A small-volume wide-angle day-night dual-use optical system and a camera module using the same

Abstract

The present application provides a small-volume, wide-angle, day-and-night optical system and a camera module used therein. The optical system is mainly composed of 7 lenses, with a reasonable number of lenses, a simple structure, a small volume, a light weight, a low cost, and a high pixel count. Through the mutual combination of different lenses and the reasonable distribution of optical focal length, a sufficient field of view can be ensured while pursuing miniaturization, and there is no out-of-focus during the day or at night, and the system is particularly suitable for smart doorbells or smart home systems.

Description

Technical Field

[0001] The present application relates to an optical system and a camera module used therein, and in particular to a small-volume, wide-angle, day-and-night optical system and a camera module used therein for use in a smart doorbell or smart home system. Background Art

[0002] At present, photography modules are widely used in smart home systems such as video doorbell products. Previous camera modules or optical systems have defects such as complex structure, large size, small viewing angle, low pixel, and poor day and night effects, which can hardly meet the needs of users. Summary of the invention

[0003] In order to overcome the problems of complex structure and large size of existing photographic modules or optical systems, the present application provides a small-volume, wide-angle, day and night dual-use optical system.

[0004] A small-volume wide-angle day and night 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;

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

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

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

[0008] The fourth lens has a convex object surface and a convex image surface, and its optical power is positive;

[0009] The object side of the fifth lens is concave, the image side is concave, and its optical power is negative;

[0010] The object side of the sixth lens is convex, the image side is concave, and its optical power is positive;

[0011] The object side of the seventh lens is convex, the image side is convex, and its optical power is positive.

[0012] Preferably, the optical system meets the following conditions:

[0013] -5.84<f1 / f<-5.54; and / or

[0014] -2.64<f2 / f<-2.41; and / or

[0015] 3.98<f3 / f<4.22; and / or

[0016] 2.68<f4 / f<2.92; and / or

[0017] -2.31<f56 / f<-2.09; and / or

[0018] 2.29<f7 / f<2.51;

[0019] Among them, 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, f56 is the combined focal length of the fifth lens and the sixth lens, and f7 is the focal length of the seventh lens.

[0020] Preferably, the material refractive index Nd1 and the material Abbe constant Vd1 of the first lens satisfy: Nd1>1.68, Vd1<55; and / or

[0021] The material refractive index Nd2 and the material Abbe constant Vd2 of the second lens satisfy: Nd2<1.55, Vd2>54; and / or

[0022] The material refractive index Nd3 and the material Abbe constant Vd3 of the third lens satisfy: Nd3>1.65, Vd3<21; and / or

[0023] The material refractive index Nd4 and the material Abbe constant Vd4 of the fourth lens satisfy: Nd4<1.51, Vd4>80; and / or

[0024] The material refractive index Nd5 and the material Abbe constant Vd5 of the fifth lens satisfy: Nd5>1.65, Vd5<21; and / or

[0025] The material refractive index Nd6 and the material Abbe constant Vd6 of the sixth lens satisfy: Nd6<1.55, Vd6>54; and / or

[0026] The material refractive index Nd7 and the material Abbe constant Vd7 of the seventh lens satisfy: Nd7<1.55, Vd7>54.

[0027] Preferably, the fifth lens and the sixth lens are glued together to form a combined lens.

[0028] Preferably, the aperture is arranged between the third lens and the fourth lens.

[0029] Preferably, the second lens, the third lens, the fifth lens, the sixth lens and the seventh lens are plastic aspherical lenses.

[0030] Preferably, the horizontal field of view angle satisfies: 140°≤HFOV≤160°.

[0031] On the other hand, an embodiment of the present application also provides a camera module.

[0032] A camera module comprises at least an optical lens, in which the above-mentioned small-volume wide-angle day and night dual-purpose optical system is installed.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present application provides a small-volume, wide-angle, day and night dual-purpose optical system, which is mainly composed of 7 lenses, has a reasonable number of lenses, a simple structure, a small volume, a light weight, a low cost, and a high pixel. Through the mutual combination of different lenses and the reasonable distribution of optical focal length, it can ensure a sufficient field of view while pursuing miniaturization, and there is no out-of-focus during the day and at night. It is particularly suitable for smart doorbells or smart home systems.

[0035] The present application provides a camera module, the optical system of which is mainly composed of 7 lenses. The number of lenses is reasonable and the structure is simple. Through the mutual combination of different lenses and the reasonable distribution of optical focal length, it can ensure a sufficient field of view while pursuing miniaturization, and there is no out-of-focus during the day and at night. It is especially suitable for smart doorbells or smart home systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] 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.

