WO2022061904A1 - Optical system, camera module, and terminal device - Google Patents

Abstract

Disclosed in embodiments of the present application are an optical system, a camera module, and a terminal device. The optical system comprises a first lens having positive refractive power, an object side surface of the first lens being convex at a near optical axis, and an image side surface of the first lens being concave at the near optical axis; a second lens, third lens, fifth lens, and seventh lens having negative refractive power; and a fourth lens and sixth lens having positive refractive power. The optical system satisfies that 1<(|SAG71|+SAG72)/CT7<1.5. According to the present application, reasonably setting the refractive power and surface types of the first lens to the seventh lens and defining (|SAG71|+SAG72)/CT7 enable the optical system satisfies all requirements of high pixel, large aperture, and miniaturization.

Description

Optical system, camera module and terminal equipment technical field

The present application belongs to the technical field of optical imaging, and in particular relates to an optical system, a camera module and a terminal device.

Background technique

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

The size of the photographic optical system must be miniaturized under the market trend. In addition to the requirement of miniaturization, the improvement of semiconductor process technology has reduced the size of the pixel of the photosensitive element, so that higher pixel requirements can be achieved. However, at present, it is difficult for imaging devices of electronic devices such as mobile phones to meet the requirements of high pixel, large aperture, and miniaturization at the same time.

Therefore, how to simultaneously realize the miniaturization, large aperture and high pixel imaging quality of the camera lens should be the research and development direction of the industry.

SUMMARY OF THE INVENTION

Embodiments of the present application provide an optical system, a camera module, and a terminal device, and the optical system simultaneously meets the requirements of high pixel, large aperture, and miniaturization.

In a first aspect, an embodiment of the present application provides an optical system, the optical system includes a plurality of lenses, and the plurality of lenses includes from the object side (the object side refers to the side where light enters) to the image side (the image side is Refers to the side where the light exits) the first lenses arranged in sequence have 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 at the near-optical axis. a concave surface; the second lens has a negative refractive power, the object side of the second lens is convex at the near-optical axis, and the image side of the second lens is concave at the near-optical axis; the third lens has a negative refractive index The fourth lens has a positive refractive power; the image side of the fourth lens is convex at the near optical axis; the fifth lens has a negative refractive power; the sixth lens has a positive refractive power, and the sixth lens The object side of the lens is convex at the near optical axis, and the image side of the sixth lens is convex at the near optical axis; the seventh lens has negative refractive power, and the object side of the seventh lens is at the near optical axis. Convex, the image side 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 object of the seventh lens The maximum distance from the off-axis point within the effective radius of the side surface to the on-axis vertex of the object side of the seventh lens on the optical axis, SAG72 is the off-axis point within the effective radius of the image side of the seventh lens to the The maximum distance from the axial vertex of the image side surface of the seven lenses to the optical axis, and CT7 is the thickness of the seventh lens on the optical axis.

Among them, the refractive power is the optical power, which represents the ability of the optical system to deflect light. A positive refractive power means that the lens has a converging effect on the light beam, and a negative refractive power means that the lens has a divergent effect on the light beam. When the lens has no refractive power, that is, when the optical power is zero, it is plane refraction. At this time, the parallel beam along the axis is still a parallel beam along the axis after refraction, and no refractive phenomenon occurs.

This application reasonably configures the refractive power of the first lens to the seventh lens in the optical system and the surface shapes and definitions of the first lens, the second lens, the fourth lens, the sixth lens and the seventh lens (|SAG71|+SAG72) /CT7, making the optical system meet the requirements of high pixel, large aperture and miniaturization at the same time.

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, so as to avoid the seventh lens from being too thin and too thick, and reduce the impact of light on the imaging surface. The angle of incidence reduces the sensitivity of the optical system. In addition, the seventh lens is provided with a plurality of inflection points, which is beneficial to correct the distortion and field curvature generated by the first lens to the sixth lens, so that the configuration of the refractive power close to the imaging surface is relatively uniform.

In one embodiment, the object side or the image side of at least one of the lenses is aspherical, which is beneficial for correcting aberrations of the optical system and improving the imaging quality of the optical system.

In one embodiment, the optical system satisfies the conditional formula: f1>0mm, and f1 is the focal length of the first lens. The first lens has a positive refractive power, which has a converging effect on the light beam. By limiting the value of f1, light with a large angle enters the first lens and can better converge the light.

In an embodiment, the optical system satisfies the conditional formula: |V2-V1|>30, V2 is the Abbe number of the second lens, V1 is the Abbe number of the first lens, and the Abbe The reference wavelength of the number is 587.6 nm. By limiting the value of |V2-V1|, it is beneficial to correct chromatic aberration and improve image quality.

