Wide-angle day and night confocal optical system and application camera module thereof

Abstract

The application provides a wide-angle day and night confocal optical system and an application camera module thereof, which comprises the following: a first lens, the object side of which is a convex surface, the image side is a concave surface, and the optical power is negative; a second lens, the object side of which is a convex surface, the image side is a concave surface, and the optical power is negative; a third lens, the object side and the image side of which are both concave surfaces, and the optical power is negative; a fourth lens, the object side and the image side of which are both convex surfaces, and the optical power is positive; a fifth lens, the object side and the image side of which are both convex surfaces, and the optical power is positive; a sixth lens, which has optical power; a seventh lens, which has optical power; and an eighth lens, which has positive optical power, the object side and the image side of which are both convex surfaces; by reasonably distributing the optical power of the lenses, optimizing the lens aberration, and improving the imaging quality of the optical system, the characteristics of high illumination, large aperture, day and night confocal, and excellent temperature characteristics are considered, and the optical system has great potential in the IPC market.

Description

Technical Field

[0001] This application relates to the field of optical imaging, and more particularly to a wide-angle day and night confocal optical system and its application in camera modules. Background Technology

[0002] With the advancement of science and technology and the development of society and the economy, camera lenses are widely used in various fields, especially in the field of doorbell security monitoring. However, previous camera lenses or optical systems have shortcomings such as low pixel count, small field of view, poor day and night performance, and low light intake, which make it difficult to meet the needs of users. Summary of the Invention

[0003] To overcome the technical problems of existing optical lenses, such as low pixel count, small field of view, poor day and night performance, and low light intake, this application provides a wide-angle day and night confocal optical system. By rationally allocating the surface shape and optical power of each lens, the lens aberration is optimized, resulting in excellent resolution, high pixel count, wide angle, large aperture, and day and night confocal performance, making it more competitive in the IPC market.

[0004] A wide-angle day-night confocal optical system, comprising, along the optical axis 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, a seventh lens, and an eighth lens; The first lens has negative optical power, and its object side is convex while its image side is concave. The second lens has negative optical power, with its object side being convex and its image side being concave. The third lens has negative optical power, and both its object-side and image-side surfaces are concave. The fourth lens has positive optical power, and both its object side and image side are convex. The fifth lens has positive optical power, and both its object-side and image-side surfaces are convex. The sixth lens has optical power; The seventh lens has optical power; The eighth lens has positive optical power, and both its object side and image side are convex.

[0005] Furthermore, each lens in this optical system satisfies the following condition: -5.0 < f1 / f < -4.0; -2.5 < f² / f < -1.3; -3.0 < f3 / f < -1.5; 1.7 < f4 / f < 2.2; 1.7 < f5 / f < 3.0; -11.0 < f6 / f < -1.5; -5.0 < f7 / f < 4.5; 1.4 < f8 / f < 3.5; Where 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, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, and f8 is the focal length of the eighth lens.

[0006] Furthermore, each lens in this optical system satisfies the following condition: 1.65<Nd1<2.02, 15<Vd1<65; 1.45<Nd2<1.75, 15<Vd2<65; 1.45<Nd3<1.75, 18<Vd3<76; 1.45<Nd4<1.95, 15<Vd4<65; 1.45<Nd5<1.75, 20<Vd5<75; 1.41<Nd6<1.75, 18<Vd6<76; 1.45<Nd7<1.75, 19<Vd7<76; 1.43<Nd8<1.75, 20<Vd8<76; 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; Nd8 is the refractive index of the eighth lens, and Vd8 is the Abbe number of the eighth lens.

[0007] Furthermore, the first and fourth lenses are glass spherical lenses, while the other lenses are plastic aspherical lenses.

[0008] Furthermore, the aperture of the optical system is positioned between the fourth lens and the fifth lens.

[0009] Furthermore, the sixth and seventh lenses are bonded together to form a combined lens.

[0010] Furthermore, the optical system satisfies: 11.0 < TTL / (ImgH / 2) < 14.5; 41.0 < TTL / (EPD / 2) < 45.5; where TTL is the on-axis distance from the object side of the first lens to the imaging plane, ImgH is half the diagonal length of the effective pixel area on the imaging plane, and EPD is the entrance pupil diameter of the optical imaging lens.

