Vehicle-mounted lens optical system and camera module using same

Abstract

The application provides a vehicle-mounted lens optical system and a camera module applied in the same, which is mainly composed of five lenses, the first lens has a convex object plane and a concave image plane, and has negative optical power; the second lens has a convex or concave object plane and a concave image plane, and has negative optical power; the third lens has a convex object plane and a convex image plane, and has positive optical power; the fourth lens has a convex object plane and a concave image plane, and has negative optical power; and the fifth lens has a convex object plane and a convex image plane, and has positive optical power. The number of lenses is reasonable, the structure is simple, the optical power of the lenses is reasonably distributed, the lens aberration is optimized, the imaging quality of the optical system is improved, the optical system has the characteristics of super wide angle, small caliber, large aperture, stable performance under temperature and the like, and has stronger competitiveness in the same type of lens.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical imaging, in particular to a vehicle-mounted lens optical system and a camera module using the same. BACKGROUND

[0002] In recent years, with the continuous popularization of intelligent driving, surround view lenses are increasingly applied to various vehicles, but the imaging effect of the current surround view lenses is generally not ideal, especially in dark conditions such as at night, it is difficult to meet the use requirements, and in terms of appearance, the existing surround view lenses have the problems of complex structure and large volume, and the provision of a miniaturized vehicle-mounted surround view lens will have greater competitiveness in the market. SUMMARY

[0003] In order to overcome the problems of poor imaging effect and complex structure of the existing surround view lenses, the present application provides a vehicle-mounted lens optical system mainly composed of five lens elements, which has the characteristics of ultra-wide angle, small aperture, large aperture and stable performance at low temperature, wherein the configuration of the large aperture can increase the light quantity of the optical system and improve the imaging quality, so that it has stronger competitiveness in the same type of lens.

[0004] A vehicle-mounted lens optical system, sequentially composed of a first lens, a second lens, a third lens, a diaphragm, a fourth lens and a fifth lens along an optical axis from an object plane to an image plane;

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

[0006] The object plane side of the second lens is convex or concave, and the image plane side is concave, and the focal power thereof is negative;

[0007] The object plane side and the image plane side of the third lens are both convex, and the focal power thereof is positive;

[0008] The object plane side of the fourth lens is convex, and the image plane side is concave, and the focal power thereof is negative;

[0009] The object plane side and the image plane side of the fifth lens are both convex, and the focal power thereof is positive.

[0010] Preferably, each lens of the optical system satisfies the following conditions:

[0011] -5.1mm < f1 < -3.2mm;

[0012] -3.5mm < f2 < -2.5mm;

[0013] 3.6mm < f3 < 4.3mm;

[0014] -2mm < f4 < -1.5mm;

[0015] 1.5mm < f5 < 1.7mm;

[0016] 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, and f5 is the focal length of the fifth lens.

[0017] Preferably, each lens of the optical system meets the following conditions:

[0018] Nd1>1.85,Vd1<30;

[0019] Nd2>1.51,Vd2>54.21;

[0020] Nd3>1.81,Vd3<25;

[0021] Nd4>1.6,Vd4<21;

[0022] Nd5<1.6,Vd5>50.5;

[0023] Wherein, Nd1 is the refractive index of the first lens, Vd1 is the Abbe number of the first lens; Nd2 is the refractive index of the second lens, Vd2 is the Abbe number of the second lens; Nd3 is the refractive index of the third lens, Vd3 is the Abbe number of the third lens; Nd4 is the refractive index of the fourth lens, Vd4 is the Abbe number of the fourth lens; Nd5 is the refractive index of the fifth lens, Vd5 is the Abbe number of the fifth lens.

[0024] Preferably, the maximum angle CRA of the full-field chief ray of the optical system incident on the image plane satisfies: CRA <17°.

[0025] Preferably, the curvature radius R1 of the object surface side of the first lens satisfies: 10<R1<19.

