E-06 6 1.17E-03 -3.45E-04 6.28E-05 -6.45E-06 2.85E-07 10 -1.19E-03 5.13E-04 -1.18E-04 1.42E-05 -7.02E-07 11 2.71E-03 -5.15E-04 6.02E-05 -3.95E-06 1.11E-07 12 2.01E-03 -3.67E-04 4.23E-05 -2.80E-06 8.15E-08 13 1.22E-04 -3.54E-05 6.52E-06 -6.52E-07 2.64E-08

[0082] Figure 2 The astigmatism and distortion curves of the optical imaging lens of Example 1 are shown. Astigmatism represents meridional image curvature and sagittal image curvature; distortion represents the distortion magnitude corresponding to different image heights.

[0083] Figure 3 The MTF curve of the optical imaging lens of Example 1 is shown, which represents the MTF values ​​in the meridional and sagittal directions of different fields of view.

[0084] Depend on Figure 2 and Figure 3 It can be seen that the optical lens provided in Example 1 can achieve good imaging quality.

[0085] Specifically, as a preferred embodiment of the present invention but not limiting, Figure 4 FIG. 1 shows a schematic structural diagram of an optical imaging lens according to Example 2 of the present application. Figure 4As shown, the first lens E1 has negative focal power, the object side surface S1 is convex, and the image side surface S2 is concave. The second lens E2 has positive focal power, the object side surface S3 is concave, and the image side surface S4 is convex. The third lens E3 has positive focal power, the object side surface S5 is concave, and the image side surface S6 is convex. The fourth lens E4 has positive focal power, the object side surface S8 is convex, and the image side surface S9 is convex. The fifth lens E5 has negative focal power, the object side surface S10 is concave, and the image side surface S11 is concave. The sixth lens E6 has positive focal power, the object side surface S12 is convex, and the image side surface S13 is convex. The filter E7 has an object side surface S14 and an image side surface S15. Light from an object sequentially passes through the surfaces S1 to S15 and is finally imaged on the imaging surface S16.

[0086] Table 3 shows the surface type, the radius of curvature, the thickness and the material of each lens of the optical imaging lens of Example 2, wherein the units of the radius of curvature and the thickness are millimeter (mm):

[0087] Table 3: Basic parameters of the optical system of Example 2

[0088] Face number Surface type Curvature radius (mm) Thickness (mm) Material OBJ spherical surface endless endless S1 spherical surface 10.95 1.58 1.80，46.57 S2 spherical surface 2.32 1.97 S3 Aspheric -4.55 1.96 1.64，23.55 S4 Aspheric -4.26 0.41 S5 Aspheric -5.01 1.46 1.53，55.63 S6 Aspheric -3.81 0.47 STOP spherical surface endless 0.85 S8 spherical surface 4.38 2.34 1.49,81.61 S9 spherical surface -4.38 0.14 S10 Aspheric -18.13 0.60 1.64,23.53 S11 Aspheric 3.17 0.09 S12 Aspheric 3.18 1.21 1.53,55.63 S13 Aspheric -14.43 2.44 S14 spherical surface endless 0.70 1.52,64.20 S15 spherical surface endless 1.06 S16 spherical surface endless

[0089] In Table 3 above, the object side surface and the image side surface of each of the second lens E2, the fourth lens E4, the fifth lens E5 to the sixth lens E6 are aspherical surfaces, and the surface type of each aspherical lens can be defined by, but not limited to, the following aspherical surface formula:

[0090]

[0091] wherein x is the distance from a corresponding point on the aspherical surface to a plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the vertex of the aspherical surface, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th high order term in the aspherical surface formula. Table 4 shows the conic coefficient and the high order term coefficients A4, A6, A8, A10, A12, A14, A16, A20 of each aspherical surface that can be used in Example 2.

[0092] Table 4: Aspherical surface related values of the lenses of Example 2

[0093] Face number K A4 A6 A8 A10 3 5.00E-01 -1.07E-03 1.07E-03 -4.00E-04 9.57E-05 4 -1.01E+00 2.76E-03 4.86E-04 -1.33E-03 1.13E-03 5 3.76E+00 2.45E-04 -3.60E-03 3.00E-03 -3.33E-03 6 -2.39E-02 -3.85E-03 -3.87E-03 4.26E-03 -3.47E-03 10 1.36E+01 -1.14E-02 -7.26E-03 8.27E-03 -4.54E-03 11 -5.39E+00 1.74E-02 -3.34E-02 2.82E-02 -1.42E-02 12 -4.29E+00 1.73E-02 -2.72E-02 1.99E-02 -8.80E-03 13 -9.80E+01 -6.04E-03 3.19E-04 3.30E-04 -3.28E-04 Face number A12 A14 A16 A18 A20 3 1.17E-05 -1.18E-05 2.80E-06 -3.05E-07 1.29E-08 4 -5.14E-04 1.37E-04 -2.02E-05 1.37E-06 -2.23E-08 5 2.52E-03 -1.21E-03 3.50E-04 -5.58E-05 3.72E-06 6 1.83E-03 -6.24E-04 1.31E-04 -1.54E-05 7.75E-07 10 1.37E-03 -2.02E-04 3.25E-06 2.77E-06 -2.45E-07 11 4.54E-03 -9.34E-04 1.19E-04 -8.61E-06 2.70E-07 12 2.50E-03 -4.57E-04 5.23E-05 -3.41E-06 9.60E-08 13 1.94E-04 -6.41E-05 1.19E-05 -1.15E-06 4.42E-08

