Vehicle-mounted optical lens

Abstract

The invention discloses a vehicle-mounted optical lens. The optical 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 from an object side to an image side along an optical axis, wherein the first lens, the second lens and the fifth lens are glass spherical lenses with negative focal power; the third lens, the fourth lens and the seventh lens are glass spherical lenses with positive focal power; the sixth lens is a glass aspheric lens with positive focal power; according to the utility model, defocus and imaging blur caused by environment temperature change are avoided through an all-glass framework with a low thermal expansion coefficient, and the imaging quality is improved by arranging an aspheric glass lens and adjusting the shape and arrangement of the lens; the optical lens is large in field angle, small in distortion, small in chromatic aberration, small in size and reasonable in cost. The invention is suitable for the optical imaging field.

Description

Technical Field

[0001] The present invention relates to the technical field of optical imaging, and more specifically, to a vehicle-mounted optical lens. Background Art

[0002] In increasingly congested urban roads and complex traffic environments, the driver's field of vision blind spots often become the source of safety hazards. Electronic mirrors (CMS) can provide a wider field of vision, eliminate blind spots, help drivers better understand the surrounding environment, reduce the impact of bad weather, have better night vision, improve driving quality, and reduce the occurrence of accidents. With the increasing demand for "intelligent vehicles" in the current market, electronic mirrors are gradually becoming practical, and the requirements for vehicle-mounted optical lenses used in electronic mirrors are also constantly increasing.

[0003] In current vehicle-mounted optical lenses, although the glass-plastic hybrid architecture can achieve low cost and miniaturization, due to the large thermal expansion coefficient of plastic, changes in environmental temperature will cause problems such as defocusing and image plane blurring of vehicle-mounted monitoring lenses; in addition, in order to improve image quality, vehicle-mounted optical lenses often adopt a lens architecture with multiple glass aspherical lenses, which has a high cost and limits the application scenarios. Therefore, there is an urgent need to design an optical lens with a simple structure, high image quality, large field of view, strong temperature adaptability, and low cost as a vehicle-mounted lens for electronic mirrors. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a vehicle-mounted optical lens, which solves the problems of temperature change affecting lens imaging and high cost.

[0005] A vehicle-mounted optical lens according to the first aspect of an embodiment of the present invention 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 sequence from the object side to the image side along the optical axis. The first lens is a negative lens, the second lens is a negative lens, the third lens is a positive lens, the fourth lens is a positive lens, the fifth lens is a negative lens, the sixth lens is a positive lens, and the seventh lens is a positive lens; Wherein, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the seventh lens are glass spherical lenses, the sixth lens is a glass aspherical lens, and the fourth lens and the fifth lens are glued together to form a glued lens.

[0006] A vehicle-mounted optical lens according to an embodiment of the present invention has at least the following beneficial effects: The present invention adopts an all-glass lens structure with a low coefficient of thermal expansion to avoid the blurring of the viewing angle and the image plane caused by temperature changes in the optical lens, achieve athermal design, and improve the stability of the optical lens. By adding an aspherical glass lens and performing reasonable lens arrangement and structural design, the aberration is corrected, the imaging quality is improved, and the performance requirements of the optical lens are balanced while meeting the cost requirements.

[0007] According to some embodiments of the present invention, the object side of the first lens is convex, and the image side is concave; The object side of the second lens is concave, and the image side is concave; The object side of the third lens is convex, and the image side is flat; The object side of the fourth lens is convex, and the image side is convex; The object side of the fifth lens is concave, and the image side is concave; The object side of the sixth lens is convex, and the image side is convex; The object side of the seventh lens is convex, and the image side is concave.

[0008] According to some embodiments of the present invention, the vehicle-mounted optical lens satisfies the following conditional expressions: -4.6 < f1 / f < -2.6; -3.6 < f2 / f < -1.6; 2.1 < f3 / f < 4.1; 2.6 < f4 / f < 4.6; -3.0 < f5 / f < -1.0; 1.9 < f6 / f < 3.9; 4.6 < f7 / f < 6.6; Wherein, f is the focal length of the vehicle-mounted optical 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, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens.

