Optical System, Camera Module and Vehicle

Abstract

The present application relates to an optical system, a camera module and an automobile. The optical system sequentially includes, from the object side to the image side: a first lens with negative refractive power, the object side surface of the first lens being convex and the image side surface being concave; a second lens with negative refractive power, the image side surface of the second lens being concave; a third lens with positive refractive power, the object side surface and the image side surface of the third lens being convex respectively; a fourth lens with positive refractive power, the object side surface and the image side surface of the fourth lens being convex respectively; a lens unit with refractive power; a diaphragm, disposed on the object side of the fourth lens; the optical system satisfies the relationship: FOV / CRA > 10; FOV is the field of view angle in the diagonal direction of the imaging surface of the optical system, and CRA is the incident angle of the chief ray. At this time, the optical system has a relatively large field of view angle, and at the same time, it can also reduce the angle at which light enters the imaging surface of the optical system, thereby improving the imaging clarity.

Description

Technical Field

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

[0002] Currently, common cameras generally have the problem of a small field of view. Therefore, when used as vehicle-mounted camera devices, there are still large blind spots in the field of view of the vehicle, and the driver cannot obtain sufficient peripheral body images. Especially when the vehicle is changing lanes at a high speed, the vehicle information in the side and rear cannot be obtained in time, thus prone to safety hazards. Summary of the Invention

[0003] Based on this, it is necessary to provide an optical system, a camera module and an automobile for the problem of how to obtain a larger field of view.

[0004] An optical system sequentially includes, from the object side to the image side:

[0005] A first lens with negative refractive power, the object side surface of the first lens is convex, and the image side surface is concave;

[0006] A second lens with negative refractive power, the image side surface of the second lens is concave;

[0007] A third lens with positive refractive power, the object side surface and the image side surface of the third lens are convex respectively;

[0008] A fourth lens with positive refractive power, the object side surface and the image side surface of the fourth lens are convex respectively;

[0009] A lens unit with refractive power;

[0010] An aperture, disposed on the object side of the fourth lens;

[0011] The optical system satisfies the following relationship:

[0012] FOV / CRA>10;

[0013] Wherein, FOV is the field of view in the diagonal direction of the imaging surface of the optical system, and CRA is the incident angle of the chief ray.

[0014] When the above relationship is satisfied, the optical system has a large field of view to meet the requirements of large viewing angles for electronic products such as mobile phones, vehicle-mounted devices, monitoring devices, and medical devices, and at the same time can reduce the angle of light incident on the imaging surface of the optical system, thereby improving imaging clarity.

[0015] In one of the embodiments, the optical system includes any one of the following:

[0016] The lens unit includes a fifth lens having refractive power, and the image side surface of the fifth lens is convex;

[0017] The lens unit includes a fifth lens having refractive power and a sixth lens having negative refractive power. The sixth lens is disposed on the image side of the fifth lens. The image side surface of the fifth lens is convex. The object side surface of the sixth lens is concave, and the image side surface of the sixth lens is convex.

[0018] In one embodiment, the optical system satisfies the following relationship:

[0019] BFL / TTL > 0.2;

[0020] Wherein, BFL is the back focal length of the optical system, and TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis. When the above relationship is satisfied, the optical system has a relatively large back focal length, and thus has a telecentric effect. At the same time, the sensitivity and length of the optical system can be reduced, so that the volume of the optical system is smaller.

[0021] In one embodiment, the optical system satisfies the following relationship:

[0022] (SD S2) / (RDY S2) < 0.95;

[0023] Wherein, SD S2 is the half-aperture in the Y direction of the image side surface of the first lens, and RDY S2 is the radius of curvature of the image side surface of the first lens. When the above relationship is satisfied, the bending degree of the first lens can be effectively controlled by controlling the radius of curvature and the half-aperture in the Y direction of the image side surface of the first lens, the processing difficulty of the first lens can be reduced, and at the same time, the problem of uneven coating caused by excessive bending degree of the first lens can be avoided, and the risk of ghosting can be reduced.

[0024] In one embodiment, the optical system satisfies the following relationship:

[0025] -65 ≤ Dist ≤ 65;

[0026] Wherein, Dist is the optical distortion of the optical system, and the unit is %. When the above relationship is satisfied, the amount of distortion of the optical system can be controlled to weaken the phenomenon of excessive distortion commonly existing in wide-angle lenses.

[0027] In one embodiment, the optical system satisfies the following relationship:

[0028] Nd1 < 1.8; Vd1 > 25;

[0029] Wherein, Nd1 is the refractive index of the first lens under d light, and Vd1 is the Abbe number of the first lens under d light. When the above relationship is satisfied, it is beneficial to correct the off-axis chromatic aberration of the optical system, thereby improving the resolution of the optical system.

[0030] In one embodiment, a protective film layer is coated on the object side surface of the first lens and / or the optical system satisfies the following relationship:

[0031] H K >500; F A >50;

[0032] Wherein, H K is the hardness of the first lens, and H K is in the unit of 10 7 Pa, and F A is the wear degree of the first lens, and F A is in the unit of %. When the above relationship is satisfied, the first lens has high hardness and wear degree. At the same time, by providing the protective film layer to enable the first lens to have a waterproof and scratch-resistant function, the first lens can be effectively prevented from being scratched, and the imaging quality can be prevented from being affected by problems such as scratches and water droplet adhesion, and the service life of the optical system can be improved.

[0033] In one embodiment, the optical system satisfies the following relationship:

[0034] Nd2>1.9; Vd2<25;

[0035] Wherein, Nd2 is the d-light refractive index of the lens closest to the image side in the optical system, and Vd2 is the d-light Abbe number of the lens closest to the image side in the optical system. When the above relationship is satisfied, it is beneficial to correct the off-axis chromatic aberration of the optical system, thereby improving the resolution of the optical system.

