A day-night confocal optical system and its application in camera modules

Abstract

This invention provides a day / night confocal optical system and its application in a camera module, mainly composed of seven lenses. The first lens has a convex object side and a concave image side, with negative optical power. The second lens has a concave object side and a convex image side, with negative optical power. The third lens has either a convex or concave object side and a convex image side, with positive optical power. The fourth lens has convex object and image sides, with positive optical power. The fifth and sixth lenses each have optical power. The seventh lens has a convex object side and a concave image side, with positive optical power. The system has a reasonable number of lenses and a simple structure. By rationally allocating the optical power of the lenses, lens aberrations are optimized, and resolution performance is improved. It features a wide angle, a large aperture, light weight, and excellent resolution, making the miniaturized wide-angle lens more competitive in the market.

Description

Technical Field

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

[0002] With the advancement of science and technology and socio-economic development, camera lenses are widely used in smart doorbells or smart home systems. However, previous camera lenses or optical systems have shortcomings such as complex structure, large size, small angle of view, and poor day and night performance, making it difficult to meet users' needs. Summary of the Invention

[0003] This application aims to overcome the problems of small angle of view, large size and small light intake that exist in existing optical systems. On the one hand, this 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 optical power of the lenses, the lens aberration is optimized and the resolution performance is improved. It has a wide angle, a large aperture, light weight and excellent resolution, making the miniaturized wide-angle lens more competitive in fields such as smart doorbells and smart homes.

[0004] A day-night confocal optical system, consisting of a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially along the optical axis from the object plane to the image plane;

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

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

[0007] The object side of the third lens is convex or concave, and the image side is convex, and its optical power is positive.

[0008] The fourth lens has convex surfaces on both the object plane and the image plane, and its optical power is positive.

[0009] The fifth lens has optical power;

[0010] The sixth lens has optical power;

[0011] The seventh lens has a convex object plane and a concave image plane, and its optical power is positive.

[0012] As described above, in the day-night confocal wide-angle optical system, each lens of the optical system satisfies the following condition:

[0013] -6.7mm < f1 < -3.5mm;

[0014] -9.2mm < f2 < -5.50mm;

[0015] 2.50mm < f3 < 12.50mm;

[0016] 2.50mm < f4 < 8.5mm;

[0017] -5.3mm < f5 < 7.3mm;

[0018] -7.5mm < f6 < 8.5mm;

[0019] 5.7mm < f7 < 15mm;

[0020] Where 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.

[0021] As described above, in the day-night confocal wide-angle optical system, the radius of curvature R1 of the first lens object surface satisfies: R1 < 17 mm.

[0022] The day-night confocal wide-angle optical system described above satisfies the following condition: TTL ≤ 17.6mm;

[0023] Where TTL is the on-axis distance from the object side of the first lens to the imaging plane.

[0024] As described above, in the day-night confocal wide-angle optical system, each lens of the optical system satisfies the following condition:

[0025] 1.80<Nd1<2.00, 20.00<Vd1<50;

[0026] 1.51<Nd2<1.62, 52.50<Vd2<58.00;

[0027] 1.61<Nd3<2.1, 16<Vd3<35;

[0028] 1.45<Nd4<1.62, 52.50<Vd4<85;

[0029] 1.51<Nd5<1.73, 20.00<Vd5<57.00;

[0030] 1.51<Nd6<1.67, 20.00<Vd6<60.00;

[0031] 1.51<Nd7<1.62, 52.50<Vd7<58.00;

[0032] Wherein, 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.

[0033] In the day-night confocal wide-angle optical system described above, the third lens is either a spherical or aspherical lens.

[0034] The day-night confocal wide-angle optical system described above has an FNO that satisfies: FNO≤1.65.

[0035] As described above, the day-night confocal wide-angle optical system has a field of view (FOV) that satisfies: 160° ≤ FOV.

[0036] In the day-night confocal wide-angle optical system described above, the fourth lens and the fifth lens, or the fifth lens and the sixth lens, are cemented lenses; the refractive index Nda, Abbe number Vda, and refractive index Ndb, Abbe number Vdb of the two cemented lenses satisfy: 1.45 < Nda < 1.62, 52.50 < Vda < 85; 1.51 < Ndb < 1.73, 20.00 < Vdb < 57.00.

[0037] As described above, in the day-night confocal wide-angle optical system, the aperture stop of the optical system is located between the third lens and the fourth lens.

[0038] On the other hand, this application embodiment also provides a camera module, which includes at least an optical lens, and the above-mentioned day and night confocal optical system is installed in the optical lens.