In one embodiment, the optical system satisfies the conditional formula: 0.5mm ^-1 <(n1+n2)/f<1mm ^-1 , n1 is the refractive index of the first lens, and n2 is the refractive index of the second lens. The refractive index, the reference wavelength of the refractive index is 587.6 nm, and f is the focal length of the optical system. By reasonably configuring the refractive power of the first lens and the second lens, the chromatic aberration and spherical aberration can be minimized, and the image quality can be improved. The size of the optical system.

In one embodiment, the optical system satisfies the conditional formula: f23<0mm, 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 is beneficial to the effective convergence of edge light, and at the same time, it can ensure the compact structure of the optical system, effectively compress the size, and realize the characteristics of wide-angle and miniaturization.

In one embodiment, the optical system satisfies the conditional formula: 0<(CT1+CT2+CT3)/TTL<0.5, CT1 is the thickness of the first lens on the optical axis, and CT2 is the thickness of the second lens on the optical axis. The thickness 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 in the optical system to the imaging surface on the optical axis. By limiting the range of (CT1+CT2+CT3)/TTL, the thickness of the first lens, the second lens, and the third lens is reasonably configured, which is beneficial to reduce the sensitivity of the optical system, and at the same time, is beneficial to the miniaturization of the optical system.

In one embodiment, the optical system satisfies the conditional formula: (|f2|+|f3|)/|R71|>50, f2 is the focal length of the second lens, f3 is the focal length of the third lens, 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|, the refractive powers of the second lens and the third lens are reasonably configured, which helps to reduce the comprehensive spherical aberration of the first lens, the second lens and the third lens , chromatic aberration and distortion are reduced to a reasonable position, reducing the design difficulty of the fourth lens, fifth lens, sixth lens and seventh lens; Improve the performance of the optical system.

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, and 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 the 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, it is beneficial to the first lens, the second lens and the third lens The size reduction of the lens, the second lens and the third lens helps to form a small size optical system.

In one embodiment, the optical system satisfies the conditional formula: R62/f<-1, R62 is the radius of curvature of the image side surface of the sixth lens at the optical axis, and f is the focal length of the optical system. By reasonably limiting the value of R62/f, the surface complexity of the sixth lens can be reduced, which is conducive to suppressing field curvature and distortion, reducing the difficulty of forming, and improving the overall image quality. too long.

In one embodiment, the optical system satisfies the conditional formula: |f6|+|f7|<20mm, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens. By reasonably configuring the size and refractive power of the sixth lens and the seventh lens and limiting 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, and the optical system can be controlled. The configuration of the refractive power of the sixth lens and the seventh lens of the system corrects the aberration around the optical system, and at the same time facilitates size compression to form a small-sized optical system.

In one embodiment, the optical system satisfies the conditional formula: 0<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. By reasonably limiting the value of R72/f, the surface complexity of the seventh lens can be reduced, which is conducive to suppressing field curvature and distortion, reducing the difficulty of forming, and improving the overall image quality. too long.

In one embodiment, the optical system satisfies the conditional formula: 0<Yc72/SD72<0.5, and Yc72 is the off-axis vertex on the image side of the seventh lens (the vertex refers to a tangent at this point, and the tangent is vertical. The vertical distance from the point on the optical axis) to the optical axis, SD72 is the maximum effective aperture of the image side surface of the seventh lens in the vertical axis 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 and too thick, reducing the incident angle of light on the imaging plane, and reducing the sensitivity of the optical system. In addition, the seventh lens is provided with a plurality of inflection points, which is beneficial to correct the distortion and field curvature generated by the first lens to the sixth lens, so that the configuration of the refractive power close to the imaging surface is relatively uniform.

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 , ImgH is the image height corresponding to the maximum angle of view of the optical system. The value of TTL/(ImgH*2) is limited within a small range, and through a reasonable structural layout, the characteristics of miniaturization of the optical system are realized.

In one embodiment, the optical system satisfies the conditional formula: 38°<HFOV<45°, and HFOV is half of the maximum angle of view of the optical system. By limiting the range of HFOV, it is beneficial to wide-angle shooting of the optical system.

In one embodiment, the optical system satisfies the conditional formula 0.75<DL/TTL<1, DL is the distance on the optical axis from the object side of the first lens to the image side of the seventh lens, and TTL is the The distance on the optical axis from the object side of the first lens to the imaging plane in the optical system. By limiting the value of DL/TTL, on the basis of realizing 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.

In one embodiment, the optical system satisfies the conditional formula: 1.0<TTL/f<1.4, 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 the focal length of the optical system. By properly configuring the TTL/f range, the optical system can have a lower height, making the optical system easy to install into portable equipment. The setting of the aspheric surface makes the TTL larger than the focal length f. At the same time, under the condition of wide-angle shooting, it is beneficial to balance aberrations such as chromatic aberration, spherical aberration, and distortion, so that the optical system has good imaging quality.

In one embodiment, the optical system satisfies the conditional formula: 1.5<FNO<2.0, where FNO is the aperture number of the optical system. By defining the value of FNO, the optical system has the characteristics of large aperture.