[0036] In one embodiment, the lens unit includes a fifth lens, the image side surface of the fifth lens is convex, the fourth lens and the fifth lens form a cemented lens, and the optical system satisfies at least one of the following relationships:

[0037] |((cuy s1)*(map s1)-(cuy s2)*(map s2)) / 2|>0.12;

[0038] 0<FH / f<10;

[0039] ET S6>0.5;

[0040] Wherein, cuy s1 is the reciprocal of the curvature radius of the object side of the fifth lens, map s1 is the Y-direction semi-aperture of the object side of the fifth lens, cuy s2 is the reciprocal of the curvature radius of the image side of the fifth lens, map s2 is the Y-direction semi-aperture of the image side of the fifth lens, FH is the focal length of the cemented lens, f is the effective focal length of the optical system, and ET S6 is the thickness of the fourth lens at the maximum effective radius. When the first relationship above is satisfied, the processing difficulty of the fifth lens can be reduced by controlling the curvature radius and the Y-direction semi-aperture of the fifth lens; when the second relationship above is satisfied, the cemented lens can provide positive refractive power for the optical system, enabling the optical system to have the characteristics of a wide viewing angle, low sensitivity, and miniaturization; when the third relationship above is satisfied, the processing difficulty of the cemented lens can be reduced by controlling the edge thickness (the thickness at the maximum effective radius) of the fourth lens.

[0041] In one embodiment, the lens unit includes a fifth lens with refractive power and a sixth lens with negative refractive power. The sixth lens is disposed on the image side of the fifth lens. The image side of the fifth lens is convex, the object side of the sixth lens is concave, and the image side of the sixth lens is convex. The fifth lens and the sixth lens form a cemented lens, and the optical system satisfies at least one of the following relationships:

[0042] |((cuy s1)*(map s1)-(cuy s2)*(map s2)) / 2|>0.12;

[0043] 0<FH / f<10;

[0044] ET S6>0.5;

[0045] Wherein, cuy s1 is the reciprocal of the curvature radius of the object side of the sixth lens, map s1 is the Y-direction semi-aperture of the object side of the sixth lens, cuy s2 is the reciprocal of the curvature radius of the image side of the sixth lens, map s2 is the Y-direction semi-aperture of the image side of the sixth lens, FH is the focal length of the cemented lens, f is the effective focal length of the optical system, and ET S6 is the thickness of the fifth lens at the maximum effective radius. The unit of ET S6 is mm. When the first relationship above is satisfied, the processing difficulty of the sixth lens can be reduced by controlling the curvature radius and the Y-direction semi-aperture of the sixth lens; when the second relationship above is satisfied, the cemented lens can provide positive refractive power for the optical system, enabling the optical system to have the characteristics of a wide viewing angle, low sensitivity, and miniaturization; when the third relationship above is satisfied, the processing difficulty of the cemented lens can be reduced by controlling the edge thickness (the thickness at the maximum effective radius) of the fifth lens.

[0046] An imaging module includes an image sensor and the optical system according to any one of the above embodiments, and the image sensor is disposed on the image side of the optical system.

[0047] A vehicle includes a vehicle body and the imaging module according to the above embodiment, the imaging module is disposed on the vehicle body, and the imaging module can acquire the environmental information around the vehicle. Description of the Drawings

[0048] Figure 1 Schematic diagram of the optical system provided by the first embodiment of the present application;

[0049] Figure 2 Spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) of the optical system in the first embodiment;

[0050] Figure 3 Schematic diagram of the optical system provided by the second embodiment of the present application;

[0051] Figure 4 Spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) of the optical system in the second embodiment;

[0052] Figure 5 Schematic diagram of the optical system provided by the third embodiment of the present application;

[0053] Figure 6 Spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) of the optical system in the third embodiment;

[0054] Figure 7 Schematic diagram of the optical system provided by the fourth embodiment of the present application;

[0055] Figure 8 Spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) of the optical system in the fourth embodiment;

[0056] Figure 9 Schematic diagram of the imaging module applying the optical system in an embodiment of the present application;

[0057] Figure 10 Schematic diagram of the vehicle applying the imaging module in an embodiment of the present application. Detailed Embodiments

[0058] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0059] It should be noted that when an element is referred to as "fixed to" another element, it can be directly on the other element or there may 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. On the contrary, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0060] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this invention belongs. The terms used in the description of this specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0061] Currently, common cameras generally have the problem of a small field of view. Therefore, when used as vehicle-mounted camera devices, there are still large blind spots in the field of vision of the vehicle, making it impossible for the driver to obtain sufficient peripheral body scenes. For example, when the vehicle is changing lanes at a high speed, the driver will not be able to obtain timely information about the vehicles in the side and rear, thus prone to safety hazards. In addition, similar cameras also have the problem of low overall clarity of the captured images. For this reason, the present application provides an optical system, a camera module and a vehicle to solve the above problems.

[0062] Reference Figure 1 As shown, the optical system 100 in an embodiment of the present application sequentially includes, from the object side to the image side: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4 and a lens unit 110. In some embodiments, the lens unit 110 includes a fifth lens L5, and at this time the optical system 100 has a five-piece structure. In other embodiments, the lens unit 110 includes a fifth lens L5 and a sixth lens L6, and at this time the optical system 100 has a six-piece structure.

[0063] The first lens L1 includes an object side S1 and an image side S2, the second lens L2 includes an object side S3 and an image side S4, the third lens L3 includes an object side S5 and an image side S6, the fourth lens L4 includes an object side S7 and an image side S8, the fifth lens L5 includes an object side S9 and an image side S10, and the sixth lens L6 includes an object side S11 and an image side S12. Additionally, the optical system 100 further has an imaging surface S17, which is located on the image side of the sixth lens L6. The imaging surface S17 can be understood as the photosensitive surface of the photosensitive element. However, it should be noted that the five-lens structure or six-lens structure does not mean that the optical system 100 only contains five lenses or six lenses. In some embodiments, at least one of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, or the sixth lens can be a cemented lens composed of two or more lenses. That is, the optical system 100 with the above five-lens structure can actually contain six, seven, or more lenses, and the optical system 100 with the six-lens structure can actually contain seven, eight, or more lenses.

[0064] In some embodiments, a stop STO is provided in the optical system 100, and the stop STO is disposed on the object side of the fourth lens L4. Specifically, the stop STO in some embodiments can be disposed between the second lens L2 and the third lens L3, or between the third lens L3 and the fourth lens L4.

[0065] The object sides and image sides of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 can all be spherical surfaces or all be aspherical surfaces. In some other embodiments, the object sides and image sides 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 S7 and the image side S8 of the fourth lens L4 are both aspherical surfaces.

