Optical System, Camera Module, Electronic Device, and Vehicle

Abstract

The present invention relates to an optical system, a camera module, an electronic device, and a vehicle. The optical system sequentially includes, from the object side to the image side along the optical axis: a first lens having a negative refractive power, the image side surface of which is convex at least near the optical axis; a second lens having a positive refractive power; a third lens having a negative refractive power, the image side surface of which is convex at least near the optical axis; a fourth lens having a positive refractive power, the object side surface of which is convex at least near the optical axis; a fifth lens having a positive refractive power; a sixth lens having a negative refractive power; a seventh lens having a positive refractive power, the object side surface of which is convex at least near the optical axis; and the optical system satisfies the relationship: 9 mm < 2 * f * tan(FOV / 2) < 10 mm; f is the effective focal length of the optical system, and FOV is the maximum field of view angle of the optical system. The above optical system can suppress distortion, improve the resolution ability, and reduce the risk of distortion in the edge region of the captured image.

Description

Technical Field

[0001] The present invention relates to the technical field of photographic imaging, and particularly to an optical system, a camera module, an electronic device, and a vehicle. Background Art

[0002] With the gradual increase in the market's requirements for driving safety, technologies such as assisted driving technology and autonomous driving technology, which can quickly detect the surrounding environment of a vehicle and feedback it to the driver or the autonomous driving system, have also been greatly developed. The above-mentioned technologies can provide real-time monitoring, prediction, and analysis of road conditions for the driver or the autonomous driving system, thereby improving the safety of driving.

[0003] In common technologies such as assisted driving technology and autonomous driving technology, the acquisition of road conditions is very important. In general vehicles, a camera lens is often used to acquire road conditions, and then the imaging is analyzed by an analysis system to perform operations such as prediction. However, for a system that acquires road condition images, image distortion often causes the system's analysis to malfunction or causes the driver to make a wrong judgment on the image, thereby affecting the safety of driving. Summary of the Invention

[0004] Based on this, it is necessary to provide an optical system, a camera module, an electronic device, and a vehicle for the problem of how to improve imaging distortion.

[0005] An optical system sequentially includes, from the object side to the image side along the optical axis:

[0006] A first lens with negative refractive power, and the image side surface of the first lens is convex at least near the optical axis;

[0007] A second lens with positive refractive power;

[0008] A third lens with negative refractive power, and the image side surface of the third lens is convex at least near the optical axis;

[0009] A fourth lens with positive refractive power, and the object side surface of the fourth lens is convex at least near the optical axis;

[0010] A fifth lens with positive refractive power;

[0011] A sixth lens with negative refractive power;

[0012] A seventh lens with positive refractive power, and the object side surface of the seventh lens is convex at least near the optical axis;

[0013] And the optical system satisfies the relationship:

[0014] 9mm < 2*f*tan(FOV / 2) < 10mm;

[0015] f is the effective focal length of the optical system, and FOV is the maximum field of view angle of the optical system.

[0016] For an optical system with the above-mentioned number of lenses, refractive power, and surface design, when the above relationship conditions are further satisfied, a reasonable configuration can be obtained between the effective focal length and the maximum field of view angle of the optical system, so that the distortion amount of the entire optical system can be controlled, the distortion of the optical system can be suppressed, the resolution ability of the optical system can be improved, and the distortion risk in the edge area of the captured image can be reduced. In addition, when the above relationship conditions are satisfied, the optical system can also have the characteristics of a large image plane, which is beneficial to realizing high-pixel imaging. When the above optical system is applied to a vehicle to cooperate with an assisted driving system or an autonomous driving system, the distortion of imaging can be reduced to improve the analysis accuracy of the system, or a clearer and more accurate imaging picture can be directly provided to the driver, so as to improve the driver's judgment accuracy of road conditions and further improve driving safety.

[0017] In one embodiment, the second lens is glued to the third lens, the fifth lens is glued to the sixth lens, and the Abbe number Vd of at least one lens in the optical system with respect to d light is less than 30;

[0018] And the optical system also satisfies the relationship: f / (2*Imgh) > 1.5; Imgh is half of the image height corresponding to the maximum field of view angle of the optical system. When the above design is satisfied, through the gluing between the second lens and the third lens, and the gluing between the fifth lens and the sixth lens, and further controlling the Abbe number of the lenses in the optical system, the chromatic aberration of the system can be effectively corrected, and the size of the system in the optical axis direction can be shortened, which is beneficial to the miniaturization design of the system. In addition, by satisfying the relationship condition of f / (2*Imgh), the optical system can have the characteristics of a long focal length, so that a good telephoto effect can be achieved.

[0019] In one embodiment, the second lens is glued to the third lens, and the fifth lens is glued to the sixth lens. By gluing between the second lens and the third lens, and gluing between the fifth lens and the sixth lens, that is, by setting the gluing of multiple groups of lenses, the size of the system in the optical axis direction can be further effectively shortened, which is beneficial to the further miniaturization design of the system.

[0020] In one embodiment, the optical system satisfies the relationship:

[0021] -14.5 < f1 / CT1 < -7.5;

[0022] Let \(f1\) be the effective focal length of the first lens, and \(CT1\) be the thickness of the first lens on the optical axis. The lens closest to the object end in the optical system is designed as a negative lens, which can provide negative refractive power for the system, thereby facilitating the acquisition of light rays incident on the system at large angles, that is, it can expand the field of view angle range of the optical system. And when the above relationship conditions are further satisfied, a good mutual constraint can be obtained between the refractive power intensity and the central thickness of the first lens. On the one hand, it can avoid the generation of astigmatism that is difficult to correct in the optical system, which is beneficial to reducing the correction pressure of astigmatism on the lenses on the image side of the first lens, and thus can better prevent poor imaging quality of the system; on the other hand, it can also avoid the central thickness of the first lens being too large or too small. It should be noted that the larger the central thickness of the lens, the greater the weight of the lens, which is not conducive to the lightweight design of the optical system; while the smaller the central thickness, the greater the processing difficulty of the lens, and it is difficult to ensure the processing yield of the lens.

[0023] In one embodiment, the optical system satisfies the relationship:

[0024] 4 < f23 / (CT2 - CT3) < 12.5;

[0025] Let \(f23\) be the combined focal length of the second lens and the third lens, \(CT2\) be the thickness of the second lens on the optical axis, and \(CT3\) be the thickness of the third lens on the optical axis. The second lens and the third lens have positive refractive power and negative refractive power respectively. By satisfying the above relationship conditions, through reasonable matching of the combined focal length of the second lens and the third lens and the thickness relationship between the two lenses, the second lens and the third lens with positive and negative refractive powers can be reasonably matched, so as to achieve mutual correction of the aberrations between the two lenses, thereby suppressing the aberrations generated by the lens group composed of the second lens and the third lens, and reducing the aberration contribution ratio provided by the second lens and the third lens for the optical system. When it is lower than the lower limit of the relationship formula, the difference in the central thickness between the second lens and the third lens is too large, which is not conducive to the gluing process, and in an environment with large temperature changes, the difference in the thermal deformation amount due to the thickness difference will also be amplified, so that glue cracks or delamination are likely to occur between the glued lenses, thereby causing irreversible structural damage and reducing the imaging quality. When it is higher than the upper limit of the relationship formula, the combined focal length of the second lens and the third lens is too large, and serious astigmatism is likely to occur, which is not conducive to the improvement of the imaging quality of the optical system.

[0026] In one embodiment, the optical system satisfies the relationship:

[0027] 3.5 < f4 / CT4 < 7.5;

[0028] f4 is the effective focal length of the fourth lens, and CT4 is the thickness of the fourth lens on the optical axis. By satisfying the conditions of the above relationship, the relationship between the central thickness and the effective focal length of the fourth lens can be reasonably matched, so that the fourth lens provides sufficient positive refractive power for the system to converge light, which is beneficial to reducing the exit angle of the light when it exits the lens group, that is, reducing the angle of the light relative to the optical axis when it exits the seventh lens, and further reducing the incident angle of the light when it enters the image sensor, thereby improving the photosensitive performance of the image sensor, especially beneficial to suppressing the generation of vignetting.