[0009] According to some embodiments of the present invention, the vehicle-mounted optical lens satisfies the following conditional expressions: Nd1 < 1.8; Vd1 > 45; Nd2 > 1.5; Vd2 < 65; Nd3 < 1.8; Vd3 > 25; Nd4 > 1.5; Vd4 < 69; Nd5 < 2.0; Vd5 > 18; Nd6 < 1.8; Vd6 > 45; Nd7 < 2.1; Vd7 > 25; 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, Nd6 is the refractive index of the sixth lens, Vd6 is the Abbe number of the sixth lens, Nd7 is the refractive index of the seventh lens, and Vd7 is the Abbe number of the seventh lens.

[0010] According to some embodiments of the present invention, the object side surface of the first lens is convex, and the image side surface is concave; The object side surface of the second lens is concave, and the image side surface is concave; The object side surface of the third lens is convex, and the image side surface is convex; The object side surface of the fourth lens is convex, and the image side surface is convex; The object side surface of the fifth lens is concave, and the image side surface is concave; The object side surface of the sixth lens is convex, and the image side surface is convex; The object side surface of the seventh lens is convex, and the image side surface is concave.

[0011] According to some embodiments of the present invention, the vehicle-mounted optical lens satisfies the following conditional expressions: -5.0 < f1 / f < -3.0; -3.3 < f2 / f < -1.3; 1.6 < f3 / f < 3.6; 3.7 < f4 / f < 5.7; -3.3 < f5 / f < -1.3; 2.2 < f6 / f < 4.2; 6.5 < f7 / f < 8.5; Wherein, f is the focal length of the vehicle-mounted optical 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, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens.

[0012] According to some embodiments of the present invention, the vehicle-mounted optical lens satisfies the following conditional expressions: Nd1 > 1.5; Vd1 < 61; Nd2 > 1.5; Vd2 < 59; Nd3 < 1.9; Vd3 > 30; Nd4 > 1.5; Vd4 < 69; Nd5 < 2.0; Vd5 > 18; Nd6 < 1.8; Vd6 > 50; Nd7 > 1.6; Vd7 > 32; 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, Nd6 is the refractive index of the sixth lens, Vd6 is the Abbe number of the sixth lens, Nd7 is the refractive index of the seventh lens, and Vd7 is the Abbe number of the seventh lens.

[0013] According to some embodiments of the present invention, it further includes a diaphragm, and the diaphragm is disposed between the third lens and the fourth lens.

[0014] According to some embodiments of the present invention, it further includes a filter, and the filter is disposed on the image side of the seventh lens.

[0015] According to some embodiments of the present invention, it further includes a protective lens, and the protective lens is disposed on the image side of the filter.

[0016] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. Brief Description of the Drawings

[0017] The following will further describe the present invention in conjunction with the drawings and embodiments, where: Figure 1 is a schematic structural diagram of an embodiment of an in-vehicle optical lens provided by the present invention; Figure 2 is Figure 1 a schematic diagram of the field curvature and distortion of the shown embodiment; Figure 3 is Figure 1 a defocus curve graph of the shown embodiment at a central field of view of 83 lp / mm at -40°C; Figure 4 is Figure 1 a defocus curve graph of the shown embodiment at a central field of view of 83 lp / mm at 20°C; Figure 5 is Figure 1 a defocus curve graph of the shown embodiment at a central field of view of 83 lp / mm at 85°C; Figure 6 is a schematic structural diagram of another embodiment of an in-vehicle optical lens provided by the present invention; Figure 7 is Figure 6Schematic diagram of field curvature and distortion of the illustrated embodiment; Figure 8 is Figure 6 Defocus curve graph of the central field of view at 83 lp / mm for the illustrated embodiment at -40°C; Figure 9 is Figure 6 Defocus curve graph of the central field of view at 83 lp / mm for the illustrated embodiment at 20°C; Figure 10 is Figure 6 Defocus curve graph of the central field of view at 83 lp / mm for the illustrated embodiment at 85°C; Reference numerals in the drawings: First lens L1; Second lens L2; Third lens L3; Aperture STO; Fourth lens L4; Fifth lens L5; Sixth lens L6; Seventh lens L7; Filter L8; Protective lens L9; Object side S1 of the first lens; Image side S2 of the first lens; Object side S3 of the second lens; Image side S4 of the second lens; Object side S5 of the third lens; Image side S6 of the third lens; Object side S7 of the fourth lens; Image side S8 of the fourth lens; Image side S9 of the fifth lens; Object side S10 of the sixth lens; Image side S11 of the sixth lens; Object side S12 of the seventh lens; Image side S13 of the seventh lens; Object side S14 of the filter; Image side S15 of the filter; Object side S16 of the protective glass; Image side S17 of the protective glass; Imaging surface IMG. Detailed implementation manners