[0066] When the object side or the image side of the lens is an aspherical surface, the aspherical formula can be referred to:

[0067]

[0068] Where Z is the distance from the corresponding point on the aspherical surface to the plane tangent to the surface vertex, r is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the aspherical vertex, k is the conic constant, and Ai is the coefficient corresponding to the i-th high-order term in the aspherical surface formula.

[0069] In some embodiments, the material of the first lens L1 is glass, and the materials of the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are plastics. Thus, the first lens L1 closest to the object side (the outside world) can better withstand the influence of the environmental temperature on the object side, and due to the fact that the other lenses are made of plastic, the optical system 100 can also have a lower production cost.

[0070] In addition to the material relationships of the above lenses, in some embodiments, the materials of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are all plastics. At this time, the plastic lenses can reduce the weight of the optical system 100 and lower the production cost. In some embodiments, the materials of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are all glass. At this time, the optical system 100 can withstand higher temperatures and has excellent optical performance.

[0071] It should be noted that, referring to Figure 5 , in the optical system 100 of some embodiments, the sixth lens L6 may not be provided. At this time, the optical system 100 will include the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5, that is, the optical system 100 has a five-piece structure.

[0072] For the above optical system 100 with a five-piece structure, a stop STO can also be provided, and the stop STO is provided on the object side of the fourth lens L4. Specifically, the stop STO can be provided between the second lens L2 and the third lens L3.

[0073] For the above optical system 100 with a five-piece structure, in some embodiments, the object side surfaces and image side surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 can all be spherical surfaces or all be aspherical surfaces. In some other embodiments, the object side surfaces and image side surfaces of the first lens L1, the third lens L3, the fourth lens L4, and the fifth lens L5 are all spherical surfaces, while the object side surface S3 and the image side surface S4 of the second lens L2 are both aspherical surfaces.

[0074] In addition, for the above optical system 100 with a five-piece structure, the material of the first lens L1 can be glass, and the materials of the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 can be plastics. Thus, the first lens L1 closest to the object side (the outside world) can better withstand the influence of the environmental temperature on the object side, and due to the fact that the other lenses are made of plastic, the optical system 100 can also have a lower production cost.

[0075] Further, in some embodiments, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 are all made of plastic. In this case, the plastic lenses can reduce the weight of the optical system 100 and lower the production cost. In some embodiments, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 are all made of glass. In this case, the optical system 100 can withstand higher temperatures and has excellent optical performance. In some other embodiments, the first lens L1, the third lens L3, the fourth lens L4, and the fifth lens L5 are made of glass, and the second lens L2 is made of plastic.

[0076] In some embodiments, an infrared filter L7 made of glass is disposed on the image side of the lens unit 110. For the five-lens optical system 100, the infrared filter L7 is disposed on the image side of the fifth lens L5; for the six-lens optical system 100, the infrared filter L7 is disposed on the image side of the sixth lens L6. The infrared filter L7 includes an object side surface S13 and an image side surface S14. The infrared filter L7 is used to filter infrared light to prevent the infrared light from reaching the imaging surface S17, thereby preventing the infrared light from affecting the imaging of a normal image. The infrared filter L7 can be assembled with each lens to be a part of the optical system 100, or it can also be installed between the optical system 100 and the photosensitive element when the optical system 100 and the photosensitive element are assembled into a module. In some embodiments, the infrared filter L7 can also be disposed on the object side of the first lens L1.

[0077] In some embodiments, a protective glass L8 is disposed on the image side of the last lens of the optical system 100. The protective glass L8 is disposed on the image side of the infrared filter L7 so as to be close to the photosensitive element during assembly, thereby protecting the photosensitive element. The protective glass L8 includes an object side surface S15 and an image side surface S16.

[0078] In addition, in addition to the lenses having refractive power, the optical system 100 may further include elements such as a diaphragm STO, a filter, a protective glass, a photosensitive element, and a mirror for changing the incident light path.

[0079] It should be noted that the following embodiments related to the relationships respectively include the cases where the optical system 100 is of a five-lens structure and a six-lens structure.

[0080] In some embodiments, the optical system 100 satisfies the relationship:

[0081] FOV / CRA > 10. Here, FOV is the field of view angle in the diagonal direction of the imaging surface of the optical system 100, and CRA is the incident angle of the chief ray. FOV / CRA can be 10.5, 10.6, 10.7, 10.8, or 10.9. When the above relationship is satisfied, the optical system 100 has a relatively large field of view angle to meet the requirements of electronic products such as mobile phones, vehicle-mounted devices, monitoring devices, and medical devices for large viewing angles. At the same time, it can also reduce the angle of light incident on the imaging surface S17 of the optical system 100, thereby improving the imaging clarity.

[0082] In some embodiments, the optical system 100 satisfies the relationship: |((cuy s1)*(map s1)-(cuy s2)*(maps2)) / 2| > 0.12. In the embodiment of the five-lens structure, cuy s1 is the reciprocal of the radius of curvature (at the optical axis) of the object side surface S9 of the fifth lens L5, map s1 is the semi-aperture in the Y direction of the object side surface S9 of the fifth lens L5, cuy s2 is the reciprocal of the radius of curvature (at the optical axis) of the image side surface S10 of the fifth lens L5, and map s2 is the semi-aperture in the Y direction of the image side surface S10 of the fifth lens L5. In the embodiment of the six-lens structure, cuy s1 is the reciprocal of the radius of curvature (at the optical axis) of the object side surface S11 of the sixth lens L6, map s1 is the semi-aperture in the Y direction of the object side surface S11 of the sixth lens L6, cuy s2 is the reciprocal of the radius of curvature (at the optical axis) of the image side surface S12 of the sixth lens L6, and map s2 is the semi-aperture in the Y direction of the image side surface S12 of the sixth lens L6. |((cuy s1)*(map s1)-(cuy s2)*(map s2)) / 2| can be 0.22, 0.24, 0.25, 0.26, 0.27, or 0.28. When the above relationship is satisfied, the processing difficulty of the fifth lens L5 in the five-lens structure can be reduced by controlling the radius of curvature and the semi-aperture in the Y direction of the fifth lens L5; or the processing difficulty of the sixth lens L6 in the six-lens structure can be reduced by controlling the radius of curvature and the semi-aperture in the Y direction of the sixth lens L6.

[0083] It should be noted that in the embodiments of the present application involving the cemented lens 111, when the optical system 100 has a five-lens structure, the cemented lens 111 is composed of the fourth lens L4 and the fifth lens L5; when the optical system 100 has a six-lens structure, the cemented lens 111 is composed of the fifth lens L5 and the sixth lens L6.