[0029] In one embodiment, the optical system satisfies the relationship:

[0030] -12.5 < f56 / (CT5 - CT6) < -5.5;

[0031] f56 is the combined focal length of the fifth lens and the sixth lens, CT5 is the thickness of the fifth lens on the optical axis, and CT6 is the thickness of the sixth lens on the optical axis. By satisfying the conditions of the above relationship, the combined focal length of the fifth lens and the sixth lens and the thickness relationship between the two lenses can be reasonably matched, so that the fifth lens and the sixth lens with positive and negative refractive powers are reasonably matched, so as to achieve mutual correction of the aberrations between the two lenses, thereby suppressing the aberrations generated by the lens group composed of the fifth lens and the sixth lens. At the same time, through the constraint of the above relationship conditions, the difference in the central thickness between the fifth lens and the sixth lens can also be better suppressed, which is beneficial to the processing, molding and gluing of the lens. When it is higher than the upper limit of the relationship conditions, the difference in the central thickness between the fifth lens and the sixth lens is too large, which is not conducive to the gluing process, and in an environment with large temperature changes, the difference in the thermal deformation amount due to the thickness difference will also be amplified, so that glue cracks or delamination are likely to occur between the glued lenses. When it is lower than the lower limit of the relationship conditions, the combined focal length of the fifth lens and the sixth lens is too large, resulting in a more serious astigmatism phenomenon, which is not conducive to improving the imaging quality of the optical system.

[0032] In one embodiment, the optical system satisfies the relationship:

[0033] 1.5 < f7 / f < 4;

[0034] f7 is the effective focal length of the seventh lens. The seventh lens provides positive refractive power for the system. When the above relationship is satisfied, as the last lens of the optical system, the intensity of the positive refractive power provided by the seventh lens can be well constrained, so that chromatic aberration can be effectively corrected. At the same time, as the last lens in the system, the seventh lens can finally correct the aberration generated by the decentration of each lens on the object side, that is, the decentration sensitivity of the system can be reduced, and the astigmatism generated by the decentration of each lens on the object side can be suppressed, so as to realize the correction of system aberration and improve the imaging resolution. When exceeding the range of the above relational formula, the refractive power provided by the seventh lens will be too large or too small, which is not conducive to the correction of the aberration of the optical system, thus reducing the imaging quality.

[0035] In one embodiment, the optical system satisfies the relationship:

[0036] 8.5 < CT7 / Sag7 < 12;

[0037] CT7 is the thickness of the seventh lens on the optical axis, and Sag7 is the sagitta of the seventh lens at the maximum effective aperture of the image side. By controlling the ratio relationship between the central thickness of the seventh lens and the sagitta at the maximum effective aperture of the image side, it is possible to avoid the central thickness of the seventh lens being too large or the image side being too curved, which increases the manufacturing difficulty of the lens, thereby improving the preparation yield of the lens and reducing the production cost. When lower than the lower limit of the conditional formula, the image side of the seventh lens will be too curved, increasing the processing difficulty of the lens, thus increasing the production cost of the lens; at the same time, the lens surface is too curved, resulting in edge aberrations being easily generated in the edge field of view, which is not conducive to improving the image quality of the optical system. When exceeding the upper limit of the conditional formula, it will cause the central thickness of the seventh lens to be too large, which is not conducive to the lightweight and miniaturized design of the optical system.

[0038] In one embodiment, the optical system includes an aperture stop, the aperture stop is arranged on the object side of the first lens or between any two adjacent lenses, and the optical system satisfies the relationship:

[0039] 6 < EPL / DOS < 12.5;

[0040] EPL is the distance from the aperture stop to the imaging plane of the optical system on the optical axis, and DOS is the distance from the object side of the first lens to the aperture stop on the optical axis. When the above relational conditions are satisfied, the aperture stop can be set at a reasonable position in the optical system, so that the incident light can reach the photosensitive element (i.e., the image sensor) in a nearly perpendicular incident manner, thereby enabling the optical system to have a telecentric characteristic. The telecentric characteristic is extremely important for the photosensitive ability of the solid-state electronic photosensitive element, and the above design can effectively improve the photosensitive sensitivity of the electronic photosensitive element and enhance the imaging resolution of the system to improve the picture clarity. When it is lower than the lower limit of the relational condition, it is not conducive to the aperture stop being far from the imaging plane of the optical system, resulting in insufficient telecentric characteristic of the optical system.

[0041] An imaging module includes an image sensor and the optical system described in any one of the above. The image sensor is disposed on the image side of the optical system. By adopting the above optical system, the image distortion received by the image sensor of the imaging module can be suppressed, thereby reducing the distortion risk in the edge area of the captured picture and improving the imaging accuracy of the module. In addition, by adopting the above optical system, the imaging module can also have a large image plane characteristic, which is beneficial to achieving high-pixel imaging. When the above imaging module is applied to a vehicle to cooperate with an assisted driving system or an autonomous driving system, it can reduce the imaging distortion to make the magnification of each area of the picture tend to be consistent, thereby improving the analysis accuracy of the system, or directly providing a clear and accurate imaging picture to the driver, thereby improving the driver's judgment accuracy of the road conditions and further improving driving safety.

[0042] An electronic device includes a fixing member and the above imaging module, and the imaging module is disposed on the fixing member. By adopting the above imaging module, the distortion of the imaging picture obtained by the electronic device can be suppressed, thereby improving the imaging accuracy of the device. In addition, by adopting the above imaging module, the electronic device can also have a large image plane characteristic, which is beneficial to achieving high-pixel imaging. When the electronic device is used as an in-vehicle imaging device and applied to a vehicle, it can cooperate with an assisted driving system or an autonomous driving system, reduce the imaging distortion to improve the analysis accuracy of the system, or directly provide a clear and accurate imaging picture to the driver, thereby improving the driver's judgment accuracy of the road conditions and further improving driving safety.

[0043] A vehicle includes a mounting portion and the above-mentioned electronic device, and the electronic device is disposed on the mounting portion. By adopting the electronic device, the vehicle can not only achieve high-pixel imaging, but also reduce the distortion of imaging so that the magnification of each area of the picture tends to be consistent, enabling in-vehicle systems such as the assisted driving system and the autonomous driving system to more accurately analyze the real-time road conditions, and thus providing warnings in a timely manner; or it can also directly provide visual images for the driver, enabling the driver to accurately judge the road conditions based on the images, thereby improving the driving safety of the vehicle. Description of the Drawings

[0044] Figure 1 Schematic structural diagram of the optical system provided by the first embodiment of the present application;

[0045] Figure 2 Including the longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the first embodiment;

[0046] Figure 3 Schematic structural diagram of the optical system provided by the second embodiment of the present application;

[0047] Figure 4 Including the longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the second embodiment;

[0048] Figure 5 Schematic structural diagram of the optical system provided by the third embodiment of the present application;

[0049] Figure 6 Including the longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the third embodiment;

[0050] Figure 7 Schematic structural diagram of the optical system provided by the fourth embodiment of the present application;

[0051] Figure 8 Including the longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the fourth embodiment;

[0052] Figure 9 Schematic structural diagram of the optical system provided by the fifth embodiment of the present application;

[0053] Figure 10 Including the longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the fifth embodiment;

[0054] Figure 11 Schematic diagram of the camera module provided by an embodiment of the present application;

[0055] Figure 12 Schematic structural diagram of the electronic device provided by an embodiment of the present application;

[0056] Figure 13Structural schematic diagram of a vehicle provided by an embodiment of the present application. Detailed implementation manners

[0057] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following provides a detailed description of the specific implementation manners of the present invention with reference to the accompanying drawings. Many specific details are set forth in the following description to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0058] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These are 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. Therefore, it should not be construed as a limitation of the present invention.

[0059] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0060] In the present invention, unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] In the present invention, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply indicates that the horizontal height of the first feature is less than that of the second feature.

[0062] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation.

[0063] Reference Figure 1 , an embodiment of the present application provides an optical system 10 with a seven-lens structure. The optical system 10 sequentially 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 from the object side to the image side along the optical axis 101. Each lens in the optical system 10 is coaxially arranged, that is, the optical axes of the lenses are all on the same straight line, and this straight line can be called the optical axis 101 of the optical system 10. The above-mentioned optical elements in the optical system 10 and the diaphragm not yet mentioned can be assembled with the lens barrel to form a camera lens.