[0037] Figure 1 It is a structural schematic diagram of the optical system or camera module of the present application;

[0038] Figure 2 It is a visible light MTF curve of the lens of the optical system or camera module of the present application;

[0039] Figure 3 It is the infrared light MTF curve of the lens of the optical system or camera module of the present application;

[0040] Figure 4 It is a lens distortion curve diagram of the optical system or camera module of the present application. DETAILED DESCRIPTION

[0041] like Figure 1 As shown, the present application provides a small-volume wide-angle day and night optical system, which is composed of a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6 and a seventh lens 7 in sequence from the object plane to the image plane along the optical axis.

[0042] The object side of the first lens 1 is convex, the image side is concave, and its optical power is negative;

[0043] The object side of the second lens 2 is convex, the image side is concave, and its optical power is negative;

[0044] The object side of the third lens 3 is convex, the image side is convex, and its optical power is positive;

[0045] The fourth lens 4 has a convex surface on the object side and a convex surface on the image side, and its optical power is positive;

[0046] The object side of the fifth lens 5 is concave, the image side is concave, and its optical power is negative;

[0047] The object side of the sixth lens 6 is convex, the image side is concave, and its optical power is positive;

[0048] The object side of the seventh lens 7 is convex, the image side is convex, and its optical power is positive.

[0049] The present application provides a small-volume, wide-angle, day and night dual-purpose optical system, which is mainly composed of 7 lenses, has a reasonable number of lenses, a simple structure, a small volume, a light weight, a low cost, and a high pixel. Through the mutual combination of different lenses and the reasonable distribution of optical focal length, it can ensure a sufficient field of view while pursuing miniaturization, and there is no out-of-focus during the day and at night. It is particularly suitable for smart doorbells or smart home systems.

[0050] Preferably, the optical system meets the following conditions:

[0051] -5.84<f1 / f<-5.54; and / or

[0052] -2.64<f2 / f<-2.41; and / or

[0053] 3.98<f3 / f<4.22; and / or

[0054] 2.68<f4 / f<2.92; and / or

[0055] -2.31<f56 / f<-2.09; and / or

[0056] 2.29<f7 / f<2.51;

[0057] Among them, 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, f56 is the combined focal length of the fifth lens and the sixth lens, and f7 is the focal length of the seventh lens. Through the mutual combination of different lenses and the reasonable distribution of optical focal length, sufficient field of view can be guaranteed while pursuing miniaturization, and there is no out-of-focus during the day and at night.

[0058] Preferably, the material refractive index Nd1 and the material Abbe constant Vd1 of the first lens satisfy: Nd1>1.68, Vd1<55; the structure is simple and good optical performance can be guaranteed.

[0059] The material refractive index Nd2 and the material Abbe constant Vd2 of the second lens satisfy: Nd2<1.55, Vd2>54; the structure is simple and good optical performance can be guaranteed.

[0060] The material refractive index Nd3 and the material Abbe constant Vd3 of the third lens satisfy: Nd3>1.65, Vd3<21; the structure is simple and good optical performance can be guaranteed.

[0061] The material refractive index Nd4 and the material Abbe constant Vd4 of the fourth lens satisfy: Nd4<1.51, Vd4>80; the structure is simple and good optical performance can be guaranteed.

[0062] The material refractive index Nd5 and the material Abbe constant Vd5 of the fifth lens satisfy: Nd5>1.65, Vd5<21; the structure is simple and good optical performance can be guaranteed.

[0063] The material refractive index Nd6 and the material Abbe constant Vd6 of the sixth lens satisfy: Nd6<1.55, Vd6>54; the structure is simple and good optical performance can be guaranteed.

[0064] The material refractive index Nd7 and the material Abbe constant Vd7 of the seventh lens satisfy: Nd7<1.55, Vd7>54. The structure is simple and good optical performance can be guaranteed.

[0065] Preferably, the fifth lens 5 and the sixth lens 6 are glued together to form a combined lens, which has a simple and compact structure and a small volume.

[0066] Preferably, the aperture 9 is disposed between the third lens 3 and the fourth lens 4, close to the fourth lens 4, for adjusting the intensity of the light beam.

