Vehicle-mounted surround-view imaging lens and camera device with same

Abstract

The invention discloses a vehicle-mounted surround-view imaging lens and a camera device with the vehicle-mounted surround-view imaging lens, the vehicle-mounted surround-view imaging lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged in the direction from the object side to the image side along the optical axis of the lens, and the third lens and the fourth lens are glued. And the fifth lens is glued with the sixth lens. The lens is mainly composed of seven lenses, the low-order aberration of the lens can be effectively balanced by reasonably controlling the positive and negative focal length distribution of each lens of the lens, meanwhile, the tolerance sensitivity of the lens can be reduced, and the imaging quality of the lens is ensured while the miniaturization of the lens is kept; the imaging quality is excellent, the image quality is clear and bright, and the large aperture brings excellent low-illumination processing capability and small depth of field, so that the lens can adapt to more shooting environments; the system is simple in structure and compact in structure, has better imaging quality under the condition of ensuring a large visual angle, increases the tolerance limit of the whole system, and improves the imaging quality.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical lenses, and particularly relates to a vehicle surround-view imaging lens and an imaging device having the same. Background Art

[0002] Currently, the imaging quality requirements of vehicle-mounted lenses in extremely dark environments are getting higher and higher. Not only is the picture required to be bright, but also high clarity is required. However, the lenses used in the prior art have a dark picture, large noise, and low recognition when shooting in extremely dark environments, which cannot meet the market demand. If the shooting use requirements in extremely dark environments are to be met, the lens needs to have a large aperture and high pixels, which leads to an increase in the number of lens lenses and the diameter of the lenses, and the lens volume and cost increase accordingly. In addition, the lenses used in the prior art also have the following deficiencies:

[0003] 1) The total length of the lens is long and cannot meet the requirement of lens miniaturization;

[0004] 2) The light passing through long focal length lenses is generally small. In low light environments, the amount of light entering is low and the captured picture is dark;

[0005] 3) The lens has poor control over distortion, and it is easy for the image and the object to be deformed, resulting in inaccurate recognition. Summary of the Invention

[0006] To solve the problems in the prior art, the purpose of the present invention is to provide a vehicle surround-view imaging lens and an imaging device having the same.

[0007] To achieve the above object and reach the above technical effect, the technical solution adopted by the present invention is:

[0008] A vehicle surround-view imaging lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially arranged along the optical axis of the lens from the object side to the image side. The third lens and the fourth lens are cemented together to form a first cemented lens, and the fifth lens and the sixth lens are cemented together to form a second cemented lens. The vehicle surround-view imaging lens satisfies the following condition: 0.010 ≤ TTL / H / FOV ≤ 0.022;

[0009] Wherein, TTL is the distance from the vertex of the object surface side of the first lens to the imaging surface of the lens on the optical axis, H is the image plane diameter, and FOV is the maximum field of view angle of the lens.

[0010] Further, the vehicle surround-view imaging lens satisfies the following condition:

[0011] 9.01 ≤ TTL / f ≤ 9.40;

[0012] Wherein, f is the overall focal length of the lens.

[0013] Furthermore, the on-vehicle panoramic imaging lens satisfies the following conditions:

[0014] 2.07 ≤ BFL / f ≤ 2.32;

[0015] Wherein, BFL is the shortest distance from the image plane side of the seventh lens to the imaging surface of the lens.

[0016] Furthermore, the first lens, the second lens, the third lens and the fourth lens form the front group of the lens, and the focal length of the front group is f1, satisfying:

[0017] -4.4 ≤ f1 / f ≤ -3.4.

[0018] Furthermore, the fifth lens, the sixth lens and the seventh lens form the rear group of the lens, and the focal length of the rear group is f2, satisfying:

[0019] 1.8 ≤ f2 / f ≤ 2.5.