[0064] The first lens L1 includes an object side surface S1 and an image side surface S2, the second lens L2 includes an object side surface S3 and an image side surface S4, the third lens L3 includes an object side surface S5 and an image side surface S6, the fourth lens L4 includes an object side surface S7 and an image side surface S8, the fifth lens L5 includes an object side surface S9 and an image side surface S10, the sixth lens L6 includes an object side surface S11 and an image side surface S12, and the seventh lens L7 includes an object side surface S13 and an image side surface S14. In addition, the optical system 10 further has an imaging surface S15, and the imaging surface S15 is located on the image side of the seventh lens L7. Generally, the imaging surface S15 of the optical system 10 coincides with the photosensitive surface of the image sensor. For the convenience of understanding, the imaging surface S15 can be regarded as the photosensitive surface of the photosensitive element.

[0065] In an embodiment of the present application, the first lens L1 has a negative refractive power, and its image side S2 is convex at least near the optical axis; the second lens L2 has a positive refractive power; the third lens L3 has a negative refractive power, and its image side S6 is convex at least near the optical axis; the fourth lens L4 has a positive refractive power, and its object side S7 is convex at least near the optical axis; the fifth lens L5 has a positive refractive power; the sixth lens L6 has a negative refractive power; the seventh lens L7 has a positive refractive power, and its object side S13 is convex at least near the optical axis. The above structure is beneficial to the telephoto design of the optical system 10, and the refractive power properties and surface type combinations of the lenses arranged from the object side to the image side in the system are reasonable, which is also beneficial to the correction of aberrations.

[0066] It should be noted that when an embodiment of the present application describes that a side surface of a lens is convex near the optical axis, it can be understood that this side surface of the lens is convex in the area near the optical axis; when describing that a side surface of a lens is concave at the circumference, it can be understood that this side surface is concave in the area near the maximum effective aperture. For example, when this side surface is convex near the optical axis and also convex at the circumference, the shape of this side surface from the center (optical axis) to the edge direction can be a pure convex surface; or it can be a convex surface shape at the center that first transitions to a concave surface shape and then becomes convex when approaching the maximum effective aperture. When describing that a lens surface is convex at least near the optical axis, this lens surface can be convex or concave at the circumference. On the other hand, when describing that a lens surface is convex, then this lens surface is entirely convex, that is, it is convex both near the optical axis and near the circumference, but the curvatures of each part of this surface can be the same or different. For the sake of saving space, only specific surface types are used as examples above.

[0067] On the other hand, in an embodiment of the present application, the optical system 10 also satisfies the relationship: 9mm < 2 * f * tan(FOV / 2) < 10mm; f is the effective focal length of the optical system 10, and FOV is the maximum field of view angle of the optical system 10. For the optical system 10 with the above lens quantity, refractive power, and surface type design, when further satisfying the conditions of the above relational expression, a reasonable configuration can be obtained between the effective focal length and the maximum field of view angle of the optical system 10, so that the distortion amount of the entire optical system 10 can be controlled, the distortion of the optical system 10 can be suppressed, the resolution ability of the optical system 10 can be improved, and the distortion risk in the edge area of the captured image can be reduced. In addition, when satisfying the conditions of the above relational expression, the optical system 10 can also have a large image plane characteristic, which is beneficial to realizing high-pixel imaging.

[0068] In particular, when the above optical system 10 is applied to a vehicle to cooperate with an assisted driving system or an autonomous driving system, it can improve the analysis accuracy of the system by reducing the distortion of imaging, or directly provide a clearer and more accurate imaging picture for the driver, so as to improve the driver's judgment accuracy of the road conditions and thus improve driving safety. It should be noted that the optical system 10 is generally assembled with an image sensor to form an imaging module. The rectangular effective pixel area of the image sensor has a diagonal direction. After the image sensor is assembled, the FOV can also be understood as the maximum field of view angle of the optical system 10 in the direction parallel to this diagonal. In some embodiments, the above relationship satisfied by the optical system 10 can specifically be 9.62 mm, 9.622 mm, 9.623 mm, 9.624 mm, 9.625 mm, or 9.626 mm.

[0069] In addition, in some embodiments, the optical system 10 further satisfies at least one of the following relationships, and when any of the relational expressions is satisfied, corresponding technical effects can be brought:

[0070] -14.5 < f1 / CT1 < -7.5; f1 is the effective focal length of the first lens L1, and CT1 is the thickness of the first lens L1 on the optical axis. The lens closest to the object end in the optical system 10 is designed as a negative lens, so as to provide negative refractive power for the system, which is beneficial to obtaining the light rays incident on the system at large angles, that is, it can expand the field of view angle range of the optical system 10. And when the above relational expression conditions are further satisfied, a good mutual constraint can be obtained between the refractive power intensity and the central thickness of the first lens L1. On the one hand, it can avoid the astigmatism that is difficult to correct in the optical system 10, which is beneficial to reducing the astigmatism correction pressure of the lenses on the image side of the first lens L1 to prevent poor imaging quality of the system; on the other hand, it can also avoid the central thickness of the first lens L1 being too large or too small. It should be noted that the larger the central thickness of the lens, the greater the weight of the lens, which is not conducive to the lightweight design of the optical system 10; while the smaller the central thickness, the greater the processing difficulty of the lens, and it is difficult to ensure the processing yield of the lens. In some embodiments, the above relationship satisfied by the optical system 10 can specifically be -14.4, -14.2, -14, -13.5, -13, -12, -10, -9.5, -9, -8.5, -8.2, -8, or -7.8.

[0071] 4 < f23 / (CT2 - CT3) < 12.5; f23 is the combined focal length of the second lens L2 and the third lens L3, CT2 is the thickness of the second lens L2 on the optical axis, and CT3 is the thickness of the third lens L3 on the optical axis. The second lens L2 and the third lens L3 have positive and negative refractive powers respectively. By satisfying the above relational condition, the combined focal length of the second lens L2 and the third lens L3 and the thickness relationship between the two lenses can be reasonably matched, so that the second lens L2 and the third lens L3 with positive and negative refractive powers are reasonably matched, thereby enabling the mutual correction of the aberrations between the two lenses, suppressing the aberrations generated by the lens group composed of the second lens L2 and the third lens L3, and reducing the aberration contribution ratio provided by the second lens L2 and the third lens L3 to the optical system 10. When it is lower than the lower limit of the relational formula, the difference in the central thickness between the second lens L2 and the third lens L3 is too large, which is not conducive to the gluing process. Moreover, in an environment with a large temperature change, the difference in the thermal expansion and contraction amounts due to the thickness difference will also be amplified, resulting in phenomena such as glue cracking or delamination between the glued lenses, further causing irreversible structural damage and reducing the imaging quality. When it is higher than the upper limit of the relational formula, the combined focal length of the second lens L2 and the third lens L3 is too large, and serious astigmatism is likely to occur, which is not conducive to improving the imaging quality of the optical system 10. In some embodiments, the above relationship satisfied by the optical system 10 can specifically be 4.3, 4.5, 4.8, 5, 7, 9, 11, 11.5, 11.8, 12 or 12.1.

[0072] 3.5 < f4 / CT4 < 7.5; f4 is the effective focal length of the fourth lens L4, and CT4 is the thickness of the fourth lens L4 on the optical axis. By satisfying the above relational condition, the relationship between the central thickness and the effective focal length of the fourth lens L4 can be reasonably matched, enabling the fourth lens L4 to provide sufficient positive refractive power to converge light, which is conducive to reducing the exit angle of the light when it exits the lens group, that is, reducing the angle of the light relative to the optical axis when it exits the seventh lens L7, and further reducing the incident angle of the light when it enters the image sensor, thereby improving the photosensitive performance of the image sensor, especially conducive to suppressing the generation of vignetting. In some embodiments, the above relationship satisfied by the optical system 10 can specifically be 4, 4.2, 4.4, 5, 5.5, 6, 6.5, 6.8, 7 or 7.2.