[0011] Furthermore, the optical system satisfies: 2.8 < f * tan(FOV) / (DT1 / 2) < 4.0; where f is the focal length of the entire optical system, FOV is half of the maximum field of view of the imaging system, and DT1 is the effective half-aperture of the object side of the first lens.

[0012] On the other hand, embodiments of this application also provide a camera module, which includes at least an optical lens, and the optical system described above is installed in the optical lens.

[0013] Compared with the prior art, the beneficial effects of this application are as follows: This invention provides a wide-angle day and night confocal optical system and its application in a camera module. It mainly consists of 8 lenses with a reasonable number of lenses and a simple structure. By rationally allocating the optical power of the lenses, lens aberrations are optimized, and the imaging quality of the optical system is improved. It has excellent resolution, high pixel count, wide field of view, large aperture, and day and night confocality, making it more competitive in the IPC market. Attached Figure Description

[0014] 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.

[0015] Figure 1 This is a schematic diagram of the structure of the optical system or camera module in Embodiment 1 of this application; Figure 2 This is the defocus curve of the optical system or camera module in the visible light band of Embodiment 1 of this application; Figure 3 This is the defocus curve of the optical system or camera module in the near-infrared band of Embodiment 1 of this application; Figure 4 This is a schematic diagram of the structure of the optical system or camera module in Embodiment 2 of this application; Figure 5 This is the defocus curve of the optical system or camera module in the visible light band of Embodiment 2 of this application; Figure 6 This is the defocus curve of the optical system or camera module in the near-infrared band of Embodiment 2 of this application; Figure 7 This is a schematic diagram of the structure of the optical system or camera module in Embodiment 3 of this application; Figure 8 This is the defocus curve of the optical system or camera module in the visible light band of Embodiment 3 of this application; Figure 9 This is the defocus curve of the near-infrared band of the optical system or camera module in Embodiment 3 of this application. Detailed Implementation

[0016] like Figure 1-9 As shown, this application provides a wide-angle day-night confocal optical system, which includes, along the optical axis from the object plane to the image plane, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, an aperture stop STO, a sixth lens 6, a seventh lens 7, an eighth lens 8, a color filter 9, and a chip protection sheet 10, wherein: The first lens 1 has negative optical power, and its object side is convex and its image side is concave. The second lens 2 has negative optical power, and its object side is convex and its image side is concave. The third lens 3 has negative optical power, and both its object side and image side are concave. The fourth lens 4 has positive optical power, and both its object side and image side are convex. The fifth lens 5 has positive optical power, and both its object side and image side are convex. The sixth lens 6 has optical power; The seventh lens 7 has optical power; The eighth lens 8 has positive optical power, and both its object side and image side are convex.

[0017] This invention provides a wide-angle day and night confocal optical system and its application in a camera module, which is mainly composed of eight 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 imaging quality of the optical system is improved. With its excellent characteristics such as high pixel count, wide angle, and day and night confocality, it has great potential in the IPC market.