[0018] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0019] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as up, down, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0020] In the description of the present invention, "a plurality of" means two or more. If there is a description of first and second, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0021] In the description of the present invention, unless otherwise clearly defined, terms such as "set", "installed", "connected", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0022] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the following described embodiments are some embodiments of the present invention, not all embodiments.

[0023] In increasingly congested urban roads and complex traffic environments, the driver's blind spot of vision often becomes the source of safety hazards. Electronic rearview mirrors (CMS) can provide a wider field of vision, eliminate blind spots, help drivers better understand the surrounding environment, reduce the impact of bad weather, have better night vision, improve driving quality, and reduce the occurrence of accidents. With the increasing demand for "intelligent vehicles" in the current market, electronic rearview mirrors are gradually becoming practical, and the requirements for on-vehicle optical lenses applied to electronic rearview mirrors are also constantly increasing.

[0024] In current on-vehicle optical lenses, although the hybrid glass and plastic architecture can achieve low cost and miniaturization, due to the large thermal expansion coefficient of plastic, changes in environmental temperature will cause defocusing and image plane blurring problems of on-vehicle monitoring lenses; in addition, in order to improve image quality, on-vehicle optical lenses often adopt a lens architecture with multiple glass aspherical lenses, which has a high cost and limits the application scenarios. Therefore, there is an urgent need to design an optical lens with a simple structure, high image quality, large field of view, strong temperature adaptability, and low cost as an on-vehicle lens for electronic rearview mirrors.

[0025] To solve the above problems, the present invention proposes an on-vehicle optical lens, which can effectively solve the problems of defocusing and image plane blurring of on-vehicle monitoring lenses caused by changes in environmental temperature and the problem of too high cost, maintain high resolution within a very wide range of environmental temperature changes, meet the performance requirements of large field of view angle, small distortion, and small chromatic aberration, and has the advantages of small size, large aperture, and low cost.

[0026] Refer to Figures 1 to 10 , the accompanying drawings show specific embodiments of the on-vehicle optical lens proposed by the present invention, where Figures 1 to 5 is the first embodiment of the on-vehicle optical lens proposed by the present invention, Figures 6 to 10 is the second embodiment of the on-vehicle optical lens proposed by the present invention.

[0027] Refer to Figure 1 and Figure 6 As shown, the on-vehicle optical lens has an object side and an image side that are relatively arranged along the optical axis direction. The on-vehicle optical lens includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7 that are sequentially arranged along the optical axis from the object side to the image side.

[0028] Among them, to ensure that the optical lens maintains high resolution within a very wide temperature range, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are all made of glass material. The vehicle-mounted optical lens provided by the present invention has an all-glass structure. Since the glass material has a low coefficient of thermal expansion, the optical lens with an all-glass structure is not easily caused by problems such as lens defocus and image plane blur under environmental temperature changes.

[0029] Furthermore, the first lens L1 is a negative lens, the second lens L2 is a negative lens, the third lens L3 is a positive lens, the fourth lens L4 is a positive lens, the fifth lens L5 is a negative lens, the sixth lens L6 is a positive lens, and the seventh lens L7 is a positive lens. By comprehensively setting the cooperation relationship between the optical powers and shapes of each lens, an athermal design is effectively achieved. Through the cooperation of each lens, no defocus occurs within the temperature difference range of -40°C to 85°C. By setting the first lens L1 to have a negative optical power, it is beneficial to collect light, thereby effectively increasing the field of view range.