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

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

By rationally configuring the refractive power of the first lens to the seventh lens in the optical system and the surface shape and definition of the first lens, the second lens, the fourth lens, the sixth lens and the seventh lens (|SAG71|+SAG72)/CT7 , so that the optical system can meet the requirements of high pixel, large aperture and miniaturization at the same time.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background technology, the accompanying drawings required in the embodiments or the background technology of the present application will be described below.

1 is a schematic structural diagram of an optical system provided by a first embodiment of the present application;

Fig. 2 is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the first embodiment;

3 is a schematic structural diagram of an optical system provided by a second embodiment of the present application;

Fig. 4 is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the second embodiment;

5 is a schematic structural diagram of an optical system provided by a third embodiment of the present application;

6 is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the optical system of the third embodiment;

7 is a schematic structural diagram of an optical system provided by a fourth embodiment of the present application;

8 is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the optical system of the fourth embodiment;

9 is a schematic structural diagram of an optical system provided by a fifth embodiment of the present application;

10 is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the optical system of the fifth embodiment;

FIG. 11 is a schematic diagram of the application of the optical system provided in the present application in a terminal device.

detailed description

The embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application.

An optical system provided by the present application includes seven lenses, and the seven lenses are sequentially distributed from the object side to the image side as a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. and the seventh lens.

Specifically, the surface shape and refractive power of the seven lenses are as follows:

The first lens has positive refractive power, the object side of the first lens is convex at the near optical axis, the image side of the first lens is concave at the near optical axis; the second lens has negative refractive power, the The object side of the second lens is convex at the near optical axis, and the image side of the second lens is concave at the near optical axis; the third lens has a negative refractive power; the fourth lens has a positive refractive power; the fourth lens has a positive refractive power; The image side of the 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 of the sixth lens is convex at the near optical axis, and the sixth lens has a positive refractive power. The image side is convex at the near optical axis; the seventh lens has negative refractive power, the object side of the seventh lens is convex at the near optical axis, and the image side 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, and SAG71 is the distance from the off-axis point within the effective radius of the object side of the seventh lens to the object side of the seventh lens. The maximum distance from the vertex on the axis to the optical axis, SAG72 is the maximum distance on the optical axis from the off-axis point within the effective diameter of the image side of the seventh lens to the vertex on the axis of the image side of the seventh lens, CT7 is the thickness of the seventh lens on the optical axis.

By rationally configuring the refractive power of the first lens to the seventh lens in the optical system and the surface shape and definition of the first lens, the second lens, the fourth lens, the sixth lens and the seventh lens (|SAG71|+SAG72)/CT7 , so that the optical system can meet the requirements of high pixel, large aperture and miniaturization at the same time.

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, so as to avoid the seventh lens from being too thin and too thick, and reduce the impact of light on the imaging surface. The angle of incidence reduces the sensitivity of the optical system. In addition, the seventh lens is provided with a plurality of inflection points, which is beneficial to correct the distortion and field curvature generated by the first lens to the sixth lens, so that the configuration of the refractive power close to the imaging surface is relatively uniform.

In one embodiment, the object side or image side of at least one of the lenses is aspherical, which is beneficial to correct the aberration of the optical system and improve the imaging quality of the optical system.

In one embodiment, the optical system satisfies the conditional formula: f1>0mm, and f1 is the focal length of the first lens. The first lens has a positive refractive power, which has a converging effect on the light beam. By limiting the value of f1, light with a large angle enters the first lens and can better converge the light.

In an embodiment, the optical system satisfies the conditional formula: |V2-V1|>30, V2 is the Abbe number of the second lens, V1 is the Abbe number of the first lens, and the Abbe The reference wavelength of the number is 587.6 nm. By limiting the value of |V2-V1|, it is beneficial to correct chromatic aberration and improve image quality.

In one embodiment, the optical system satisfies the conditional formula: 0.5mm ^-1 <(n1+n2)/f<1mm ^-1 , n1 is the refractive index of the first lens, and n2 is the refractive index of the second lens. The refractive index, the reference wavelength of the refractive index is 587.6 nm, and f is the focal length of the optical system. By reasonably configuring the refractive power of the first lens and the second lens, chromatic aberration and spherical aberration can be minimized, and image quality can be improved. Through reasonable power distribution, the light-receiving ability of the optical system can be strengthened, and at the same time, it is conducive to compression. The size of the optical system.

In one embodiment, the optical system satisfies the conditional formula: f23<0mm, 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 is beneficial to the effective convergence of edge light, and at the same time, it can ensure the compact structure of the optical system, effectively compress the size, and realize the characteristics of wide-angle and miniaturization.