[0020] Furthermore, the object plane side of the first lens is convex and the image plane side is concave, and it is a meniscus negative power lens;

[0021] The object plane side of the second lens is convex and the image plane side is concave, and it is a meniscus negative power lens;

[0022] The third lens and the sixth lens respectively have negative optical powers;

[0023] The fourth lens and the fifth lens respectively have positive optical powers;

[0024] The object plane side of the first cemented lens is concave and the image plane side is convex;

[0025] The image plane side of the second cemented lens is convex;

[0026] The object plane side of the seventh lens is convex and the image plane side is convex, and it uses aspherical glass with positive optical power.

[0027] Furthermore, the Abbe number Vd5 of the fifth lens ≥ 70, and the Abbe number Vd6 of the sixth lens ≤ 30.

[0028] Furthermore, the on-vehicle panoramic imaging lens further includes a diaphragm, a filter and a protective sheet. The diaphragm is arranged between the first cemented lens and the second cemented lens, the filter is arranged on the image plane side of the seventh lens, and the protective sheet is arranged on the image plane side of the filter.

[0029] Furthermore, the thickness of the first lens is 1.2 mm.

[0030] The present invention also discloses a camera device, including an electronic photosensitive element and a vehicle-mounted surround-view imaging lens as described above.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] (1) The aperture F-number of the vehicle-mounted surround-view imaging lens of the present invention can reach 2, with excellent imaging quality, no obvious purple fringing and chromatic dispersion, clear and bright image quality, and the excellent low-light processing ability and small depth of field brought by the large aperture can adapt to more shooting environments. Moreover, the lens itself has a compact structure and a large field of view angle, meeting the miniaturization requirements of the development of vehicle-mounted lenses;

[0033] (2) The vehicle-mounted surround-view imaging lens of the present invention has a large light transmission amount (FNO 2.0), can obtain more incident light, the captured picture is brighter, and the relative illuminance > 50%, enabling the lens to better capture pictures in a dim environment;

[0034] (3) The optical F-Theta distortion of the vehicle-mounted surround-view imaging lens of the present invention is less than -1%, with small image distortion and more accurate image restoration;

[0035] (4) The present invention is mainly composed of 7 lenses. By reasonably controlling the positive and negative distribution of the focal lengths of each lens of the lens, the low-order aberrations of the lens can be effectively balanced. At the same time, the tolerance sensitivity of the lens can be reduced, and while maintaining the miniaturization of the lens, the imaging quality of the lens can be ensured;

[0036] (5) The vehicle-mounted surround-view imaging lens of the present invention adopts a 6G-1GMO all-glass lens structure, with a compact structure and good processing technology. Under the conditions of meeting the small overall optical length and optical performance, it meets the requirements of miniaturization, wide-angle, and low cost. With a large viewing angle, it has good imaging quality. At the same time, the tolerance limit of the entire system is increased, improving the imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention;

[0038] Figure 2 is a field curvature curve graph of Embodiment 1 of the present invention;

[0039] Figure 3 is an optical distortion graph of Embodiment 1 of the present invention;

[0040] Figure 4 is an MTF VS Field curve graph of Embodiment 1 of the present invention;

[0041] Figure 5 is a relative illuminance graph of Embodiment 1 of the present invention;

[0042] Figure 6Schematic diagram of Embodiment 2 of the present invention;

[0043] Figure 7 Field curvature curve graph of Embodiment 2 of the present invention;

[0044] Figure 8 Optical distortion graph of Embodiment 2 of the present invention;

[0045] Figure 9 MTF VS Field curve graph of Embodiment 2 of the present invention;

[0046] Figure 10 Relative illuminance graph of Embodiment 2 of the present invention;

[0047] Figure 11 Schematic diagram of Embodiment 3 of the present invention;

[0048] Figure 12 Field curvature curve graph of Embodiment 3 of the present invention;

[0049] Figure 13 Optical distortion graph of Embodiment 3 of the present invention;

[0050] Figure 14 MTF VS Field curve graph of Embodiment 3 of the present invention;

[0051] Figure 15 Relative illuminance graph of Embodiment 3 of the present invention. Detailed implementation manners

[0052] The present invention will be elaborated in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making the protection scope of the present invention more clearly defined.

