Day and night confocal optical system and camera module applying same

Abstract

The invention provides a day and night confocal optical system and a camera module applying the same, the day and night confocal optical system is mainly composed of seven lenses, the object plane side of the first lens is a convex surface, the image plane side is a concave surface, the focal power of the first lens is negative, the object plane side of the second lens is a concave surface, the image plane side is a convex surface, the focal power of the second lens is negative, the object plane side of the third lens is a convex surface or a concave surface, and the object plane side of the fourth lens is a convex surface or a concave surface. The object plane side and the image plane side of the fourth lens are both convex surfaces and have positive focal power, the fifth lens has focal power, the sixth lens has focal power, the object plane side of the seventh lens is convex, the image plane side of the seventh lens is concave, the focal power of the seventh lens is positive, the number of the lenses is reasonable, the structure is simple, and the lens can be widely applied to the field of optical imaging. By reasonably distributing the focal power of the lenses, optimizing the aberration of the lens and improving the resolution performance, the wide-angle wide-angle lens has the advantages of large wide angle, large aperture, light weight and excellent resolution, so that the miniaturized wide-angle lens has higher competitiveness in the market.

Description

Technical Field

[0001] The present application relates to the field of optical imaging, and in particular provides a day and night confocal optical system for use in a smart doorbell or smart home system and a camera module for its application. Background Art

[0002] With the advancement of science and technology and social and economic development, camera lenses are widely used in smart doorbells or smart home systems. However, previous camera lenses or optical systems have the defects of complex structure, large size, small viewing angle, and poor day and night effects, which can hardly meet the needs of users. Summary of the invention

[0003] The present application aims to overcome the common problems of small viewing angle, large size and small amount of light input in existing optical systems. On the one hand, the present application provides a day and night confocal wide-angle optical system with a reasonable number of lenses and a simple structure. By reasonably allocating the lens focal length, lens aberrations are optimized and the resolution performance is improved. The system has a large wide angle, a large aperture, a light weight and excellent resolution, making the miniaturized wide-angle lens more competitive in the fields of smart doorbells, smart homes, etc.

[0004] A day-night confocal optical system, which is composed of a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens in sequence from the object plane to the image plane along the optical axis; 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 negative; The object side of the third lens is convex or concave, the image side is convex, and its optical power is positive; The object side and the image side of the fourth lens are both convex, and its optical power is positive; The fifth lens has optical power; The sixth lens has optical power; The object side of the seventh lens is convex, the image side is concave, and its optical power is positive.

[0005] As described above, the day and night confocal wide-angle optical system, each lens of the optical system satisfies the following conditions: -6.7mm<f1<-3.5mm; -9.2mm<f2<-5.50mm; 2.50mm<f3<12.50mm; 2.50mm<f4<8.5mm; -5.3mm<f5<7.3mm; -7.5mm<f6<8.5mm; 5.7mm<f7<15mm; Among them, 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, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens.

[0006] In the day-night confocal wide-angle optical system as described above, the curvature radius R1 of the object surface side of the first lens satisfies: R1<17mm.

[0007] The day and night confocal wide-angle optical system as described above satisfies the following conditions: TTL ≤ 17.6 mm; Wherein, TTL is the axial distance from the object side of the first lens to the imaging surface.

[0008] As described above, the day and night confocal wide-angle optical system, each lens of the optical system satisfies the following conditions: 1.80<Nd1<2.00, 20.00<Vd1<50; 1.51<Nd2<1.62, 52.50<Vd2<58.00; 1.61<Nd3<2.1, 16<Vd3<35; 1.45<Nd4<1.62, 52.50<Vd4<85; 1.51<Nd5<1.73, 20.00<Vd5<57.00; 1.51<Nd6<1.67, 20.00<Vd6<60.00; 1.51<Nd7<1.62, 52.50<Vd7<58.00; Among them, Nd1 is the refractive index of the first lens, and Vd1 is the Abbe number of the first lens; Nd2 is the refractive index of the second lens, and Vd2 is the Abbe number of the second lens; Nd3 is the refractive index of the third lens, and Vd3 is the Abbe number of the third lens; Nd4 is the refractive index of the fourth lens, and Vd4 is the Abbe number of the fourth lens; Nd5 is the refractive index of the fifth lens, and Vd5 is the Abbe number of the fifth lens; Nd6 is the refractive index of the sixth lens, and Vd6 is the Abbe number of the sixth lens; Nd7 is the refractive index of the seventh lens, and Vd7 is the Abbe number of the seventh lens.