[0094] Specifically, as a preferred embodiment of the present application but not limited, Figure 5 shows a structure schematic diagram of an optical imaging lens according to Example 3 of the present application, like Figure 5As shown, the first lens E1 has negative focal power, the object side surface S1 is convex, and the image side surface S2 is concave. The second lens E2 has positive focal power, the object side surface S3 is concave, and the image side surface S4 is convex. The third lens E3 has positive focal power, the object side surface S6 is convex, and the image side surface S7 is convex. The fourth lens E4 has positive focal power, the object side surface S8 is convex, and the image side surface S9 is convex. The fifth lens E5 has negative focal power, the object side surface S9 is concave, and the image side surface S10 is concave. The sixth lens E6 has positive focal power, the object side surface S11 is convex, and the image side surface S12 is convex. The filter E7 has an object side surface S13 and an image side surface S14. Light from the object sequentially passes through the surfaces S1 to S14 and is finally imaged on the imaging surface S15.

[0095] Table 5 shows the surface type, radius of curvature, thickness and material of each lens of the optical imaging lens of Example 3, wherein the units of the radius of curvature and the thickness are millimeters (mm):

[0096] Table 5: Basic parameters of the optical system of Example 3

[0097] Face number Surface type Curvature radius (mm) Thickness (mm) Material OBJ spherical surface endless endless S1 spherical surface 13.90 1.44 1.77，49.61 S2 spherical surface 2.52 2.44 S3 Aspheric -5.40 2.47 1.64，23.55 S4 Aspheric -5.40 1.13 STOP spherical surface endless 0.38 S6 spherical surface 8.74 2.19 1.59，68.34 S7 spherical surface -5.48 0.30 S8 Aspheric 10.89 1.65 1.54，55.71 S9 Aspheric -6.71 0.9 1.64，23.55 S10 Aspheric 3.30 0.14 S11 Aspheric 3.02 2.10 1.53，55.63 S12 Aspheric -18.99 0.37 S13 spherical surface endless 0.7 1.52,64.20 S14 spherical surface endless 2.51 S15 spherical surface endless

[0098] In Table 5 above, the object side surface and the image side surface of any one of the second lens E2, the third lens E3, the fifth lens E5 to the sixth lens E6 are aspherical surfaces, and the surface type of each aspherical lens can be defined by, but not limited to, the following aspherical surface formula:

[0099]

[0100] wherein x is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the vertex of the aspherical surface, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th high order term in the aspherical surface formula. Table 6 shows the conic coefficient and the high order term coefficients A4, A6, A8, A10, A12, A14, A16, A20 of each aspherical surface that can be used in Example 3.

[0101] Table 6: Aspherical surface related values of the lenses of Example 3

[0102] Face number K A4 A6 A8 A10 3 3.53E+00 -4.15E-04 1.00E-03 -5.51E-04 3.75E-04 4 -5.86E+00 -5.06E-03 6.92E-04 -1.20E-04 -5.20E-05 8 7.82E+00 -5.79E-04 -7.96E-04 6.99E-04 -4.32E-04 9 -8.69E+00 -2.68E-02 1.62E-02 -9.38E-03 3.95E-03 10 -7.71E+00 -5.61E-03 7.75E-03 -3.91E-03 1.41E-03 11 -7.49E+00 -2.38E-03 3.18E-03 -1.37E-03 4.25E-04 12 -1.85E+01 -1.38E-03 -1.48E-04 9.70E-05 -1.82E-05 Face number A12 A14 A16 A18 A20 3 -1.58E-04 4.32E-05 -7.00E-06 6.08E-07 -2.07E-08 4 8.00E-05 -3.75E-05 8.77E-06 -1.03E-06 4.92E-08 8 1.50E-04 -3.01E-05 3.45E-06 -2.08E-07 5.06E-09 9 -1.09E-03 1.80E-04 -1.65E-05 6.91E-07 -6.79E-09 10 -3.52E-04 5.81E-05 -5.98E-06 3.48E-07 -8.73E-09 11 -8.92E-05 1.22E-05 -1.04E-06 5.02E-08 -1.04E-09 12 2.42E-06 -1.50E-07 3.65E-09 1.83E-36 1.83E-36

[0103] In Examples 1-3, the basic data is shown in Table 7 below:

[0104] Table 7: Basic data of Examples 1-3

[0105]

[0106]

[0107] A camera module includes at least an optical lens. The optical system is composed of a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens in sequence along the optical axis from the object plane to the image plane. By rationally allocating the surface shape and optical focal length of each lens and optimizing the lens aberration, the module has excellent resolution, high pixel count, large aperture, athermalization, day and night confocality, and light weight, making it more competitive in the IPC market.