[0039] Compared with the prior art, the beneficial effects of this application are as follows:

[0040] This invention provides a day and night confocal optical system and its application in a camera module, which mainly consists of 7 lenses. The number of lenses is reasonable and the structure is simple. By rationally allocating the optical power of the lenses, the lens aberration is optimized and the resolution performance is improved. It has a wide angle, a large aperture, light weight and excellent resolution, making the miniaturized wide-angle lens more competitive in the market. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0042] Figure 1This is a schematic diagram of the structure of the optical system or camera module in Embodiment 1 of this application;

[0043] Figure 2 This is a field curvature and distortion curve diagram of the optical system or camera module of Embodiment 1 of this application;

[0044] Figure 3 This is the MTF curve of the optical system or camera module of Embodiment 1 of this application;

[0045] Figure 4 This is a schematic diagram of the structure of the optical system or camera module in Embodiment 2 of this application;

[0046] Figure 5 This is a field curvature and distortion curve diagram of the optical system or camera module of Embodiment 2 of this application;

[0047] Figure 6 This is the MTF curve of the optical system or camera module in Embodiment 2 of this application;

[0048] Figure 7 This is a schematic diagram of the structure of the optical system or camera module in Embodiment 3 of this application;

[0049] Figure 8 This is a field curvature and distortion curve diagram of the optical system or camera module of Embodiment 3 of this application;

[0050] Figure 9 This is the MTF curve of the optical system or camera module in Embodiment 3 of this application. Detailed Implementation

[0051] like Figure 1-9 As shown, this 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 stop STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, and a seventh lens E7 in sequence along the optical axis from the object plane to the image plane.

[0052] The object plane side of the first lens is convex, and the image plane side is concave, and its optical power is negative.

[0053] The object plane side of the second lens is concave, and the image plane side is convex, and its optical power is negative.

[0054] The object side of the third lens is convex or concave, and the image side is convex, and its optical power is positive.

[0055] The fourth lens has convex surfaces on both the object plane and the image plane, and its optical power is positive.

[0056] The fifth lens has optical power;

[0057] The sixth lens has optical power;

[0058] The object plane side of the seventh lens is convex, the image plane side is concave, and its optical power is positive.

[0059] The optical system of this application embodiment mainly consists of 7 lenses. The number of lenses is reasonable and the structure is simple. By reasonably allocating the optical power of the lenses, the lens aberration is optimized and the resolution performance is improved. It has a wide angle, a large aperture, light weight and excellent resolution, which makes the miniaturized wide-angle lens more competitive in the market.

[0060] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, each lens of the optical system satisfies the following condition:

[0061] -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;

[0062] -9.2mm < f2 < -5.50mm; By constraining the effective focal length of the second lens E2 within a reasonable range, lens aberrations are optimized and image quality is improved;

[0063] 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 can be finely adjusted and controlled, thereby effectively improving the imaging quality of the system.

[0064] 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.

[0065] -5.3mm < f5 < 7.3mm; By constraining the effective focal length of the fifth lens E5 within a reasonable range, image quality is improved;

[0066] -7.5mm < f6 < 8.5mm; By constraining the effective focal length of the sixth lens E6 within a reasonable range, lens aberrations are optimized and resolving performance is improved;

[0067] 5.7mm < f7 < 15mm; By constraining the effective focal length of the seventh lens E7 within a reasonable range, lens aberrations are optimized and field curvature of the system is improved.

[0068] Where 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.

[0069] Furthermore, the refractive index Nd1 and 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.

[0070] Furthermore, the refractive index Nd2 and 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.

[0071] Furthermore, the refractive index Nd3 and 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.

[0072] Furthermore, the refractive index Nd4 and Abbe number Vd4 of the fourth lens 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.

[0073] Furthermore, the refractive index Nd5 and Abbe number Vd5 of the fifth lens 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.

[0074] Furthermore, the refractive index Nd6 and 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.

[0075] Furthermore, the refractive index Nd7 and 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.

[0076] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, the third lens E3 is a spherical or aspherical lens. By rationally allocating the lens surface shape, the lens aberration is optimized, the resolution performance is improved, and it has a wide angle, a large aperture, light weight, and excellent resolution.

[0077] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, the radius of curvature R1 of the object surface side of the first lens satisfies: R1 < 17mm. By controlling the object surface side of the first lens 1, the total deflection angle of the object surface side of the first lens 1 at the edge field of view can be reasonably controlled within a reasonable range.

[0078] Furthermore, as a preferred embodiment of the invention and not a limitation thereof, the optical system satisfies the following condition: TTL ≤ 17.6mm. This design can reduce the total optical length, thereby miniaturizing the lens and making the miniaturized wide-angle lens more competitive in the market.

[0079] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, 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 intake of the lens.

[0080] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, the refractive index Nda, Abbe number Vda, and refractive index Ndb, Abbe number Vdb of the two lenses in the cemented lens satisfy the following: 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.