[0026] Preferably, the curvature radius R1 of the object surface side of the fifth lens satisfies: R1 < 0.95.

[0027] Preferably, the total optical length TTL of the optical system satisfies: TTL ≤ 18.5 mm.

[0028] Preferably, the third lens is a glass lens.

[0029] Preferably, the F number of the optical system is: 1.9≤F number≤2.1.

[0030] Preferably, the full field of view FOV of the optical system satisfies: 97.5°≤FOV≤100.5°.

[0031] Preferably, the fourth lens and the fifth lens are bonded together to form a combined lens.

[0032] In another aspect, the embodiment of the present application also provides a camera module, comprising at least an optical lens, wherein the optical lens is internally mounted with the vehicle-mounted lens optical system.

[0033] Compared with the prior art, the present application has the following advantages:

[0034] The present application provides a vehicle-mounted lens optical system and a camera module using the same, which mainly comprises five lenses, wherein the first lens has a convex object surface, a concave image surface and a negative focal power; the second lens has a convex or concave object surface, a concave image surface and a negative focal power; the third lens has a convex object surface and a convex image surface and a positive focal power; the fourth lens has a convex object surface, a concave image surface and a negative focal power; and the fifth lens has a convex object surface and a convex image surface and a positive focal power. The number of lenses is reasonable, the structure is simple, the focal power of the lenses is reasonably distributed, the lens aberration is optimized, the imaging quality of the optical system is improved, the optical system has the characteristics of super-wide angle, small aperture, large aperture and stable performance at low temperature, and has stronger competitiveness in the same type of lens. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows.

[0036] Figure 1 is a structural schematic diagram of the optical system or the camera module of the embodiment 1 of the present application;

[0037] Figure 2 is an astigmatism and distortion curve diagram of the optical system or the camera module of the embodiment 1 of the present application;

[0038] Figure 3 is an MTF curve diagram of the optical system or the camera module of the embodiment 1 of the present application;

[0039] Figure 4 is a structural schematic diagram of the optical system or the camera module of the embodiment 2 of the present application;

[0040] Figure 5 is an astigmatism and distortion curve diagram of the optical system or the camera module of the embodiment 2 of the present application;

[0041] Figure 6 is an MTF curve diagram of the optical system or the camera module of the embodiment 2 of the present application;

[0042] Figure 7 is a structural schematic diagram of the optical system or the camera module of the embodiment 3 of the present application;

[0043] Figure 8 is an astigmatism and distortion curve diagram of the optical system or the camera module of the embodiment 3 of the present application;

[0044] Figure 9 This is the MTF curve diagram of the optical system or camera module of Example 3 of the present application. DETAILED DESCRIPTION

[0045] like Figures 1-9 As shown, the present application provides a vehicle-mounted lens, which is composed of a first lens 1, a second lens 2, a third lens 3, an aperture 6, a fourth lens 4, a fifth lens 5, and an infrared filter 7 in sequence from the object plane to the image plane 8 along the optical axis.

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

[0047] The object side of the second lens is convex or concave, the image side is concave, and its optical power is negative;

[0048] The object side and image side of the third lens are both convex, and its optical power is positive;

[0049] The fourth lens has a convex object side and a concave image side, and its optical power is negative;

[0050] The object side and the image side of the fifth lens are both convex, and its optical power is positive.

[0051] The optical system of the embodiment of the present application is mainly composed of 5 lenses. The object side of the first lens is convex, the image side is concave, and the optical power is negative. The object side of the second lens is convex or concave, the image side is concave, and the optical power is negative. The object side and image side of the third lens are both convex, and the optical power is positive. The object side of the fourth lens is convex, the image side is concave, and the optical power is negative. The object side and image side of the fifth lens are both convex, and the optical power is positive. The number of lenses is reasonable and the structure is simple. By reasonably allocating the optical power of the lenses, the lens aberrations are optimized, and the imaging quality of the optical system is improved, so that the optical system has the characteristics of ultra-wide angle, small aperture, large aperture, and stable performance under temperature, and has stronger competitiveness among lenses of the same type.