[0108] The above descriptions are provided in conjunction with specific content to provide one or more embodiments, and the specific implementation of the present invention is not limited to these descriptions. Any similarity or similarity with the methods, structures, etc. of the present invention, or any technical deduction or substitution based on the concept of the present invention, shall be considered within the scope of protection of the present invention.

Claims

1. A day / night confocal optical system, comprising, in order from the object plane to the image plane along the optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, characterized in that: The object side of the first lens is convex, the image side is concave, and its optical power is negative; The object side of the second lens is concave, the image side is convex, and its optical power is positive; The image side of the third lens is convex and has positive optical power; The object side and image side of the fourth lens are both convex, and its optical power is positive; The object side and image side of the fifth lens are both concave, and its optical power is negative; The object side and image side of the sixth lens are both convex, and its optical power is positive; Each lens of the optical system meets the following conditions: -1.70<f1 / f<-1; 9.5<f2 / f<12.30; 2.0<f3 / f<8.9; 1.80<f4 / f<3.00; -2.1<f5 / f<-1.15; 1.7<f6 / f<2.5; Wherein, f is the effective focal length of the optical system, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, and f6 is the focal length of the sixth lens; The curvature radius R1 of the object side of the first lens and the curvature radius R2 of the image side satisfy: 5.1<(R1+R2) / R2<7.

1.

2. The day and night confocal optical system according to claim 1, characterized in that: The optical system meets the following conditions: 0.3mm<f / TTL*ImgH<0.55mm; Wherein, f is the effective focal length of the optical system, TTL is the on-axis distance from the object side of the first lens to the imaging surface, and ImgH is half the diagonal length of the effective pixel area on the imaging surface.

3. The day / night confocal optical system according to any one of claims 1 to 2, characterized in that: The material refractive index Nd1 and the material Abbe number Vd1 of the first lens satisfy the following conditions: 1.70<Nd1<2.00, 45.00<Vd1<52.00; The refractive index Nd2 and Abbe number Vd2 of the material of the second lens satisfy the following conditions: 1.55<Nd2<1.66, 21.30<Vd2<24.00; The refractive index Nd3 and Abbe number Vd3 of the material of the third lens satisfy the following conditions: 1.51<Nd3<1.65, 53.00<Vd3<70.00; The material refractive index Nd4 and the material Abbe number Vd4 of the fourth lens satisfy the following conditions: 1.45<Nd4<1.60, 55.00<Vd4<83.00; The refractive index Nd5 and Abbe number Vd5 of the material of the fifth lens satisfy the following conditions: 1.55<Nd5<1.73, 20.00<Vd5<30.00; The material refractive index Nd6 and the material Abbe number Vd6 of the sixth lens satisfy: 1.47<Nd6<1.65, 50.00<Vd6<60.

00.

4. The day and night confocal optical system according to any one of claims 1 to 2, characterized in that: The first lens is a spherical lens, the second lens, the fifth lens, and the sixth lens are aspherical lenses, and the third lens and the fourth lens are spherical or aspherical lenses.

5. The day and night confocal optical system according to any one of claims 1 to 2, characterized in that: The optical system meets the following requirements: 0.6<(CT5+CT6) / f<1.3; Wherein, CT5 is the center thickness of the fifth lens on the optical axis, CT6 is the center thickness of the sixth lens on the optical axis, and f is the effective focal length of the optical system.

6. The day and night confocal optical system according to any one of claims 1 to 2, characterized in that: The full field of view FOV of the optical system satisfies: 150°≤FOV≤160°.

7. The day and night confocal optical system according to any one of claims 1 to 2, characterized in that: The refractive index Nd6 and Abbe number Vd6 of the sixth lens, and the refractive index Nd5 and Abbe number Vd5 of the fifth lens satisfy the following conditions: 0.85<Nd5 / Nd6<1.15, 0.35<Vd5 / Vd6<0.

55.

8. The day and night confocal optical system according to any one of claims 1 to 2, characterized in that: The fourth lens and the fifth lens constitute a cemented lens.

9. A camera module, comprising at least an optical lens, characterized in that: The optical lens is equipped with the day and night confocal optical system according to any one of claims 1 to 8.

Images