In one embodiment, the optical system satisfies the conditional formula: 0<(CT1+CT2+CT3)/TTL<0.5, CT1 is the thickness of the first lens on the optical axis, and CT2 is the thickness of the second lens on the optical axis. The thickness 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 in the optical system to the imaging surface on the optical axis. By limiting the range of (CT1+CT2+CT3)/TTL, the thickness of the first lens, the second lens, and the third lens is reasonably configured, which is beneficial to reduce the sensitivity of the optical system, and at the same time, is beneficial to the miniaturization of the optical system.

In one embodiment, the optical system satisfies the conditional formula: (|f2|+|f3|)/|R71|>50, f2 is the focal length of the second lens, f3 is the focal length of the third lens, 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|, the refractive powers of the second lens and the third lens are reasonably configured, which helps to reduce the comprehensive spherical aberration of the first lens, the second lens and the third lens , chromatic aberration and distortion are reduced to a reasonable position, reducing the design difficulty of the fourth lens, fifth lens, sixth lens and seventh lens; Improve the performance of the optical system.

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, and 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 the 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, it is beneficial to the first lens, the second lens and the third lens The size reduction of the lens, the second lens and the third lens helps to form a small size optical system.

In one embodiment, the optical system satisfies the conditional formula: R62/f<-1, R62 is the radius of curvature of the image side surface of the sixth lens at the optical axis, and f is the focal length of the optical system. By reasonably limiting the value of R62/f, the surface complexity of the sixth lens can be reduced, which is conducive to suppressing field curvature and distortion, reducing the difficulty of forming, and improving the overall image quality. too long.

In one embodiment, the optical system satisfies the conditional formula: |f6|+|f7|<20mm, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens. By reasonably configuring the size and refractive power of the sixth lens and the seventh lens and limiting 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, and the optical system can be controlled. The configuration of the refractive power of the sixth lens and the seventh lens of the system corrects the aberration around the optical system, and at the same time facilitates size compression to form a small-sized optical system.

In one embodiment, the optical system satisfies the conditional formula: 0<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. By reasonably limiting the value of R72/f, the surface complexity of the seventh lens can be reduced, which is conducive to suppressing field curvature and distortion, reducing the difficulty of forming, and improving the overall image quality. too long.

In an embodiment, the optical system satisfies the conditional formula: 0<Yc72/SD72<0.5, Yc72 is the vertical distance from the off-axis vertex on the image side of the seventh lens to the optical axis, and SD72 is the seventh lens. The maximum effective aperture of the image side of the lens in the vertical axis 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 and too thick, reducing the incident angle of light on the imaging plane, and reducing the sensitivity of the optical system. In addition, the seventh lens is provided with a plurality of inflection points, which is beneficial to correct the distortion and field curvature generated by the first lens to the sixth lens, so that the configuration of the refractive power close to the imaging surface is relatively uniform.

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 , ImgH is the image height corresponding to the maximum angle of view of the optical system. The value of TTL/(ImgH*2) is limited within a small range, and through a reasonable structural layout, the characteristics of miniaturization of the optical system are realized.

In one embodiment, the optical system satisfies the conditional formula: 38°<HFOV<45°, and HFOV is half of the maximum angle of view of the optical system. By limiting the range of HFOV, it is beneficial to wide-angle shooting of the optical system.

In one embodiment, the optical system satisfies the conditional formula 0.75<DL/TTL<1, DL is the distance on the optical axis from the object side of the first lens to the image side of the seventh lens, and TTL is the The distance on the optical axis from the object side of the first lens to the imaging plane in the optical system. By limiting the value of DL/TTL, on the basis of realizing 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.

In one embodiment, the optical system satisfies the conditional formula: 1.0<TTL/f<1.4, 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 the focal length of the optical system. By properly configuring the TTL/f range, the optical system can have a lower height, making the optical system easy to install into portable equipment. The setting of the aspheric surface makes the TTL larger than the focal length f. At the same time, under the condition of wide-angle shooting, it is beneficial to balance aberrations such as chromatic aberration, spherical aberration, and distortion, so that the optical system has good imaging quality.

In one embodiment, the optical system satisfies the conditional formula: 1.5<FNO<2.0, where FNO is the aperture number of the optical system. By defining the value of FNO, the optical system has the characteristics of large aperture.

The present application will be described in detail through five specific embodiments below.

Example 1

As shown in FIG. 1 , 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 in this embodiment, from the object side 12 to the image side 13 are the diaphragm STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the Six lens L6, seventh lens L7, infrared filter element IRCF.

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

The second lens L2 has a negative refractive power and is made of plastic material, and its object side S3 is convex at the near optical axis and at the circumference, and its image side S4 is concave at the near optical axis and at the circumference, and both are non- spherical.

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

The fourth lens L4 has a positive refractive power and is a plastic material, its object side S7 is a concave surface at the near optical axis, its object side S7 is a convex surface at the circumference, and its image side S8 is at the near optical axis and at the circumference. Convex, and all are aspheric.