[0052] Furthermore, as a preferred embodiment of the present invention but not limiting, each lens of the optical system satisfies the following conditions, 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, and f5 is the focal length of the fifth lens:

[0053] -5.1mm<f1<-3.2mm. This design can make the first lens 1 have a large negative optical power, which is beneficial to reducing the astigmatism and field curvature of the optical system;

[0054] -3.5mm<f2<-2.5mm, by constraining the ratio of the optical power of the second lens 2 to the effective focal length of the optical imaging system within a reasonable range, the spherical aberration of the system is fine-tuned and controlled, thereby effectively improving the imaging quality of the system;

[0055] 3.6mm<f3<4.3mm, by constraining the ratio of the focal power of the third lens 3 to the effective focal length of the optical imaging system to a reasonable range, the optical system has the advantages of wide angle, large aperture, small size, and excellent temperature characteristics;

[0056] -2mm<f4<-1.5mm, by constraining the ratio of the optical power of the fourth lens 4 to the effective focal length of the optical imaging system within a reasonable range, the spherical aberration of the system is fine-tuned and controlled, thereby effectively improving the imaging quality of the system;

[0057] 1.5mm<f5<1.7mm. By constraining the ratio of the fifth lens's focal length to the effective focal length of the optical imaging system within a reasonable range, the configured vehicle-mounted surround-view optical system has the advantages of a wide angle, a small aperture, and excellent temperature characteristics. It also has a compact structure and is easy to process and install. At the same time, the large aperture configuration can increase the amount of light entering the optical system and achieve higher imaging quality.

[0058] Furthermore, the refractive index Nd1 and Abbe number Vd1 of the first lens 1 satisfy: Nd1>1.85, Vd1<30. This design can effectively reduce chromatic aberration, optimize lens aberration, and thus effectively improve the imaging quality of the system.

[0059] Furthermore, the refractive index Nd2 and Abbe number Vd2 of the second lens 2 satisfy: Nd2>1.51, Vd2>54.21. This design can effectively reduce chromatic aberration, optimize lens aberration, and thus effectively improve the imaging quality of the system.

[0060] Furthermore, the refractive index Nd3 and Abbe number Vd3 of the third lens 3 satisfy: Nd3>1.81, Vd3<25. This design can effectively reduce chromatic aberration, optimize lens aberration, and thus effectively improve the imaging quality of the system.

[0061] Furthermore, the refractive index Nd4 and Abbe number Vd4 of the fourth lens element 4 satisfy the following conditions: Nd4>1.6, Vd4<21. This design can effectively reduce chromatic aberration, optimize lens aberration, and thereby effectively improve the imaging quality of the system.

[0062] Furthermore, the refractive index Nd5 and Abbe number Vd5 of the fifth lens element 5 satisfy the following conditions: Nd5 < 1.6, Vd5 > 50.5. This design can effectively reduce chromatic aberration, optimize lens aberrations, and thereby effectively improve the imaging quality of the system.

[0063] Furthermore, as a preferred embodiment of the present invention but not a limitation thereof, the maximum angle CRA of the full-field chief ray incident on the image plane of the optical system satisfies: CRA < 17°. This design can make the CRA of the lens more compatible with the CRA of the chip, thereby improving the photosensitivity efficiency of the chip.

[0064] Furthermore, as a preferred embodiment of the present invention but not a limitation, the curvature radius R1 of the object side of the first lens element satisfies: 10 < R1 < 19. By controlling the object side of the first lens element 1, the total deflection angle of the object side of the first lens element 1 at the edge of the field of view can be reasonably controlled to be within a reasonable range.