[0018] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, each lens of the optical system satisfies the following condition, wherein 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, f7 is the focal length of the seventh lens, and f8 is the focal length of the eighth lens: -5.0 < f1 / f < -4.0; This design allows the optical power of the first lens 1 to be within a reasonable range, which helps to reduce astigmatism and field curvature of the optical system. -2.5 < f2 / f < -1.3; By constraining the optical power of the second lens 2 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. -3.0 < f3 / f < -1.5; By constraining the optical power of the third lens 3 within a reasonable range, the optical system has the advantages of wide angle, day and night confocality, and excellent temperature characteristics. 1.7 < f4 / f < 2.2; By constraining the optical power of the fourth lens 4 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. 1.7 < f5 / f < 3.0; By constraining the optical power of the fifth lens 5 within a reasonable range, the coma of the system can be finely adjusted and controlled, achieving day and night cofocality and excellent temperature characteristics. -11.0 < f6 / f < -1.5; By constraining the optical power of the sixth lens 6 within a reasonable range, the field curvature astigmatism of the system is compensated, thereby effectively improving the imaging quality of the system. -5.0 < f7 / f < 4.5; By constraining the optical power of the seventh lens 7 within a reasonable range, the field curvature astigmatism of the system is compensated, thereby effectively improving the imaging quality of the system. 1.4 < f8 / f < 3.5; By constraining the optical power of the eighth lens 8 within a reasonable range, the overall aberration of the system can be finely adjusted and controlled, thereby effectively improving the imaging quality of the system. Furthermore, the refractive index Nd1 and Abbe number Vd1 of the first lens 1 satisfy: 1.65 < Nd1 < 2.02, 15 < Vd1 < 65; 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 Abbe number Vd2 of the second lens 2 satisfy: 1.45 < Nd2 < 1.75, 15 < Vd2 < 65; 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 Abbe number Vd3 of the third lens 3 satisfy: 1.45 < Nd3 < 1.75, 18 < Vd3 < 76; 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 Abbe number Vd4 of the fourth lens 4 satisfy: 1.45 < Nd4 < 1.95, 15 < Vd4 < 65; 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 Abbe number Vd5 of the fifth lens 5 satisfy: 1.45 < Nd5 < 1.75, 20 < Vd5 < 75; 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 Abbe number Vd6 of the sixth lens 6 satisfy: 1.41 < Nd6 < 1.75, 18 < Vd6 < 76; 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 Abbe number Vd7 of the seventh lens 7 satisfy: 1.45 < Nd7 < 1.75, 19 < Vd7 < 76; this design can effectively reduce chromatic aberration, optimize lens aberration, and thus effectively improve the imaging quality of the system. Furthermore, the refractive index Nd8 and Abbe number Vd8 of the eighth lens 8 satisfy: 1.43 < Nd8 < 1.75, 20 < Vd8 < 76; 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 and not a limitation thereof, the first lens 1 and the fourth lens 4 are glass spherical lenses, and the other lenses are aspherical lenses, namely the second lens 2, the third lens 3, the fifth lens 5, the sixth lens 6, the seventh lens 7 and the eighth lens 8 are aspherical lenses, thereby enabling reasonable control of the temperature drift.

[0019] Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, the aperture stop is disposed between the fourth lens 4 and the fifth lens 5, which can effectively improve the resolution of the system; Furthermore, the optical system satisfies the following conditions: 11.0 < TTL / (ImgH / 2) < 14.5, 41.0 < TTL / (EPD / 2) < 45.5, which can effectively control the total length of the lens, thereby increasing the field of view and aperture of the lens. Here, TTL is the on-axis distance from the object side of the first lens 1 to the imaging plane, ImgH is half the diagonal length of the effective pixel area on the imaging plane, and EPD is the entrance pupil diameter of the optical imaging lens. By controlling the relationship between the total length of the optical system and the imaging area and the entrance pupil diameter, the miniaturization of high-pixel wide-angle lenses can be achieved. Furthermore, the optical system has a diagonal half-field angle (FOV) of ≥80° and a maximum image circle (MIC) of ≥6.1mm, which helps to expand the field of view and meet user needs. Furthermore, as a preferred embodiment of the present invention and not a limitation thereof, the sixth lens 6 and the seventh lens 7 are bonded together to form a combined lens. This design increases the difference between the refractive index and the Abbe number of the lens, which can effectively reduce chromatic aberration. Specific implementation examples: Example 1: The following is for reference Figures 1 to 3 Describes an optical imaging lens according to Embodiment 1 of this application. Figure 1 A schematic diagram of the structure of an optical imaging lens according to Embodiment 1 of this application is shown.

[0021] like Figure 1 As shown, the optical imaging lens according to an exemplary embodiment of this application includes, in sequence along the optical axis from the object side to the image side: first lenses S1 and S2, second lenses S3 and S4, third lenses S5 and S6, fourth lenses S7 and S8, aperture S10, fifth lenses S9 and S10, sixth lenses S11 and S12, seventh lenses S12 and S13, eighth lenses S14 and S15, filters S16 and S17, chip protection sheets S18 and S19, and an imaging surface.

