Optical systems, camera modules and terminal equipment

Abstract

The embodiments of the present application disclose an optical system, a camera module and a terminal device. The optical system includes a first lens with positive refractive power, the object side of the first lens is convex at the near optical axis, and the image side of the first lens is concave at the near optical axis; a second lens, a third lens, a fifth lens, and a seventh lens with negative refractive power; a fourth lens and a sixth lens with positive refractive power; and a negative refractive power; the optical system satisfies: 1<(|SAG71|+SAG72) / CT7<1.5. The present application reasonably configures the refractive power and surface shape of the first lens to the seventh lens and limits (|SAG71|+SAG72) / CT7, so that the optical system simultaneously meets the requirements of high pixel, large aperture and miniaturization.

Description

Technical Field

[0001] The present application belongs to the field of optical imaging technology, and in particular, relates to an optical system, a camera module and a terminal device. Background Art

[0002] In recent years, with the rapid development of manufacturing technology for electronic products such as smartphones, tablets, and cameras and the emergence of increasingly diversified user needs, the market demand for miniaturized, high-pixel imaging devices has gradually increased.

[0003] The size of the optical system for photography must be miniaturized under the market trend. In addition to the requirement of miniaturization, the pixel size of the photosensitive element has been reduced due to the advancement of semiconductor process technology, thus achieving the requirement of higher pixels. However, the imaging devices of electronic devices such as mobile phones are currently difficult to meet the requirements of high pixels, large aperture and miniaturization at the same time.

[0004] Therefore, how to simultaneously achieve miniaturization, large aperture and high-pixel imaging quality of camera lenses should be the research and development direction of the industry. Summary of the invention

[0005] The embodiments of the present application provide an optical system, a camera module and a terminal device, wherein the optical system simultaneously meets the requirements of high pixel, large aperture and miniaturization.

[0006] In a first aspect, an embodiment of the present application provides an optical system, which includes a plurality of lenses, wherein the plurality of lenses include a first lens arranged in sequence from an object side (the object side refers to the side where light is incident) to an image side (the image side refers to the side where light is emitted), and having a positive refractive power, wherein the object side surface of the first lens is convex at the near optical axis, and the image side surface of the first lens is concave at the near optical axis; a second lens having a negative refractive power, wherein the object side surface of the second lens is convex at the near optical axis, and the image side surface of the second lens is concave at the near optical axis; a third lens having a negative refractive power; a fourth lens having a positive refractive power; wherein the image side surface of the fourth lens is convex at the near optical axis; a fifth lens having a negative refractive power; a sixth lens having a positive refractive power, wherein the The object side surface of the sixth lens is convex at the near optical axis, and the image side surface of the sixth lens is convex at the near optical axis; the seventh lens has negative refractive power, the object side surface of the seventh lens is convex at the near optical axis, and the image side surface of the seventh lens is concave at the near optical axis; the optical system satisfies the following condition: 1<(|SAG71|+SAG72) / CT7<1.5, SAG71 is the maximum distance from an off-axis point within the effective diameter of the object side surface of the seventh lens to the on-axis vertex of the object side surface of the seventh lens on the optical axis, SAG72 is the maximum distance from an off-axis point within the effective diameter of the image side surface of the seventh lens to the on-axis vertex of the image side surface of the seventh lens on the optical axis, and CT7 is the thickness of the seventh lens on the optical axis.

[0007] Among them, the refractive power is the focal length, which represents the ability of the optical system to deflect light. Positive refractive power means that the lens converges the light beam, and negative refractive power means that the lens diverges the light beam. When the lens has no refractive power, that is, when the focal length is zero, it is a plane refraction. At this time, the parallel light beam along the axis is still a parallel light beam along the axis after refraction, and no refraction occurs.

[0008] The present application reasonably configures the refractive power of the first lens to the seventh lens in the optical system, the surface shapes of the first lens, the second lens, the fourth lens, the sixth lens and the seventh lens, and defines (|SAG71|+SAG72) / CT7, so that the optical system simultaneously meets the requirements of high pixel, large aperture and miniaturization.

[0009] Specifically, by limiting the range of (|SAG71|+SAG72) / CT7, the refractive power and thickness of the seventh lens in the vertical direction can be reasonably controlled to avoid the seventh lens being too thin or too thick, reduce the incident angle of light on the imaging surface, and reduce the sensitivity of the optical system. In addition, the seventh lens is provided with multiple inflection points, which is conducive to correcting the distortion and field curvature generated by the first lens to the sixth lens, so that the refractive power configuration close to the imaging surface is more uniform.

[0010] In one embodiment, the object side surface or the image side surface of at least one of the lenses is aspherical, which is beneficial to correcting the aberration of the optical system and improving the imaging quality of the optical system.

[0011] In one embodiment, the optical system satisfies the condition: f1>0mm, where f1 is the focal length of the first lens. The first lens has positive refractive power and converges the light beam. By limiting the value of f1, light beams with large angles enter the first lens and can better converge the light beams.

[0012] In one embodiment, the optical system satisfies the condition: |V2-V1|>30, V2 is the Abbe number of the second lens, V1 is the Abbe number of the first lens, and the reference wavelength of the Abbe number is 587.6nm. By limiting the value of |V2-V1|, it is beneficial to correct chromatic aberration and improve imaging quality.

[0013] In one embodiment, the optical system satisfies the condition: 0.5 mm -1 <(n1+n2) / f<1mm -1, n1 is the refractive index of the first lens, n2 is the refractive index of the second lens, the reference wavelength of the refractive index is 587.6nm, and f is the focal length of the optical system. By properly configuring the refractive power of the first lens and the second lens, chromatic aberration and spherical aberration can be minimized, image quality can be improved, and by properly allocating the focal power, the light-collecting ability of the optical system can be enhanced, and at the same time, the size of the optical system can be compressed.

[0014] In one embodiment, the optical system satisfies the condition: f23 < 0 mm, where f23 is the combined focal length of the second lens and the third lens. By limiting the value of f23, it is beneficial to correct aberrations and effectively converge marginal light, while ensuring the compact structure of the optical system, effectively compressing the size, and achieving wide-angle and miniaturization characteristics.

[0015] In one embodiment, the optical system satisfies the condition: 0<(CT1+CT2+CT3) / TTL<0.5, CT1 is the thickness of the first lens on the optical axis, CT2 is the thickness of the second lens on the optical axis, CT3 is the thickness of the third lens on the optical axis, and TTL is the distance from the object side of the first lens to the imaging surface on the optical axis in the optical system. By limiting the range of (CT1+CT2+CT3) / TTL and rationally configuring the thickness of the first lens, the second lens, and the third lens, it is beneficial to reduce the sensitivity of the optical system and facilitate the miniaturization of the optical system.

[0016] In one embodiment, the optical system satisfies the condition: (|f2|+|f3|) / |R71|>50, f2 is the focal length of the second lens, f3 is the focal length of the third lens, and R71 is the radius of curvature of the object side of the seventh lens at the optical axis. By limiting the range of (|f2|+|f3|) / |R71| and rationally configuring the refractive power of the second lens and the third lens, it is helpful to reduce the comprehensive spherical aberration, chromatic aberration, and distortion of the first lens, the second lens, and the third lens to a reasonable position, and reduce the design difficulty of the fourth lens, the fifth lens, the sixth lens, and the seventh lens; at the same time, through the rational allocation of the radius of curvature of the seventh lens, the light collecting ability of the system can be enhanced, and the performance of the optical system can be improved.