[0065] Furthermore, as a preferred embodiment of the present invention but not limiting, the curvature radius R1 of the object side of the fifth lens element satisfies: R1 < 0.95. By limiting the curvature radius of the object side of the fifth lens element 5, the shape of the fifth lens element 5 can be effectively constrained, thereby effectively improving the imaging quality of the system.

[0066] Furthermore, as a preferred embodiment of the present invention but not limitation, the total optical length TTL of the optical system satisfies: TTL ≤ 18.5 mm. This design can reduce the total optical length and effectively miniaturize the lens.

[0067] Furthermore, as a preferred embodiment of the present invention but not limiting, the third lens is a glass lens. This design can improve the performance at high and low temperatures;

[0068] Furthermore, as a preferred embodiment of the present invention but not limiting, the F number and FOV of the optical system satisfy the following conditions: 1.9 ≤ F number ≤ 2.1, 97.5° ≤ FOV ≤ 100.5°. The large aperture configuration can increase the amount of light entering the optical system and improve the imaging quality. The ultra-wide angle meets the needs of users.

[0069] Furthermore, as a preferred embodiment of the present invention but not limiting, the fourth lens and the fifth lens are bonded together to form a combined lens;

[0070] The refractive index Nd4 and Abbe number Vd4 of the fourth lens element, as well as the refractive index Nd5 and Abbe number Vd5 of the fifth lens element, satisfy the following conditions: Nd4>1.6, Vd4<21; Nd5<1.6, Vd5>50.5. This design increases the difference between the refractive index and Abbe number of the lenses, effectively reducing chromatic aberration.

[0071] Specifically, as a preferred embodiment of the present invention but not limiting, Figures 1-3As shown, in this embodiment 1, the focal length f1 of the first lens 1 is -4.076 mm, the focal length f2 of the second lens 2 is -3.18 mm, the focal length f3 of the third lens 3 is 4.17 mm, the focal length f4 of the fourth lens 4 is -1.817 mm, the focal length f5 of the fifth lens 5 is 1.62 mm, and the total optical length TTL is 17.94 mm. The surface type, curvature radius, thickness and material parameters of each lens are shown in Table 1:

[0072] Table 1: Basic parameters of the optical system of Example 1

[0073]

[0074] In Table 1 above, along the optical axis from the object plane to the image plane 8, 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; S5 and S6 correspond to the two surfaces of the third lens 3; S8 and S9 correspond to the two surfaces of the fourth lens 4; S9 and S10 correspond to the two surfaces of the fifth lens 5; STO is the position of the aperture 6; S11 and S12 correspond to the two surfaces of the filter 7; and IMA corresponds to the image plane 8.

[0075] Furthermore, in Table 1, the object side and image side of any one of the second lens 2, the fourth lens 4, and the fifth lens 5 are aspherical surfaces. The surface shape of each aspherical lens can be defined by, but not limited to, the following aspherical surface formula:

[0076]

[0077] Where x is the distance from the corresponding point on the aspheric surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the aspheric vertex, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspheric surface shape formula. Table 2 shows the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 for various aspheric surfaces that can be used in Example 1.

[0078] Table 2: Aspheric surface related values ​​of the lens surface of Example 1

[0079]

[0080] Figure 2 The astigmatism and distortion curves of the optical imaging lens of Example 1 are shown. Astigmatism represents meridional image curvature and sagittal image curvature, and distortion represents the distortion magnitude corresponding to different image heights. Figure 3 The MTF curve of the optical imaging lens of Example 1 is shown, which represents the MTF values ​​in the meridian and sagittal directions of different fields of view at different spatial frequencies. Figure 2 andFigure 3 It can be seen that the optical imaging system provided in Example 1 can achieve good imaging quality and has higher imaging quality.