[0084] In some embodiments, the optical system 100 satisfies the relation: 0 < FH / f < 10. Wherein, FH is the focal length of the cemented lens 111, and f is the effective focal length of the optical system 100. FH / f can be 4.70, 4.75, 4.80, 5.00, 5.30, 5.70, 5.90, 6.10, 6.15 or 6.20. When the above relation is satisfied, the cemented lens 111 can provide positive refractive power for the optical system 100, enabling the optical system 100 to have the characteristics of wide viewing angle, low sensitivity and miniaturization.

[0085] In some embodiments, the optical system 100 satisfies the relation: ET S6 > 0.5, and the unit of ET S6 is mm. Wherein, in the embodiment of the five-lens structure, ET S6 is the thickness of the fourth lens L4 at the maximum effective radius; in the embodiment of the six-lens structure, ET S6 is the thickness of the fifth lens L5 at the maximum effective radius. ET S6 can be 1.5, 1.6, 1.7 or 1.8. When the above relation is satisfied, the processing difficulty of the cemented lens 111 can be reduced by controlling the edge thickness (the thickness of the lens at the maximum effective radius) of the fifth lens L5 in the five-lens structure or the sixth lens L6 in the six-lens structure.

[0086] In some embodiments, the optical system 100 satisfies the relation: BFL / TTL > 0.2. Wherein, BFL is the back focal length of the optical system 100, and TTL is the distance from the object side surface S1 of the first lens L1 to the imaging surface S17 of the optical system 100 on the optical axis. BFL / TTL can be 0.24, 0.25 or 0.26. When the above relation is satisfied, the optical system 100 has a large back focal length, and thus has a telecentric effect. At the same time, the sensitivity and length of the optical system 100 can be reduced, so that the volume of the optical system 100 is smaller. The back focal length is the distance from the image side surface of the last lens in the optical system 100 to the imaging surface S17 on the optical axis, and the last lens is the lens closest to the imaging surface S17 in the optical system 100. In the five-lens structure, the back focal length of the optical system 100 is the distance from the image side surface S10 of the fifth lens L5 to the imaging surface S17 on the optical axis; in the six-lens structure, the back focal length of the optical system 100 is the distance from the image side surface S12 of the sixth lens L6 to the imaging surface S17 on the optical axis.

[0087] In some embodiments, the optical system 100 satisfies the relationship: (SD S2) / (RDY S2) < 0.95. Wherein, SD S2 is the semi-aperture in the Y direction of the image side S2 of the first lens L1, and RDY S2 is the radius of curvature of the image side S2 of the first lens L1 at the optical axis. (SD S2) / (RDY S2) can be 0.908, 0.912, 0.915, 0.917 or 0.918. When the above relationship is satisfied, by controlling the radius of curvature and the semi-aperture in the Y direction of the image side S2 of the first lens L1, the bending degree of the first lens L1 can be effectively controlled, the processing difficulty of the first lens L1 can be reduced, and at the same time, the problem of uneven coating caused by excessive bending degree of the first lens L1 can be avoided, and the risk of generating ghost images can be reduced.

[0088] In some embodiments, the optical system 100 satisfies the relationship: -65 ≤ Dist ≤ 65. Wherein, Dist is the optical distortion of the optical system 100, and the unit is %. Dist can be -64, -63, -62, -61, 61, 62, 63 or 64. When the above relationship is satisfied, the amount of distortion of the optical system 100 can be controlled to weaken the phenomenon of excessive distortion commonly existing in wide-angle lenses.

[0089] In some embodiments, the optical system 100 satisfies the relationship: Nd1 < 1.8; Vd1 > 25. Wherein, Nd1 is the refractive index of the first lens L1 under d light, and Vd1 is the Abbe number of the first lens L1 under d light. Nd1 can be 1.600, 1.610, 1.630, 1.660, 1.700, 1.730, 1.740, 1.760 or 1.765. Vd1 can be 50.00, 61.00, 53.00, 57.00, 60.00, 60.80, 61.00 or 62.00. When the above relationship is satisfied, it is beneficial to correct the off-axis chromatic aberration of the optical system 100, thereby improving the resolution of the optical system 100.

[0090] In some embodiments, the optical system 100 satisfies the relationships: Nd2 > 1.9; Vd2 < 25. Here, Nd2 is the refractive index of the d-line of the lens closest to the image side in the optical system 100 (in the five-lens configuration, the lens closest to the image side is the fifth lens L5; in the six-lens configuration, the lens closest to the image side is the sixth lens L6), and Vd2 is the Abbe number of the d-line of the lens closest to the image side in the optical system 100. The wavelength of the d-line is 587.56 nm. Nd2 can be 1.928, 1.930, 1.935, 1.950, 1.970, 1.980, or 1.950. Vd2 can be 19.40, 19.50, 19.70, 20.00, 20.30, 20.60, 20.70, 20.80, or 20.85. When the above relationships are satisfied, it is beneficial to correct the off-axis chromatic aberration of the optical system 100, thereby improving the resolution of the optical system 100.

[0091] In some embodiments, the object side surface S1 of the first lens L1 is coated with a protective film layer. In some embodiments, the optical system 100 satisfies the relationships: H K > 500; F A > 50. Here, H K is the hardness of the first lens L1, and H K is in units of 10 7 Pa, and F A is the abrasion degree of the first lens L1, and F A is in units of %. H K can be 600, 610, 620, 650, 680, or 690. F A can be 70, 75, 80, 90, 100, 105, 110, or 113. When the above relationships are satisfied, the first lens L1 has a high hardness and abrasion degree. At the same time, by setting the protective film layer to enable the first lens L1 to have a waterproof and scratch-resistant function, it can effectively prevent the first lens L1 from being scratched, prevent problems such as scratches and water droplet adhesion from affecting the imaging quality, and improve the service life of the optical system 100.