[0053] The following gives a brief overview of one or more aspects to provide a basic understanding of these aspects. This overview is not an exhaustive survey of all contemplated aspects, and is neither intended to identify key or decisive elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that follows.

[0054] Figures 1 - 15 As shown, a vehicle surround view imaging lens includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a diaphragm 5, a fifth lens 6, a sixth lens 7, a seventh lens 8, a filter 9, and a protective sheet 10 sequentially arranged in the direction from the object side to the image side along the optical axis of the lens, wherein the third lens 3 and the fourth lens 4 are cemented, and the fifth lens 6 and the sixth lens 7 are cemented.

[0055] The object side of the first lens 1 is convex, and the image side is concave. The first lens 1 is a meniscus negative power lens with a thickness of 1.2 mm. Such a setting can meet the reliability requirements such as vehicle - specification ball drop and gravel impact, prevent cracking, and the meniscus design convex towards the object side is also conducive to the sliding of water droplets, enabling it to be used without hindrance in rainy and snowy environments and reducing the impact on imaging.

[0056] The object side of the second lens 2 is convex, and the image side is concave. In addition to balancing the power distribution, it also has the function of deflecting light, making the incident angle of the marginal field light on the subsequent optical elements smaller, achieving an imaging range of a hemispherical field of view, and making the optical system structure compact and the volume smaller.

[0057] Both the first lens 1 and the second lens 2 are meniscus negative power lenses, which can ensure a large field of view, large angle, and large aperture ratio of the optical system, facilitating the compression of the aperture of the optical elements to achieve the miniaturization of the lens.

[0058] The third lens 3 and the fourth lens 4 are cemented together to form the first cemented lens. The object side is concave, and the image side is convex. It can effectively balance the aberration caused by the first lens 1 and the second lens 2 at a large field of view angle. Using this design can make the light pass through the diaphragm 5 at a gentle angle, thereby reducing the sensitivity to tolerances and improving the stability of the optical system in the front - to - back direction, and can also effectively solve problems such as insufficient image brightness.

[0059] The fifth lens 6 is made of a low - dispersion material. The refractive index temperature coefficient dn / dt of this material is negative, that is, the refractive index decreases as the temperature increases. The power of the fifth lens 6 is positive. As the temperature increases, the change in back focal length of this lens due to temperature increase is larger, which can effectively control the temperature drift.

[0060] The fifth lens 6 and the sixth lens 7 are cemented together to form the second cemented lens. The Abbe number Vd5 of the fifth lens 6 ≥ 70, and the Abbe number Vd6 of the sixth lens 7 ≤ 30. The combination of high - and low - dispersion materials is beneficial to correcting chromatic aberration, optimizing image quality, and improving system performance.

[0061] The seventh lens 8 is a molded aspheric glass with positive power. Selecting aspheric glass can effectively eliminate spherical aberration. Using the characteristics of the aspheric surface can better focus the light on a small point, thereby relatively reducing the imaging blur phenomenon and improving the image quality. Moreover, the aspheric surface of the seventh lens has no inflection point, which is convenient for mold manufacturing and interference measurement.

[0062] In some embodiments, the on - vehicle surround - view imaging lens of the present invention meets the following conditions:

[0063] 0.010 ≤ TTL / H / FOV ≤ 0.022;

[0064] Among them, TTL is the distance from the vertex on the object side of the first lens 1 to the imaging surface of the lens on the optical axis, H is the image plane diameter, and FOV is the maximum field of view angle of the lens.

[0065] In some embodiments, the vehicle surround imaging lens of the present invention satisfies the following conditions:

[0066] 9.01 ≤ TTL / f ≤ 9.40;

[0067] Among them, f is the overall focal length of the lens.

[0068] In some embodiments, the vehicle surround imaging lens of the present invention satisfies the following conditions:

[0069] 2.07 ≤ BFL / f ≤ 2.32;

[0070] Among them, BFL is the shortest distance from the image side of the seventh lens 8 to the imaging surface of the lens.