[0022] Figure 2 The visible light defocus curve of the optical imaging lens of Embodiment 1 is shown, which represents the on-axis peak value and back focus shift of the central field of view at the same spatial frequency. Figure 3 The infrared defocus curve of the optical imaging lens of Embodiment 1 is shown, which represents the on-axis peak value and back focus shift of the central field of view at the same spatial frequency. Figure 2 , Figure 3 It can be seen that the optical system given in Example 1 can achieve good imaging quality and has higher imaging quality.

[0023] Specifically, this is a preferred embodiment of the invention and not a limitation thereof, such as Figures 1 to 3 As shown, in this embodiment 1, the focal length of the first lens 1 is f1 = -9.36 mm, the focal length of the second lens 2 is f2 = -4.83 mm, the focal length of the third lens 3 is f3 = -5.62 mm, the focal length of the fourth lens 4 is f4 = 3.96 mm, the focal length of the fifth lens 5 is f5 = 3.67 mm, the focal length of the sixth lens 6 is f6 = -3.19 mm, the focal length of the seventh lens 7 is f7 = 8.43 mm, the focal length of the eighth lens 8 is f8 = 6.64 mm, and the total optical length TTL = 18.00 mm. The surface type, radius of curvature, thickness, and material parameters of each lens are shown in Table 1. Table 1: Basic parameters of the optical system in Example 1

[0024] In Table 1, along the optical axis from the object plane to the image plane, OBJ is the object plane; S1 and S2 correspond to the two surfaces of the first lens 1; S3 and S4 correspond to the two surfaces of the second lens 2; STO is the location of the aperture stop; S5 and S6 correspond to the two surfaces of the third lens 3; S7 and S8 correspond to the two surfaces of the fourth lens 4; S8 and S9 correspond to the two surfaces of the fifth lens 5; S10 and S11 correspond to the two surfaces of the sixth lens 6; S12 and S13 correspond to the two surfaces of the seventh lens 7; S14 and S15 correspond to the two surfaces of the eighth lens 8; S16 and S17 correspond to the two surfaces of the color filter 9; S18 and S19 correspond to the two surfaces of the chip protection sheet 10; IMA corresponds to the image plane 11.

[0025] Furthermore, in Table 1, the surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formulas:

[0026] 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 coefficients A4, A6, A8, A10, A12, A14, and A16 that can be used for each aspherical surface in Example 1.

[0027] Table 2: Aspherical correlation values ​​of the lens surface in Example 1

[0028] Example 2: The following is for reference Figures 4 to 6 Describes an optical imaging lens according to Embodiment 2 of this application. Figure 4 A schematic diagram of the structure of an optical imaging lens according to Embodiment 2 of this application is shown.

[0029] like Figure 4 As shown, the optical imaging lens according to an exemplary embodiment of this application includes, in sequence along the optical axis from the object side to the image side: first lenses S1 and S2, second lenses S3 and S4, third lenses S5 and S6, fourth lenses S7 and S8, aperture S10, fifth lenses S9 and S10, sixth lenses S11 and S12, seventh lenses S12 and S13, eighth lenses S14 and S15, filters S16 and S17, chip protection sheets S18 and S19, and an imaging surface.

[0030] Figure 5 The visible light defocus curve of the optical imaging lens of Embodiment 2 is shown, which represents the on-axis peak value and back focus shift of the central field of view at the same spatial frequency. Figure 6 The infrared defocus curve of the optical imaging lens of Embodiment 2 is shown, which represents the on-axis peak value and back focus shift of the central field of view at the same spatial frequency. Figure 5 , Figure 6 It can be seen that the optical system given in Example 2 can achieve good imaging quality and has higher imaging quality.