[0009] In the day-night confocal wide-angle optical system as described above, the third lens is a spherical or aspherical lens.

[0010] As for the day and night confocal wide-angle optical system as described above, the FNO of the optical system satisfies: FNO≤1.65.

[0011] As described above, the day and night confocal wide-angle optical system, the full field of view FOV of the optical system satisfies: 160°≤FOV.

[0012] In the day and night confocal wide-angle optical system as described above, the fourth lens and the fifth lens or the fifth lens and the sixth lens are cemented lenses; the refractive index Nda, the Abbe number Vda, and the refractive index Ndb, the Abbe number Vdb of the two lenses of the cemented lens satisfy: 1.45<Nda<1.62, 52.50<Vda<85; 1.51<Ndb<1.73, 20.00<Vdb<57.00.

[0013] As described above, in the day and night confocal wide-angle optical system, the aperture of the optical system is located between the third lens and the fourth lens.

[0014] On the other hand, an embodiment of the present application further provides a camera module, comprising at least an optical lens, wherein the optical lens is installed with the above-mentioned day and night confocal optical system.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a day and night confocal optical system and a camera module using the same, which is mainly composed of 7 lenses, has a reasonable number of lenses and a simple structure. By reasonably distributing the lens optical power, lens aberrations are optimized, and the resolution performance is improved. The system has a wide angle, a large aperture, a light weight, and excellent resolution, making the miniaturized wide-angle lens more competitive in the market. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for describing the embodiments are briefly introduced below.

[0017] Figure 1 It is a structural schematic diagram of the optical system or camera module of Example 1 of the present application; Figure 2 is a field curvature and distortion curve diagram of the optical system or camera module of Example 1 of the present application; Figure 3 is an MTF curve diagram of the optical system or camera module of Example 1 of the present application; Figure 4 It is a structural schematic diagram of an optical system or a camera module according to Embodiment 2 of the present application; Figure 5 is a field curvature and distortion curve diagram of the optical system or camera module of Example 2 of the present application; Figure 6 is an MTF curve diagram of the optical system or camera module of Example 2 of the present application; Figure 7 It is a structural schematic diagram of an optical system or a camera module according to Embodiment 3 of the present application; Figure 8 is a field curvature and distortion curve diagram of the optical system or camera module of Example 3 of the present application; Fig. 9 It is an MTF curve diagram of the optical system or camera module of Example 3 of the present application. DETAILED DESCRIPTION

[0018] like Figure 1-9 As shown, 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, an aperture STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, and a seventh lens E7 in sequence from the object plane to the image plane along the optical axis; 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 negative; The object side of the third lens is convex or concave, the image side is convex, and its optical power is positive; The object side and the image side of the fourth lens are both convex, and its optical power is positive; The fifth lens has optical power; The sixth lens has optical power; The object side of the seventh lens is convex, the image side is concave, and its optical power is positive; The optical system of the embodiment of the present application is mainly composed of 7 lenses. The number of lenses is reasonable and the structure is simple. By reasonably allocating the lens optical power, optimizing the lens aberration, and improving the resolution performance, it has a wide angle, a large aperture, a light weight and excellent resolution, making the miniaturized wide-angle lens more competitive in the market.