[0071] The first lens 1, the second lens 2, the third lens 3, and the fourth lens 4 form the front group of the lens, and the front group focal length is f1. The fifth lens 6, the sixth lens 7, and the seventh lens 8 form the rear group of the lens, and the rear group focal length is f2, satisfying:

[0072] -4.4 ≤ f1 / f ≤ -3.4;

[0073] 1.8 ≤ f2 / f ≤ 2.5.

[0074] The present invention is mainly composed of 7 lenses. By reasonably controlling the positive and negative distribution of the focal lengths of each lens of the lens, the low-order aberrations of the lens can be effectively balanced. At the same time, the tolerance sensitivity of the lens can be reduced, and while maintaining the miniaturization of the lens, the imaging quality of the lens can be ensured.

[0075] The F-number of the vehicle surround imaging lens of the present invention can reach 2, with excellent imaging quality, no obvious purple fringing and chromatic aberration, clear and bright image quality. Moreover, the excellent low-light processing ability and small depth of field brought by the large aperture can adapt to more shooting environments, and the lens itself has a compact structure, meeting the miniaturization requirements of the development of vehicle-mounted lenses.

[0076] Embodiment 1

[0077] As Figures 1 - 5 shown, a vehicle surround imaging lens includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a diaphragm 5, a fifth lens 6, a sixth lens 7, a seventh lens 8, a filter 9, and a protective sheet 10 sequentially arranged along the optical axis of the lens from the object side to the image side. Among them, the third lens 3 and the fourth lens 4 are cemented, and the fifth lens 6 and the sixth lens 7 are cemented.

[0078] The object side of the first lens 1 is convex, and the image side is concave. The first lens 1 is a meniscus negative power lens. The thickness of the first lens 1 is 1.2 mm. The meniscus shape convex towards the object side is beneficial for water droplets to slide off, enabling it to be used without obstruction in rainy and snowy environments and reducing the impact on imaging.

[0079] The object side of the second lens 2 is convex, and the image side is concave. In addition to balancing the power distribution, it also has the function of deflecting light rays, making the incident angle of marginal field light rays on the subsequent optical elements smaller, achieving an imaging range of a hemispherical field of view, and making the optical system structure compact and small in size.

[0080] Both the first lens 1 and the second lens 2 are meniscus negative power lenses, which can ensure a large field of view, large angle, and large aperture ratio of the optical system, facilitating the compression of the aperture of the optical elements to achieve miniaturization of the lens.

[0081] The third lens 3 and the fourth lens 4 are cemented together to form the first cemented lens. The object side is concave, and the image side is convex. It can effectively balance the aberration caused by the first lens 1 and the second lens 2 at a large field of view angle. Using this design, light rays can pass through the aperture stop 5 at a gentle angle, thereby reducing the sensitivity to tolerances and improving the stability of the optical system in the front-back direction. It can also effectively solve problems such as insufficient image brightness.

[0082] The fifth lens 6 is made of a low-dispersion material. The refractive index temperature coefficient dn / dt of this material is negative, that is, the refractive index decreases as the temperature increases. The power of the fifth lens 6 is positive. As the temperature increases, the change in back focal length of this lens due to temperature increase is larger, which can effectively control the temperature drift.

[0083] The seventh lens 8 is a molded aspherical glass with positive power. Selecting aspherical glass can effectively eliminate spherical aberration. Utilizing the characteristics of the aspherical surface can better focus light rays onto a small point, thereby relatively reducing the imaging blur phenomenon and improving the image quality. Moreover, the aspherical surface of the seventh lens has no inflection point, which is convenient for mold manufacturing and interferometric measurement.

[0084] The optical parameters of each lens in this embodiment are shown in Table 1.

[0085] Table 1

[0086]

[0087]

[0088] In Table 1, Infinity indicates that the radius of curvature is infinite, indicating that the corresponding surface number represents a plane.