[0067] Preferably, the second lens 2, the third lens 3, the fifth lens 5, the sixth lens 6 and the seventh lens 7 are plastic aspheric lenses, and the first lens 1 and the fourth lens 4 are glass lenses. This patent adopts a glass-plastic hybrid optical configuration, reasonably selects the position of the plastic aspheric surface, balances the aberration, and adopts a glass-plastic hybrid configuration design to achieve ultra-short TTL and a large viewing angle while ensuring excellent temperature characteristics, which is particularly suitable for smart doorbells or smart home systems.

[0068] Preferably, the horizontal field of view angle satisfies: 140°≤HFOV≤160°, which can ensure a sufficient field of view.

[0069] Preferably, the total optical length TTL satisfies: TTL = 12.50-15.03 mm. While ensuring excellent temperature characteristics, an ultra-large viewing angle is achieved, ensuring a sufficient field of view, and no out-of-focus during the day and at night.

[0070] Specifically, as a preferred embodiment of the present invention but not limiting, in this embodiment, the focal length f of the optical system is 1.22 mm, the field of view HFOV is 150°, the total optical length TTL is 13.58 mm, the focal length f1 of the first lens 1 is -6.92 mm, the focal length f2 of the second lens 2 is -3.09 mm, the focal length f3 of the third lens 3 is 5.00 mm, the focal length f4 of the fourth lens 4 is 3.41 mm, the focal length f5 of the fifth lens 5 is -2.27 mm, the focal length f6 of the sixth lens 6 is 9.42 mm, and the focal length f7 of the seventh lens 7 is 2.93 mm. The basic parameters of the optical system can be shown in Table 1 below:

[0071] Table 1: Basic parameters of the optical system

[0072] surface Curvature radius R(mm) Interval D(mm) Refractive index Nd Dispersion Vd S1 12.00 0.70 1.69 54.54 S2 3.35 1.00 S3 22.50 0.45 1.54 55.71 S4 1.53 2.00 S5 40.87 2.50 1.66 20.37 S6 -3.54 0.45 STO INFINITY 0.01 S8 6.60 1.40 1.50 81.61 S9 -2.13 0.05 S10 -3.70 0.30 1.66 20.37 S11 2.65 1.25 1.54 55.71 S12 4.65 0.10 S13 2.01 0.85 1.54 55.71 S14 -6.12 0.13 S15 INFINITY 0.61 1.52 58.57 S16 INFINITY 1.78 IMA INFINITY 0.00

[0073] In the above Table 1, along the optical axis from the object plane to the image plane 8, 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; S5 and S6 correspond to the two surfaces of the third lens 3; STO is the position of the aperture 9; S8 and S9 correspond to the two surfaces of the fourth lens 4; S10 and S11 correspond to the two surfaces of the fifth lens 5, S11 and S12 correspond to the two surfaces of the sixth lens 6, wherein the fifth lens 5 and the sixth lens 6 are cemented lenses; S13 and S14 correspond to the two surfaces of the seventh lens 7; S15 and S16 correspond to the two surfaces of the filter 10 located between the seventh lens 7 and the image plane 8; IMA is the image plane 8.

[0074] Further, the surfaces of the second lens 2, the third lens 3, the fifth lens 5, the sixth lens 6 and the seventh lens 7 are all aspherical shapes, which satisfy the following equation:

[0075]

[0076] Among them, parameter c=1 / R, that is, the curvature corresponding to the radius, y is the radial coordinate, and its unit is the same as the lens length unit, k is the conic quadratic curve coefficient, and a1 to a8 are the coefficients corresponding to each radial coordinate. The aspheric surface related values ​​of the second lens 2, the third lens 3, the fifth lens 5, the sixth lens 6, and the seventh lens 7 can be shown in the following Table 2:

[0077] Table 2: Asphericity-related values ​​of lens surfaces

[0078]

[0079] As another preferred embodiment of the present invention but not limiting, in this embodiment, the total optical length TTL of the optical system is 15.03 mm, the focal length f1 of the first lens 1 is -7.66 mm, the focal length f2 of the second lens 2 is -3.38 mm, the focal length f3 of the third lens 3 is 5.50 mm, the focal length f4 of the fourth lens 4 is 3.76 mm, the focal length f5 of the fifth lens 5 is -2.49 mm, the focal length f6 of the sixth lens 6 is 10.29 mm, and the focal length f7 of the seventh lens 7 is 3.22 mm. The basic parameters of the optical system can be shown in Table 3 below:

[0080] Table 3: Basic parameters of the optical system

[0081] surface Curvature radius R(mm) Interval D(mm) Refractive index Nd Dispersion Vd S1 13.18 0.77 1.69 54.54 S2 3.70 1.21 S3 24.68 0.48 1.54 55.71 S4 1.68 2.20 S5 44.90 2.75 1.66 20.37 S6 -3.89 0.49 STO INFINITY 0.01 S8 7.31 1.54 1.50 81.61 S9 -2.34 0.05 S10 -4.05 0.33 1.66 20.37 S11 2.90 1.37 1.54 55.71 S12 5.10 0.12 S13 2.21 0.93 1.54 55.71 S14 -6.72 0.16 S15 INFINITY 0.61 1.52 58.57 S16 INFINITY 2.00 IMA INFINITY 0.00

[0082] In the above Table 3, along the optical axis from the object plane to the image 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; S5 and S6 correspond to the two surfaces of the third lens 3; STO is the position of the aperture 9; S8 and S9 correspond to the two surfaces of the fourth lens 4; S10 and S11 correspond to the two surfaces of the fifth lens 5, S11 and S12 correspond to the two surfaces of the sixth lens 6, wherein the fifth lens 5 and the sixth lens 6 are cemented lenses; S13 and S14 correspond to the two surfaces of the seventh lens 7; S15 and S16 correspond to the two surfaces of the filter 10 located between the seventh lens 7 and the image plane 8; IMA is the image plane 8.

[0083] Further, the surfaces of the second lens 2, the third lens 3, the fifth lens 5, the sixth lens 6 and the seventh lens 7 are all aspherical shapes, which satisfy the following equation:

[0084]

[0085] Among them, parameter c=1 / R, that is, the curvature corresponding to the radius, y is the radial coordinate, and its unit is the same as the lens length unit, k is the conic quadratic curve coefficient, and a1 to a8 are the coefficients corresponding to each radial coordinate. The aspheric surface related values ​​of the second lens 2, the third lens 3, the fifth lens 5, the sixth lens 6, and the seventh lens 7 can be shown in the following Table 4:

[0086] Table 4: Asphericity-related values ​​of lens surfaces

[0087]

[0088] As another preferred embodiment of the present invention but not limiting, in this embodiment, the total optical length TTL of the optical system is 12.52 mm, the focal length f1 of the first lens 1 is -6.36 mm, the focal length f2 of the second lens 2 is -2.82 mm, the focal length f3 of the third lens 3 is 4.57 mm, the focal length f4 of the fourth lens 4 is 3.12 mm, the focal length f5 of the fifth lens 5 is -2.07 mm, the focal length f6 of the sixth lens 6 is 8.57 mm, and the focal length f7 of the seventh lens 7 is 2.67 mm. The basic parameters of the optical system can be shown in Table 5 below:

[0089] Table 5: Basic parameters of the optical system

[0090] surface Curvature radius R(mm) Interval D(mm) Refractive index Nd Dispersion Vd S1 10.96 0.64 1.69 54.54 S2 3.07 1.00 S3 20.53 0.40 1.54 55.71 S4 1.40 1.83 S5 37.34 2.28 1.66 20.37 S6 -3.24 0.41 STO INFINITY 0.01 S8 6.08 1.28 1.50 81.61 S9 -1.95 0.05 S10 -3.37 0.27 1.66 20.37 S11 2.42 1.14 1.54 55.71 S12 4.24 0.10 S13 1.84 0.77 1.54 55.71 S14 -5.59 0.14 S15 INFINITY 0.61 1.52 58.57 S16 INFINITY 1.60 IMA INFINITY 0.00

[0091] In Table 5 above, along the optical axis from the object plane to the image 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; S5 and S6 correspond to the two surfaces of the third lens 3; STO is the position of the aperture 9; S8 and S9 correspond to the two surfaces of the fourth lens 4; S10 and S11 correspond to the two surfaces of the fifth lens 5, S11 and S12 correspond to the two surfaces of the sixth lens 6, wherein the fifth lens 5 and the sixth lens 6 are cemented lenses; S13 and S14 correspond to the two surfaces of the seventh lens 7; S15 and S16 correspond to the two surfaces of the filter 10 located between the seventh lens 7 and the image plane 8; IMA is the image plane 8.