The fifth lens L5 has a negative refractive power and is made of plastic material, its object side S9 is convex at the near optical axis, its object side S9 is concave at the circumference, its image side S10 is concave at the near optical axis, and its image is concave at the near optical axis. The side surface S10 is convex at the circumference, and all are aspherical.

The sixth lens L6 has a positive refractive power and is made of plastic material. Its object side S11 is convex at the near optical axis, its object side S11 is concave at the circumference, and its image side S12 is at the near optical axis and at the circumference. Convex, and both are aspherical.

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

The diaphragm STO may be located on the object side of the first lens L1 or between any two adjacent lenses, and the diaphragm STO in this embodiment is disposed on the object side of the first lens L1.

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

The imaging surface S17 is the surface where the image formed by the light of the subject passing through the optical system is located.

Table 1a 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.

Table 1a

where 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 surface of the optical system on the optical axis, and ImgH is The image height corresponding to the maximum angle of view of the optical system, DL is the distance on the optical axis from the object side of the first lens to the image side of the seventh lens.

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, and 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.

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

where Z is the distance from the corresponding point on the aspheric surface to the plane tangent to the surface vertex, r is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the aspheric vertex, k is the conic constant, and Ai is the aspheric surface formula The coefficients corresponding to the higher-order terms of the i-th term in .

Table 1b shows the high-order term coefficients A4, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, and S14 that can be used for the aspheric mirror surfaces S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, and S14 in the first embodiment. A6, A8, A10, A12, A14, A16, A18 and A20.

Table 1b

face number	S1	S2	S3	S4	S5	S6	S7
K	-1.934962	-4.676764	-2.436334	-0.942357	-6923.722959	44.168745	-41.490626
A4	0.031882	-0.109469	-0.127227	-0.023658	0.010793	0.228335	0.260083
A6	0.047918	0.170106	0.111444	-0.168850	-0.363920	-1.544799	-1.621115
A8	-0.197506	-0.172578	0.280428	1.186265	1.529110	5.343334	5.392145
A10	0.446179	0.092910	-1.126640	-3.503994	-4.340113	-11.905031	-11.425610
A12	-0.596048	0.001362	1.913392	6.051350	7.797663	16.872757	15.293074
A14	0.483035	-0.048536	-1.885968	-6.419756	-8.897638	-15.246457	-12.945884
A16	-0.233613	0.039317	1.110047	4.118150	6.230965	8.567228	6.767343

A18	0.061756	-0.014109	-0.360181	-1.462245	-2.424185	-2.726217	-1.995324
A20	-0.006871	0.001962	0.049485	0.221672	0.398861	0.373118	0.253332
face number	S8	S9	S10	S11	S12	S13	S14
K	19.537139	-31.729225	-26.860733	-13.557654	-0.848706	-11.749464	-5.500435
A4	0.021750	0.026477	0.078547	0.212228	0.135806	-0.276025	-0.139359
A6	-0.265146	-0.460995	-0.469347	-0.363417	-0.035118	0.211580	0.085223
A8	0.554983	1.032510	0.709101	0.352584	-0.075796	-0.143511	-0.041613
A10	-0.612569	-1.533915	-0.647791	-0.284924	0.074951	0.067070	0.012733
A12	0.221566	1.631244	0.380775	0.170866	-0.034809	-0.019324	-0.002316
A14	0.188820	-1.253903	-0.143409	-0.069844	0.009470	0.003417	0.000239
A16	-0.224832	0.651403	0.033790	0.017870	-0.001518	-0.000364	-0.000012
A18	0.079135	-0.200527	-0.004608	-0.002525	0.000132	0.000022	0.000000
A20	-0.007498	0.027181	0.000281	0.000149	-0.000005	-0.000001	0.000000

FIG. 2 shows longitudinal spherical aberration curves, astigmatism curves, and distortion curves of the optical system of the first embodiment. Among them, the longitudinal spherical aberration curve represents the deviation of the focusing point of light of different wavelengths after passing through each lens of the optical system, and the reference wavelengths of the longitudinal spherical aberration curve are 650.0000nm, 610.0000nm, 555.0000nm, 510.0000nm, 470.0000nm; the astigmatism curve represents Meridional image surface curvature and sagittal image surface curvature, where S represents the sagittal direction, T represents the meridional direction, and the reference wavelength of the astigmatism curve is 555.0000 nm; the distortion curve represents the distortion value corresponding to different field angles. The reference wavelength is 555.0000nm. It can be seen from FIG. 2 that the optical system provided in the first embodiment can achieve good imaging quality.

Embodiment 2

As shown in FIG. 3 , 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 in this embodiment, from the object side 12 to the image side 13 are the diaphragm STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the Six lens L6, seventh lens L7, infrared filter element IRCF.