[0073] -12.5 < f56 / (CT5 - CT6) < -5.5; where f56 is the combined focal length of the fifth lens L5 and the sixth lens L6, CT5 is the thickness of the fifth lens L5 on the optical axis, and CT6 is the thickness of the sixth lens L6 on the optical axis. By satisfying the above relational conditions, the combined focal length of the fifth lens L5 and the sixth lens L6 and the thickness relationship between the two lenses can be reasonably matched, enabling the fifth lens L5 and the sixth lens L6, which have positive and negative refractive powers respectively, to be reasonably matched, thereby achieving mutual correction of the aberrations between the two lenses and suppressing the aberrations generated by the lens group composed of the fifth lens L5 and the sixth lens L6. At the same time, through the constraint of the above relational conditions, the difference in the central thickness between the fifth lens L5 and the sixth lens L6 can also be better suppressed, which is beneficial to the processing, shaping, and gluing of the lenses. When higher than the upper limit of the relational conditions, the difference in the central thickness between the fifth lens L5 and the sixth lens L6 is too large, which is not conducive to the gluing process, and in an environment with large temperature changes, the difference in the thermal deformation amounts due to the thickness difference will also be amplified, resulting in phenomena such as glue cracking or delamination between the glued lenses. When lower than the lower limit of the relational conditions, the combined focal length of the fifth lens L5 and the sixth lens L6 is too large, thus easily generating relatively serious astigmatism phenomena, which is not conducive to improving the imaging quality of the optical system 10. In some embodiments, the above relationship satisfied by the optical system 10 can specifically be -12.2, -12, -11.8, -11.4, -11, -10.5, -9, -7, -6.5, -6.2, or -6.

[0074] 1.5 < f7 / f < 4; where f7 is the effective focal length of the seventh lens L7. The seventh lens L7 provides positive refractive power for the system, and when the above relationship is satisfied, as the last lens of the optical system 10, the intensity of the positive refractive power provided by the seventh lens L7 can be better constrained, thereby effectively correcting chromatic aberration. At the same time, as the last lens in the system, the seventh lens can finally correct the aberrations generated by the decentration differences of the lenses on the object side, that is, it can systematically reduce the decentration sensitivity and suppress the astigmatism generated by the decentration of the lenses on the object side, thereby achieving the correction of system aberrations and improving the imaging resolution. When exceeding the range of the above relational formula, the refractive power provided by the seventh lens L7 will be too large or too small, which is not conducive to the correction of the aberrations of the optical system 10, thereby reducing the imaging quality. In some embodiments, the above relationship satisfied by the optical system 10 can specifically be 2, 2.2, 2.5, 2.8, 3, 3.2, 3.5, 3.6, or 3.8.

[0075] 8.5 < CT7 / Sag7 < 12; CT7 is the thickness of the seventh lens L7 on the optical axis, and Sag7 is the sagitta of the seventh lens L7 at the maximum effective aperture of the image side S14. Specifically, Sag7 is the distance from the intersection of the image side S14 of the seventh lens L7 and the optical axis 101 to the maximum effective aperture of this surface in the direction parallel to the optical axis 101. By controlling the ratio relationship between the central thickness of the seventh lens L7 and the sagitta at the maximum effective aperture of the image side S14, it is possible to avoid an overly large central thickness of the seventh lens L7 or an overly curved image side S14, which increases the manufacturing difficulty of the lens. Thus, the preparation yield of the lens can be improved, and the production cost can be reduced. When below the lower limit of the conditional formula, the image side S14 of the seventh lens L7 will be overly curved, increasing the lens processing difficulty and thus increasing the production cost of the lens. At the same time, the overly curved lens surface causes marginal aberrations to easily occur in the marginal field of view, which is not conducive to improving the image quality of the optical system 10. When exceeding the upper limit of the conditional formula, it will in turn lead to an overly large central thickness of the seventh lens L7, which is not conducive to the lightweight and miniaturized design of the optical system 10. In some embodiments, the above relationship satisfied by the optical system 10 may specifically be 9, 9.2, 9.4, 9.8, 10, 10.5, 10.9, 11, 11.2, 11.6, or 11.8.

[0076] The optical system 10 includes an aperture stop. The aperture stop is provided on the object side of the first lens L1 or between any two adjacent lenses, and the optical system 10 satisfies the relationship: 6 < EPL / DOS < 12.5; EPL is the distance from the aperture stop to the imaging surface of the optical system 10 on the optical axis, and DOS is the distance from the object side S1 of the first lens L1 to the aperture stop on the optical axis. When the above relational formula conditions are satisfied, the aperture stop can be set at a reasonable position in the optical system 10, enabling the incident light to reach the photosensitive element (i.e., the image sensor) in a nearly perpendicular incident manner, so that the optical system 10 has a telecentric characteristic. The telecentric characteristic is extremely important for the photosensitive ability of the solid-state electronic photosensitive element, and the above design can effectively improve the photosensitive sensitivity of the electronic photosensitive element and enhance the imaging resolution of the system to improve the image clarity. When below the lower limit of the relational formula conditions, it is not conducive to the aperture stop being far from the imaging surface of the optical system 10, resulting in insufficient telecentric characteristic of the optical system 10. In some embodiments, the above relationship satisfied by the optical system 10 may specifically be 6.2, 6.4, 6.8, 7.5, 8, 8.5, 9, 10, 11, 11.5, 11.8, 12, or 12.2.

[0077] f / (2*Imgh) > 1.5; Imgh is half of the image height corresponding to the maximum field of view angle of the optical system 10. It should be noted that Imgh can also be understood as half of the diagonal length of the rectangular effective imaging area on the imaging surface S15, that is, when the optical system 10 is assembled with the image sensor, Imgh corresponds to half of the diagonal length of the rectangular effective pixel area on the image sensor. Additionally, by satisfying the condition of this relational expression, the optical system 10 can have a long focal length characteristic, thereby enabling a good telephoto effect. In some embodiments, the above relationship satisfied by the optical system 10 can specifically be 1.6405, 1.6407, 1.6409, 1.6411, or 1.6413.

[0078] The second lens L2 and the third lens L3 are cemented together, the fifth lens L5 and the sixth lens L6 are cemented together, and the Abbe number Vd of at least one lens in the optical system 10 with respect to d light is less than 30. When the above design is satisfied, through the cementing between the second lens L2 and the third lens L3, and the cementing between the fifth lens L5 and the sixth lens L6, and further controlling the Abbe number of the lenses in the optical system 10, the chromatic aberration of the system can be effectively corrected, and the size of the system in the optical axis direction can be shortened, which is beneficial for the further miniaturization design of the system.

[0079] The above relational expression conditions and their resulting technical effects are applicable to the seven-piece optical system 10 with the above lens design. When it is impossible to ensure the lens design (the number of lenses, refractive power configuration, surface configuration, etc.) of the aforementioned optical system 10, it will be difficult to ensure that the optical system 10 can still have the corresponding technical effects when satisfying these relationships, and there may even be a significant decline in imaging performance.

[0080] The optical system 10 includes a stop STO. The stop STO is an aperture stop, and the stop STO is used to control the light input amount of the optical system 10 and can simultaneously block non-effective light rays. When the projection of the stop STO on the optical axis 101 overlaps with the projection of the object side surface S1 of the first lens L1 on the optical axis 101, it can also be considered that the stop STO is disposed on the object side of the first lens L1. At this time, at least a part of the object side surface S1 of the first lens L1 passes through the stop STO towards the object side. The stop STO can be disposed on the object side of the first lens L1 or between any two adjacent lenses among the first lens L1 to the seventh lens L7. The stop STO can be formed by the barrel structure clamping the lens or can be a washer separately assembled between the lens and the barrel.