[0089] The optical parameter information of this embodiment is shown in Table 2.

[0090] Table 2

[0091] Parameter Value F - number (Aperture number) 2 Overall focal length f (mm) 2.09 TTL (mm) 19 BFL (mm) 4.45 Field of view angle FOV (°) 180 Image plane diameter H (mm) 6.6 Front group focal length f1 -8.43 Rear group focal length f2 4.44 f1 / f -4.04 f2 / f 2.13 BFL / f 2.13 TTL / f 9.09 TTL / H / FOV 0.016

[0092] Figures 2 - 3 They are respectively the field curvature curve graph and the F-Theta optical distortion graph at a wavelength of 436 - 650 nm in this embodiment. The field curvature curve graph shows that both the T line and the S line have good convergence, and the field curvature and astigmatism are both excellent, which can ensure the requirement of uniform imaging of the entire picture. The distortion graph represents the distortion percentage of the optical lens with the change of the field of view. The vertical coordinate represents the normalized aperture. The distortion graph shows that the optical F-Theta distortion of the lens is very small, indicating that the lens achieves wide-angle and low distortion.

[0093] Figure 4 It is the MTF VS Field curve graph of the change of the field of view position at a wavelength of 436 - 650 nm in this embodiment. The horizontal coordinate is the Y field of view angle (i.e., the semi-field angle), and the vertical coordinate is the OTF modulus, which reflects the resolution ability of the lens. It can be seen that the curve is smooth when the frequency is 20 - 166 lp / mm and the MTF value is above 0.3.

[0094] Figure 5 It is the relative illumination graph of this embodiment. The vertical coordinate is the relative illumination value, and the horizontal coordinate is the Y field of view angle (i.e., the semi-field angle). It can be seen that the overall uniformity of the image plane brightness is good, and the relative illumination of the system is greater than 50% in the diagonal direction, which will not make the brightness contrast between the center and the periphery of the lens image plane obvious, that is, the peripheral brightness is significantly darker than the peripheral edge.

[0095] Embodiment 2

[0096] As Figures 6 - 10 shown, a vehicle surround-view imaging lens includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a diaphragm 5, a fifth lens 6, a sixth lens 7, a seventh lens 8, a filter 9, and a protective sheet 10 sequentially arranged in the direction from the object side to the image side along the optical axis of the lens. Among them, the third lens 3 and the fourth lens 4 are cemented, and the fifth lens 6 and the sixth lens 7 are cemented.

[0097] The object side of the first lens 1 is convex, and the image side is concave. The first lens 1 is a meniscus negative power lens. The thickness of the first lens 1 is 1.2 mm. The meniscus design convex to the object side is conducive to the sliding of water droplets, and it can be used without obstacles in rainy and snowy environments, reducing the impact on imaging.

[0098] The object side of the second lens 2 is convex, and the image side is concave. In addition to being used to balance the distribution of optical power, it also has the function of deflecting light rays, making the incident angle of the marginal field light rays on the subsequent optical elements smaller, realizing the imaging range of the hemispherical field of view, and making its optical system structure compact and the volume smaller.

[0099] Both the first lens 1 and the second lens 2 are meniscus negative lenses, which can ensure a large field of view, large angle, and large aperture ratio of the optical system, facilitating the compression of the aperture of the optical elements to achieve the miniaturization of the lens.

[0100] The third lens 3 and the fourth lens 4 are cemented together to form the first cemented lens. The object side is concave and the image side is convex, which can effectively balance the aberration caused by the first lens 1 and the second lens 2 at a large field angle. Using this design, light can pass through the diaphragm 5 at a gentle angle, thereby reducing the sensitivity to tolerances and improving the stability of the optical system in the front-back direction. It can also effectively solve problems such as insufficient image brightness.

[0101] The fifth lens 6 is made of a low-dispersion material. The refractive index temperature coefficient dn / dt of this material is negative, that is, the refractive index decreases as the temperature rises. The optical power of the fifth lens 6 is positive. As the temperature rises, the change in back focal length of this lens due to temperature increase is greater, which can effectively control the temperature drift.