[0019] Further, as a preferred embodiment of the present invention but not limiting, each lens of the optical system satisfies the following conditions: -6.7mm<f1<-3.5mm, by constraining the effective focal length of the first lens E1 within a reasonable range, the distortion of the system is controlled, so that the imaging center has a higher angular resolution; -9.2mm<f2<-5.50mm; By restricting the effective focal length of the second lens E2 to a reasonable range, the lens aberration is optimized and the imaging quality is improved; 2.50mm<f3<12.50mm; By constraining the effective focal length of the third lens E3 within a reasonable range, the spherical aberration of the system is fine-tuned and controlled, thereby effectively improving the imaging quality of the system; 2.50mm<f4<8.5mm; By reasonably controlling the effective focal length of the fourth lens E4 within a reasonable range, the imaging quality of the system is effectively improved; -5.3mm<f5<7.3mm; By restricting the effective focal length of the fifth lens E5 to a reasonable range, the imaging quality is improved; -7.5mm<f6<8.5mm; By restricting the effective focal length of the sixth lens E6 to a reasonable range, the lens aberration is optimized and the analytical performance is improved; 5.7mm<f7<15mm; By restricting the effective focal length of the seventh lens E7 to a reasonable range, the lens aberration is optimized and the field curvature of the system is improved; Among them, 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, f6 is the focal length of the sixth lens E6, and f7 is the focal length of the seventh lens E7.

[0020] Furthermore, the refractive index Nd1 and the Abbe number Vd1 of the first lens E1 satisfy: 1.80<Nd1<2.00, 20.00<Vd1<50. This design can effectively reduce chromatic aberration, optimize lens aberration, and thus effectively improve the imaging quality of the system. Furthermore, the refractive index Nd2 and the Abbe number Vd2 of the second lens E2 satisfy: 1.51<Nd2<1.62, 52.50<Vd2<58.00. This design can effectively reduce chromatic aberration, optimize lens aberration, and thus effectively improve the imaging quality of the system. Furthermore, the refractive index Nd3 and the Abbe number Vd3 of the third lens E3 satisfy: 1.61<Nd3<2.1, 16<Vd3<35. This design can effectively reduce chromatic aberration, optimize lens aberration, and thus effectively improve the imaging quality of the system. Furthermore, the refractive index Nd4 and the Abbe number Vd4 of the fourth lens element E4 satisfy: 1.45<Nd4<1.62, 52.50<Vd4<85. This design can effectively reduce chromatic aberration, optimize lens aberration, and thus effectively improve the imaging quality of the system. Furthermore, the refractive index Nd5 and the Abbe number Vd5 of the fifth lens element E5 satisfy: 1.51<Nd5<1.73, 20.00<Vd5<57.00. This design can effectively reduce chromatic aberration, optimize lens aberration, and thus effectively improve the imaging quality of the system. Furthermore, the refractive index Nd6 and the Abbe number Vd6 of the sixth lens E6 satisfy: 1.51<Nd6<1.67, 20.00<Vd6<60.00. This design can effectively reduce chromatic aberration, optimize lens aberration, and thus effectively improve the imaging quality of the system. Furthermore, the refractive index Nd7 and the Abbe number Vd7 of the seventh lens E7 satisfy: 1.51<Nd7<1.62, 52.50<Vd7<58.00. This design can effectively reduce chromatic aberration, optimize lens aberration, and thus effectively improve the imaging quality of the system. Furthermore, as a preferred embodiment of the present invention but not limitation, the third lens E3 is a spherical or aspherical lens. By reasonably distributing the lens surface, optimizing the lens aberration, and improving the resolution performance, the lens has a wide angle, a large aperture, a light weight, and excellent resolution.

[0021] Further, as a preferred embodiment of the present invention but not limitation, the curvature radius R1 of the object side of the first lens satisfies: R1 < 17 mm. By controlling the object side of the first lens 1, the total deflection angle of the object side of the first lens 1 at the edge field of view can be reasonably controlled within a reasonable range.

[0022] Furthermore, as a preferred embodiment of the present invention but not a limitation, the optical system satisfies the following condition: TTL ≤ 17.6 mm. This design can reduce the total optical length and miniaturize the lens, making the miniaturized wide-angle lens more competitive in the market.