[0092] First Embodiment

[0093] As Figure 1In the first embodiment shown, the optical system 100 sequentially includes, from the object side to the image side, a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a stop STO, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, and a sixth lens L6 with negative refractive power. Thus, the optical system 100 has a six-lens structure. Additionally, the fifth lens L5 and the sixth lens L6 are cemented together to form a cemented lens 111. An infrared filter L7 and a protective glass L8 are sequentially disposed on the image side of the sixth lens L6. The infrared filter L7 and the protective glass L8 may or may not belong to a part of the optical system 100. When the infrared filter L7 and the protective glass L8 are not provided, the distance from the image side surface S12 of the sixth lens L6 to the imaging surface S17 is still 5.499 mm. Similar to the following embodiments, the distance from the image side surface S12 of the sixth lens L6 to the imaging surface S17 is independent of whether the infrared filter L7 or the protective glass L8 is provided. Figure 2 FIGS. Figure 2 are the spherical aberration diagram (mm), astigmatism diagram (mm), and distortion diagram (%) of the optical system 100 in the first embodiment. The astigmatism diagram and the distortion diagram therein are data diagrams at the reference wavelength. The reference wavelength in the following embodiments is 587.56 nm. Additionally, the unit of the vertical coordinate IMG HT in the astigmatism diagrams and the distortion diagrams in the following embodiments is mm.

[0094] The object side surface S1 of the first lens L1 is convex, and the image side surface S2 of the first lens L1 is concave.

[0095] The object side surface S3 of the second lens L2 is convex; the image side surface S4 of the second lens L2 is concave.

[0096] The object side surface S5 of the third lens L3 is convex, and the image side surface S6 of the third lens L3 is convex.

[0097] The object side surface S7 of the fourth lens L4 is convex, and the image side surface S8 of the fourth lens L4 is convex.

[0098] The object side surface S9 of the fifth lens L5 is convex, and the image side surface S10 of the fifth lens L5 is convex.

[0099] The object side surface S11 of the sixth lens L6 is concave, and the image side surface S12 of the sixth lens L6 is convex.

[0100] The object side surfaces and the image side surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are all spherical surfaces.

[0101] The materials of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are all glass.

[0102] The optical system 100 satisfies the following relationship:

[0103] FOV / CRA = 10.4. Here, FOV is the field of view angle in the diagonal direction of the imaging surface of the optical system 100, and CRA is the incident angle of the chief ray. When the above relationship is satisfied, the optical system 100 has a relatively large field of view angle to meet the requirements of electronic products such as mobile phones, vehicle-mounted devices, monitoring devices, and medical devices for a large viewing angle. At the same time, it can also reduce the angle of light incident on the photosensitive element located on the image side of the optical system 100, thereby improving the imaging clarity.

[0104] The optical system 100 satisfies the relationship: |((cuy s1)*(map s1)-(cuy s2)*(map s2)) / 2| = 0.21. Here, cuy s1 is the reciprocal of the radius of curvature (at the optical axis) of the object side surface S11 of the sixth lens L6, map s1 is the semi-aperture in the Y direction of the object side surface S11 of the sixth lens L6, cuy s2 is the reciprocal of the radius of curvature (at the optical axis) of the image side surface S12 of the sixth lens L6, and map s2 is the semi-aperture in the Y direction of the image side surface S12 of the sixth lens L6. When the above relationship is satisfied, the processing difficulty of the sixth lens L6 can be reduced by controlling the radius of curvature and the semi-aperture in the Y direction of the sixth lens L6. It should be noted that in the embodiments of the present application involving the cemented lens 111, when the optical system 100 has a five-piece structure, the cemented lens 111 is composed of the fourth lens L4 and the fifth lens L5; when the optical system 100 has a six-piece structure, the cemented lens 111 is composed of the fifth lens L5 and the sixth lens L6.

[0105] The optical system 100 satisfies the relationship: FH / f = 4.63. Here, FH is the focal length of the cemented lens 111, and f is the effective focal length of the optical system 100. When the above relationship is satisfied, the cemented lens 111 can provide a positive refractive power for the optical system 100, making the optical system 100 have the characteristics of a wide viewing angle, low sensitivity, and miniaturization.

[0106] The optical system 100 satisfies the relationship: ET S6 = 1.5, where ET S6 is the thickness of the fifth lens L5 at the maximum effective radius, and the unit of ET S6 is mm. When the above relationship is satisfied, the processing difficulty of the cemented lens 111 can be reduced by controlling the edge thickness (the thickness of the lens at the maximum effective radius) of the sixth lens L6.

[0107] The optical system 100 satisfies the relation: BFL / TTL = 0.26. Wherein, BFL is the optical back focal length of the optical system 100, and TTL is the distance on the optical axis from the object side surface S1 of the first lens L1 to the imaging surface S17 of the optical system 100. When the above relation is satisfied, the optical system 100 has a relatively large optical back focal length, and thus has a telecentric effect. At the same time, the sensitivity and length of the optical system 100 can be reduced, so that the volume of the optical system 100 is smaller.

[0108] The optical system 100 satisfies the relation: (SD S2) / (RDY S2) = 0.906. Wherein, SD S2 is the Y-direction semi-aperture of the image side surface S2 of the first lens L1, and RDY S2 is the radius of curvature of the image side surface S2 of the first lens L1 at the optical axis. When the above relation is satisfied, the curvature radius and the Y-direction semi-aperture of the image side surface S2 of the first lens L1 can be controlled to effectively control the bending degree of the first lens L1, reduce the processing difficulty of the first lens L1, and at the same time avoid the problem of uneven coating caused by the excessive bending degree of the first lens L1, and reduce the risk of ghosting.

[0109] The optical system 100 satisfies the relation: Dist = -65. Wherein, Dist is the optical distortion of the optical system 100, and the unit is %. When the above relation is satisfied, the distortion amount of the optical system 100 can be controlled to weaken the phenomenon of excessive distortion commonly existing in wide-angle lenses.

[0110] The optical system 100 satisfies the relation: Nd1 = 1.773; Vd1 = 49.62. Wherein, Nd1 is the refractive index of the first lens L1 under d light, and Vd1 is the Abbe number of the first lens L1 under d light. When the above relation is satisfied, it is beneficial to correct the off-axis chromatic aberration of the optical system 100, thereby improving the resolution of the optical system 100.

[0111] The optical system 100 satisfies the relation: Nd2 = 2.003; Vd2 = 19.32. Wherein, Nd2 is the d-light refractive index of the lens closest to the image side in the optical system 100 (the fifth lens L5 in the five-piece structure scheme and the sixth lens L6 in the six-piece structure scheme), and Vd2 is the d-light Abbe number of the lens closest to the image side in the optical system 100. When the above relation is satisfied, it is beneficial to correct the off-axis chromatic aberration of the optical system 100, thereby improving the resolution of the optical system 100.