[0017] In one embodiment, the optical system satisfies the conditional formula: (f1+|f2|+|f3|) / f>40, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, and f is the focal length of the optical system. Reasonable configuration of the size and refractive power of the first lens, the second lens, and the third lens can avoid large spherical aberration of the first lens, the second lens, and the third lens, improve the overall resolution of the optical system, and at the same time, facilitate the size compression of the first lens, the second lens, and the third lens, which helps to form a small-sized optical system.

[0018] In one embodiment, the optical system satisfies the conditional formula: R62 / f < -1, where R62 is the radius of curvature of the image side of the sixth lens at the optical axis, and f is the focal length of the optical system. By reasonably defining the value of R62 / f, the surface complexity of the sixth lens can be reduced, which is beneficial to suppressing field curvature and distortion, reducing the forming difficulty, improving the overall image quality, and effectively controlling the back focal length of the system to avoid an overly long overall system length.

[0019] In one embodiment, the optical system satisfies the conditional formula: |f6| + |f7| < 20 mm, where f6 is the focal length of the sixth lens and f7 is the focal length of the seventh lens. By reasonably configuring the sizes and refractive powers of the sixth lens and the seventh lens and defining the value of |f6| + |f7|, the spherical aberration generated by the first lens to the fifth lens can be balanced, the resolution of the overall optical system can be improved, the refractive power configuration of the sixth lens and the seventh lens of the optical system can be controlled, the off-axis aberration of the optical system can be corrected, and at the same time, it is beneficial to size compression to form a small-sized optical system.

[0020] In one embodiment, the optical system satisfies the conditional formula: 0 < R72 / f < 1, where R72 is the radius of curvature of the image side of the seventh lens at the near optical axis, and f is the focal length of the optical system. By reasonably defining the value of R72 / f, the surface complexity of the seventh lens can be reduced, which is beneficial to suppressing field curvature and distortion, reducing the forming difficulty, improving the overall image quality, and effectively controlling the back focal length of the system to avoid an overly long overall system length.

[0021] In one embodiment, the optical system satisfies the conditional formula: 0 < Yc72 / SD72 < 0.5, where Yc72 is the perpendicular distance from the off-axis vertex (the vertex is the point where the tangent is made and the tangent is perpendicular to the optical axis) on the image side of the seventh lens to the optical axis, and SD72 is the maximum effective aperture of the image side of the seventh lens in the vertical direction. By limiting the range of Yc72 / SD72, the refractive power and thickness of the seventh lens in the vertical direction can be reasonably controlled, avoiding the seventh lens being too thin or too thick, reducing the incident angle of light on the imaging surface, and reducing the sensitivity of the optical system. In addition, the seventh lens is provided with multiple inflection points, which is beneficial to correcting the distortion and field curvature generated by the first lens to the sixth lens, making the refractive power configuration near the imaging surface more uniform.

[0022] In one embodiment, the optical system satisfies the conditional formula: 0.6 < TTL / (ImgH * 2) < 0.8, where TTL is the distance from the object side of the first lens in the optical system to the imaging surface on the optical axis, and ImgH is the image height corresponding to the maximum field of view angle of the optical system. By limiting the value of TTL / (ImgH * 2) within a small range and through a reasonable structural layout, the feature of miniaturization of the optical system is achieved.

[0023] In one embodiment, the optical system satisfies the conditional formula: 38° < HFOV < 45°, where HFOV is half of the maximum field of view angle of the optical system. By defining the range of HFOV, it is beneficial to the wide-angle shooting of the optical system.

[0024] In one embodiment, the optical system satisfies the conditional formula 0.75 < DL / TTL < 1, where DL is the distance from the object side of the first lens to the image side of the seventh lens on the optical axis, and TTL is the distance from the object side of the first lens to the imaging surface on the optical axis in the optical system. By defining the value of DL / TTL, on the basis of achieving miniaturization, the distance between the seventh lens and the imaging surface is increased, which is beneficial to the reasonable structural layout of the optical system.

[0025] In one embodiment, the optical system satisfies the conditional formula: 1.0 < TTL / f < 1.4, where TTL is the distance from the object side of the first lens to the imaging surface on the optical axis in the optical system, and f is the focal length of the optical system. By reasonably configuring the range of TTL / f, the optical system can have a lower height, making it easy to install the optical system into a portable device. The setting of the aspherical surface makes TTL greater than the focal length f. At the same time, under the condition of achieving wide-angle shooting, it is beneficial to balance aberration such as chromatic aberration, spherical aberration, and distortion, so that the optical system has good imaging quality.

[0026] In one embodiment, the optical system satisfies the conditional formula: 1.5 < FNO < 2.0, where FNO is the f-number of the optical system. By defining the value of FNO, the optical system has the characteristic of a large aperture.

[0027] In a second aspect, the present application provides a camera module, including a photosensitive element and the optical system according to any one of the foregoing embodiments, and the photosensitive element is located on the image side of the optical system.

[0028] In a third aspect, the present application provides a terminal device, including the camera module.

[0029] By reasonably configuring the refractive power of the first lens to the seventh lens in the optical system, the surface types of the first lens, the second lens, the fourth lens, the sixth lens, and the seventh lens, and defining (|SAG71| + SAG72) / CT7, the optical system simultaneously meets the requirements of high pixels, large aperture, and miniaturization. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background art, the following will describe the drawings required to be used in the embodiments of the present application or the background art.

[0031] Figure 1is a schematic structural diagram of an optical system provided in the first embodiment of the present application;

[0032] Figure 2 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the first embodiment;

[0033] Figure 3 is a schematic structural diagram of an optical system provided in a second embodiment of the present application;

[0034] Figure 4 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the second embodiment;

[0035] Figure 5 is a schematic structural diagram of an optical system provided in the third embodiment of the present application;

[0036] Figure 6 are a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical system of the third embodiment;

[0037] Figure 7 is a schematic structural diagram of an optical system provided in a fourth embodiment of the present application;

[0038] Figure 8 are a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical system of the fourth embodiment;

[0039] Fig. 9 is a schematic structural diagram of an optical system provided in a fifth embodiment of the present application;

[0040] Fig.10 are a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical system of the fifth embodiment;

[0041] Fig.11 It is a schematic diagram of the optical system provided by the present application applied in a terminal device. DETAILED DESCRIPTION

[0042] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0043] The present application provides an optical system including seven lenses, which are arranged in order from the object side to the image side as a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens.

[0044] Specifically, the surface shapes and refractive powers of the seven lenses are as follows:

[0045] The first lens has positive refractive power, the object side surface of the first lens is convex at the near optical axis, and the image side surface of the first lens is concave at the near optical axis; the second lens has negative refractive power, the object side surface of the second lens is convex at the near optical axis, and the image side surface of the second lens is concave at the near optical axis; the third lens has negative refractive power; the fourth lens has positive refractive power; the image side surface of the fourth lens is convex at the near optical axis; the fifth lens has negative refractive power; the sixth lens has positive refractive power, the object side surface of the sixth lens is convex at the near optical axis, and the image side surface of the sixth lens is convex at the near optical axis; the seventh lens has negative refractive power, the object side surface of the seventh lens is convex at the near optical axis, and the image side surface of the seventh lens is concave at the near optical axis.