[0030] It should be noted that the fourth lens L4 and the fifth lens L5 are glued together to form a cemented lens. The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the seventh lens L7 are spherical lenses, and the sixth lens L6 is an aspherical lens.

[0031] The surface shape of the aspherical lens satisfies the following equation:

[0032] Among them, X is the sagitta height from the vertex of the aspherical surface when the aspherical surface is along the optical axis direction at a position with a height of h; C is the paraxial curvature of the aspherical surface; k is the conic constant; A4, A6, A8, and A10 are all high-order term coefficients. The shape dimensions of the object side and the image side of the aspherical lens are set through the above several parameters.

[0033] By setting the fourth lens L4 and the fifth lens L5 to form a cemented lens to correct chromatic aberration, reduce chromatic aberration and spherical aberration of the vehicle-mounted optical lens, and since one side of the fourth lens L4 and the fifth lens L5 is closely attached, the light energy loss is reduced and the imaging brightness is increased; by setting the sixth lens L6 as an aspherical lens to eliminate aberrations such as spherical aberration, chromatic aberration, and field curvature, improve the edge image quality, and improve the performance of the optical lens.

[0034] An aperture stop is also provided between the third lens L3 and the fourth lens L4. The aperture stop is used to limit the width of the imaging beam and the size of the imaging range to ensure sufficient light input, so that clear imaging can also be achieved in low light. At the same time, stray light is restricted from reaching the image plane, improving the clarity of the imaging picture.

[0035] On the image side of the seventh lens L7, a filter L8 and a protective lens L9 are sequentially provided. The filter L8 is used to filter out stray light, reduce the interference components in the background, improve the contrast of the target against the background, and further improve the imaging quality. The light collected by the vehicle-mounted optical lens forms an image on the imaging surface after passing through each lens. In order to obtain an image, an external photosensitive device is provided on the imaging surface. The protective lens L9 is used to protect the photosensitive device, so as to improve the stability and reliability of the vehicle-mounted optical lens, thus adapting to different usage scenarios and preventing the photosensitive device from being impacted and causing the lens to fail.

[0036] The following details the specific structures and parameters of the vehicle-mounted optical lenses provided in two embodiments respectively.

[0037] Embodiment 1 Referring to Figure 1 As shown, in the first embodiment of the present invention, the object side surface S1 of the first lens L1 is convex, and the image side surface S2 is concave; the object side surface S3 of the second lens L2 is concave, and the image side surface S4 is concave; the object side surface S5 of the third lens L3 is convex, and the image side surface S6 is flat; the object side surface S7 of the fourth lens L4 is convex, and the image side surface S8 is convex; the object side surface S8 of the fifth lens L5 is concave, and the image side surface S9 is concave; the object side surface S10 of the sixth lens L6 is convex, and the image side surface S11 is convex; the object side surface S12 of the seventh lens L7 is convex, and the image side surface S13 is concave.

[0038] For the focal lengths of each lens, the vehicle-mounted optical lens of this embodiment satisfies the following relational expressions: -4.6 < f1 / f < -2.6; -3.6 < f2 / f < -1.6; 2.1 < f3 / f < 4.1; 2.6 < f4 / f < 4.6; -3.0 < f5 / f < -1.0; 1.9 < f6 / f < 3.9; 4.6 < f7 / f < 6.6; where f is the focal length of the vehicle-mounted optical lens, f1 is the focal length of the first lens L1, f2 is the focal length of the second lens L2, f3 is the focal length of the third lens L3, f4 is the focal length of the fourth lens L4, f5 is the focal length of the fifth lens L5, f6 is the focal length of the sixth lens L6, and f7 is the focal length of the seventh lens L7.

[0039] By optimizing the combination of the focal lengths of each lens, a wide-angle lens is formed. The lens has a large field of view, can provide a large-field environmental perception for the driver, meets the usage requirements of vehicle-mounted electronic rearview mirrors, and can well control the refraction of light passing through the vehicle-mounted optical lens. While introducing more light, the structure is more compact, and the total length of the lens is controlled within 25 mm, having the advantages of simple structure, low cost, and miniaturization.