[0023] Further, as a preferred embodiment of the present invention but not a limitation, the full field of view FOV of the optical system satisfies: 160°≤FOV and FNO≤1.65, which is beneficial to expanding the field of view of the lens and improving the light-entry capability of the lens.

[0024] Furthermore, as a preferred embodiment of the present invention but not a limitation, the refractive index Nda, Abbe number Vda, and the refractive index Ndb, Abbe number Vdb of the two lenses of the glued lens satisfy: 1.45<Nda<1.62, 52.50<Vda<85; 1.51<Ndb<1.73, 20.00<Vdb<57.00. This design increases the difference between the refractive index and the Abbe number of the lens, which can effectively reduce chromatic aberration.

[0025] Specifically, as a preferred embodiment of the present invention but not limiting, Figure 1 FIG. 4 shows a schematic structural diagram of an optical imaging lens according to Embodiment 1 of the present application. Figure 1As shown, the object side S1 of the first lens E1 is convex, the image side S2 is concave, and its optical power is negative; the object side S3 of the second lens E2 is concave, the image side S4 is convex, and its optical power is negative; the object side S5 of the third lens E3 is convex, the image side S6 is convex, and its optical power is positive; the object side S8 and the image side S9 of the fourth lens E4 are both convex, and its optical power is positive; the fifth lens E5 has optical power; the sixth lens E6 has optical power; the object side S13 of the seventh lens E7 is convex, the image side S14 is concave, and its optical power is positive; filter E8; light from the object passes through each surface in sequence and is finally imaged on the imaging surface.

[0026] Table 1 shows the surface type, curvature radius, thickness and material of each lens of the optical imaging lens of Example 1, wherein the units of the curvature radius and thickness are both millimeters (mm): Table 1: Basic parameters of the optical system of Example 1

[0027] In Table 1 above, any one of the object side and image side of the second lens E2, the third lens E3, the fifth lens E5, the sixth lens E6, and the seventh lens E7 is an aspherical surface, and the surface shape of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0028] Wherein, 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 vertex of the aspheric surface, k is the cone coefficient, and Ai is the coefficient corresponding to the i-th high-order term in the aspheric surface shape formula. Table 2 shows the cone coefficients and high-order term coefficients A4, A6, A8, A10, A12, A14, A16, and A20 of each aspheric surface that can be used in Example 1.

[0029] Table 2: Aspheric surface related values ​​of the lens surface of Example 1

[0030] Figure 2 The astigmatism and distortion curves of the optical imaging lens of Example 1 are shown. Astigmatism refers to the meridional image curvature and the sagittal image curvature; and distortion refers to the distortion magnitude values ​​corresponding to different image heights.

[0031] Figure 3 The MTF curve of the optical imaging lens of Example 1 is shown, which represents the MTF values ​​in the meridian direction and sagittal direction of different fields of view.

[0032] Depend on Figure 2 and Figure 3 It can be seen that the optical lens provided in Example 1 can achieve good imaging quality.

[0033] Specifically, as a preferred embodiment of the present invention but not limiting, Figure 4 FIG. 4 shows a schematic structural diagram of an optical imaging lens according to Embodiment 2 of the present application. Figure 4 As shown, the object side S1 of the first lens E1 is convex, the image side S2 is concave, and its optical power is negative; the object side S3 of the second lens E2 is concave, the image side S4 is convex, and its optical power is negative; the object side S5 of the third lens E3 is convex, the image side S6 is convex, and its optical power is positive; the object side S8 and the image side S9 of the fourth lens E4 are both convex, and their optical power is positive; the fifth lens E5 has optical power; the sixth lens E6 has optical power; the object side S1 of the seventh lens E7 is convex, the image side S2 is concave, and its optical power is positive; filter E8; light from the object passes through each surface in sequence and is finally imaged on the imaging surface.