[0102] The seventh lens 8 is a molded aspherical glass with positive optical power. Selecting aspherical glass can effectively eliminate spherical aberration. Utilizing the characteristics of the aspherical surface can better focus light onto a small point, thereby relatively reducing the imaging blur phenomenon and improving the image quality. Moreover, there is no inflection point on the aspherical surface of the seventh lens, which is convenient for mold manufacturing and interference measurement.

[0103] The optical parameters of each lens in this embodiment are shown in Table 3.

[0104] Table 3

[0105] Surface number Surface Radius of curvature Thickness Material Refractive index nd Abbe number vd Focal length S1 First lens 11.66 1.200 Glass 1.77 49.60 -9.10 S2 4.20 1.664 S3 Second lens 7.80 0.800 Glass 1.80 46.58 -4.85 S4 2.35 1.948 S5 Third lens -10.20 0.800 Glass 1.49 70.44 -6.42 S6 Fourth lens 4.70 1.464 Glass 1.95 32.31 4.15 S7 -23.05 0.313 S8 Diaphragm Infinity 1.012 S9 Fifth lens 74.85 1.967 Glass 1.59 68.34 3.58 S10 Sixth lens -2.35 0.800 Glass 1.95 17.94 -6.50 S11 -4.20 0.100 S12 Seventh lens 8.13 2.429 Glass 1.50 81.56 6.89 S13 -5.51 0.500 S14 Filter Infinity 0.300 Glass 1.52 64.20 S15 Infinity 3.185 S16 Protective glass Infinity 0.400 Glass 1.52 64.20 S17 Infinity 0.125 S18 Image plane Infinity

[0106] In Table 3, Infinity indicates that the radius of curvature is infinite, indicating that the corresponding surface number represents a plane.

[0107] The optical parameter information of this embodiment is shown in Table 4.

[0108] Table 4

[0109]

[0110]

[0111] Figures 7 - 8 They are respectively the field curvature curve graph and the F-Theta optical distortion graph at a wavelength of 436 - 650 nm in this embodiment. The field curvature curve graph shows that both the T line and the S line have good convergence, and the field curvature and astigmatism are both excellent, which can ensure the requirement of uniform imaging of the entire picture. The distortion graph represents the distortion percentage of the optical lens with the change of the field of view. The vertical axis represents the normalized aperture. The distortion graph shows that the optical F-Theta distortion of the lens is very small, indicating that the lens achieves wide-angle low distortion.

[0112] Figure 9 This is the MTF VS Field curve graph of the field position change of this embodiment at a wavelength of 436 - 650 nm. The abscissa is the Y field angle (i.e., the semi-field angle), and the ordinate is the OTF modulus, which reflects the resolution ability of the lens. It can be seen that the curve is smooth at a frequency of 20 - 166 lp / mm and the MTF value is above 0.25.

[0113] Figure 10 This is the relative illumination graph of this embodiment. The ordinate is the relative illumination value, and the abscissa is the Y field angle (i.e., the semi-field angle). It can be seen that the overall uniformity of the image plane brightness is good. In the diagonal direction, the relative illumination of the system is greater than 50%, and it will not make the brightness contrast between the center and the periphery of the lens image plane obvious, that is, the peripheral brightness is not significantly darker than the peripheral edge.

[0114] The rest is the same as in Embodiment 1.

[0115] Embodiment 3

[0116] As Figures 11 - 15 shown, a vehicle surround-view imaging lens includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a diaphragm 5, a fifth lens 6, a sixth lens 7, a seventh lens 8, a filter 9, and a protective sheet 10 sequentially arranged along the optical axis of the lens from the object side to the image side. Among them, the third lens 3 is glued to the fourth lens 4, and the fifth lens 6 is glued to the sixth lens 7.