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

The second lens L2 has a negative refractive power and is made of plastic material, the object side S3 is convex at the near optical axis and the circumference, and the image side S4 is concave at the near optical axis and the circumference, and both are non- spherical.

The third lens L3 has negative refractive power and is made of plastic material, its object side S5 is concave at the near optical axis and at the circumference, and its image side S6 is convex at the near optical axis and at the circumference, and both are non- spherical.

The fourth lens L4 has a positive refractive power and is a plastic material, its object side S7 is a concave surface at the near optical axis, its object side S7 is a convex surface at the circumference, and its image side S8 is at the near optical axis and at the circumference. Convex, and all are aspheric.

The fifth lens L5 has a negative refractive power and is made of plastic material, its object side S9 is convex at the near optical axis, its object side S9 is concave at the circumference, its image side S10 is concave at the near optical axis, and its image is concave at the near optical axis. The side surface S10 is convex at the circumference, and all are aspherical.

The sixth lens L6 has a positive refractive power and is made of plastic material. Its object side S11 is convex at the near optical axis, its object side S11 is concave at the circumference, and its image side S12 is at the near optical axis and at the circumference. Convex, and both are aspherical.

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

The diaphragm STO may be located on the object side of the first lens L1 or between any two adjacent lenses, and the diaphragm STO in this embodiment is arranged on the object side of the first lens L1.

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

The imaging plane S17 is the plane where the image formed by the light of the subject passing through the optical system is located.

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.

Table 2a

Where, 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 surface of the optical system on the optical axis, and ImgH is The image height corresponding to the maximum angle of view of the optical system, DL is the distance on the optical axis from the object side of the first lens to the image side of the seventh lens.

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, and the combined focal length f45 of the fourth lens L4 and the fifth lens L5 It is 24.1886mm, the combined focal length f56 of the fifth lens L5 and the sixth lens L6 is 9.2549mm, and the combined focal length f67 of the sixth lens L6 and the seventh lens L7 is -11.4932mm.

Table 2b shows the high-order term coefficients A4, S1, S13, S14 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. A6, A8, A10, A12, A14, A16, A18 and A20, wherein each aspherical surface type can be defined by the formula given in the first embodiment.

Table 2b

face number	S1	S2	S3	S4	S5	S6	S7
K	-1.924319	-3.688611	-2.578689	-1.255831	99.000000	-99.000000	-99.000000
A4	0.034306	-0.073000	-0.110637	-0.046452	0.006971	0.208155	0.237057
A6	0.026063	0.072618	0.109870	0.014828	-0.349223	-1.346569	-1.362731
A8	-0.090826	-0.092087	-0.062082	0.230597	1.513267	4.528451	4.233298
A10	0.190358	0.185205	0.117243	-0.719570	-4.439913	-10.121784	-8.651603
A12	-0.248137	-0.304204	-0.248706	1.326549	8.320409	14.700818	11.378308
A14	0.201741	0.297839	0.271059	-1.607695	-9.994229	-13.848937	-9.602652
A16	-0.100020	-0.166314	-0.143096	1.229069	7.395418	8.213077	5.080536
A18	0.027483	0.048846	0.032091	-0.525115	-3.042732	-2.774046	-1.536464
A20	-0.003235	-0.005829	-0.001404	0.096141	0.529826	0.403251	0.202070
face number	S8	S9	S10	S11	S12	S13	S14
K	25.920307	90.347914	-44.059317	-13.296613	-1.489655	-11.337094	-5.099219
A4	0.019458	0.027697	0.078211	0.214393	0.132337	-0.262920	-0.130349
A6	-0.252494	-0.488925	-0.478004	-0.371686	-0.034481	0.189482	0.076174
A8	0.571020	1.207044	0.762881	0.362395	-0.070488	-0.123794	-0.034466
A10	-0.841995	-1.984937	-0.760103	-0.284677	0.068655	0.056939	0.009363
A12	0.813423	2.259834	0.502136	0.163097	-0.031305	-0.016192	-0.001377
A14	-0.558861	-1.768161	-0.218769	-0.063543	0.008359	0.002823	0.000082
A16	0.295535	0.899913	0.060844	0.015578	-0.001314	-0.000296	0.000003
A18	-0.112193	-0.266290	-0.009826	-0.002124	0.000112	0.000017	-0.000001
A20	0.021494	0.034525	0.000700	0.000122	-0.000004	0.000000	0.000000

FIG. 4 shows longitudinal spherical aberration curves, astigmatism curves, and distortion curves of the optical system of the second embodiment. Among them, the longitudinal spherical aberration curve represents the deviation of the focusing point of light of different wavelengths after passing through each lens of the optical system, and the reference wavelengths of the longitudinal spherical aberration curve are 650.0000nm, 610.0000nm, 555.0000nm, 510.0000nm, 470.0000nm; the astigmatism curve represents Meridional image surface curvature and sagittal image surface curvature, where S represents the sagittal direction, T represents the meridional direction, and the reference wavelength of the astigmatism curve is 555.0000 nm; the distortion curve represents the distortion value corresponding to different field angles. The reference wavelength is 555.0000nm. It can be seen from FIG. 4 that the optical system provided in the second embodiment can achieve good imaging quality.