[0040] Furthermore, for the refractive index and dispersion coefficient of each lens, the vehicle-mounted optical lens of this embodiment satisfies the following relational expressions: Nd1 < 1.8, Vd1 > 45, where Nd1 is the refractive index of the first lens L1 and Vd1 is the Abbe number of the first lens L1; Nd2 > 1.5, Vd2 < 65, where Nd2 is the refractive index of the second lens L2 and Vd2 is the Abbe number of the second lens L2; Nd3 < 1.8, Vd3 > 25, where Nd3 is the refractive index of the third lens L3 and Vd3 is the Abbe number of the third lens L3; Nd4 > 1.5, Vd4 < 69, where Nd4 is the refractive index of the fourth lens L4 and Vd4 is the Abbe number of the fourth lens L4; Nd5 < 2.0, Vd5 > 18, where Nd5 is the refractive index of the fifth lens L5 and Vd5 is the Abbe number of the fifth lens L5; Nd6 < 1.8, Vd6 > 45, where Nd6 is the refractive index of the sixth lens L6 and Vd6 is the Abbe number of the sixth lens L6; Nd7 < 2.1, Vd7 > 25, where Nd7 is the refractive index of the seventh lens L7 and Vd7 is the Abbe number of the seventh lens L7.

[0041] By optimizing the combination of the refractive indices and dispersion coefficients of each lens and cooperating with glass materials of different Abbe numbers, chromatic aberration is corrected, imaging quality is improved, and at the same time, it is beneficial to the athermalization of the vehicle-mounted optical lens.

[0042] Specifically, in this embodiment, the parameters of the vehicle-mounted optical lens are as follows: The total length of the lens TTL is 23.8 mm, the aperture value Fno = 1.8, the semi-image height aperture D in the D direction is 3.46 mm, the semi-image height H in the H direction is 2.88 mm, the field of view FOV = 146°, and the back focal length BFL = 4.3 mm.

[0043] From the above data, it can be seen that the total length of the lens is small, which is beneficial to reducing the volume and weight of the lens, making the lens structure compact, light and portable, meeting the installation space requirements as an electronic rearview mirror, and adapting to the use scenarios of vehicle-mounted optical lenses; the aperture value is 1.8, and the light throughput is sufficient, so as to ensure that the lens can also clearly image in low-light environments and has adaptability to complex light environments; the field of view is large to ensure that the field of view is large enough to meet the driver's field of view environment perception needs and improve the use experience.

[0044] Specifically, in the first embodiment, the parameters such as the radius of curvature, central thickness, and material refractive index of each lens are shown in the following table: Table 1

[0045] Among them, infinity indicates that the radius of this spherical surface is infinite, indicating that this surface is a plane.

[0046] From the data in the above table, it can be seen that the focal lengths, refractive indices, and Abbe numbers of each lens meet the relational requirements.

[0047] In the first embodiment, the aspheric coefficients of the aspheric lens are shown in the following table: Table 2

[0048] In this embodiment, the field curvature and distortion curves of the vehicle-mounted optical lens are as shown in Figure 2 In the field curvature curve, the vertical axis is the field angle, the horizontal axis is the distance of the image point deviating from the paraxial image plane, T represents the meridional field curvature, and S represents the sagittal field curvature; it can be seen that the field curvature is controlled within 0.04 mm, and both the field curvature and astigmatism are well corrected; in the distortion curve, the vertical axis is the field angle, and the horizontal axis is the distortion percentage. From Figure 2 it can be observed that the distortion percentage of the vehicle-mounted optical lens is controlled within 60%, the distortion percentage meets the standard, and the vehicle-mounted optical lens maintains high resolution within a very wide range of ambient temperature changes.

[0049] Figure 3 、 Figure 4 and Figure 5 are the defocus curves of the vehicle-mounted optical lens at ambient temperatures of -40°C, 20°C, and 85°C respectively, where the horizontal axis is the defocus amount in millimeters, the vertical axis is the contrast, and TS0.00(deg) represents the diffraction curves in the meridional and sagittal directions on the 0.00 field of the image plane.