[0112] The object side surface S1 of the first lens L1 is coated with a protective film layer and the optical system 100 satisfies the relation: H K = 700; F A = 65. Wherein, H K is the hardness of the first lens L1, H K The unit is 10 7 Pa, FA is the wear degree of the first lens L1, F A The unit is %. When the above relationship is satisfied, the first lens L1 has high hardness and wear degree. At the same time, by setting the protective film layer to enable the first lens L1 to have the functions of waterproof and scratch resistance, it can effectively prevent the first lens L1 from being scratched, prevent the imaging quality from being affected by problems such as scratches and water droplet adhesion, and improve the service life of the optical system 100.

[0113] In the first embodiment, the focal length f of the optical system 100 is 2.8923 mm, the aperture value FNO is 2.1, and half of the diagonal field of view angle (1 / 2) FOV is 73 degrees (deg.).

[0114] In addition, the parameters of the optical system 100 are given in Table 1. The elements from the object surface to the imaging surface S17 are arranged in the order of the elements in Table 1 from top to bottom. The surface numbers 1 and 2 respectively represent the object side surface S1 and the image side surface S2 of the first lens L1. That is, in the same lens, the surface with the smaller surface number is the object side surface, and the surface with the larger surface number is the image side surface. The Y radius in Table 1 is the paraxial curvature radius of the object side surface or the image side surface with the corresponding surface number. The first value in the "thickness" parameter column of the first lens L1 is the thickness of the lens on the optical axis, and the second value is the distance between the image side surface of the lens and the object side surface of the subsequent lens on the optical axis. The "thickness" parameter of surface number 6 is the distance between the image side surface S6 of the third lens L3 and the stop STO. The value of the stop STO in the "thickness" parameter column is the distance between the stop STO and the vertex of the object side surface of the subsequent lens (the vertex refers to the intersection of the lens and the optical axis) on the optical axis. We default that the direction from the object side surface of the first lens L1 to the image side surface of the last lens is the positive direction of the optical axis. When this value is negative, it indicates that the stop STO is set on the right side of the vertex of the object side surface of the lens. When the "thickness" parameter of the stop STO is positive, the stop STO is on the left side of the vertex of the object side surface of the lens. The value of the "thickness" parameter of surface number 12 is the distance between the image side surface S12 of the sixth lens L6 and the object side surface S13 of the infrared filter L7 on the optical axis. The value corresponding to surface number 13 in the "thickness" parameter of the infrared filter L7 is the distance between the image side surface S14 of the infrared filter L7 and the object side surface S15 of the protective glass L8 on the optical axis.

[0115] In addition, in the following embodiments, the refractive index, Abbe number and focal length of each lens are the values at the reference wavelength, and the reference wavelength is 587.56 nm.

[0116] Table 1

[0117]

[0118] Second Embodiment

[0119] Such as Figure 3In the second embodiment shown, the optical system 100 sequentially includes, from the object side to the image side, a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a stop STO, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, and a sixth lens L6 with negative refractive power. Thus, the optical system 100 has a six-lens structure. Additionally, the fifth lens L5 and the sixth lens L6 are cemented together to form a cemented lens 111. An infrared filter L7 and a protective glass L8 are sequentially arranged on the image side of the sixth lens L6. The infrared filter L7 and the protective glass L8 may or may not belong to the optical system 100. Figure 4 FIGURES Figure 4 are the spherical aberration diagram (mm), astigmatism diagram (mm), and distortion diagram (%) of the optical system 100 in the second embodiment, where the astigmatism diagram and the distortion diagram are data diagrams at the reference wavelength.

[0120] The object side surface S1 of the first lens L1 is convex, and the image side surface S2 of the first lens L1 is concave.

[0121] The object side surface S3 of the second lens L2 is concave; the image side surface S4 of the second lens L2 is concave.

[0122] The object side surface S5 of the third lens L3 is convex, and the image side surface S6 of the third lens L3 is convex.

[0123] The object side surface S7 of the fourth lens L4 is convex, and the image side surface S8 of the fourth lens L4 is convex.

[0124] The object side surface S9 of the fifth lens L5 is convex, and the image side surface S10 of the fifth lens L5 is convex.

[0125] The object side surface S11 of the sixth lens L6 is concave, and the image side surface S12 of the sixth lens L6 is convex.

[0126] The object side surfaces and the 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, and the object side surface S7 and the image side surface S8 of the fourth lens L4 are aspherical surfaces.

[0127] The materials of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are all glass.

[0128] In the second embodiment, the effective focal length f of the optical system 100 is 2.8761 mm, the f-number FNO is 2.1, and half of the diagonal field of view (1 / 2) FOV is 71 degrees (deg.).

[0129] In addition, the parameters of the optical system 100 are given in Table 3 and Table 4, and the definitions of the parameters can be obtained from the first embodiment, which will not be elaborated here. Table 4 is a table of relevant parameters of the aspherical surfaces of the lenses in Table 3, where k is the conic constant and Ai is the coefficient corresponding to the i-th high-order term in the aspherical surface formula.

[0130] Table 3

[0131]

[0132] Table 4

[0133]

[0134] Based on the parameter information provided above, the following data can be deduced:

[0135]

[0136] Third Embodiment

[0137] As Figure 5 In the third embodiment shown, the optical system 100 includes, in order from the object side to the image side, a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a stop STO, a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, and a fifth lens L5 with negative refractive power. Thus, the optical system 100 has a five-lens structure. In addition, the fourth lens L4 and the fifth lens L5 are cemented together to form a cemented lens 111. An infrared filter L7 and a protective glass L8 are sequentially arranged on the image side of the fifth lens L5. The infrared filter L7 and the protective glass L8 may or may not belong to the optical system 100. Figure 6 Figures of spherical aberration (mm), astigmatism (mm), and distortion (%) of the optical system 100 in the third embodiment, where the astigmatism and distortion figures are data figures at the reference wavelength.

[0138] The object side surface S1 of the first lens L1 is convex, and the image side surface S2 of the first lens L1 is concave.

[0139] The object side surface S3 of the second lens L2 is concave; the image side surface S4 of the second lens L2 is concave.