[0031] Specifically, this is a preferred embodiment of the invention and not a limitation thereof, such as Figures 4 to 6As shown, in this embodiment 2, the focal length of the first lens 1 is f1 = -13.25mm, the focal length of the second lens 2 is f2 = -4.18mm, the focal length of the third lens 3 is f3 = -5.21mm, the focal length of the fourth lens 4 is f4 = 5.27mm, the focal length of the fifth lens 5 is f5 = 5.33mm, the focal length of the sixth lens 6 is f6 = -31.22mm, the focal length of the seventh lens 7 is f7 = -13.56mm, the focal length of the eighth lens 8 is f8 = 4.44mm, and the total optical length TTL is 19.02mm. The surface type, radius of curvature, thickness, and material parameters of each lens are shown in Table 3. Table 3: Basic parameters of the optical system in Example 2

[0032] In Table 3 above, along the optical axis from the object plane to the image plane, OBJ is the object plane; S1 and S2 correspond to the two surfaces of the first lens 1; S3 and S4 correspond to the two surfaces of the second lens 2; STO is the location of the aperture stop; S5 and S6 correspond to the two surfaces of the third lens 3; S7 and S8 correspond to the two surfaces of the fourth lens 4; S8 and S9 correspond to the two surfaces of the fifth lens 5; S10 and S11 correspond to the two surfaces of the sixth lens 6; S12 and S13 correspond to the two surfaces of the seventh lens 7; S14 and S15 correspond to the two surfaces of the eighth lens 8; S16 and S17 correspond to the two surfaces of the color filter 9; S18 and S19 correspond to the two surfaces of the chip protection sheet 10; IMA corresponds to the image plane 11.

[0033] Furthermore, the surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formulas:

[0034] 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, A18, and A20 that can be used for each aspherical surface in Example 2.

[0035] Table 4: Aspherical correlation values ​​of the lens surface in Example 2

[0036] Example 3: The following is for reference Figures 7 to 9 Describes an optical imaging lens according to Embodiment 3 of this application. Figure 7 A schematic diagram of the structure of an optical imaging lens according to Embodiment 3 of this application is shown.

[0037] like Figure 7 As shown, the optical imaging lens according to an exemplary embodiment of this application includes, in sequence along the optical axis from the object side to the image side: first lenses S1 and S2, second lenses S3 and S4, third lenses S5 and S6, fourth lenses S7 and S8, aperture S10, fifth lenses S9 and S10, sixth lenses S11 and S12, seventh lenses S12 and S13, eighth lenses S14 and S15, filters S16 and S17, chip protection sheets S18 and S19, and an imaging surface.

[0038] Figure 8 The visible light defocus curve of the optical imaging lens of Embodiment 3 is shown, which represents the on-axis peak value and back focus shift of the central field of view at the same spatial frequency. Figure 9 The infrared defocus curve of the optical imaging lens of Embodiment 3 is shown, which represents the on-axis peak value and back focus shift of the central field of view at the same spatial frequency. Figure 8 , Figure 9 It can be seen that the optical system given in Example 3 can achieve good imaging quality and has higher imaging quality.

[0039] Specifically, this is a preferred embodiment of the invention and not a limitation thereof, such as Figure 7-9 As shown, in this embodiment 3, the focal length of the first lens 1 is f1 = -8.36mm, the focal length of the second lens 2 is f2 = -4.39mm, the focal length of the third lens 3 is f3 = -5.35mm, the focal length of the fourth lens 4 is f4 = 4.08mm, the focal length of the fifth lens 5 is f5 = 5.88mm, the focal length of the sixth lens 6 is f6 = -14.67mm, the focal length of the seventh lens 7 is f7 = -9.25mm, the focal length of the eighth lens 8 is f8 = 3.85mm, and the total optical length TTL is 18.01mm. The surface type, radius of curvature, thickness, and material parameters of each lens are shown in Table 5. Table 5: Basic parameters of the optical system in Example 3

[0040] In Table 5 above, along the optical axis from the object plane to the image plane, OBJ is the object plane; S1 and S2 correspond to the two surfaces of the first lens 1; S3 and S4 correspond to the two surfaces of the second lens 2; STO is the location of the aperture stop; S5 and S6 correspond to the two surfaces of the third lens 3; S7 and S8 correspond to the two surfaces of the fourth lens 4; S8 and S9 correspond to the two surfaces of the fifth lens 5; S10 and S11 correspond to the two surfaces of the sixth lens 6; S12 and S13 correspond to the two surfaces of the seventh lens 7; S14 and S15 correspond to the two surfaces of the eighth lens 8; S16 and S17 correspond to the two surfaces of the color filter 9; S18 and S19 correspond to the two surfaces of the chip protection sheet 10; IMA corresponds to the image plane 11.