[0050] From Figures 3 to 5 it can be observed that the defocus curves at low temperature of -40°C, normal temperature of 20°C, and high temperature of 85°C all meet the requirements of slow high resolution. The vehicle-mounted optical lens maintains high resolution within a very wide range of ambient temperature changes, has a high concentration and a low defocus amount. The defocus amount is controlled within the range of ±0.005 mm, and there is no defocus or image plane blur within a large temperature difference range, and the thermal drift effect is stable.

[0051] In summary, compared with the prior art, this embodiment adopts an all-glass structure, realizes an athermal design through a glass material with a small coefficient of thermal expansion, and at the same time reduces the volume of the optical lens by reasonably using aspheric lenses. By reasonably arranging aspheric lenses and cemented lenses, aberrations such as spherical aberration and chromatic aberration are eliminated, and the imaging performance is improved, obtaining an optical lens with a compact structure, a large viewing angle, and high imaging quality, which can be used as an electronic rearview mirror to clearly image and accurately identify the surrounding environment of the vehicle, and has a wide application prospect.

[0052] Embodiment Two Refer to Figure 6As shown in the figure, in the second embodiment of the present invention, the object side surface S1 of the first lens L1 is convex, and the image side surface S2 is concave; the object side surface S3 of the second lens L2 is concave, and the image side surface S4 is concave; the object side surface S5 of the third lens L3 is convex, and the image side surface S6 is convex; the object side surface S7 of the fourth lens L4 is convex, and the image side surface S8 is convex; the object side surface S8 of the fifth lens L5 is concave, and the image side surface S9 is concave; the object side surface S10 of the sixth lens L6 is convex, and the image side surface S11 is convex; the object side surface S12 of the seventh lens L7 is convex, and the image side surface S13 is concave.

[0053] Regarding the focal lengths of the respective lenses, the vehicle-mounted optical lens of this embodiment satisfies the following relational expressions: -5.0 < f1 / f < -3.0; -3.3 < f2 / f < -1.3; 1.6 < f3 / f < 3.6; 3.7 < f4 / f < 5.7; -3.3 < f5 / f < -1.3; 2.2 < f6 / f < 4.2; 6.5 < f7 / f < 8.5; where f is the focal length of the vehicle-mounted optical lens, f1 is the focal length of the first lens L1, f2 is the focal length of the second lens L2, f3 is the focal length of the third lens L3, f4 is the focal length of the fourth lens L4, f5 is the focal length of the fifth lens L5, f6 is the focal length of the sixth lens L6, and f7 is the focal length of the seventh lens L7.

[0054] By optimizing and matching the focal lengths of the respective lenses, a wide-angle lens is formed. The lens has a large field of view, can provide a large-field environmental perception for the driver, meets the usage requirements of vehicle-mounted electronic rearview mirrors, and can well control the refraction of light passing through the vehicle-mounted optical lens. While introducing more light, the structure is more compact, and the total length of the lens is controlled within 25 mm, having the advantages of simple structure, low cost, and miniaturization.

[0055] Furthermore, regarding the refractive indices and dispersion coefficients of the respective lenses, the vehicle-mounted optical lens of this embodiment satisfies the following relational expressions: Nd1 > 1.5; Vd1 < 61, where Nd1 is the refractive index of the first lens L1 and Vd1 is the Abbe number of the first lens L1; Nd2 > 1.5, Vd2 < 59, where Nd2 is the refractive index of the second lens L2 and Vd2 is the Abbe number of the second lens L2; Nd3 < 1.9, Vd3 > 30, where Nd3 is the refractive index of the third lens L3 and Vd3 is the Abbe number of the third lens L3; Nd4 > 1.5, Vd4 < 69, where Nd4 is the refractive index of the fourth lens L4 and Vd4 is the Abbe number of the fourth lens L4; Nd5 < 2.0, Vd5 > 18, where Nd5 is the refractive index of the fifth lens L5 and Vd5 is the Abbe number of the fifth lens L5; Nd6 < 1.8, Vd6 > 50, where Nd6 is the refractive index of the sixth lens L6 and Vd6 is the Abbe number of the sixth lens L6; Nd7 > 1.6, Vd7 > 32, where Nd7 is the refractive index of the seventh lens L7 and Vd7 is the Abbe number of the seventh lens L7.