[0081] In some embodiments, the object side and / or the image side of at least one of the first lens L1 to the seventh lens L7 is an aspherical surface, that is, at least one of the first lens L1 to the seventh lens L7 has an aspherical surface profile. For example, the object side and the image side of the first lens L1 to the seventh lens L7 can both be designed as aspherical surfaces. The setting of the aspherical surface profile can further help the optical system 10 eliminate aberration and solve the problem of vision distortion. At the same time, it is also beneficial to the miniaturized design of the optical system 10, enabling the optical system 10 to have excellent optical effects while maintaining a miniaturized design. Of course, in some other embodiments, the object side and / or the image side of at least one of the first lens L1 to the seventh lens L7 can also be a spherical surface. It should be noted that the actual surface profile of the lens is not limited to the spherical or aspherical shapes shown in the drawings, and the drawings are only for illustrative reference and not drawn strictly to scale. Additionally, it should also be noted that when the object side or the image side of a certain lens is an aspherical surface, this surface can be a structure that is convex as a whole or concave as a whole. Or, this surface can also be designed to have an inflection point, in which case the surface profile from the center to the edge will change. For example, this surface is convex at the center and concave at the edge. The examples here are only for explaining the relationship between the paraxial region and the circumferential region, and the specific surface profile structure (concave-convex relationship) of any side of any lens can be diverse and is not limited to the above examples.

[0082] The aspherical surface profile calculation can refer to the aspherical formula:

[0083]

[0084] where Z is the distance from the corresponding point on the aspherical surface to the tangent plane of the surface at the optical axis, r is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the aspherical surface at the optical axis, k is the conic coefficient, and Ai is the high-order term coefficient corresponding to the i-th order high-order term in the aspherical surface profile formula.

[0085] On the other hand, in some embodiments, the material of each lens in the optical system 10 is plastic. Of course, the material of each lens in some embodiments can also be glass. Lenses made of plastic can reduce the weight of the optical system 10 and lower the production cost, while lenses made of glass can withstand higher temperatures and have excellent optical effects. In some other embodiments, the material of the first lens L1 is glass, while the materials of the second lens L2 to the seventh lens L7 are all plastic. At this time, since the material of the lens located on the object side in the optical system 10 is glass, these glass lenses located on the object side have a good tolerance effect on extreme environments and are not easily affected by the object-side environment and aged. Thus, when the optical system 10 is in extreme environments such as intense sunlight and high temperature, this structure can better balance the optical performance and cost of the system. In some embodiments, the material of at least one of the first lens L1 to the seventh lens L7 is plastic, and the material of at least one of them is glass.

[0086] Of course, the configuration relationship of the lens materials in the optical system 10 is not limited to the above embodiments. The material of any lens can be plastic or glass, and the specific design can be determined according to actual requirements.

[0087] In some embodiments, the optical system 10 includes an infrared cut-off filter 110. The infrared cut-off filter 110 is disposed on the image side of the seventh lens L7 and is fixedly arranged relative to each lens in the optical system 10. The infrared cut-off filter 110 is used to filter out infrared light to prevent the infrared light from reaching the imaging surface S15 of the system, thereby preventing the infrared light from interfering with normal imaging. The infrared cut-off filter 110 can be assembled together with each lens to be a part of the optical system 10. In some other embodiments, the infrared cut-off filter 110 does not belong to the components of the optical system 10. In this case, the infrared cut-off filter 110 can be installed between the optical system 10 and the photosensitive element when the optical system 10 and the photosensitive element are assembled into an imaging module. In some embodiments, the infrared cut-off filter 110 can also be disposed on the object side of the first lens L1. Additionally, in some embodiments, the function of filtering out infrared light can also be achieved by providing a filter coating on at least one of the first lens L1 to the seventh lens L7.

[0088] Next, the optical system 10 of the present application will be described with more specific and detailed embodiments:

[0089] First Embodiment

[0090] Reference Figure 1 and Figure 2 , in the first embodiment, the optical system 10 sequentially includes a first lens L1 with negative refractive power, a stop STO, a second lens L2 with positive refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with negative refractive power, and a seventh lens L7 with positive refractive power along the optical axis 101 from the object side to the image side. Figure 2 It includes the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system 10 in the first embodiment, where the reference wavelengths of the astigmatism diagram and the distortion diagram are 546 nm.

[0091] The object side surface S1 of the first lens L1 is concave, and the image side surface S2 is convex.

[0092] The object side surface S3 of the second lens L2 is convex, and the image side surface S4 is convex.

[0093] The object side surface S5 of the third lens L3 is concave, and the image side surface S6 is convex.

[0094] The object side surface S7 of the fourth lens L4 is convex, and the image side surface S8 is convex.

[0095] The object side surface S9 of the fifth lens L5 is convex, and the image side surface S10 is convex.

[0096] The object side surface S11 of the sixth lens L6 is concave, and the image side surface S12 is concave.

[0097] The object side surface S13 of the seventh lens L7 is convex, and the image side surface S14 is concave.

[0098] The above structure is beneficial to the long focal length design of the optical system 10, and the refractive powers and surface types of the lenses arranged from the object side to the image side in the system are reasonably matched, which is also beneficial to the correction of aberrations.

[0099] In addition, the second lens L2 and the third lens L3 in this embodiment are cemented, the fifth lens L5 and the sixth lens L6 are cemented, and the Abbe number of the sixth lens L6 is less than 30. Therefore, the chromatic aberration of the optical system 10 can be effectively corrected, and the size of the system in the optical axis direction can be shortened, which is beneficial to the further miniaturization design of the system.

[0100] The object side surfaces and image side surfaces of the first lens L1, the second lens L2, the third lens L3, the fifth lens L5 and the sixth lens L6 are all spherical surfaces, while the object side surfaces and image side surfaces of the fourth lens L4 and the seventh lens L7 are all aspherical surfaces. Through the above matching of the spherical and aspherical surface types of the lenses in the optical system 10, the aberrations can be well corrected, and at the same time, the manufacturing difficulty of the optical system 10 can be reduced to a great extent.

[0101] In addition, the materials of the lenses in the optical system 10 are all glass, which can ensure that the optical system 10 has better optical properties and makes the imaging more stable. In particular, when the optical system 10 is applied to in-vehicle imaging devices, aerial imaging devices, and outdoor monitoring devices, the influence of the environmental temperature on the system imaging can be effectively reduced.

[0102] In this embodiment, the parameters of each lens of the optical system 10 are given in Table 1 and Table 2 below. Table 2 shows the aspherical coefficients of the corresponding lens surfaces in Table 1, where K is the conic coefficient and Ai is the coefficient corresponding to the i-th order higher term in the aspherical surface formula. The components from the object side to the image side of the system are arranged in the order from top to bottom in Table 1 in sequence. The surfaces corresponding to surface numbers 1 and 2 respectively represent the object surface S1 and the image surface S2 of the first lens L1. That is, in the same lens, the surface with a smaller surface number is the object surface, and the surface with a larger surface number is the image surface. The Y radius is the radius of curvature of the corresponding lens surface at the optical axis. The absolute value of the first value in the "Thickness" parameter column of the lens is the thickness of the lens on the optical axis, and the absolute value of the second value is the distance from the image surface of the lens to the next optical element (lens or diaphragm) on the optical axis. IR is an infrared cut-off filter. In the parameter tables of the following embodiments (the first embodiment to the fifth embodiment), the reference wavelengths of the refractive index, Abbe number, and focal length of each lens are all 546 nm, and the numerical units of the Y radius, thickness, and focal length (effective focal length) are all millimeters (mm). In addition, the relational calculations and lens structures of each embodiment are based on the data provided in the parameter tables (such as Table 1, Table 2, Table 3, Table 4, etc.).

[0103] In the first embodiment, the effective focal length f of the optical system 10 is 15.28 mm, the f-number FNO is 1.6, and the maximum field of view FOV is 35°.