[0117] The object side of the first lens 1 is convex, and the image side is concave. The first lens 1 is a meniscus negative power lens. The thickness of the first lens 1 is 1.2 mm. The meniscus design convex to the object side is beneficial for water droplets to slide off, enabling it to be used without obstacles in rainy and snowy environments and reducing the impact on imaging.

[0118] The object side of the second lens 2 is convex, and the image side is concave. In addition to being used to balance the power distribution, it also has the function of deflecting light, making the incident angle of the marginal field light on the subsequent optical elements smaller, realizing the imaging range of the hemispherical field, and making the optical system structure compact and the volume smaller.

[0119] Both the first lens 1 and the second lens 2 are meniscus negative power lenses, which can ensure a large field of view, large angle, and large aperture ratio of the optical system, and are beneficial for compressing the aperture of the optical elements to realize the miniaturization of the lens.

[0120] The third lens 3 is cemented to the fourth lens 4 to form a first cemented lens. The object side is concave and the image side is convex, which can effectively balance the aberration caused by the first lens 1 and the second lens 2 at a large field angle. Using this design, light can pass through the aperture 5 at a gentle angle, thereby reducing the sensitivity to tolerances and improving the stability of the optical system in the front-back direction. It can also effectively solve problems such as insufficient image brightness.

[0121] The fifth lens 6 is made of a low-dispersion material. The refractive index temperature coefficient dn / dt of this material is negative, that is, the refractive index decreases as the temperature increases. The optical power of the fifth lens 6 is positive. As the temperature increases, the change in back focal length of this lens due to temperature increase is larger, which can effectively control the temperature drift.

[0122] The seventh lens 8 is a molded aspheric glass with positive optical power. Selecting aspheric glass can effectively eliminate spherical aberration. Using the characteristics of the aspheric surface, light can be better focused to a small point, thereby relatively reducing the imaging blur phenomenon and improving the image quality. Moreover, there is no inflection point on the aspheric surface of the seventh lens, which is convenient for mold manufacturing and interference measurement.

[0123] The optical parameters of each lens in this embodiment are shown in Table 5.

[0124] Table 5

[0125] Surface number Surface Radius of curvature Thickness Material Refractive index nd Abbe number vd Focal length S1 First lens 11.80 1.200 Glass 1.77 49.60 -9.35 S2 4.30 1.714 S3 Second lens 7.75 0.800 Glass 1.80 46.58 -5.25 S4 2.45 1.948 S5 Third lens -10.15 0.800 Glass 1.49 70.44 -6.25 S6 Fourth lens 4.74 1.500 Glass 1.90 31.32 4.25 S7 -23.60 0.513 S8 Diaphragm Infinity 0.812 S9 Fifth lens 70.25 1.870 Glass 1.59 68.34 3.75 S10 Sixth lens -2.35 0.800 Glass 1.95 17.94 -6.35 S11 -4.28 0.100 S12 Seventh lens 8.25 2.430 Glass 1.50 81.56 7.15 S13 -5.35 0.500 S14 Filter Infinity 0.300 Glass 1.52 64.20 S15 Infinity 3.125 S16 Protective glass Infinity 0.400 Glass 1.52 64.20 S17 Infinity 0.125 S18 Image plane Infinity

[0126] In Table 5, Infinity indicates that the radius of curvature is infinite, indicating that the surface number corresponding to it represents a plane.

[0127] The optical parameter information of this embodiment is shown in Table 6.

[0128] Table 6

[0129]

[0130]

[0131] Figures 12 - 13 They are respectively the field curvature curve graph and the F-Theta optical distortion graph at a wavelength of 436 - 650nm in this embodiment. The field curvature curve graph shows that both the T line and the S line have good convergence, and the field curvature and astigmatism are both excellent, which can ensure the requirement of uniform imaging of the entire picture. The distortion graph represents the distortion percentage of the optical lens as the field of view changes. The vertical coordinate represents the normalized aperture. The distortion graph shows that the optical F-Theta distortion of the lens is very small, indicating that the lens achieves wide-angle low distortion.