[0056] By optimizing and matching the refractive indices and dispersion coefficients of each lens, and through the mutual cooperation of glass materials with different Abbe numbers, chromatic aberration is corrected, imaging quality is improved, and at the same time, it is beneficial to the athermalization of vehicle-mounted optical lenses.

[0057] Specifically, in this embodiment, the parameters of the vehicle-mounted optical lens are as follows: The total lens length TTL is 24.6 mm, the aperture value Fno = 1.8, the semi-image height aperture D in the D direction is 3.46 mm, the semi-image height H in the H direction is 2.88 mm, the field of view FOV = 146°, and the back focal length BFL = 3.95 mm.

[0058] From the above data, it can be seen that the total lens length is small, which is beneficial to reducing the volume and weight of the lens, making the lens structure compact, light and portable, meeting the installation space requirements as an electronic rearview mirror, and adapting to the usage scenarios of vehicle-mounted optical lenses; the aperture value is 1.8, and the light throughput is sufficient, so as to ensure that the lens can also form clear images in low-light environments and has adaptability to complex light environments; the field of view is large to ensure that the field of view range is large enough to meet the driver's field of view environment perception requirements and improve the usage experience.

[0059] Specifically, in the second embodiment, the parameters such as the curvature radius, central thickness, and material refractive index of each lens are as shown in the following table: Table 3

[0060] Among them, infinity indicates that the radius of this spherical surface is infinite, indicating that this surface is a plane.

[0061] In the second embodiment, the aspherical coefficients of the aspherical lenses are as shown in the following table: Table 4

[0062] In this embodiment, the field curvature and distortion curves of the vehicle-mounted optical lens are as Figure 7 shown. In the field curvature curve, the ordinate is the field of view angle, the abscissa is the distance of the image point deviating from the paraxial image plane, T represents the meridional field curvature, and S represents the sagittal field curvature; it can be seen that the field curvature is controlled within 0.04 mm, and both the field curvature and astigmatism are well corrected; in the distortion curve, the ordinate is the field of view angle, the abscissa is the distortion percentage. From Figure 7 it can be observed that the distortion percentage of the vehicle-mounted optical lens is controlled within 60%, the distortion percentage meets the standard, and the vehicle-mounted optical lens maintains high resolution within a very wide range of ambient temperature changes.

[0063] Figure 8 、 Figure 9 andFigure 10 They are the defocus curves of the vehicle-mounted optical lens at ambient temperatures of -40°C, 20°C, and 85°C respectively. The abscissa is the defocus amount in millimeters, and the ordinate is the contrast. TS0.00(deg) represents the diffraction curves in the meridional and sagittal directions on the 0.00 field of the image plane.

[0064] From Figures 8 to 10 it can be observed that the defocus curves at low temperature of -40°C, normal temperature of 20°C, and high temperature of 85°C all meet the requirements of slow and high resolution. The vehicle-mounted optical lens maintains high resolution within a very wide range of ambient temperature changes, has a high concentration and a low defocus amount. The defocus amount is controlled within the range of ±0.0051 mm, and there is no defocus or image plane blur within a large temperature difference range, and the thermal drift effect is stable.

[0065] In summary, compared with the prior art, this embodiment adopts a full-glass structure, realizes an athermal design through a glass material with a small coefficient of thermal expansion, and at the same time reduces the volume of the optical lens by reasonably using aspherical lenses. By reasonably arranging aspherical lenses and cemented lenses, aberrations such as spherical aberration and chromatic aberration are eliminated, and the imaging performance is improved, obtaining an optical lens with a compact structure, a large viewing angle, and high imaging quality, which can be used as an electronic rearview mirror to clearly image and accurately identify the surrounding environment of the vehicle, and has a wide application prospect.

[0066] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0067] The above has described the embodiments of the present invention in detail with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the art.