[0046] The optical system satisfies the following condition: 1<(|SAG71|+SAG72) / CT7<1.5, SAG71 is the maximum distance from an off-axis point within the effective diameter of the object side surface of the seventh lens to the on-axis vertex of the object side surface of the seventh lens on the optical axis, SAG72 is the maximum distance from an off-axis point within the effective diameter of the image side surface of the seventh lens to the on-axis vertex of the image side surface of the seventh lens on the optical axis, and CT7 is the thickness of the seventh lens on the optical axis.

[0047] By reasonably configuring the refractive powers of the first lens to the seventh lens in the optical system and the surface shapes of the first lens, the second lens, the fourth lens, the sixth lens and the seventh lens and limiting (|SAG71|+SAG72) / CT7, the optical system can simultaneously meet the requirements of high pixel, large aperture and miniaturization.

[0048] Specifically, by limiting the range of (|SAG71|+SAG72) / CT7, the refractive power and thickness of the seventh lens in the vertical direction can be reasonably controlled to avoid the seventh lens being too thin or too thick, reduce the incident angle of light on the imaging surface, and reduce the sensitivity of the optical system. In addition, the seventh lens is provided with multiple inflection points, which is conducive to correcting the distortion and field curvature generated by the first lens to the sixth lens, so that the refractive power configuration close to the imaging surface is more uniform.

[0049] In one embodiment, the object side surface or the image side surface of at least one of the lenses is aspherical, which is beneficial to correcting the aberration of the optical system and improving the imaging quality of the optical system.

[0050] In one embodiment, the optical system satisfies the condition: f1>0mm, where f1 is the focal length of the first lens. The first lens has positive refractive power and converges the light beam. By limiting the value of f1, light beams with large angles enter the first lens and can better converge the light beams.

[0051] In one embodiment, the optical system satisfies the condition: |V2-V1|>30, V2 is the Abbe number of the second lens, V1 is the Abbe number of the first lens, and the reference wavelength of the Abbe number is 587.6nm. By limiting the value of |V2-V1|, it is beneficial to correct chromatic aberration and improve imaging quality.

[0052] In one embodiment, the optical system satisfies the condition: 0.5 mm -1 <(n1+n2) / f<1mm -1 , n1 is the refractive index of the first lens, n2 is the refractive index of the second lens, the reference wavelength of the refractive index is 587.6nm, and f is the focal length of the optical system. By properly configuring the refractive power of the first lens and the second lens, chromatic aberration and spherical aberration can be minimized, image quality can be improved, and by properly allocating the focal power, the light-collecting ability of the optical system can be enhanced, and at the same time, the size of the optical system can be compressed.

[0053] In one embodiment, the optical system satisfies the condition: f23 < 0 mm, where f23 is the combined focal length of the second lens and the third lens. By limiting the value of f23, it is beneficial to correct aberrations and effectively converge marginal light, while ensuring the compact structure of the optical system, effectively compressing the size, and achieving wide-angle and miniaturization characteristics.

[0054] In one embodiment, the optical system satisfies the condition: 0<(CT1+CT2+CT3) / TTL<0.5, CT1 is the thickness of the first lens on the optical axis, CT2 is the thickness of the second lens on the optical axis, CT3 is the thickness of the third lens on the optical axis, and TTL is the distance from the object side of the first lens to the imaging surface on the optical axis in the optical system. By limiting the range of (CT1+CT2+CT3) / TTL and rationally configuring the thickness of the first lens, the second lens, and the third lens, it is beneficial to reduce the sensitivity of the optical system and facilitate the miniaturization of the optical system.

[0055] In one embodiment, the optical system satisfies the condition: (|f2|+|f3|) / |R71|>50, f2 is the focal length of the second lens, f3 is the focal length of the third lens, and R71 is the radius of curvature of the object side of the seventh lens at the optical axis. By limiting the range of (|f2|+|f3|) / |R71| and rationally configuring the refractive power of the second lens and the third lens, it is helpful to reduce the comprehensive spherical aberration, chromatic aberration, and distortion of the first lens, the second lens, and the third lens to a reasonable position, and reduce the design difficulty of the fourth lens, the fifth lens, the sixth lens, and the seventh lens; at the same time, through the rational allocation of the radius of curvature of the seventh lens, the light collecting ability of the system can be enhanced, and the performance of the optical system can be improved.

[0056] In one embodiment, the optical system satisfies the conditional formula: (f1 + |f2| + |f3|) / f > 40, where f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, and f is the focal length of the optical system. By reasonably configuring the sizes and refractive powers of the first lens, the second lens, and the third lens, large spherical aberration generated by the first lens, the second lens, and the third lens can be avoided, the overall resolution of the optical system can be improved. At the same time, it is beneficial to compress the sizes of the first lens, the second lens, and the third lens, which helps to form a small-sized optical system.

[0057] In one embodiment, the optical system satisfies the conditional formula: R62 / f < -1, where R62 is the curvature radius of the image side surface of the sixth lens on the optical axis, and f is the focal length of the optical system. By reasonably defining the value of R62 / f, the surface type complexity of the sixth lens can be reduced, which is beneficial to suppressing field curvature and distortion, reducing the forming difficulty, improving the overall image quality, and at the same time, the back focal length of the system can be effectively controlled to avoid the overall length of the system being too long.

[0058] In one embodiment, the optical system satisfies the conditional formula: |f6| + |f7| < 20 mm, where f6 is the focal length of the sixth lens and f7 is the focal length of the seventh lens. By reasonably configuring the sizes and refractive powers of the sixth lens and the seventh lens and defining the value of |f6| + |f7|, the spherical aberration generated by the first lens to the fifth lens can be balanced, the overall resolution of the optical system can be improved, the configuration of the refractive powers of the sixth lens and the seventh lens of the optical system can be controlled, the aberration around the optical system can be corrected, and at the same time, it is beneficial to size compression to form a small-sized optical system.

[0059] In one embodiment, the optical system satisfies the conditional formula: 0 < R72 / f < 1, where R72 is the curvature radius of the image side surface of the seventh lens near the optical axis, and f is the focal length of the optical system. By reasonably defining the value of R72 / f, the surface type complexity of the seventh lens can be reduced, which is beneficial to suppressing field curvature and distortion, reducing the forming difficulty, improving the overall image quality, and at the same time, the back focal length of the system can be effectively controlled to avoid the overall length of the system being too long.

[0060] In one embodiment, the optical system satisfies the conditional formula: 0 < Yc72 / SD72 < 0.5, where Yc72 is the perpendicular distance from the off-axis vertex on the image side of the seventh lens to the optical axis, and SD72 is the maximum effective aperture of the image side of the seventh lens in the vertical direction. By limiting the range of Yc72 / SD72, the refractive power and thickness of the seventh lens in the vertical direction can be reasonably controlled, avoiding the seventh lens being too thin or too thick, reducing the incident angle of light on the imaging surface, and lowering the sensitivity of the optical system. In addition, the seventh lens is provided with multiple inflection points, which is beneficial to correcting the distortion and field curvature generated by the first lens to the sixth lens, and making the refractive power configuration near the imaging surface more uniform.

[0061] In one embodiment, the optical system satisfies the conditional formula: 0.6 < TTL / (ImgH*2) < 0.8, where TTL is the distance from the object side of the first lens in the optical system to the imaging surface on the optical axis, and ImgH is the image height corresponding to the maximum field of view angle of the optical system. By limiting the value of TTL / (ImgH*2) within a small range and through a reasonable structural layout, the feature of miniaturization of the optical system is achieved.