Embodiment 3

As shown in FIG. 5 , 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 in this embodiment, from the object side 12 to the image side 13 are the diaphragm STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the Six lens L6, seventh lens L7, infrared filter element IRCF.

The first lens L1 has a positive refractive power and is made of plastic material, and its object side S1 is convex at the near optical axis and at the circumference, and its image side S2 is concave at the near optical axis and at the circumference, and both are non-concave. spherical.

The second lens L2 has a negative refractive power and is made of plastic material, the object side S3 is convex at the near optical axis and the circumference, and the image side S4 is concave at the near optical axis and the circumference, and both are non- spherical.

The third lens L3 has negative refractive power and is made of plastic material, its object side S5 is concave at the near optical axis and at the circumference, and its image side S6 is convex at the near optical axis and at the circumference, and both are non- spherical.

The fourth lens L4 has a positive refractive power and is a plastic material, its object side S7 is a concave surface at the near optical axis, its object side S7 is a convex surface at the circumference, and its image side S8 is at the near optical axis and at the circumference. Convex, and all are aspheric.

The fifth lens L5 has a negative refractive power and is made of plastic material, its object side S9 is concave at the near optical axis and at the circumference, its image side S10 is concave at the near optical axis, and its image side S10 is at the circumference. Convex, and both are aspherical.

The sixth lens L6 has a positive refractive power and is made of plastic material. Its object side S11 is convex at the near optical axis, its object side S11 is concave at the circumference, and its image side S12 is at the near optical axis and at the circumference. Convex, and both are aspherical.

The seventh lens L7 has a negative refractive power and is made of plastic material, its object side S13 is convex at the near optical axis and at the circumference, its image side S14 is concave at the near optical axis, and its image side S14 is at the circumference. Convex, and both are aspherical.

The diaphragm STO may be located on the object side of the first lens L1 or between any two adjacent lenses, and the diaphragm STO in this embodiment is arranged on the object side of the first lens L1.

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

The imaging plane S17 is the plane where the image formed by the light of the subject passing through the optical system is located.

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.

Table 3a

where 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 surface of the optical system on the optical axis, and ImgH is The image height corresponding to the maximum angle of view of the optical system, DL is the distance on the optical axis from the object side of the first lens to the image side of the seventh lens.

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, and the combined focal length f45 of the fourth lens L4 and the fifth lens L5 is 25.0957mm, the combined focal length f56 of the fifth lens L5 and the sixth lens L6 is 8.5989mm, and the combined focal length f67 of the sixth lens L6 and the seventh lens L7 is -152.8332mm.

Table 3b shows the high-order term coefficients A4, S1, S13, S14 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. A6, A8, A10, A12, A14, A16, A18 and A20, wherein each aspherical surface type can be defined by the formula given in the first embodiment.

Table 3b

face number	S1	S2	S3	S4	S5	S6	S7
K	-1.937303	-5.315152	-3.779112	-1.302078	99.000000	-99.000000	-80.580843
A4	0.028621	-0.053649	-0.077745	-0.022676	0.029190	0.192327	0.202379
A6	0.076041	-0.002940	0.030376	-0.036212	-0.474867	-1.105708	-1.053359
A8	-0.280876	0.057790	-0.055676	0.158668	1.911676	3.434074	3.031060
A10	0.627552	0.016369	0.429073	-0.175654	-5.597956	-7.659784	-6.255250
A12	-0.874123	-0.285973	-1.049808	-0.021991	10.893280	11.726858	8.907685
A14	0.761226	0.519436	1.356620	0.304148	-13.966061	-12.051978	-8.513970
A16	-0.401359	-0.445118	-0.986954	-0.359385	11.263991	7.908911	5.194965
A18	0.116241	0.187625	0.378095	0.186437	-5.138749	-2.951478	-1.802729

A20	-0.014165	-0.031089	-0.058914	-0.035968	1.008215	0.470209	0.267613
face number	S8	S9	S10	S11	S12	S13	S14
K	40.616220	-99.000000	99.000000	-9.098781	4.771686	-10.057682	-4.527319
A4	0.039368	0.044418	0.078874	0.240739	0.044798	-0.272773	-0.135757
A6	-0.318870	-0.454137	-0.524604	-0.474546	0.174724	0.188297	0.076390
A8	0.796828	1.138384	0.940841	0.581053	-0.290678	-0.120894	-0.033845
A10	-1.629426	-1.950191	-1.091663	-0.544998	0.200959	0.056780	0.009058
A12	2.354874	2.213735	0.847588	0.343518	-0.080539	-0.016606	-0.001248
A14	-2.281822	-1.650709	-0.425946	-0.137964	0.019874	0.002975	0.000047
A16	1.413805	0.783242	0.131939	0.033590	-0.002955	-0.000320	0.000008
A18	-0.508033	-0.216565	-0.022823	-0.004487	0.000241	0.000019	-0.000001
A20	0.081137	0.026702	0.001684	0.000251	-0.000008	0.000000	0.000000