[0104] Table 1

[0105]

[0106] Table 2

[0107] Surface serial number 7 8 12 13 K -4.579E-01 1.342E+01 1.361E+00 2.716E+00 A4 -8.407E-05 -4.517E-05 -1.908E-04 -2.358E-04 A6 -8.339E-07 -3.107E-07 -2.061E-06 -8.733E-06 A8 1.433E-09 -6.029E-09 1.365E-07 4.218E-07 A10 -2.088E-10 -3.614E-11 -6.289E-09 -2.434E-08 A12 9.519E-13 3.472E-13 1.530E-10 5.232E-10 A14 0.000E+00 0.000E+00 0.000E+00 0.000E+00 A16 0.000E+00 0.000E+00 0.000E+00 0.000E+00 A18 0.000E+00 0.000E+00 0.000E+00 0.000E+00 A20 0.000E+00 0.000E+00 0.000E+00 0.000E+00

[0108] In the first embodiment, the optical system 10 satisfies the following relationships:

[0109] 2 * f * tan(FOV / 2) = 9.626 mm; f is the effective focal length of the optical system 10, and FOV is the maximum field of view angle of the optical system 10. For the optical system 10 with the above lens number, refractive power, and surface design, when the above relationship condition is further satisfied, a reasonable configuration can be obtained between the effective focal length and the maximum field of view angle of the optical system 10, thereby controlling the distortion amount of the entire optical system 10, suppressing the distortion of the optical system 10, improving the resolution of the optical system 10, and reducing the distortion risk in the edge area of the captured image. In addition, satisfying the above parameter configuration can also endow the optical system 10 with a large image plane characteristic, which is conducive to realizing high-pixel imaging. In particular, when the above optical system 10 is applied to a vehicle to cooperate with an assisted driving system or an autonomous driving system, it can improve the analysis accuracy of the system by reducing the distortion of imaging, or directly provide a clearer and more accurate imaging picture for the driver, thereby improving the driver's judgment accuracy of the road conditions and further improving driving safety.

[0110] f / (2 * Imgh) = 1.6405. Imgh is half of the image height corresponding to the maximum field of view angle of the optical system 10. By satisfying this parameter configuration, the optical system 10 will have a telephoto characteristic, thereby enabling good long-distance imaging.

[0111] f1 / CT1 = -9.356; f1 is the effective focal length of the first lens L1, and CT1 is the thickness of the first lens L1 on the optical axis. Designing the lens closest to the object end in the optical system 10 as a negative lens can provide a negative refractive power for the system, which is conducive to obtaining the light rays incident on the system at a large angle, that is, expanding the field of view angle range of the optical system 10. And when the above relationship condition is further satisfied, a good mutual constraint can be obtained between the refractive power intensity and the central thickness of the first lens L1. On the one hand, it can avoid the astigmatism that is difficult to correct in the optical system 10, which is beneficial to reducing the astigmatism correction pressure of the lenses on the image side of the first lens L1 and preventing poor imaging quality of the system; on the other hand, it can also avoid the central thickness of the first lens L1 being too large or too small, which is conducive to system miniaturization and improving the lens processing yield.

[0112] f23 / (CT2 - CT3) = 4.231; f23 is the combined focal length of the second lens L2 and the third lens L3, CT2 is the thickness of the second lens L2 on the optical axis, and CT3 is the thickness of the third lens L3 on the optical axis. The second lens L2 and the third lens L3 have positive and negative refractive powers respectively. By satisfying the above relational condition, through a reasonable combination of the combined focal length of the second lens L2 and the third lens L3 and the thickness relationship between the two lenses, the second lens L2 and the third lens L3 with positive and negative refractive powers can be reasonably matched, so that the aberration between the two lenses can be mutually corrected, thereby suppressing the aberration generated by the lens group composed of the second lens L2 and the third lens L3, and reducing the aberration contribution ratio provided by the second lens L2 and the third lens L3 to the optical system 10.

[0113] f4 / CT4 = 3.851; f4 is the effective focal length of the fourth lens L4, and CT4 is the thickness of the fourth lens L4 on the optical axis. By satisfying the above relational condition, the relationship between the central thickness and the effective focal length of the fourth lens L4 can be reasonably matched, so that the fourth lens L4 provides sufficient positive refractive power for the system to converge light, which is beneficial to reducing the exit angle when the light exits the lens group, that is, reducing the angle of the light relative to the optical axis when it exits the seventh lens L7, and further reducing the incident angle when the light enters the image sensor, thereby giving full play to the photosensitive performance of the image sensor, especially beneficial to suppressing the generation of vignetting.

[0114] f56 / (CT5 - CT6) = -5.928; f56 is the combined focal length of the fifth lens L5 and the sixth lens L6, CT5 is the thickness of the fifth lens L5 on the optical axis, and CT6 is the thickness of the sixth lens L6 on the optical axis. By satisfying the above relational condition, the combined focal length of the fifth lens L5 and the sixth lens L6 and the thickness relationship between the two can be reasonably matched, so that the fifth lens L5 and the sixth lens L6 with positive and negative refractive powers respectively can be reasonably matched, so that the aberration between the two lenses can be mutually corrected, thereby suppressing the aberration generated by the lens group composed of the fifth lens L5 and the sixth lens L6. At the same time, through the constraint of the above relational condition, the difference in the central thickness between the fifth lens L5 and the sixth lens L6 can also be better suppressed, which is beneficial to the processing, forming and gluing of the lens.

[0115] f7 / f = 2.014; f7 is the effective focal length of the seventh lens L7. The seventh lens L7 provides positive refractive power for the system, and when the above relationship is satisfied, as the last lens of the optical system 10, the intensity of the positive refractive power provided by the seventh lens L7 for the optical system 10 can be better constrained, so that chromatic aberration can be effectively corrected, and at the same time, the eccentricity sensitivity can be reduced to facilitate the correction of system aberration and improve the imaging resolution.

[0116] CT7 / Sag7 = 8.919; CT7 is the thickness of the seventh lens L7 on the optical axis, and Sag7 is the sagitta of the seventh lens L7 at the maximum effective aperture of the image side S14. By controlling the ratio relationship between the central thickness of the seventh lens L7 and the sagitta at the maximum effective aperture of the image side S14, it is possible to avoid an excessive central thickness of the seventh lens L7 or an overly curved image side S14, which increases the manufacturing difficulty of the lens. Thus, the preparation yield can be improved and the production cost can be reduced.

[0117] EPL / DOS = 12.323; EPL is the distance from the aperture stop to the imaging plane of the optical system 10 on the optical axis, and DOS is the distance from the object side S1 of the first lens L1 to the aperture stop (i.e., the stop in Table 1) on the optical axis 101. When the above relational condition is satisfied, the aperture stop can be set at a reasonable position in the optical system 10, enabling the incident light to reach the photosensitive element (i.e., the image sensor) in a manner close to normal incidence. Thus, the optical system 10 has a telecentric characteristic. The telecentric characteristic is extremely important for the photosensitive ability of the solid-state electronic photosensitive element, and the above design can effectively improve the photosensitive sensitivity of the electronic photosensitive element and enhance the imaging brightness of the system to improve the image clarity. In particular, when the aperture stop is disposed between the first lens L1 and the second lens L2, the above effect on the light in the system will be more significant, enabling the optical system 10 to have a more excellent telecentric characteristic.

[0118] In addition, Figure 2 Including the longitudinal spherical aberration diagram (Longitudinal Spherical Aberration) of the optical system 10, which represents the deviation of the converging focal points of light rays of different wavelengths after passing through the lens. The ordinate of the longitudinal spherical aberration diagram represents the normalized pupil coordinate (Normalized Pupil Coordinator) from the center of the pupil to the edge of the pupil, and the abscissa represents the distance from the imaging plane to the intersection point of the light ray and the optical axis (in mm). From the longitudinal spherical aberration diagram, it can be seen that the deviation degrees of the converging focal points of the light rays of each wavelength in the first embodiment tend to be consistent, and the blur spots or chromatic halos in the imaging picture are effectively suppressed. Figure 2 Also including the astigmatic field curves (Astigmatic Field Curves) of the optical system 10, where the S curve represents the sagittal field curve at 546 nm, and the T curve represents the meridional field curve at 546 nm. It can be seen from the figure that the meridional and sagittal field curves of the system are small, and the spacing is small. Thus, it can be known that the field curvature and astigmatism of each field of view are well corrected, the imaging curvature is not obvious, and both the center and the edge of the field of view can have clear imaging. Figure 2 Also including the distortion diagram (Distortion) of the optical system 10. It can be seen from the figure that the image distortion caused by the chief ray is small, and the imaging quality of the system is excellent.