[0062] In one embodiment, the optical system satisfies the conditional formula: 38° < HFOV < 45°, where HFOV is half of the maximum field of view angle of the optical system. By limiting the range of HFOV, it is beneficial for wide-angle shooting of the optical system.

[0063] In one embodiment, the optical system satisfies the conditional formula 0.75 < DL / TTL < 1, where DL is the distance from the object side of the first lens to the image side of the seventh lens on the optical axis, and TTL is the distance from the object side of the first lens in the optical system to the imaging surface on the optical axis. By limiting the value of DL / TTL, on the basis of achieving miniaturization, the distance between the seventh lens and the imaging surface is increased, which is beneficial for a reasonable structural layout of the optical system.

[0064] In one embodiment, the optical system satisfies the conditional formula: 1.0 < TTL / f < 1.4, where TTL is the distance from the object side of the first lens in the optical system to the imaging surface on the optical axis, and f is the focal length of the optical system. By reasonably configuring the range of TTL / f, the optical system can have a lower height, making it easy to install the optical system into a portable device. The setting of the aspherical surface makes TTL greater than the focal length f. At the same time, under the condition of achieving wide-angle shooting, it is beneficial to balance aberrations such as chromatic aberration, spherical aberration, and distortion, making the optical system have good imaging quality.

[0065] In one embodiment, the optical system satisfies the conditional formula: 1.5 < FNO < 2.0, where FNO is the f-number of the optical system. By limiting the value of FNO, the optical system has the feature of a large aperture.

[0066] The present application is described in detail below through five specific embodiments.

[0067] Embodiment 1

[0068] like Figure 1 As shown, the straight line 11 represents the optical axis, the side of the first lens L1 away from the second lens L2 is the object side 12, and the side of the seventh lens L7 away from the sixth lens L6 is the image side 13. In the optical system provided by this embodiment, from the object side 12 to the image side 13 are the aperture STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the infrared filter element IRCF.

[0069] The first lens L1 has positive refractive power and is made of plastic. Its object side surface S1 is convex at the near optical axis and at the circumference, and its image side surface S2 is concave at the near optical axis and convex at the circumference, and both are aspherical.

[0070] The second lens L2 has negative refractive power and is made of plastic. Its object-side surface S3 is convex near the optical axis and at the circumference, and its image-side surface S4 is concave near the optical axis and at the circumference, and both are aspherical.

[0071] The third lens L3 has negative refractive power and is made of plastic. Its object-side surface S5 is convex at the near optical axis and concave at the circumference. Its image-side surface S6 is concave at the near optical axis and convex at the circumference, and all are aspherical.

[0072] The fourth lens L4 has positive refractive power and is made of plastic. Its object-side surface S7 is concave at the near optical axis and convex at the circumference. Its image-side surface S8 is convex at the near optical axis and at the circumference, and both are aspherical.

[0073] The fifth lens L5 has negative refractive power and is made of plastic. Its object-side surface S9 is convex at the near optical axis and concave at the circumference. Its image-side surface S10 is concave at the near optical axis and convex at the circumference, and both are aspherical.

[0074] The sixth lens L6 has positive refractive power and is made of plastic. Its object-side surface S11 is convex near the optical axis and concave at the circumference. Its image-side surface S12 is convex near the optical axis and at the circumference, and both are aspherical.

[0075] The seventh lens L7 has negative refractive power and is made of plastic. Its object-side surface S13 is convex at the near optical axis and concave at the circumference. Its image-side surface S14 is concave at the near optical axis and convex at the circumference, and both are aspherical.

[0076] The stop STO may be located on the object side of the first lens L1 or between any two adjacent lenses. In this embodiment, the stop STO is disposed on the object side of the first lens L1.

[0077] The infrared filter element IRCF is arranged after the seventh lens L7, and includes an object-side surface S15 and an image-side surface S16. The infrared filter element IRCF is used to filter out infrared light so that the light incident on the imaging surface is visible light. The wavelength of visible light is 380nm-780nm. The material of the infrared filter element IRCF is glass.

[0078] The imaging plane S17 is the plane where the image of the object is formed after the light passes through the optical system.

[0079] Table 1a shows the characteristics of the optical system of this embodiment, wherein the curvature radius in this embodiment is the curvature radius of each lens at the near optical axis.

[0080] Table 1a

[0081]

[0082]

[0083] Wherein, f is the focal length of the optical system, FNO is the aperture number of the optical system, FOV is the maximum field of view of the optical system, TTL is the distance from the object side of the first lens to the imaging plane of the optical system on the optical axis, ImgH is the image height corresponding to the maximum field of view of the optical system, and DL is the distance from the object side of the first lens to the image side of the seventh lens on the optical axis.

[0084] In addition, the combined focal length f23 of the second lens L2 and the third lens L3 is -13.0277 mm, the combined focal length f34 of the third lens L3 and the fourth lens L4 is 31.7286 mm, the combined focal length f45 of the fourth lens L4 and the fifth lens L5 is 31.5062 mm, the combined focal length f56 of the fifth lens L5 and the sixth lens L6 is 9.1374 mm, and the combined focal length f67 of the sixth lens L6 and the seventh lens L7 is -11.1171 mm.

[0085] In this embodiment, the object side surface or the image side surface of at least one of the first lens L1 to the seventh lens L7 is an aspherical surface, and the surface shape of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0086]

[0087] Among them, Z is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, 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 cone constant, and Ai is the coefficient corresponding to the i-th high-order term in the aspherical surface shape formula.

[0088] Table 1b gives the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for each aspherical mirror surface S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14 in the first embodiment.

[0089] Table 1b

[0090]

[0091]

[0092] Figure 2 The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the first embodiment are shown. Among them, the longitudinal spherical aberration curve represents the deviation of light rays of different wavelengths from the focal point after passing through the lenses of the optical system, and the reference wavelengths of the longitudinal spherical aberration curve are 650.0000nm, 610.0000nm, 555.0000nm, 510.0000nm and 470.0000nm; the astigmatism curve represents the meridional image curvature and the sagittal image curvature, wherein S represents the sagittal direction, T represents the meridional direction, and the reference wavelength of the astigmatism curve is 555.0000nm; the distortion curve represents the distortion magnitude values ​​corresponding to different field angles, and the reference wavelength of the distortion curve is 555.0000nm. According to Figure 2 It can be seen that the optical system provided in the first embodiment can achieve good imaging quality.

[0093] Embodiment 2

[0094] like Figure 3 As shown, the straight line 11 represents the optical axis, the side of the first lens L1 away from the second lens L2 is the object side 12, and the side of the seventh lens L7 away from the sixth lens L6 is the image side 13. In the optical system provided by this embodiment, from the object side 12 to the image side 13 are the aperture STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the infrared filter element IRCF.

[0095] The first lens L1 has positive refractive power and is made of plastic. Its object side surface S1 is convex at the near optical axis and at the circumference, and its image side surface S2 is concave at the near optical axis and convex at the circumference, and both are aspherical.

[0096] The second lens L2 has negative refractive power and is made of plastic. Its object-side surface S3 is convex near the optical axis and at the circumference, and its image-side surface S4 is concave near the optical axis and at the circumference, and both are aspherical.

[0097] The third lens L3 has negative refractive power and is made of plastic. Its object-side surface S5 is concave near the optical axis and at the circumference, and its image-side surface S6 is convex near the optical axis and at the circumference, and both are aspherical.