Claims

1. An in-vehicle optical lens, characterized in that, There are an object side and an image side, including: A first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged in sequence from the object side to the image side along the optical axis. The first lens is a negative lens, the second lens is a negative lens, the third lens is a positive lens, the fourth lens is a positive lens, the fifth lens is a negative lens, the sixth lens is a positive lens, and the seventh lens is a positive lens; Among them, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the seventh lens are glass spherical lenses, the sixth lens is a glass aspherical lens, and the fourth lens and the fifth lens are glued together to form a cemented lens.

2. The optical lens according to claim 1, wherein: The object side surface of the first lens is convex, and the image side surface is concave; The object side surface of the second lens is concave, and the image side surface is concave; The object side surface of the third lens is convex, and the image side surface is flat; The object side surface of the fourth lens is convex, and the image side surface is convex; The object side surface of the fifth lens is concave, and the image side surface is concave; The object side surface of the sixth lens is convex, and the image side surface is convex; The object side surface of the seventh lens is convex, and the image side surface is concave.

3. The optical lens according to claim 2, wherein: The vehicle-mounted optical lens satisfies the following conditional expressions: -4.6 < f1 / f < -2.6; -3.6 < f2 / f < -1.6; 2.1 < f3 / f < 4.1; 2.6 < f4 / f < 4.6; -3.0 < f5 / f < -1.0; 1.9 < f6 / f < 3.9; 4.6 < f7 / f < 6.6; Wherein, f is the focal length of the vehicle-mounted optical 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, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens.

4. The optical lens according to claim 2, wherein: The vehicle-mounted optical lens satisfies the following conditional expressions: Nd1 < 1.8; Vd1 > 45; Nd2 > 1.5; Vd2 < 65; Nd3 < 1.8; Vd3 > 25; Nd4 > 1.5; Vd4 < 69; Nd5 < 2.0; Vd5 > 18; Nd6 < 1.8; Vd6 > 45; Nd7 < 2.1; Vd7 > 25; 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, Nd6 is the refractive index of the sixth lens, Vd6 is the Abbe number of the sixth lens, Nd7 is the refractive index of the seventh lens, and Vd7 is the Abbe number of the seventh lens.

5. The optical lens according to claim 1, wherein: The object side of the first lens is convex, and the image side is concave; The object side of the second lens is concave, and the image side is concave; The object side of the third lens is convex, and the image side is convex; The object side of the fourth lens is convex, and the image side is convex; The object side of the fifth lens is concave, and the image side is concave; The object side of the sixth lens is convex, and the image side is convex; The object side of the seventh lens is convex, and the image side is concave.

6. The optical lens according to claim 5, wherein: The vehicle-mounted optical lens satisfies the following conditional expressions: -5.0 < f1 / f < -3.0; -3.3 < f2 / f < -1.3; 1.6 < f3 / f < 3.6; 3.7 < f4 / f < 5.7; -3.3 < f5 / f < -1.3; 2.2 < f6 / f < 4.2; 6.5 < f7 / f < 8.5; Wherein, f is the focal length of the vehicle-mounted optical 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, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens.

7. The optical lens according to claim 5, wherein: The vehicle-mounted optical lens satisfies the following conditional expressions: Nd1 > 1.5; Vd1 < 61; Nd2 > 1.5; Vd2 < 59; Nd3 < 1.9; Vd3 > 30; Nd4 > 1.5; Vd4 < 69; Nd5 < 2.0; Vd5 > 18; Nd6 < 1.8; Vd6 > 50; Nd7 > 1.6; Vd7 > 32; 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, Nd6 is the refractive index of the sixth lens, Vd6 is the Abbe number of the sixth lens, Nd7 is the refractive index of the seventh lens, and Vd7 is the Abbe number of the seventh lens.

8. The optical lens according to any one of claims 1 to 7, characterized in that: It further includes a diaphragm, and the diaphragm is arranged between the third lens and the fourth lens.

9. The optical lens according to any one of claims 1 to 7, characterized in that: It further includes a filter, and the filter is arranged on the image side of the seventh lens.

10. The optical lens according to claim 9, characterized in that: It further includes a protective lens, and the protective lens is arranged on the image side of the filter.

Images