[0119] Second Embodiment

[0120] Reference Figure 3 And Figure 4 In the second embodiment, the optical system 10 sequentially includes, from the object side to the image side along the optical axis 101, a first lens L1 having a negative refractive power, a diaphragm STO, a second lens L2 having a positive refractive power, a third lens L3 having a negative refractive power, a fourth lens L4 having a positive refractive power, a fifth lens L5 having a positive refractive power, a sixth lens L6 having a negative refractive power, and a seventh lens L7 having a positive refractive power. Figure 4 Including the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system 10 in this embodiment, where the reference wavelengths of the astigmatism diagram and the distortion diagram are 546 nm.

[0121] The object side surface S1 of the first lens L1 is concave, and the image side surface S2 is convex.

[0122] The object side surface S3 of the second lens L2 is convex, and the image side surface S4 is convex.

[0123] The object side surface S5 of the third lens L3 is concave, and the image side surface S6 is convex.

[0124] The object side surface S7 of the fourth lens L4 is convex, and the image side surface S8 is concave.

[0125] The object side surface S9 of the fifth lens L5 is convex, and the image side surface S10 is convex.

[0126] The object side surface S11 of the sixth lens L6 is concave, and the image side surface S12 is concave.

[0127] The object side surface S13 of the seventh lens L7 is convex, and the image side surface S14 is concave.

[0128] In addition, the parameters of each lens of the optical system 10 in the second embodiment are given in Tables 3 and 4, where the definitions of each structure and parameter can be obtained from the first embodiment and will not be elaborated here.

[0129] Table 3

[0130]

[0131]

[0132] Table 4

[0133] Surface serial number 12 13 K 1.634E+00 7.303E-01 A4 -4.219E-04 -2.313E-04 A6 -8.996E-06 -1.259E-05 A8 2.089E-07 2.883E-07 A10 -1.570E-08 -1.918E-08 A12 2.384E-10 4.774E-10 A14 0.000E+00 0.000E+00 A16 0.000E+00 0.000E+00 A18 0.000E+00 0.000E+00 A20 0.000E+00 0.000E+00

[0134] The imaging module 10 in this embodiment satisfies the following relationship:

[0135] 2*f*tan(FOV / 2) 9.620 CT7 / Sag7 11.994 f1 / CT1 -14.450 EPL / DOS 8.038 f23 / (CT2 - CT3) 8.594 f56 / (CT5 - CT6) -10.123 f4 / CT4 7.295 f7 / f 2.173 f / (2*Imgh) 1.6409

[0136] ByFigure 4 From the aberration diagram in [reference], it can be seen that the longitudinal spherical aberration, field curvature, and distortion of the optical system 10 are all well controlled, so that the optical system 10 in this embodiment has good imaging quality.

[0137] The Third Embodiment

[0138] Reference Figure 5 and Figure 6 , in the third embodiment, the optical system 10 sequentially includes a first lens L1 with negative refractive power, a stop STO, a second lens L2 with positive refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with negative refractive power, and a seventh lens L7 with positive refractive power along the optical axis 101 from the object side to the image side. Figure 6 It includes the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system 10 in this embodiment, and the reference wavelength of the astigmatism diagram and distortion diagram therein is 546 nm.

[0139] The object side surface S1 of the first lens L1 is concave, and the image side surface S2 is convex.

[0140] The object side surface S3 of the second lens L2 is convex, and the image side surface S4 is convex.

[0141] The object side surface S5 of the third lens L3 is concave, and the image side surface S6 is convex.

[0142] The object side surface S7 of the fourth lens L4 is convex, and the image side surface S8 is concave.

[0143] The object side surface S9 of the fifth lens L5 is convex, and the image side surface S10 is convex.

[0144] The object side surface S11 of the sixth lens L6 is concave, and the image side surface S12 is concave.

[0145] The object side surface S13 of the seventh lens L7 is convex, and the image side surface S14 is concave.

[0146] In addition, the parameters of each lens of the optical system 10 in the third embodiment are given in Tables 5 and 6, and the definitions of each structure and parameter can be obtained from the first embodiment, so they will not be elaborated here.

[0147] Table 5

[0148]

[0149] Table 6

[0150] Surface serial number 12 13 K 1.064E+00 1.853E+00 A4 -3.501E-04 -1.969E-04 A6 -8.607E-06 -1.489E-05 A8 2.623E-07 5.210E-07 A10 -1.649E-08 -3.293E-08 A12 2.413E-10 7.140E-10 A14 0.000E+00 0.000E+00 A16 0.000E+00 0.000E+00 A18 0.000E+00 0.000E+00 A20 0.000E+00 0.000E+00

[0151] The imaging module 10 in this embodiment satisfies the following relationship:

[0152] 2*f*tan(FOV / 2) 9.620 CT7 / Sag7 10.174 f1 / CT1 -13.269 EPL / DOS 8.894 f23 / (CT2 - CT3) 11.300 f56 / (CT5 - CT6) -9.519 f4 / CT4 7.378 f7 / f 1.955 f / (2*Imgh) 1.6409

[0153] From Figure 6 the aberration diagrams, it can be seen that the longitudinal spherical aberration, field curvature, and distortion of the optical system 10 are all well controlled, so that the optical system 10 of this embodiment has good imaging quality.

[0154] Fourth Embodiment

[0155] Refer to Figure 7 and Figure 8 , in the fourth embodiment, the optical system 10 sequentially includes, from the object side to the image side along the optical axis 101, a first lens L1 with negative refractive power, a stop STO, a second lens L2 with positive refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with negative refractive power, and a seventh lens L7 with positive refractive power. Figure 8 Include the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system 10 in this embodiment, where the reference wavelengths of the astigmatism diagram and the distortion diagram are 546 nm.

[0156] The object side surface S1 of the first lens L1 is concave, and the image side surface S2 is convex.

[0157] The object side surface S3 of the second lens L2 is convex, and the image side surface S4 is convex.

[0158] The object side surface S5 of the third lens L3 is concave, and the image side surface S6 is convex.

[0159] The object side surface S7 of the fourth lens L4 is convex, and the image side surface S8 is convex.

[0160] The object side surface S9 of the fifth lens L5 is convex, and the image side surface S10 is convex.

[0161] The object side surface S11 of the sixth lens L6 is concave, and the image side surface S12 is concave.

[0162] The object side surface S13 of the seventh lens L7 is convex, and the image side surface S14 is concave.

[0163] In addition, the parameters of each lens of the optical system 10 in the fourth embodiment are given in Tables 7 and 8, where the definitions of each structure and parameter can be obtained from the first embodiment and will not be elaborated here.

[0164] Table 7

[0165]

[0166] Table 8

[0167] Surface serial number 7 8 12 13 K 0.000E+00 0.000E+00 3.076E+00 -5.916E+00 A4 -1.754E-04 -1.117E-04 -5.218E-04 -1.864E-04 A6 -2.102E-06 -1.416E-06 -6.236E-06 -1.518E-05 A8 -1.800E-09 -5.445E-09 -2.283E-07 2.504E-07 A10 -4.363E-10 -1.789E-10 7.182E-09 -1.527E-08 A12 0.000E+00 0.000E+00 -2.978E-10 2.327E-10 A14 0.000E+00 0.000E+00 0.000E+00 0.000E+00 A16 0.000E+00 0.000E+00 0.000E+00 0.000E+00 A18 0.000E+00 0.000E+00 0.000E+00 0.000E+00 A20 0.000E+00 0.000E+00 0.000E+00 0.000E+00

[0168] The imaging module 10 in this embodiment satisfies the following relationship:

[0169]

[0170]

[0171] From Figure 8 the aberration diagram, it can be seen that the longitudinal spherical aberration, field curvature, and distortion of the optical system 10 are all well controlled, so that the optical system 10 in this embodiment has good imaging quality.

[0172] The Fifth Embodiment

[0173] Referring to Figure 9 and Figure 10 , in the fifth embodiment, the optical system 10 sequentially includes a first lens L1 with negative refractive power, a stop STO, a second lens L2 with positive refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with negative refractive power, and a seventh lens L7 with positive refractive power along the optical axis 101 from the object side to the image side. Figure 10 It includes the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system 10 in this embodiment, where the reference wavelengths of the astigmatism diagram and distortion diagram are 546 nm.

[0174] The object side surface S1 of the first lens L1 is concave, and the image side surface S2 is convex.