[0098] The fourth lens L4 has positive refractive power and is made of plastic. Its object-side surface S7 is concave at the near optical axis and convex at the circumference. Its image-side surface S8 is convex at the near optical axis and at the circumference, and both are aspherical.

[0099] The fifth lens L5 has negative refractive power and is made of plastic. Its object-side surface S9 is convex at the near optical axis and concave at the circumference. Its image-side surface S10 is concave at the near optical axis and convex at the circumference, and both are aspherical.

[0100] The sixth lens L6 has positive refractive power and is made of plastic. Its object-side surface S11 is convex near the optical axis and concave at the circumference. Its image-side surface S12 is convex near the optical axis and at the circumference, and both are aspherical.

[0101] The seventh lens L7 has negative refractive power and is made of plastic. Its object-side surface S13 is convex at the near optical axis and concave at the circumference. Its image-side surface S14 is concave at the near optical axis and convex at the circumference, and both are aspherical.

[0102] The stop STO may be located on the object side of the first lens L1 or between any two adjacent lenses. In this embodiment, the stop STO is disposed on the object side of the first lens L1.

[0103] The infrared filter element IRCF is arranged after the seventh lens L7, and includes an object-side surface S15 and an image-side surface S16. The infrared filter element IRCF is used to filter out infrared light so that the light incident on the imaging surface is visible light. The wavelength of visible light is 380nm-780nm. The material of the infrared filter element IRCF is glass.

[0104] The imaging plane S17 is the plane where the image of the object is formed after the light passes through the optical system.

[0105] Table 2a shows the characteristic table of the optical system of this embodiment, wherein the curvature radius in this embodiment is the curvature radius of each lens at the near optical axis.

[0106] Table 2a

[0107]

[0108]

[0109] Wherein, f is the focal length of the optical system, FNO is the aperture number of the optical system, FOV is the maximum field of view of the optical system, TTL is the distance from the object side of the first lens to the imaging plane of the optical system on the optical axis, ImgH is the image height corresponding to the maximum field of view of the optical system, and DL is the distance from the object side of the first lens to the image side of the seventh lens on the optical axis.

[0110] In addition, the combined focal length f23 of the second lens L2 and the third lens L3 is -16.4058 mm, the combined focal length f34 of the third lens L3 and the fourth lens L4 is 22.9984 mm, the combined focal length f45 of the fourth lens L4 and the fifth lens L5 is 24.1886 mm, the combined focal length f56 of the fifth lens L5 and the sixth lens L6 is 9.2549 mm, and the combined focal length f67 of the sixth lens L6 and the seventh lens L7 is -11.4932 mm.

[0111] Table 2b gives the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for each aspherical mirror surface S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14 in the second embodiment, wherein the surface shape of each aspherical surface can be defined by the formula given in the first embodiment.

[0112] Table 2b

[0113]

[0114]

[0115] Figure 4The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the second embodiment are shown. Among them, the longitudinal spherical aberration curve represents the deviation of light rays of different wavelengths from the focal point after passing through the lenses of the optical system, and the reference wavelengths of the longitudinal spherical aberration curve are 650.0000nm, 610.0000nm, 555.0000nm, 510.0000nm and 470.0000nm; the astigmatism curve represents the meridional image curvature and the sagittal image curvature, wherein S represents the sagittal direction, T represents the meridional direction, and the reference wavelength of the astigmatism curve is 555.0000nm; the distortion curve represents the distortion magnitude values ​​corresponding to different field angles, and the reference wavelength of the distortion curve is 555.0000nm. According to Figure 4 It can be seen that the optical system provided in the second embodiment can achieve good imaging quality.

[0116] Embodiment 3

[0117] like Figure 5 As shown, the straight line 11 represents the optical axis, the side of the first lens L1 away from the second lens L2 is the object side 12, and the side of the seventh lens L7 away from the sixth lens L6 is the image side 13. In the optical system provided by this embodiment, from the object side 12 to the image side 13 are the aperture STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the infrared filter element IRCF.

[0118] The first lens L1 has positive refractive power and is made of plastic. Its object-side surface S1 is convex near the optical axis and at the circumference, and its image-side surface S2 is concave near the optical axis and at the circumference, and both are aspherical.

[0119] The second lens L2 has negative refractive power and is made of plastic. Its object-side surface S3 is convex near the optical axis and at the circumference, and its image-side surface S4 is concave near the optical axis and at the circumference, and both are aspherical.

[0120] The third lens L3 has negative refractive power and is made of plastic. Its object-side surface S5 is concave near the optical axis and at the circumference, and its image-side surface S6 is convex near the optical axis and at the circumference, and both are aspherical.

[0121] The fourth lens L4 has positive refractive power and is made of plastic. Its object-side surface S7 is concave at the near optical axis and convex at the circumference. Its image-side surface S8 is convex at the near optical axis and at the circumference, and both are aspherical.

[0122] The fifth lens L5 has negative refractive power and is made of plastic. Its object-side surface S9 is concave at the near optical axis and at the circumference, its image-side surface S10 is concave at the near optical axis, and its image-side surface S10 is convex at the circumference, and both are aspherical.

[0123] The sixth lens L6 has positive refractive power and is made of plastic. Its object-side surface S11 is convex near the optical axis and concave at the circumference. Its image-side surface S12 is convex near the optical axis and at the circumference, and both are aspherical.

[0124] The seventh lens L7 has negative refractive power and is made of plastic. Its object-side surface S13 is convex at the near optical axis and at the circumference, its image-side surface S14 is concave at the near optical axis, and its image-side surface S14 is convex at the circumference, and both are aspherical.

[0125] The stop STO may be located on the object side of the first lens L1 or between any two adjacent lenses. In this embodiment, the stop STO is disposed on the object side of the first lens L1.

[0126] The infrared filter element IRCF is arranged after the seventh lens L7, and includes an object-side surface S15 and an image-side surface S16. The infrared filter element IRCF is used to filter out infrared light so that the light incident on the imaging surface is visible light. The wavelength of visible light is 380nm-780nm. The material of the infrared filter element IRCF is glass.

[0127] The imaging plane S17 is the plane where the image of the object is formed after the light passes through the optical system.

[0128] Table 3a shows the characteristic table of the optical system of this embodiment, wherein the curvature radius in this embodiment is the curvature radius of each lens at the near optical axis.

[0129] Table 3a

[0130]

[0131] Wherein, f is the focal length of the optical system, FNO is the aperture number of the optical system, FOV is the maximum field of view of the optical system, TTL is the distance from the object side of the first lens to the imaging plane of the optical system on the optical axis, ImgH is the image height corresponding to the maximum field of view of the optical system, and DL is the distance from the object side of the first lens to the image side of the seventh lens on the optical axis.

[0132] In addition, the combined focal length f23 of the second lens L2 and the third lens L3 is -36.5896 mm, the combined focal length f34 of the third lens L3 and the fourth lens L4 is 21.1467 mm, the combined focal length f45 of the fourth lens L4 and the fifth lens L5 is 25.0957 mm, the combined focal length f56 of the fifth lens L5 and the sixth lens L6 is 8.5989 mm, and the combined focal length f67 of the sixth lens L6 and the seventh lens L7 is -152.8332 mm.

[0133] Table 3b gives the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for each aspherical mirror surface S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14 in the third embodiment, wherein the surface shape of each aspherical surface can be defined by the formula given in the first embodiment.