[0034] Table 3 shows the surface type, curvature radius, thickness and material of each lens of the optical imaging lens of Example 2, wherein the units of the curvature radius and thickness are both millimeters (mm): Table 3: Basic parameters of the optical system of Example 2

[0035] In Table 3 above, any one of the object side and image side of the second lens E2, the fourth lens E4, the fifth lens E5, the sixth lens E6, and the seventh lens E7 is an aspherical surface, and the surface shape of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0036] Wherein, 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 vertex of the aspheric surface, k is the cone coefficient, and Ai is the coefficient corresponding to the i-th high-order term in the aspheric surface shape formula. Table 4 shows the cone coefficients and high-order term coefficients A4, A6, A8, A10, A12, A14, A16, and A20 of each aspheric surface that can be used in Example 2.

[0037] Table 4: Aspheric surface related values ​​of lens surface in Example 2

[0038] Figure 5 The astigmatism and distortion curves of the optical imaging lens of Example 2 are shown. Astigmatism refers to the meridional image curvature and the sagittal image curvature; and distortion refers to the distortion magnitude values ​​corresponding to different image heights.

[0039] Figure 6The MTF curve of the optical imaging lens of Example 2 is shown, which represents the MTF values ​​in the meridian direction and sagittal direction of different fields of view.

[0040] Depend on Figure 5 and Figure 6 It can be seen that the optical lens provided in Example 2 can achieve good imaging quality.

[0041] Specifically, as a preferred embodiment of the present invention but not limiting, Figure 7 FIG. 4 shows a schematic structural diagram of an optical imaging lens according to Embodiment 3 of the present application. Figure 4 As shown, the object side S1 of the first lens E1 is convex, the image side S2 is concave, and its optical power is negative; the object side S3 of the second lens E2 is concave, the image side S4 is convex, and its optical power is negative; the object side S5 of the third lens E3 is convex, the image side S6 is convex, and its optical power is positive; the object side S8 and the image side S9 of the fourth lens E4 are both convex, and its optical power is positive; the fifth lens E5 has optical power; the sixth lens E6 has optical power; the object side S13 of the seventh lens E7 is convex, the image side S14 is concave, and its optical power is positive; filter E8; light from the object passes through each surface in sequence and is finally imaged on the imaging surface.

[0042] Table 5 shows the surface type, curvature radius, thickness and material of each lens of the optical imaging lens of Example 3, wherein the units of the curvature radius and thickness are both millimeters (mm): Table 5: Basic parameters of the optical system of Example 3

[0043] In Table 5 above, any one of the object side and image side of the second lens E2, the fourth lens E4, the fifth lens E5, the sixth lens E6, and the seventh lens E7 is an aspherical surface, and the surface shape of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0044] Wherein, 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 vertex of the aspheric surface, k is the cone coefficient, and Ai is the coefficient corresponding to the i-th high-order term in the aspheric surface shape formula. Table 6 shows the cone coefficients and high-order term coefficients A4, A6, A8, A10, A12, A14, A16, and A20 of each aspheric surface that can be used in Example 3.

[0045] Table 6: Aspheric surface related values ​​of lens surface in Example 3

[0046] Figure 8The astigmatism and distortion curves of the optical imaging lens of Example 3 are shown. Astigmatism refers to the meridional image curvature and the sagittal image curvature; and distortion refers to the distortion magnitude values ​​corresponding to different image heights.

[0047] Fig. 9 The MTF curve of the optical imaging lens of Example 3 is shown, which represents the MTF values ​​in the meridian direction and sagittal direction of different fields of view.

[0048] Depend on Figure 8 and Fig. 9 It can be seen that the optical lens provided in Example 3 can achieve good imaging quality.