[0041] Furthermore, the surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formulas:

[0042] 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, A18, and A20 of each aspherical surface that can be used in Example 3.

[0043] Table 6: Aspherical Correlation Values ​​of Lens Surface in Example 3

[0044] Furthermore, in Examples 1-3, the basic data is as follows: Table 7: Basic Data for Examples 1-3

[0045] An embodiment of a camera module includes at least an optical lens. The optical system, along the optical axis from the object plane to the image plane, includes a first lens 1, a second lens 2, an aperture stop 10, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, a color filter 9, and a chip protection sheet 10. By rationally allocating the surface shape and optical power of each lens, the lens aberrations are optimized, giving it excellent resolution, high pixel count, large aperture, no pyrolysis, day and night cofocus, and light weight, making it more competitive in the IPC market.

[0046] 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 wide-angle day-night confocal optical system, characterized in that: Along the optical axis from the object plane to the image plane, the lenses are sequentially arranged as follows: first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens. The first lens has negative optical power, and its object side is convex while its image side is concave. The second lens has negative optical power, with its object side being convex and its image side being concave. The third lens has negative optical power, and both its object-side and image-side surfaces are concave. The fourth lens has positive optical power, and both its object side and image side are convex. The fifth lens has positive optical power, and both its object-side and image-side surfaces are convex. The sixth lens has optical power; The seventh lens has optical power; The eighth lens has positive optical power, and both its object side and image side are convex.

2. The wide-angle day-night confocal optical system according to claim 1, characterized in that: The optical system satisfies: 11.0 < TTL / (ImgH / 2) < 14.5; Where TTL is the axial 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 wide-angle day-night confocal optical system according to claim 1, characterized in that: Each lens in this optical system satisfies the following condition: 1.65<Nd1<2.02, 15<Vd1<65; 1.45<Nd2<1.75, 15<Vd2<65; 1.45<Nd3<1.75, 18<Vd3<76; 1.45<Nd4<1.95, 15<Vd4<65; 1.45<Nd5<1.75, 20<Vd5<75; 1.41<Nd6<1.75, 18<Vd6<76; 1.45<Nd7<1.75, 19<Vd7<76; 1.43<Nd8<1.75, 20<Vd8<76; 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; Nd8 is the refractive index of the eighth lens, and Vd8 is the Abbe number of the eighth lens.

4. The wide-angle day-night confocal optical system according to any one of claims 1-3, characterized in that: Each lens in the optical system satisfies the following condition: -5.0 < f1 / f < -4.0; -2.5 < f² / f < -1.3; -3.0 < f3 / f < -1.5; 1.7 < f4 / f < 2.2; 1.7 < f5 / f < 3.0; -11.0 < f6 / f < -1.5; -5.0 < f7 / f < 4.5; 1.4 < f8 / f < 3.5; Where 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, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, and f8 is the focal length of the eighth lens.

5. The wide-angle day-night confocal optical system according to any one of claims 1-3, characterized in that: The first and fourth lenses are glass spherical lenses, while the other lenses are plastic aspherical lenses.

6. The wide-angle day-night confocal optical system according to any one of claims 1-3, characterized in that: The aperture of the optical system is positioned between the fourth lens and the fifth lens.

7. The wide-angle day-night confocal optical system according to any one of claims 1-3, characterized in that: The sixth and seventh lenses are bonded together to form a combined lens.

8. The wide-angle day-night confocal optical system according to any one of claims 1-3, characterized in that: This optical system satisfies: 41.0 < TTL / (EPD / 2) < 45.5; Where TTL is the axial distance from the object side of the first lens to the imaging plane, and EPD is the entrance pupil diameter of the optical imaging lens.

9. The wide-angle day-night confocal optical system according to any one of claims 1-3, characterized in that: The optical system satisfies the following conditions: 2.8<f*tan(FOV) / (DT1 / 2)<4.0; Wherein, FOV is half of the maximum field of view of the optical system imaging system, and DT1 is the effective half-aperture of the object side of the first lens.

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

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