[0134] Table 3b

[0135]

[0136]

[0137] Figure 6 The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the third embodiment are shown. Among them, the longitudinal spherical aberration curve represents the deviation of light rays of different wavelengths from the focal point after passing through the lenses of the optical system, and the reference wavelengths of the longitudinal spherical aberration curve are 650.0000nm, 610.0000nm, 555.0000nm, 510.0000nm and 470.0000nm; the astigmatism curve represents the meridional image curvature and the sagittal image curvature, wherein S represents the sagittal direction, T represents the meridional direction, and the reference wavelength of the astigmatism curve is 555.0000nm; the distortion curve represents the distortion magnitude values ​​corresponding to different field angles, and the reference wavelength of the distortion curve is 555.0000nm. According to Figure 6 It can be seen that the optical system provided in the third embodiment can achieve good imaging quality.

[0138] Embodiment 4

[0139] like Figure 7 As shown, the straight line 11 represents the optical axis, the side of the first lens L1 away from the second lens L2 is the object side 12, and the side of the seventh lens L7 away from the sixth lens L6 is the image side 13. In the optical system provided by this embodiment, from the object side 12 to the image side 13 are the aperture STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the infrared filter element IRCF.

[0140] The first lens L1 has positive refractive power and is made of plastic. Its object-side surface S1 is convex near the optical axis and at the circumference, and its image-side surface S2 is concave near the optical axis and at the circumference, and both are aspherical.

[0141] The second lens L2 has negative refractive power and is made of plastic. Its object-side surface S3 is convex near the optical axis and at the circumference, and its image-side surface S4 is concave near the optical axis and at the circumference, and both are aspherical.

[0142] The third lens L3 has negative refractive power and is made of plastic. Its object-side surface S5 is concave near the optical axis and at the circumference, and its image-side surface S6 is convex near the optical axis and at the circumference, and both are aspherical.

[0143] The fourth lens L4 has positive refractive power and is made of plastic. Its object-side surface S7 is convex near the optical axis and at the circumference, and its image-side surface S8 is convex near the optical axis and at the circumference, and both are aspherical.

[0144] The fifth lens L5 has negative refractive power and is made of plastic. Its object-side surface S9 is concave near the optical axis and at the circumference, and its image-side surface S10 is convex near the optical axis and at the circumference, and both are aspherical.

[0145] The sixth lens L6 has positive refractive power and is made of plastic. Its object-side surface S11 is convex near the optical axis and concave at the circumference. Its image-side surface S12 is convex near the optical axis and at the circumference, and both are aspherical.

[0146] The seventh lens L7 has negative refractive power and is made of plastic. Its object-side surface S13 is convex at the near optical axis and at the circumference, its image-side surface S14 is concave at the near optical axis, and its image-side surface S14 is convex at the circumference, and both are aspherical.

[0147] The stop STO may be located on the object side of the first lens L1 or between any two adjacent lenses. In this embodiment, the stop STO is disposed on the object side of the first lens L1.

[0148] The infrared filter element IRCF is arranged after the seventh lens L7, and includes an object-side surface S15 and an image-side surface S16. The infrared filter element IRCF is used to filter out infrared light so that the light incident on the imaging surface is visible light. The wavelength of visible light is 380nm-780nm. The material of the infrared filter element IRCF is glass.

[0149] The imaging plane S17 is the plane where the image of the object is formed after the light passes through the optical system.

[0150] Table 4a shows a characteristic table of the optical system of this embodiment, wherein the curvature radius in this embodiment is the curvature radius of each lens at the near optical axis.

[0151] Table 4a

[0152]

[0153] Wherein, f is the focal length of the optical system, FNO is the aperture number of the optical system, FOV is the maximum field of view of the optical system, TTL is the distance from the object side of the first lens to the imaging plane of the optical system on the optical axis, ImgH is the image height corresponding to the maximum field of view of the optical system, and DL is the distance from the object side of the first lens to the image side of the seventh lens on the optical axis.

[0154] In addition, the combined focal length f23 of the second lens L2 and the third lens L3 is -30.1658 mm, the combined focal length f34 of the third lens L3 and the fourth lens L4 is 17.6302 mm, the combined focal length f45 of the fourth lens L4 and the fifth lens L5 is 18.1426 mm, the combined focal length f56 of the fifth lens L5 and the sixth lens L6 is 8.1268 mm, and the combined focal length f67 of the sixth lens L6 and the seventh lens L7 is -244.9808 mm.

[0155] Table 4b gives the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for each aspheric mirror surface S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14 in the fourth embodiment, wherein the surface shape of each aspheric surface can be defined by the formula given in the first embodiment.

[0156] Table 4b

[0157] Surface number S1 S2 S3 S4 S5 S6 S7 K -1.946762 -5.039056 -3.888751 -1.266274 9.730845 99.000000 -64.771018 A4 0.025175 -0.046124 -0.077520 -0.018792 0.013185 0.197091 0.197585 A6 0.094386 -0.052766 -0.000907 -0.081239 -0.315486 -1.114911 -1.043923 A8 -0.341832 0.242378 0.119436 0.377392 1.149037 3.384806 3.080814 A10 0.761346 -0.390268 -0.026577 -0.724435 -3.587910 -7.381096 -6.525620 A12 -1.062680 0.270728 -0.384378 0.758841 7.832948 11.108539 9.472838 A14 0.925466 0.040752 0.782197 -0.331925 -11.297375 -11.303890 -9.152680 A16 -0.486134 -0.193541 -0.696603 -0.085012 10.043239 7.392438 5.605423 A18 0.139966 0.113759 0.298893 0.139834 -4.928034 -2.760003 -1.944336 A20 -0.016938 -0.021804 -0.049945 -0.037148 1.018658 0.440555 0.288061 Surface number S8 S9 S10 S11 S12 S13 S14 K 40.446062 -72.844991 46.423703 -9.218948 4.187265 -10.044293 -4.682547 A4 0.049568 0.029300 0.083022 0.231055 0.044518 -0.269155 -0.140513 A6 -0.393128 -0.343974 -0.537462 -0.435365 0.181046 0.186263 0.080071 A8 1.064620 0.736987 0.981506 0.507870 -0.305988 -0.119907 -0.035900 A10 -2.180842 -1.114439 -1.160175 -0.466691 0.216356 0.056239 0.009707 A12 3.043992 1.159981 0.912873 0.292349 -0.088786 -0.016414 -0.001338 A14 -2.810867 -0.833615 -0.463049 -0.117242 0.022421 0.002936 0.000046 A16 1.654883 0.403240 0.144431 0.028525 -0.003409 -0.000316 0.000010 A18 -0.566844 -0.119575 -0.025124 -0.003804 0.000285 0.000019 -0.000001 A20 0.086893 0.016284 0.001863 0.000212 -0.000010 0.000000 0.000000

[0158] Figure 8 The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the fourth embodiment are shown. Among them, the longitudinal spherical aberration curve represents the deviation of light rays of different wavelengths from the focal point after passing through the lenses of the optical system, and the reference wavelengths of the longitudinal spherical aberration curve are 650.0000nm, 610.0000nm, 555.0000nm, 510.0000nm and 470.0000nm; the astigmatism curve represents the meridional image curvature and the sagittal image curvature, wherein S represents the sagittal direction, T represents the meridional direction, and the reference wavelength of the astigmatism curve is 555.0000nm; the distortion curve represents the distortion magnitude values ​​corresponding to different field angles, and the reference wavelength of the distortion curve is 555.0000nm. According to Figure 8 It can be seen that the optical system provided in the fourth embodiment can achieve good imaging quality.