[0081] Specifically, as a preferred embodiment of the present invention but not limiting, Figures 4-6 As shown, in this embodiment 2, the focal length f1 of the first lens 1 is -4.01 mm, the focal length f2 of the second lens 2 is -2.88 mm, the focal length f3 of the third lens 3 is 4.1 mm, the focal length f4 of the fourth lens 4 is -1.98 mm, the focal length f5 of the fifth lens 5 is 1.65 mm, and the total optical length TTL is 17.91 mm. The surface type, curvature radius, thickness and material parameters of each lens are shown in Table 3:

[0082] Table 3: Basic parameters of the optical system of Example 2

[0083]

[0084] In Table 3 above, along the optical axis from the object plane to the image plane 8, 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; S5 and S6 correspond to the two surfaces of the third lens 3; S8 and S9 correspond to the two surfaces of the fourth lens 4; S9 and S10 correspond to the two surfaces of the fifth lens 5; STO is the location of the aperture 6; S11 and S12 correspond to the two surfaces of the filter 7; and IMA corresponds to the image plane 8.

[0085] Furthermore, in Table 3, the object side and image side of any one of the second lens 2, the fourth lens 4, and the fifth lens 5 are aspherical surfaces. The surface shape of each aspherical lens can be defined by, but not limited to, the following aspherical surface formula:

[0086]

[0087] Where x is the distance from the corresponding point on the aspheric surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the aspheric vertex, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspheric surface shape formula. Table 4 shows the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 for various aspheric surfaces that can be used in Example 2.

[0088] Table 4: Aspheric surface related values ​​of the lens surface of Example 2

[0089]

[0090] Figure 5The astigmatism and distortion curves of the optical imaging lens of Example 2 are shown. Astigmatism represents meridional image curvature and sagittal image curvature, and distortion represents the distortion magnitude corresponding to different image heights. Figure 6 The MTF curve of the optical imaging lens of Example 2 is shown, which represents the MTF values ​​in the meridian and sagittal directions of different fields of view at different spatial frequencies. Figure 5 and Figure 6 It can be seen that the optical imaging system provided in Example 2 can achieve good imaging quality and has higher imaging quality.

[0091] Specifically, as a preferred embodiment of the present invention but not limiting, Figures 7-9 As shown, in this embodiment 3, the focal length f1 of the first lens 1 is -4.13 mm, the focal length f2 of the second lens 2 is -3.01 mm, the focal length f3 of the third lens 3 is 4.1 mm, the focal length f4 of the fourth lens 4 is -1.77 mm, the focal length f5 of the fifth lens 5 is 1.65 mm, and the total optical length TTL is 17.93 mm. The surface type, curvature radius, thickness and material parameters of each lens are shown in Table 5:

[0092] Table 5: Basic parameters of the optical system of Example 3

[0093]

[0094] In Table 5 above, along the optical axis from the object plane to the image plane 8, 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; S5 and S6 correspond to the two surfaces of the third lens 3; S8 and S9 correspond to the two surfaces of the fourth lens 4; S9 and S10 correspond to the two surfaces of the fifth lens 5; STO is the location of the aperture 6; S11 and S12 correspond to the two surfaces of the filter 7; and IMA corresponds to the image plane 8.

[0095] Furthermore, in Table 5, the object side and image side of any one of the second lens 2, the fourth lens 4, and the fifth lens 5 are aspherical surfaces. The surface shape of each aspherical lens can be defined using, but not limited to, the following aspherical surface formula:

[0096]

[0097] Where x is the distance from the corresponding point on the aspheric surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the aspheric vertex, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspheric surface shape formula. Table 6 shows the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 for various aspheric surfaces that can be used in Example 3.

[0098] Table 6: Aspheric surface related values ​​of the lens surface of Example 3

[0099]

[0100] Figure 8 The astigmatism and distortion curves of the optical imaging lens of Example 3 are shown. Astigmatism represents meridional image curvature and sagittal image curvature, and distortion represents the distortion magnitude corresponding to different image heights. Figure 9 The MTF curve of the optical imaging lens of Example 3 is shown, which represents the MTF values ​​in the meridian and sagittal directions of different fields of view at different spatial frequencies. Figure 8 and Figure 9 It can be seen that the optical imaging system provided in Example 3 can achieve good imaging quality and has higher imaging quality.