[0092] Further, the surfaces of the second lens 2, the third lens 3, the fifth lens 5, the sixth lens 6 and the seventh lens 7 are all aspherical shapes, which satisfy the following equation:

[0093]

[0094] Wherein, parameter c=1 / R, that is, the curvature corresponding to the radius, y is the radial coordinate, and its unit is the same as the lens length unit, k is the conic quadratic coefficient, and a1 to a8 are the coefficients corresponding to each radial coordinate. The aspheric surface related values ​​of the second lens 2, the third lens 3, the fifth lens 5, the sixth lens 6, and the seventh lens 7 can be shown in the following Table 6:

[0095] Table 6: Asphericity-related values ​​of lens surfaces

[0096]

[0097] from Figures 2 to 4 It can be seen that the optical system of this embodiment has good day and night confocal effect, wide visual range and other effects. While ensuring excellent temperature characteristics, it achieves ultra-short TTL and large viewing angle, ensures sufficient field of view, and is not out of focus during the day and at night.

[0098] A camera module comprises at least an optical lens, in which the above-mentioned small-volume wide-angle day and night dual-purpose optical system is installed. The optical system is composed of a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6 and a seventh lens 7 in sequence from the object plane to the image plane along the optical axis. The first lens is a meniscus negative light focal length lens; the second lens is a meniscus negative light focal length lens; the third lens is a biconvex positive light focal length lens; the fourth lens is a biconvex positive light focal length lens; the fifth lens is a biconcave negative light focal length lens; the sixth lens is a meniscus positive light focal length lens; and the seventh lens is a biconvex positive light focal length lens.

[0099] The present application provides a camera module, the optical system of which is mainly composed of 7 lenses. The number of lenses is reasonable and the structure is simple. Through the mutual combination of different lenses and the reasonable distribution of optical focal length, it can ensure a sufficient field of view while pursuing miniaturization, and there is no out-of-focus during the day and at night. It is especially suitable for smart doorbells or smart home systems.

[0100] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A small-volume wide-angle day and night 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 convex, the image side is concave, and its optical power is negative; The object side of the third lens is convex, the image side is convex, and its optical power is positive; The fourth lens has a convex object surface and a convex image surface, and its optical power is positive; The object side of the fifth lens is concave, the image side is concave, and its optical power is negative; The object side of the sixth lens is convex, the image side is concave, and its optical power is positive; The object side of the seventh lens is convex, the image side is convex, and its optical power is positive; the optical system meets the following conditions: -5.84<f1 / f<-5.54; -2.64<f2 / f<-2.41; 3.98<f3 / f<4.22; 2.68<f4 / f<2.92; -2.31<f56 / f<-2.09; 2.29<f7 / f<2.51; Among them, 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, f56 is the combined focal length of the fifth lens and the sixth lens, and f7 is the focal length of the seventh lens.

2. A small-volume wide-angle day and night optical system according to claim 1, characterized in that: The material refractive index Nd1 and the material Abbe constant Vd1 of the first lens satisfy: Nd1=1.69, Vd1=54.54; The material refractive index Nd2 and the material Abbe constant Vd2 of the second lens satisfy: Nd2=1.54, Vd2=55.

71.

3. A small-volume wide-angle day and night optical system according to claim 1, characterized in that: The material refractive index Nd3 and the material Abbe constant Vd3 of the third lens satisfy: Nd3=1.66, Vd3=20.37; The material refractive index Nd4 and the material Abbe constant Vd4 of the fourth lens satisfy: Nd4=1.50, Vd4=81.

61.

4. According to the small-volume wide-angle day and night optical system of claim 1, the material refractive index Nd5 and the material Abbe constant Vd5 of the fifth lens satisfy: Nd5=1.66, Vd5=20.37; The material refractive index Nd6 and the material Abbe constant Vd6 of the sixth lens satisfy: Nd6=1.54, Vd6=55.71; The material refractive index Nd7 and the material Abbe constant Vd7 of the seventh lens satisfy: Nd7=1.54, Vd7=55.

71.

5. The small-volume wide-angle day and night optical system according to claim 1, characterized in that: The fifth lens and the sixth lens are glued together to form a combined lens.

6. The small-volume wide-angle day and night optical system according to claim 1, characterized in that: The aperture is arranged between the third lens and the fourth lens.

7. The small-volume wide-angle day and night optical system according to claim 1, characterized in that: The second lens, the third lens, the fifth lens, the sixth lens and the seventh lens are plastic aspherical lenses.

8. The small-volume wide-angle day and night optical system according to claim 1, characterized in that: The horizontal field of view meets the following requirements: 140°≤HFOV≤160°.

9. A camera module, comprising at least an optical lens, characterized in that: The optical lens is equipped with a small-volume, wide-angle, day-and-night dual-purpose optical system as described in any one of claims 1 to 8.

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