[0049] In Examples 1-3, the basic data are shown in Table 7 below: Table 7 Basic data of Examples 1-3

[0050] A camera lens comprises at least an optical lens, in which the above-mentioned day and night confocal wide-angle optical system is installed. The application has a reasonable number of lenses and a simple structure. By reasonably allocating the lens focal length, optimizing the lens aberration, and improving the resolution performance, it has a wide angle, a large aperture, a light weight, and excellent resolution, making the miniaturized wide-angle lens more competitive in the fields of smart doorbells, smart homes, etc.

[0051] As described above, one or more implementation methods are provided in combination with specific contents, and the specific implementation of the present invention is not limited to these descriptions. Any similarity or similarity with the method, structure, etc. of the present invention, or any technical deduction or replacement based on the concept of the present invention, shall be regarded as the protection scope of the present invention.

Claims

1. A day-night confocal optical system, which is composed of a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens in sequence from the object plane to the image plane along the optical axis, 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 negative; The object side of the third lens is convex or concave, the image side is convex, and its optical power is positive; The object side and the image side of the fourth lens are both convex, and its optical power is positive; The fifth lens has optical power; The sixth lens has optical power; The object side of the seventh lens is convex, the image side is concave, and its optical power is positive; Each lens of the optical system meets the following conditions: -6.7mm<f1<-3.5mm; -9.2mm<f2<-5.50mm; 2.50mm<f3<12.50mm; 2.50mm<f4<8.5mm; -5.3mm<f5<7.3mm; -7.5mm<f6<8.5mm; 5.7mm<f7<15mm; Among them, 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, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens.

2. The day and night confocal optical system according to claim 1, characterized in that: The curvature radius R1 of the object surface side of the first lens satisfies: R1<17mm.

3. The day and night confocal optical system according to claim 1, characterized in that: The optical system meets the following conditions: TTL ≤ 17.6 mm; Wherein, TTL is the axial distance from the object side of the first lens to the imaging surface.

4. The day and night confocal optical system according to claim 1, characterized in that: Each lens of the optical system meets the following conditions: 1.80<Nd1<2.00, 20.00<Vd1<50; 1.51<Nd2<1.62, 52.50<Vd2<58.00; 1.61<Nd3<2.1, 16<Vd3<35; 1.45<Nd4<1.62, 52.50<Vd4<85; 1.51<Nd5<1.73, 20.00<Vd5<57.00; 1.51<Nd6<1.67, 20.00<Vd6<60.00; 1.51<Nd7<1.62, 52.50<Vd7<58.00; Among them, Nd1 is the refractive index of the first lens, and Vd1 is the Abbe number of the first lens; Nd2 is the refractive index of the second lens, and Vd2 is the Abbe number of the second lens; Nd3 is the refractive index of the third lens, and Vd3 is the Abbe number of the third lens; Nd4 is the refractive index of the fourth lens, and Vd4 is the Abbe number of the fourth lens; Nd5 is the refractive index of the fifth lens, and Vd5 is the Abbe number of the fifth lens; Nd6 is the refractive index of the sixth lens, and Vd6 is the Abbe number of the sixth lens; Nd7 is the refractive index of the seventh lens, and Vd7 is the Abbe number of the seventh lens.

5. The day and night confocal optical system according to claim 1, characterized in that: The third lens is a spherical or aspherical lens.

6. The day and night confocal optical system according to claim 1, characterized in that: The FNO of the optical system satisfies: FNO≤1.

65.

7. The day and night confocal optical system according to claim 1, characterized in that: The full field of view FOV of the optical system satisfies: 160°≤FOV.

8. The day and night confocal optical system according to claim 1, characterized in that: The fourth lens and the fifth lens or the fifth lens and the sixth lens are cemented lenses; The refractive index Nda and Abbe number Vda of the two lenses of the glued lens, as well as the refractive index Ndb and Abbe number Vdb, satisfy: 1.45<Nda<1.62, 52.50<Vda<85; 1.51<Ndb<1.73, 20.00<Vdb<57.

00.

9. The day and night confocal optical system according to claim 1, characterized in that: The aperture stop of the optical system is located between the third lens and the fourth lens.

10. 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 described in any one of claims 1 to 9.

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