[0101] Furthermore, in Examples 1-3, the basic data are as follows:

[0102] Table 7: Basic data of Examples 1-3

[0103]

[0104] A camera module includes at least an optical lens, in which the above-mentioned vehicle-mounted optical system is installed. The vehicle-mounted lens of the present invention has the characteristics of ultra-wide angle, small aperture, large aperture and stable performance under temperature, and is more competitive among lenses of the same type.

[0105] The above descriptions are provided in conjunction with specific content to provide one or more embodiments, and the specific implementation of the present invention is not limited to these descriptions. Any similarity or similarity with the methods, structures, etc. of the present invention, or any technical deduction or substitution based on the concept of the present invention, shall be considered within the scope of protection of the present invention.

Claims

1. An automotive lens optical system, comprising, in order from the object plane to the image plane along the optical axis, a first lens, a second lens, a third lens, an aperture, a fourth lens, and a fifth lens, characterized in that: The object side of the first lens is convex, the image side is concave, and its optical power is negative; The second lens has a concave object side and a concave image side, and its optical power is negative; The object side and image side of the third lens are both convex, and its optical power is positive; The fourth lens has a convex object side and a concave image side, and its optical power is negative; The object side and image side of the fifth lens are both convex, and its optical power is positive; Each lens of the optical system meets the following conditions: Nd1>1.85,Vd1<30; -5.1mm<f1<-3.2mm; -3.5mm<f2<-2.5mm; 3.6mm<f3<4.3mm; -2mm<f4<-1.5mm; 1.5mm<f5<1.7mm; Wherein, Nd1 is the refractive index of the first lens, Vd1 is the Abbe number of the first lens; Nd2 is the refractive index of the second lens, 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, and f5 is the focal length of the fifth lens.

2. The vehicle-mounted lens optical system according to claim 1, wherein: Each lens of the optical system meets the following conditions: Nd2>1.51,Vd2>54.21; Nd3>1.81,Vd3<25; Nd4>1.6,Vd4<21; Nd5<1.6,Vd5>50.5; Wherein, Vd2 is the Abbe number of the second lens; Nd3 is the refractive index of the third lens, Vd3 is the Abbe number of the third lens; Nd4 is the refractive index of the fourth lens, Vd4 is the Abbe number of the fourth lens; Nd5 is the refractive index of the fifth lens, Vd5 is the Abbe number of the fifth lens.

3. The vehicle-mounted lens optical system according to claim 1, wherein: The fourth lens and the fifth lens are cemented together to form a combined lens.

4. The vehicle-mounted lens optical system according to any one of claims 1 to 3, wherein: The maximum angle CRA of the full-field chief ray incident on the image plane of this optical system satisfies: CRA < 17°.

5. The vehicle-mounted lens optical system according to any one of claims 1 to 3, wherein: The curvature radius R1 of the object surface side of the first lens satisfies: 10 mm < R1 < 19 mm.

6. The vehicle-mounted lens optical system according to any one of claims 1 to 3, wherein: The curvature radius R1 of the object surface side of the fifth lens satisfies: R1 < 0.95 mm.

7. The vehicle-mounted lens optical system according to any one of claims 1 to 3, wherein: The total optical length TTL of the optical system satisfies: TTL ≤ 18.5 mm.

8. The vehicle-mounted lens optical system according to any one of claims 1 to 3, characterized in that: The third lens is a glass lens.

9. The vehicle-mounted lens optical system according to any one of claims 1 to 3, wherein: The F number of the optical system: 1.9≤F number≤2.1; The full field of view FOV of the optical system satisfies: 97.5°≤ FOV≤ 100.5°.

10. A camera module, comprising at least an optical lens, characterized in that: The optical lens is equipped with the vehicle-mounted lens optical system according to any one of claims 1 to 9.

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