[0175] The object side surface S3 of the second lens L2 is convex, and the image side surface S4 is convex.

[0176] The object side surface S5 of the third lens L3 is concave, and the image side surface S6 is convex.

[0177] The object side surface S7 of the fourth lens L4 is convex, and the image side surface S8 is convex.

[0178] The object side surface S9 of the fifth lens L5 is convex, and the image side surface S10 is convex.

[0179] The object side surface S11 of the sixth lens L6 is concave, and the image side surface S12 is concave.

[0180] The object side surface S13 of the seventh lens L7 is convex, and the image side surface S14 is concave.

[0181] In addition, the parameters of each lens of the optical system 10 in the fifth embodiment are given in Table 9 and Table 10, where the definitions of each structure and parameter can be obtained from the first embodiment and will not be elaborated here.

[0182] Table 9

[0183]

[0184] Table 10

[0185]

[0186]

[0187] The imaging module 10 in this embodiment satisfies the following relationship:

[0188] 2*f*tan(FOV / 2) 9.620 CT7 / Sag7 10.419 f1 / CT1 -8.176 EPL / DOS 6.039 f23 / (CT2 - CT3) 12.223 f56 / (CT5 - CT6) -11.084 f4 / CT4 5.854 f7 / f 3.714 f / (2*Imgh) 1.6412

[0189] From Figure 10 the aberration diagram, it can be seen that the longitudinal spherical aberration, field curvature, and distortion of the optical system 10 are all well controlled, so that the optical system 10 in this embodiment has good imaging quality.

[0190] Referring to Figure 11 , in an embodiment provided by the present application, the optical system 10 and the image sensor 210 are assembled to form an imaging module 20, and the image sensor 210 is disposed on the image side of the optical system 10. The image sensor 210 can be a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). Generally, during assembly, the imaging surface S15 of the optical system 10 coincides with the photosensitive surface of the image sensor 210. The shape of the effective pixel region on the photosensitive surface is generally rectangular, and the maximum field of view angle corresponding to the diagonal direction of the rectangular effective pixel region is the maximum field of view angle of the optical system 10. By adopting the optical system 10, the imaging module 20 can reduce imaging distortion and make the magnification of each area of the picture tend to be consistent.

[0191] In some embodiments, the imaging module 20 includes an infrared filter disposed between the seventh lens L7 and the image sensor 210, and the infrared cut-off filter 110 is used to filter infrared light. In some embodiments, the imaging module 20 further includes a protective glass 120, and the protective glass 120 is disposed between the infrared cut-off filter 110 and the image sensor 210, and the protective glass 120 is used to protect the image sensor 210.

[0192] Referring to Figure 12 , some embodiments of the present application further provide an electronic device 30, and the imaging module 20 is applied to the electronic device 30 to enable the electronic device 30 to have a camera function. Specifically, the electronic device 30 includes a fixing member 310, and the imaging module 20 is installed on the fixing member 310. The fixing member 310 can be components such as a circuit board, a middle frame, and a protective case. The electronic device 30 can be, but is not limited to, an in-vehicle camera device, an aircraft camera device, a surveillance camera device, etc.

[0193] In some embodiments, the electronic device 30 is a vehicle-mounted camera device (for the specific structure, reference can be made to Figure 12 ). The camera module 20 is disposed within a fixing member 310 of the vehicle-mounted camera device. The fixing member 310 is rotatably connected to a mounting plate 320, and the mounting plate 320 is used for fixing on the vehicle body of an automobile. The electronic device 30 can cooperate with an assisted driving system or an autonomous driving system to improve the analysis accuracy of the system by reducing imaging distortion, or directly provide an accurate imaging picture to the driver, thereby improving the driver's judgment accuracy of the road conditions and further enhancing driving safety.

[0194] Referring to Figure 13 , some embodiments of the present application further provide a vehicle 40, which can be a manned or cargo-carrying tool such as an automobile or an aircraft. The vehicle 40 includes a mounting portion 410 and the above-mentioned electronic device 30, and the electronic device 30 is disposed on the mounting portion. Specifically, when the vehicle 40 is an automobile, the electronic device 30 as a vehicle-mounted camera device can be installed at any reasonable position such as a front air intake grille, a rearview mirror, a left rearview mirror, a right rearview mirror, a roof, or a rear trunk cover. When the above-mentioned electronic device 30 is used as a vehicle-mounted camera device in the vehicle 40 to obtain surrounding environment information, it can cooperate with an assisted driving system or an autonomous driving system to improve the analysis accuracy of the system by reducing imaging distortion, or directly provide an accurate imaging picture to the driver, thereby improving the driver's judgment accuracy of the road conditions and further enhancing driving safety.

[0195] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0196] The above-described embodiments merely represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. An optical system, characterized in that, The optical system consists of seven refractive lenses, which successively include, from the object side to the image side along the optical axis: A first lens with negative refractive power, and the image side of the first lens is convex at least near the optical axis; A second lens with positive refractive power; A third lens with negative refractive power, and the image side of the third lens is convex at least near the optical axis; A fourth lens with positive refractive power, and the object side of the fourth lens is convex at least near the optical axis; A fifth lens with positive refractive power; A sixth lens with negative refractive power; A seventh lens with positive refractive power, and the object side of the seventh lens is convex at least near the optical axis; The material of at least one of the first lens to the seventh lens is glass; And the optical system satisfies the relationship: 9mm < 2*f*tan(FOV / 2) < 10mm; f is the effective focal length of the optical system, and FOV is the maximum field of view angle of the optical system; The second lens and the third lens are cemented, and the optical system satisfies the relationship: 4 < f23 / (CT2 - CT3) < 12.5; f23 is the combined focal length of the second lens and the third lens, CT2 is the thickness of the second lens on the optical axis, and CT3 is the thickness of the third lens on the optical axis.

2. The optical system according to claim 1, characterized in that, The fifth lens and the sixth lens are cemented, and the Abbe number Vd of the fifth lens or the sixth lens in the optical system with respect to d light is less than 30; And the optical system also satisfies the relationship: 1.5 < f / (2*Imgh) ≤ 1.6413; Imgh is half of the image height corresponding to the maximum field of view angle of the optical system.

3. The optical system according to claim 1, characterized in that, The optical system satisfies the relationship: -14.5 < f1 / CT1 < -7.5; f1 is the effective focal length of the first lens, and CT1 is the thickness of the first lens on the optical axis.

4. The optical system according to claim 1, wherein The optical system satisfies the relationship: 3.5 < f4 / CT4 < 7.5; f4 is the effective focal length of the fourth lens, and CT4 is the thickness of the fourth lens on the optical axis.

5. The optical system according to claim 1, characterized in that, The optical system satisfies the relationship: -12.5 < f56 / (CT5 - CT6) < -5.5; f56 is the combined focal length of the fifth lens and the sixth lens, CT5 is the thickness of the fifth lens on the optical axis, and CT6 is the thickness of the sixth lens on the optical axis.

6. The optical system according to claim 1, characterized in that The optical system satisfies the relationship: 1.5 < f7 / f < 4; f7 is the effective focal length of the seventh lens.

7. The optical system according to claim 1, characterized in that, The optical system satisfies the relationship: 8.5 < CT7 / Sag7 < 12; CT7 is the thickness of the seventh lens on the optical axis, and Sag7 is the sagitta at the maximum effective aperture of the image side of the seventh lens.

8. The optical system according to claim 1, characterized in that It includes an aperture stop, the aperture stop is arranged on the object side of the first lens or between any two adjacent lenses, and the optical system satisfies the relationship: 6 < EPL / DOS < 12.5; EPL is the distance from the aperture stop to the imaging plane of the optical system on the optical axis, and DOS is the distance from the object side of the first lens to the aperture stop on the optical axis.

9. A camera module, characterized in that, Comprising an image sensor and the optical system according to any one of claims 1 to 8, wherein the image sensor is disposed on the image side of the optical system.

10. An electronic device, characterized in that, Comprising a fixing member and the imaging module according to claim 9, wherein the imaging module is disposed on the fixing member.

11. A vehicle, characterized in that, Comprising a mounting portion and the electronic device according to claim 10, wherein the electronic device is disposed on the mounting portion.

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