[0140] The object side surface S5 of the third lens L3 is convex, and the image side surface S6 of the third lens L3 is convex.

[0141] The object side surface S7 of the fourth lens L4 is convex, and the image side surface S8 of the fourth lens L4 is convex.

[0142] The object side surface S9 of the fifth lens L5 is concave, and the image side surface S10 of the fifth lens L5 is convex.

[0143] The object side and the image side of the first lens L1, the third lens L3, the fourth lens L4, and the fifth lens L5 are both spherical surfaces, and the object side S3 and the image side S4 of the second lens L2 are aspherical surfaces.

[0144] The materials of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 are all glass.

[0145] In the third embodiment, the effective focal length f of the optical system 100 is 3.0 mm, the aperture value FNO is 2.0, and half of the field of view angle in the diagonal direction (1 / 2) FOV is 72 degrees (deg.).

[0146] In addition, the parameters of the optical system 100 are given in Tables 5 and 6, and the definitions of the parameters therein can be obtained from the first embodiment and will not be elaborated here. Table 6 is a table of relevant parameters of the aspherical surfaces of the lenses in Table 5, where k is the conic constant and Ai is the coefficient corresponding to the i-th high-order term in the aspherical surface formula.

[0147] Table 5

[0148]

[0149] Table 6

[0150]

[0151] Based on the parameter information provided above, the following data can be deduced:

[0152]

[0153] Fourth Embodiment

[0154] As Figure 7 shown in the fourth embodiment, the optical system 100 includes, in order from the object side to the image side, a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a stop STO, a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, and a fifth lens L5 with negative refractive power. Thus, the optical system 100 has a five-piece structure. In addition, the fourth lens L4 and the fifth lens L5 are cemented to form a cemented lens 111. An infrared filter L7 and a protective glass L8 are sequentially arranged on the image side of the fifth lens L5. The infrared filter L7 and the protective glass L8 may or may not belong to the optical system 100. Figure 8 are the spherical aberration diagram (mm), astigmatism diagram (mm), and distortion diagram (%) of the optical system 100 in the fourth embodiment, where the astigmatism diagram and the distortion diagram are data diagrams at the reference wavelength.

[0155] The object side surface S1 of the first lens L1 is convex, and the image side surface S2 of the first lens L1 is concave.

[0156] The object side surface S3 of the second lens L2 is concave; the image side surface S4 of the second lens L2 is concave.

[0157] The object side surface S5 of the third lens L3 is convex, and the image side surface S6 of the third lens L3 is convex.

[0158] The object side surface S7 of the fourth lens L4 is convex, and the image side surface S8 of the fourth lens L4 is convex.

[0159] The object side surface S9 of the fifth lens L5 is concave, and the image side surface S10 of the fifth lens L5 is convex.

[0160] The object side surfaces and image side surfaces of the first lens L1, the third lens L3, the fourth lens L4, and the fifth lens L5 are all spherical surfaces, and the object side surface S3 and the image side surface S4 of the second lens L2 are aspherical surfaces.

[0161] The materials of the first lens L1, the third lens L3, the fourth lens L4, and the fifth lens L5 are all glass, and the material of the second lens L2 is plastic.

[0162] In the fourth embodiment, the effective focal length f of the optical system 100 is 2.99 mm, the aperture value FNO is 2.0, and half of the field of view angle in the diagonal direction (1 / 2) FOV is 71.9 degrees (deg.).

[0163] In addition, the parameters of the optical system 100 are given in Tables 7 and 8, and the definitions of the parameters can be obtained from the first embodiment and will not be elaborated here. Table 8 is a table of the relevant parameters of the aspherical surfaces of each lens in Table 7, where K is the conic constant and Ai is the coefficient corresponding to the i-th high-order term in the aspherical surface formula.

[0164] Table 7

[0165]

[0166] Table 8

[0167]

[0168]

[0169] Based on the parameter information provided above, the following data can be deduced:

[0170]

[0171] Reference Figure 9, in some embodiments, the optical system 100 can be assembled with the photosensitive element 210 into the imaging module 200, and the photosensitive element 210 is disposed on the image side of the optical system 100. The photosensitive element 210 can be a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). By adopting the optical system 100, the imaging module 200 will have the characteristics of a large viewing angle and can improve the imaging clarity.

[0172] In some embodiments, the lens in the optical system 100 is relatively fixed with respect to the photosensitive element 210. At this time, the imaging module 200 is a fixed-focus module. In some other embodiments, the driving motor can also be configured to enable the photosensitive element 210 to move relative to the lens in the optical system 100 to achieve the focusing function.

[0173] The imaging module 200 can be applied to fields such as smart phones, smart watches, automobiles, monitoring, and medical treatment, and can specifically be used as a mobile phone imaging module, a vehicle-mounted imaging module, or a monitoring imaging module. When the imaging module 200 is applied to a device, the device will have the characteristics of a large viewing angle and can improve the imaging clarity.

[0174] Reference Figure 10 , in some embodiments, when the imaging module 200 is applied as a vehicle-mounted camera to the vehicle 30, the imaging module 200 can be used as a front-view camera, a rear-view camera, or a side-view camera of the vehicle 30. Specifically, the vehicle 30 includes a vehicle body 310, and the imaging module 200 can be installed at any position on the front side of the vehicle body 310 (such as at the intake grille), the left front headlight, the right front headlight, the left rearview mirror, the right rearview mirror, the trunk lid, the roof, etc. Secondly, a display device can also be provided inside the vehicle 30, and the imaging module 200 is communicatively connected to the display device. Thus, the image obtained by the imaging module 200 on the vehicle body 310 can be displayed on the display device in real time, enabling the driver to obtain a larger range of environmental information around the vehicle body 310 and making it more convenient and safe for the driver to drive and park. When multiple imaging modules 200 are provided to obtain images in different directions, the image information obtained by the imaging modules 200 can be synthesized and presented on the display device in the form of a top view.