[0081] Specifically, this is a preferred embodiment of the invention and not a limitation thereof. Figure 1 A schematic diagram of the structure of an optical imaging lens according to Embodiment 1 of this application is shown, as follows: Figure 1 As shown, the first lens E1 has a convex surface on its object side S1 and a concave surface on its image side S2, and its optical power is negative; the second lens E2 has a concave surface on its object side S3 and a convex surface on its image side S4, and its optical power is negative; the third lens E3 has a convex surface on its object side S5 and a convex surface on its image side S6, and its optical power is positive; the fourth lens E4 has convex surfaces on both its object side S8 and its image side S9, and its optical power is positive; the fifth lens E5 has optical power; the sixth lens E6 has optical power; the seventh lens E7 has a convex surface on its object side S13 and a concave surface on its image side S14, and its optical power is positive; and there is a filter E8; light from the object passes through each surface in sequence and finally forms an image on the imaging plane.

[0082] Table 1 shows the surface type, radius of curvature, thickness, and material of each lens in the optical imaging lens of Example 1, where the units for radius of curvature and thickness are millimeters (mm):

[0083] Table 1: Basic parameters of the optical system in Example 1

[0084]

[0085] In Table 1 above, the object-side surface and image-side surface of any one of the following lenses—E2, E3, E5, E6, and E7—are aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formulas:

[0086]

[0087] Where 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 higher-order term in the aspherical surface shape formula. Table 2 gives the conic coefficients and higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, and A20 that can be used for each aspherical surface in Example 1.

[0088] Table 2: Aspherical correlation values ​​of the lens surface in Example 1

[0089]

[0090] Figure 2 The astigmatism and distortion curves of the optical imaging lens of Example 1 are shown. Astigmatism represents the meridional image plane curvature and the sagittal image plane curvature; distortion represents the distortion magnitude corresponding to different image heights.

[0091] 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.

[0092] Depend on Figure 2 and Figure 3 It can be seen that the optical lens given in Example 1 can achieve good imaging quality.

[0093] Specifically, this is a preferred embodiment of the invention and not a limitation thereof. Figure 4 A schematic diagram of the structure of an optical imaging lens according to Embodiment 2 of this application is shown, as follows: Figure 4 As shown, the first lens E1 has a convex surface on its object side S1 and a concave surface on its image side S2, and its optical power is negative; the second lens E2 has a concave surface on its object side S3 and a convex surface on its image side S4, and its optical power is negative; the third lens E3 has a convex surface on its object side S5 and a convex surface on its image side S6, and its optical power is positive; the fourth lens E4 has convex surfaces on both its object side S8 and its image side S9, and its optical power is positive; the fifth lens E5 has optical power; the sixth lens E6 has optical power; the seventh lens E7 has a convex surface on its object side S1 and a concave surface on its image side S2, and its optical power is positive; and there is a filter E8; light from the object passes through each surface in sequence and finally forms an image on the imaging plane.

[0094] Table 3 shows the surface type, radius of curvature, thickness, and material of each lens in the optical imaging lens of Example 2, where the units for radius of curvature and thickness are millimeters (mm):

[0095] Table 3: Basic parameters of the optical system in Example 2

[0096]

[0097] In Table 3 above, the object-side surface and image-side surface of any one of the following lenses—E2, E4, E5, E6, and E7—are aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formulas:

[0098]

[0099] Where 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 higher-order term in the aspherical surface shape formula. Table 4 gives the conic coefficients and higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, and A20 that can be used for each aspherical surface in Example 2.

[0100] Table 4: Aspherical correlation values ​​of the lens surface in Example 2

[0101]

[0102] Figure 5 The astigmatism and distortion curves of the optical imaging lens of Example 2 are shown. Astigmatism represents the meridional image plane curvature and the sagittal image plane curvature; distortion represents the distortion magnitude corresponding to different image heights.

[0103] Figure 6 The MTF curve of the optical imaging lens of Example 2 is shown, which represents the MTF values ​​in the meridional and sagittal directions of different fields of view.

[0104] Depend on Figure 5 and Figure 6 It can be seen that the optical lens given in Example 2 can achieve good imaging quality.

[0105] Specifically, this is a preferred embodiment of the invention and not a limitation thereof. Figure 7 A schematic diagram of the structure of an optical imaging lens according to Embodiment 3 of this application is shown, as follows: Figure 4As shown, the first lens E1 has a convex surface on its object side S1 and a concave surface on its image side S2, and its optical power is negative; the second lens E2 has a concave surface on its object side S3 and a convex surface on its image side S4, and its optical power is negative; the third lens E3 has a convex surface on its object side S5 and a convex surface on its image side S6, and its optical power is positive; the fourth lens E4 has convex surfaces on both its object side S8 and its image side S9, and its optical power is positive; the fifth lens E5 has optical power; the sixth lens E6 has optical power; the seventh lens E7 has a convex surface on its object side S13 and a concave surface on its image side S14, and its optical power is positive; and there is a filter E8; light from the object passes through each surface in sequence and finally forms an image on the imaging plane.