[0159] Embodiment 5

[0160] like Fig. 9As shown, the straight line 11 represents the optical axis, the side of the first lens L1 away from the second lens L2 is the object side 12, and the side of the seventh lens L7 away from the sixth lens L6 is the image side 13. In the optical system provided by this embodiment, from the object side 12 to the image side 13 are the aperture STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the infrared filter element IRCF.

[0161] The first lens L1 has positive refractive power and is made of plastic. Its object side surface S1 is convex at the near optical axis and at the circumference, and its image side surface S2 is concave at the near optical axis and convex at the circumference, and both are aspherical.

[0162] The second lens L2 has negative refractive power and is made of plastic. Its object-side surface S3 is convex near the optical axis and at the circumference, and its image-side surface S4 is concave near the optical axis and at the circumference, and both are aspherical.

[0163] The third lens L3 has negative refractive power and is made of plastic. Its object-side surface S5 is concave near the optical axis and at the circumference, and its image-side surface S6 is convex near the optical axis and at the circumference, and both are aspherical.

[0164] The fourth lens L4 has positive refractive power and is made of plastic. Its object-side surface S7 is convex near the optical axis and at the circumference, and its image-side surface S8 is convex near the optical axis and at the circumference, and both are aspherical.

[0165] The fifth lens L5 has negative refractive power and is made of plastic. Its object-side surface S9 is concave near the optical axis and at the circumference, and its image-side surface S10 is convex near the optical axis and at the circumference, and both are aspherical.

[0166] The sixth lens L6 has positive refractive power and is made of plastic. Its object-side surface S11 is convex near the optical axis and concave at the circumference. Its image-side surface S12 is convex near the optical axis and at the circumference, and both are aspherical.

[0167] The seventh lens L7 has negative refractive power and is made of plastic. Its object-side surface S13 is convex at the near optical axis and concave at the circumference. Its image-side surface S14 is concave at the near optical axis and convex at the circumference, and both are aspherical.

[0168] The stop STO may be located on the object side of the first lens L1 or between any two adjacent lenses. In this embodiment, the stop STO is disposed on the object side of the first lens L1.

[0169] The infrared filter element IRCF is arranged after the seventh lens L7, and includes an object-side surface S15 and an image-side surface S16. The infrared filter element IRCF is used to filter out infrared light so that the light incident on the imaging surface is visible light. The wavelength of visible light is 380nm-780nm. The material of the infrared filter element IRCF is glass.

[0170] The imaging plane S17 is the plane where the image of the object is formed after the light passes through the optical system.

[0171] Table 5a shows a characteristic table of the optical system of this embodiment, wherein the curvature radius in this embodiment is the curvature radius of each lens at the near optical axis.

[0172] Table 5a

[0173]

[0174] Wherein, f is the focal length of the optical system, FNO is the aperture number of the optical system, FOV is the maximum field of view of the optical system, TTL is the distance from the object side of the first lens to the imaging plane of the optical system on the optical axis, ImgH is the image height corresponding to the maximum field of view of the optical system, and DL is the distance from the object side of the first lens to the image side of the seventh lens on the optical axis.

[0175] In addition, the combined focal length f23 of the second lens L2 and the third lens L3 is -15.1853 mm, the combined focal length f34 of the third lens L3 and the fourth lens L4 is 18.8297 mm, the combined focal length f45 of the fourth lens L4 and the fifth lens L5 is 24.4426 mm, the combined focal length f56 of the fifth lens L5 and the sixth lens L6 is 10.3997 mm, and the combined focal length f67 of the sixth lens L6 and the seventh lens L7 is -12.1354 mm.

[0176] Table 5b gives the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 of the aspheric mirror surfaces S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14 that can be used in the fifth embodiment, wherein the surface shape of each aspheric surface can be defined by the formula given in the first embodiment.

[0177] Table 5b

[0178] Surface number S1 S2 S3 S4 S5 S6 S7 K -1.915846 -3.700589 -2.588220 -1.250820 67.168094 -99.000000 -99.000000 A4 0.035690 -0.071202 -0.107434 -0.046278 -0.010057 0.193081 0.220462 A6 0.023102 0.057315 0.079462 0.030038 -0.138076 -1.150631 -1.177774 A8 -0.089971 -0.023373 0.065563 0.103726 0.391870 3.606371 3.411264 A10 0.207397 0.012742 -0.199675 -0.243249 -0.990386 -7.872540 -6.761098 A12 -0.293175 -0.051827 0.230593 0.302708 1.720711 11.481440 8.859194 A14 0.255478 0.080741 -0.164282 -0.280613 -2.081043 -11.034070 -7.563974 A16 -0.134167 -0.059557 0.085731 0.210992 1.623454 6.731774 4.082286 A18 0.038643 0.021433 -0.031237 -0.102219 -0.702133 -2.342824 -1.261846 A20 -0.004711 -0.003027 0.005611 0.023207 0.125291 0.349897 0.169207 Surface number S8 S9 S10 S11 S12 S13 S14 K 25.677174 99.000000 -43.428575 -11.459383 -1.239310 -11.239435 -4.955623 A4 0.005216 0.028787 0.080638 0.218404 0.130750 -0.257906 -0.128621 A6 -0.131826 -0.497339 -0.500657 -0.389995 -0.035149 0.184781 0.074485 A8 0.121249 1.263947 0.831122 0.397090 -0.066405 -0.120371 -0.033241 A10 0.147628 -2.147374 -0.872801 -0.319836 0.064578 0.055161 0.008860 A12 -0.585946 2.500140 0.612915 0.184671 -0.029266 -0.015627 -0.001256 A14 0.723954 -1.976111 -0.284820 -0.071756 0.007773 0.002716 0.000065 A16 -0.440568 1.008056 0.084288 0.017469 -0.001216 -0.000284 0.000005 A18 0.127778 -0.298078 -0.014383 -0.002365 0.000103 0.000017 -0.000001 A20 -0.012339 0.038621 0.001073 0.000135 -0.000004 0.000000 0.000000

[0179] Fig.10The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the fifth embodiment are shown. Among them, the longitudinal spherical aberration curve represents the deviation of light rays of different wavelengths from the focal point after passing through the lenses of the optical system, and the reference wavelengths of the longitudinal spherical aberration curve are 650.0000nm, 610.0000nm, 555.0000nm, 510.0000nm and 470.0000nm; the astigmatism curve represents the meridional image curvature and the sagittal image curvature, wherein S represents the sagittal direction, T represents the meridional direction, and the reference wavelength of the astigmatism curve is 555.0000nm; the distortion curve represents the distortion magnitude values ​​corresponding to different field angles, and the reference wavelength of the distortion curve is 555.0000nm. According to Fig.10 It can be seen that the optical system provided in the fifth embodiment can achieve good imaging quality.

[0180] Table 6 shows the values ​​of TTL / (ImgH*2), HFOV, DL / TTL, TTL / f, f1, f23, R72 / f, |f6|+|f7|, |V2-V1|, FNO, (n1+n2) / f, (|f2|+|f3|) / |R71|, (f1+|f2|+|f3|) / f, R62 / f, Yc72 / SD72, (CT1+CT2+CT3) / TTL, and (|SAG71|+SAG72) / CT7 of the optical system of the first to fifth embodiments.