[0175] Specifically, the vehicle 30 includes at least four camera modules 200, which are respectively installed on the front side (such as at the intake grille), left side (such as at the left rearview mirror), right side (such as at the right rearview mirror), and rear side (such as at the trunk lid) of the vehicle body 310 to construct a surround view system for the vehicle. The surround view system for the vehicle includes four (or more) camera modules 200 installed around the vehicle body 310 in the front, rear, left, and right directions. The multiple camera modules 200 can simultaneously collect the scenes around the vehicle 30. Subsequently, the image information collected by the camera modules 200 undergoes steps such as distortion reduction, perspective transformation, image stitching, and image enhancement through an image processing unit, and finally forms a seamless 360-degree panoramic top view around the vehicle 30, which is displayed on a display device. Of course, in addition to displaying the panoramic view, a single-sided view in any direction can also be displayed. Additionally, a scale line corresponding to the displayed image can be configured on the display device to facilitate the driver to accurately determine the orientation and distance of obstacles.

[0176] By adopting the above-mentioned camera modules 200, the visual blind spots of the driver can be effectively reduced, enabling the driver to obtain more road condition information outside the vehicle body, thereby reducing potential safety hazards during operations such as lane changing, parking, and turning.

[0177] In some embodiments, a driving recorder is installed in the vehicle 30, and the image information obtained by the camera modules 200 can be stored in the driving recorder.

[0178] 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 these combinations of technical features do not conflict, they should be considered as falling within the scope described in this specification.

[0179] 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 limiting 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 deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. An optical system, characterized in that, From the object side to the image side, it successively includes: A first lens with negative refractive power, the object side surface of the first lens is convex, and the image side surface is concave; the material of the first lens is glass; A second lens with negative refractive power, the image side surface of the second lens is concave; A third lens with positive refractive power, the object side surface and the image side surface of the third lens are convex respectively; A fourth lens with positive refractive power, the object side surface and the image side surface of the fourth lens are convex respectively; A lens unit with refractive power; The lens unit includes a fifth lens with negative refractive power, the fifth lens is located on the image side of the fourth lens, and the image side surface of the fifth lens with negative refractive power is convex; the optical system has a total of five lenses; or, The lens unit includes a fifth lens with positive refractive power and a sixth lens with negative refractive power, the fifth lens is located on the image side of the fourth lens, the sixth lens is arranged on the image side of the fifth lens with positive refractive power, the image side surface of the fifth lens with positive refractive power is convex, the object side surface of the sixth lens is concave, and the image side surface is convex; the optical system has a total of six lenses; A diaphragm, arranged on the object side of the fourth lens; And the optical system satisfies the following relationship: FOV / CRA>10; Wherein, FOV is the field of view angle in the diagonal direction of the imaging plane of the optical system, and CRA is the incident angle of the chief ray; The optical system also satisfies the following relationship: BFL / TTL>0.2; Wherein, BFL is the back focal length of the optical system, and TTL is the distance from the object side surface of the first lens to the imaging plane of the optical system on the optical axis.

2. The optical system according to claim 1, characterized in that, The relationship of BFL / TTL satisfies: 0.2 < BFL / TTL ≤ 0.

26.

3. The optical system according to claim 1, wherein The relationship of FOV / CRA satisfies: 10 < FOV / CRA ≤ 11.

4. The optical system according to claim 1, characterized in that, Satisfy the following relationship: (SD S2) / (RDY S2)<0.95; Wherein, SD S2 is the semi-aperture in the Y direction of the image side surface of the first lens, and RDY S2 is the radius of curvature of the image side surface of the first lens.

5. The optical system according to claim 1, characterized in that, Satisfy the following relationship: -65 ≤ Dist ≤ 65; Wherein, Dist is the optical distortion of the optical system, and the unit is %.

6. The optical system according to claim 1, characterized in that Satisfy the following relationship: Nd1<1.8; Vd1>25; Wherein, Nd1 is the refractive index of the first lens under d light, and Vd1 is the Abbe number of the first lens under d light.

7. The optical system according to claim 1, wherein The object side surface of the first lens is coated with a protective film layer and / or the optical system satisfies the following relationship: H K > 500; F A > 50; Among them, H K is the hardness of the first lens, H K with the unit of 10 7 Pa, and F A is the wear degree of the first lens, F A with the unit of %.

8. The optical system according to claim 1, characterized in that, The optical system satisfies the following relationship: Nd2>1.9; Vd2<25; Wherein, Nd2 is the d light refractive index of the lens closest to the image side in the optical system, and Vd2 is the d light Abbe number of the lens closest to the image side in the optical system.

9. The optical system according to claim 1, characterized in that, When the optical system has a total of five lenses, the fourth lens and the fifth lens with negative refractive power form a cemented lens, and the optical system satisfies at least one of the following relationships: |((cuy s1)*(map s1)-(cuy s2)*(map s2)) / 2|>0.12; 0<FH / f<10; ET S6 > 0.5; Wherein, cuy s1 is the reciprocal of the curvature radius of the object side of the fifth lens with negative refractive power, map s1 is the Y-direction semi-aperture of the object side of the fifth lens with negative refractive power, cuy s2 is the reciprocal of the curvature radius of the image side of the fifth lens with negative refractive power, map s2 is the Y-direction semi-aperture of the image side of the fifth lens with negative refractive power, FH is the focal length of the cemented lens, f is the effective focal length of the optical system, ET S6 is the thickness of the fourth lens at the maximum effective radius, and the unit of ET S6 is mm.

10. The optical system according to claim 1, characterized in that, When the optical system has a total of six lenses, the fifth lens with positive refractive power and the sixth lens form a cemented lens, and the optical system satisfies at least one of the following relationships: |((cuy s1)*(map s1)-(cuy s2)*(map s2)) / 2| > 0.12; 0 < FH / f < 10; ET S6 > 0.5; Wherein, cuy s1 is the reciprocal of the curvature radius of the object side of the sixth lens, map s1 is the Y-direction semi-aperture of the object side of the sixth lens, cuy s2 is the reciprocal of the curvature radius of the image side of the sixth lens, map s2 is the Y-direction semi-aperture of the image side of the sixth lens, FH is the focal length of the cemented lens, f is the effective focal length of the optical system, ET S6 is the thickness of the fifth lens with positive refractive power at the maximum effective radius, and the unit of ET S6 is mm.

11. An imaging module, characterized in that, Comprising a photosensitive element and the optical system according to any one of claims 1 to 10, wherein the photosensitive element is disposed on the image side of the optical system.

12. An automobile, characterized in that, Comprising a vehicle body and the imaging module according to claim 11, wherein the imaging module is disposed on the vehicle body, and the imaging module can acquire environmental information around the vehicle.

Images