[0106] Table 5 shows the surface type, radius of curvature, thickness, and material of each lens in the optical imaging lens of Example 3, where the units for radius of curvature and thickness are millimeters (mm):

[0107] Table 5: Basic parameters of the optical system in Example 3

[0108]

[0109] In Table 5 above, the object-side surface and image-side surface of any one of the following lenses—E2 (second lens), E4 (fourth lens), E5 (fifth lens), E6 (sixth lens), and E7 (seventh lens)—are aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formulas:

[0110]

[0111] Where 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 higher-order term in the aspherical surface shape formula. Table 6 gives the conic coefficients and higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, and A20 that can be used for each aspherical surface in Example 3.

[0112] Table 6: Aspherical Correlation Values ​​of Lens Surface in Example 3

[0113]

[0114] Figure 8 The astigmatism and distortion curves of the optical imaging lens of Example 3 are shown. Astigmatism represents the meridional image plane curvature and the sagittal image plane curvature; distortion represents the distortion magnitude corresponding to different image heights.

[0115] Figure 9 The MTF curve of the optical imaging lens of Example 3 is shown, which represents the MTF values ​​in the meridional and sagittal directions of different fields of view.

[0116] Depend on Figure 8 and Figure 9 It can be seen that the optical lens given in Example 3 can achieve good imaging quality.

[0117] The basic data for Examples 1-3 are shown in Table 7 below:

[0118] Table 7 Basic Data for Examples 1-3

[0119]

[0120] A camera lens, comprising at least an optical lens, wherein the optical lens is equipped with the aforementioned day and night confocal wide-angle optical system, has a reasonable number of lenses and a simple structure. By rationally allocating the optical power of the lenses, the lens aberrations are optimized and the resolution performance is improved. It has a wide angle, a large aperture, light weight, and excellent resolution, making the miniaturized wide-angle lens more competitive in fields such as smart doorbells and smart homes.

[0121] The above description provides one or more embodiments in conjunction with specific content, and does not imply that the specific implementation of the present invention is limited to these descriptions. Any methods or structures that are similar to or identical to those of the present invention, or any technical deductions or substitutions made based on the concept of the present invention, should be considered within the scope of protection of the present invention.

Claims

1. A day-night confocal optical system, comprising, sequentially from the object plane to the image plane, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, characterized in that: The object plane side of the first lens is convex, and the image plane side is concave, and its optical power is negative. The object plane side of the second lens is concave, and the image plane side is convex, and its optical power is negative. The object side of the third lens is convex or concave, and the image side is convex, and its optical power is positive. The fourth lens has convex surfaces on both the object plane and the image plane, and its optical power is positive. The fifth lens has optical power; The sixth lens has optical power; The object plane side of the seventh lens is convex, the image plane side is concave, and its optical power is positive. Each lens in this optical system satisfies the following condition: -5.46mm≤f1≤-3.93mm; -7.38mm≤f2≤-6.69mm; 4.83mm≤f3≤11.15mm; 3.79mm≤f4≤6.22mm; -3.02mm≤f5≤6.41mm; -4.52mm≤f6≤6.27mm; 7.27mm≤f7≤10.89mm; Where 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-night confocal optical system according to claim 1, characterized in that: The radius of curvature R1 on the object side of the first lens satisfies: R1 < 17 mm.

3. The day-night confocal optical system according to claim 1, characterized in that: The optical system meets the following condition: TTL ≤ 17.6mm; Where TTL is the on-axis distance from the object side of the first lens to the imaging plane.

4. The day-night confocal optical system according to claim 1, characterized in that: Each lens in this optical system satisfies the following condition: 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; Wherein, 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-night confocal optical system according to claim 1, characterized in that: The third lens is either a spherical or aspherical lens.

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

65.

7. The day-night confocal optical system according to claim 1, characterized in that: The field of view (FOV) of this optical system satisfies: FOV ≥ 160°.

8. The day-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, Abbe number Vda, and refractive index Ndb, Abbe number Vdb of the two lenses in a cemented lens satisfy the following conditions: 1.45 < Nda < 1.62, 52.50 < Vda < 85. 1.51<Ndb<1.73, 20.00<Vdb<57.

00.

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

10. A camera module, comprising at least an optical lens, characterized in that: The optical lens is equipped with the day-night confocal optical system as described in any one of claims 1-9.

Images