[0132] Figure 14This is the MTF VS Field curve graph of the field position change of this embodiment at a wavelength of 436 - 650 nm. The abscissa is the Y field angle (i.e., the half field angle), and the ordinate is the OTF modulus, which reflects the resolution ability of the lens. It can be seen that the curve is smooth at a frequency of 20 - 166 lp / mm and the MTF value is above 0.2.

[0133] Figure 15 This is the relative illuminance graph of this embodiment. The ordinate is the relative illuminance value, and the abscissa is the Y field angle (i.e., the half field angle). It can be seen that the overall uniformity of the image plane brightness is good. In the diagonal direction, the relative illuminance of the system is greater than 50%, and it will not make the brightness contrast between the center and the periphery of the lens image plane obvious, that is, the peripheral brightness is not significantly darker than the peripheral edge.

[0134] The rest is the same as in Embodiment 1.

[0135] For the parts or structures not specifically described in the present invention, existing technologies or existing products can be adopted, and no further elaboration will be made here.

[0136] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A vehicle surround-view imaging lens, characterized in that, It includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in order from the object side to the image side along the optical axis of the lens. The third lens and the fourth lens are cemented together to form a first cemented lens. The fifth lens and the sixth lens are cemented together to form a second cemented lens. The vehicle surround imaging lens satisfies the following conditions: 0.010 ≤ TTL / H / FOV ≤ 0.022; Wherein, TTL is the distance from the vertex on the object surface side of the first lens to the imaging surface of the lens on the optical axis, H is the image plane diameter, and FOV is the maximum field of view angle of the lens.

2. The vehicle-mounted panoramic imaging lens according to claim 1, wherein The vehicle surround imaging lens satisfies the following conditions: 9.01 ≤ TTL / f ≤ 9.40; Wherein, f is the overall focal length of the lens.

3. The vehicle-mounted panoramic imaging lens according to claim 1, wherein The vehicle surround imaging lens satisfies the following conditions: 2.07 ≤ BFL / f ≤ 2.32; Wherein, BFL is the shortest distance from the image surface side of the seventh lens to the imaging surface of the lens.

4. The vehicle-mounted panoramic imaging lens according to claim 1, characterized in that, The first lens, the second lens, the third lens and the fourth lens form the front group of the lens, and the front group focal length is f1, satisfying: -4.4 ≤ f1 / f ≤ -3.

4.

5. The vehicle-mounted panoramic imaging lens according to claim 1, wherein, The fifth lens, the sixth lens and the seventh lens form the rear group of the lens, and the rear group focal length is f2, satisfying: 1.8 ≤ f2 / f ≤ 2.

5.

6. The vehicle-mounted panoramic imaging lens according to claim 1, wherein The object surface side of the first lens is convex, and the image surface side is concave, being a meniscus negative power lens; The object surface side of the second lens is convex, and the image surface side is concave, being a meniscus negative power lens; The third lens and the sixth lens respectively have negative optical powers; The fourth lens and the fifth lens respectively have positive optical powers; The object surface side of the first cemented lens is concave, and the image surface side is convex; The image surface side of the second cemented lens is convex; The object surface side of the seventh lens is convex, and the image surface side is convex, using aspherical glass with positive optical power.

7. The vehicle-mounted panoramic imaging lens according to claim 1, characterized in that The Abbe number Vd5 of the fifth lens ≥ 70, and the Abbe number Vd6 of the sixth lens ≤ 30.

8. The vehicle-mounted panoramic imaging lens according to claim 1, wherein, The vehicle surround imaging lens further includes a diaphragm, a filter and a protective sheet. The diaphragm is arranged between the first cemented lens and the second cemented lens. The filter is arranged on the image surface side of the seventh lens. The protective sheet is arranged on the image surface side of the filter.

9. The vehicle-mounted panoramic imaging lens according to claim 1, wherein The thickness of the first lens is 1.2 mm.

10. A camera device, characterized in that, It includes an electronic photosensitive element and a vehicle surround imaging lens according to any one of claims 1-9.

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