[0181] Table 6

[0182]

[0183] It can be seen from Table 6 that each embodiment can satisfy: 0.6 <TTL / (ImgH*2)<0.8,38°<HFOV<45°,0.75<DL / TTL<1,1.0<TTL / f<1.4,f1>0mm,f23<0mm,0<R72 / f<1,|f6|+|f7|<20mm,|V2-V1|> 30, 1.5<FNO<2.0, 0.5mm -1 <(n1+n2) / f<1mm -1 , (|f2|+|f3|) / |R71|>50, (f1+|f2|+|f3|) / f>40, R62 / f<-1, 0 <Yc72 / SD72<0.5,0<(CT1+CT2+CT3) / TTL<0.5,1<(|SAG71|+SAG72) / CT7<1.5。

[0184] See also Fig.11The optical system involved in the present application is applied to a camera module 20 in a terminal device 30. The terminal device 30 may be a mobile phone, a tablet computer, a drone, a computer, etc. The photosensitive element of the camera module 20 is located on the image side of the optical system, and the camera module 20 is assembled inside the terminal device 30.

[0185] The present application provides a camera module, including a photosensitive element and an optical system provided in an embodiment of the present application, wherein the photosensitive element is located on the image side of the optical system, and is used to convert light passing through the first lens to the seventh lens and incident on the electronic photosensitive element into an electrical signal of an image. The electronic photosensitive element may be a complementary metal oxide semiconductor (CMOS) or a charge-coupled device (CCD). By installing the optical system in the camera module, the camera module can simultaneously meet the requirements of high pixel, large aperture, and miniaturization.

[0186] The present application also provides a terminal device, which includes the camera module provided in the embodiment of the present application. The terminal device can be a mobile phone, a tablet computer, a drone, a computer, etc. By installing the camera module in the terminal device, the terminal device can simultaneously meet the requirements of high pixel, large aperture, and miniaturization.

[0187] The above is a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications are also considered to be within the scope of protection of the present application.

Claims

1. An optical system, characterized in that: There are 7 lenses with refractive power, at least one of the lens has an aspherical surface on the object side or the image side, and the 7 lenses are arranged in order from the object side to the image side: A first lens having positive refractive power, wherein the object side surface of the first lens is convex at the near optical axis, and the image side surface of the first lens is concave at the near optical axis; A second lens having negative refractive power, wherein the object side surface of the second lens is convex at the near optical axis, and the image side surface of the second lens is concave at the near optical axis; The third lens has negative refractive power; a fourth lens element having positive refractive power; the image side surface of the fourth lens element being a convex surface near the optical axis; A fifth lens element having negative refractive power; a sixth lens having positive refractive power, wherein the object side surface of the sixth lens is convex at the near optical axis, and the image side surface of the sixth lens is convex at the near optical axis; The seventh lens has negative refractive power, the object side surface of the seventh lens is convex at the near optical axis, and the image side surface of the seventh lens is concave at the near optical axis; the optical system satisfies the following conditional formula: 1<(|SAG71|+SAG72) / CT7<1.5, SAG71 is the maximum distance from an off-axis point within the effective diameter of the object side surface of the seventh lens to the on-axis vertex of the object side surface of the seventh lens on the optical axis, SAG72 is the maximum distance from an off-axis point within the effective diameter of the image side surface of the seventh lens to the on-axis vertex of the image side surface of the seventh lens on the optical axis, and CT7 is the thickness of the seventh lens on the optical axis.

2. The optical system according to claim 1, characterized in that The optical system satisfies the condition: |V2-V1|>30, V2 is the Abbe number of the second lens, V1 is the Abbe number of the first lens, and the reference wavelength of the Abbe number is 587.6 nm.

3. The optical system according to claim 1, characterized in that The optical system satisfies the condition: 0.5mm -1 <(n1+n2) / f<1mm -1 , n1 is the refractive index of the first lens, n2 is the refractive index of the second lens, the reference wavelength of the refractive index is 587.6 nm, and f is the focal length of the optical system.

4. The optical system according to claim 1, characterized in that The optical system satisfies the condition: f23<0mm, f23 is the combined focal length of the second lens and the third lens.

5. The optical system according to claim 1, characterized in that The optical system satisfies the condition: 0.219840638≤(CT1+CT2+CT3) / TTL<0.5, CT1 is the thickness of the first lens on the optical axis, CT2 is the thickness of the second lens on the optical axis, CT3 is the thickness of the third lens on the optical axis, and TTL is the distance from the object side surface to the imaging surface on the optical axis in the optical system.

6. The optical system according to claim 1, characterized in that The optical system satisfies the condition: (|f2|+|f3|) / |R71|>50, f2 is the focal length of the second lens, f3 is the focal length of the third lens, and R71 is the radius of curvature of the object side of the seventh lens at the optical axis.

7. The optical system according to claim 1, characterized in that The optical system satisfies the condition: (f1+|f2|+|f3|) / f>40, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, and f is the focal length of the optical system.

8. The optical system according to claim 1, characterized in that The optical system satisfies the condition: -3.0091≤R62 / f<-1, R62 is the curvature radius of the image side surface of the sixth lens at the optical axis, and f is the focal length of the optical system.

9. The optical system according to claim 1, characterized in that The optical system satisfies the condition: 12.839429mm≤|f6|+|f7|<20mm, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens.

10. The optical system according to claim 1, characterized in that The optical system satisfies the condition: 0.250039345≤R72 / f<1, R72 is the curvature radius of the image side surface of the seventh lens at the near optical axis, and f is the focal length of the optical system.

11. The optical system according to claim 1, characterized in that The optical system satisfies the condition: 0 <Yc72 / SD72<0.5, Yc72 is the vertical distance from the off-axis vertex on the image side surface of the seventh lens to the optical axis, and SD72 is the maximum effective aperture of the image side surface of the seventh lens in the vertical axis direction.

12. The optical system according to claim 1, characterized in that The optical system satisfies the condition: 0.6 <TTL / (ImgH*2)<0.8, TTL is the distance from the object side surface of the first lens in the optical system to the imaging surface on the optical axis, and ImgH is the image height corresponding to the maximum field angle of the optical system.

13. The optical system according to claim 1, characterized in that The optical system satisfies the condition: 38° <HFOV<45°, HFOV is half of the maximum field of view of the optical system.

14. The optical system according to claim 1, characterized in that The optical system satisfies the condition: 0.75 <DL / TTL≤0.831395349, DL is the distance from the object side surface of the first lens to the image side surface of the seventh lens on the optical axis, and TTL is the distance from the object side surface of the first lens to the imaging surface on the optical axis in the optical system.

15. The optical system according to claim 1, characterized in that The optical system satisfies the condition: 1.0 <TTL / f<1.4, TTL is the distance from the object side surface of the first lens to the imaging surface on the optical axis in the optical system, and f is the focal length of the optical system.

16. The optical system according to claim 1, characterized in that The optical system satisfies the condition: 1.5<FNO<2.0, FNO is the aperture number of the optical system.

17. A camera module, characterized in that: The optical system comprises a photosensitive element and the optical system as claimed in any one of claims 1 to 16, wherein the photosensitive element is located on the image side of the optical system.

18. A terminal device, characterized in that: Comprising the camera module as described in claim 17.

Images