FIG. 6 shows longitudinal spherical aberration curves, astigmatism curves, and distortion curves of the optical system of the third embodiment. Among them, the longitudinal spherical aberration curve represents the deviation of the focusing point of light of different wavelengths after passing through each lens of the optical system, and the reference wavelengths of the longitudinal spherical aberration curve are 650.0000nm, 610.0000nm, 555.0000nm, 510.0000nm, 470.0000nm; the astigmatism curve represents Meridional image surface curvature and sagittal image surface curvature, where S represents the sagittal direction, T represents the meridional direction, and the reference wavelength of the astigmatism curve is 555.0000 nm; the distortion curve represents the distortion value corresponding to different field angles. The reference wavelength is 555.0000nm. It can be seen from FIG. 6 that the optical system provided by the third embodiment can achieve good imaging quality.

Embodiment 4

As shown in FIG. 7 , 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 in this embodiment, from the object side 12 to the image side 13 are the diaphragm STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the Six lens L6, seventh lens L7, infrared filter element IRCF.

The first lens L1 has a positive refractive power and is made of plastic material, and its object side S1 is convex at the near optical axis and at the circumference, and its image side S2 is concave at the near optical axis and at the circumference, and both are non-concave. spherical.

The second lens L2 has a negative refractive power and is made of plastic material, the object side S3 is convex at the near optical axis and the circumference, and the image side S4 is concave at the near optical axis and the circumference, and both are non- spherical.

The third lens L3 has negative refractive power and is made of plastic material, its object side S5 is concave at the near optical axis and at the circumference, and its image side S6 is convex at the near optical axis and at the circumference, and both are non- spherical.

The fourth lens L4 has a positive refractive power and is a plastic material, and its object side surface S7 is convex at the near optical axis and at the circumference, and its image side S8 is convex at the near optical axis and at the circumference, and both are non-convex. spherical.

The fifth lens L5 has a negative refractive power and is made of plastic material, and its object side surface S9 is concave at the near optical axis and at the circumference, and its image side S10 is convex at the near optical axis and at the circumference, and both are non-concave. spherical.

The sixth lens L6 has a positive refractive power and is made of plastic material. Its object side S11 is convex at the near optical axis, its object side S11 is concave at the circumference, and its image side S12 is at the near optical axis and at the circumference. Convex, and both are aspherical.

The seventh lens L7 has a negative refractive power and is made of plastic material, its object side S13 is convex at the near optical axis and at the circumference, its image side S14 is concave at the near optical axis, and its image side S14 is at the circumference. Convex, and both are aspherical.

The diaphragm STO may be located on the object side of the first lens L1 or between any two adjacent lenses, and the diaphragm STO in this embodiment is arranged on the object side of the first lens L1.

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

The imaging plane S17 is the plane where the image formed by the light of the subject passing through the optical system is located.

Table 4a 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.

Table 4a

where 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 surface of the optical system on the optical axis, and ImgH is The image height corresponding to the maximum angle of view of the optical system, DL is the distance on the optical axis from the object side of the first lens to the image side of the seventh lens.

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, and the combined focal length f45 of the fourth lens L4 and the fifth lens L5 is 18.1426mm, the combined focal length f56 of the fifth lens L5 and the sixth lens L6 is 8.1268mm, and the combined focal length f67 of the sixth lens L6 and the seventh lens L7 is -244.9808mm.

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

Table 4b

face 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
face 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

FIG. 8 shows longitudinal spherical aberration curves, astigmatism curves, and distortion curves of the optical system of the fourth embodiment. Among them, the longitudinal spherical aberration curve represents the deviation of the focusing point of light of different wavelengths after passing through each lens of the optical system, and the reference wavelengths of the longitudinal spherical aberration curve are 650.0000nm, 610.0000nm, 555.0000nm, 510.0000nm, 470.0000nm; the astigmatism curve represents Meridional image surface curvature and sagittal image surface curvature, where S represents the sagittal direction, T represents the meridional direction, and the reference wavelength of the astigmatism curve is 555.0000 nm; the distortion curve represents the distortion value corresponding to different field angles. The reference wavelength is 555.0000nm. It can be seen from FIG. 8 that the optical system provided in the fourth embodiment can achieve good imaging quality.

Embodiment 5

As shown in FIG. 9 , 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 in this embodiment, from the object side 12 to the image side 13 are the diaphragm STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the Six lens L6, seventh lens L7, infrared filter element IRCF.

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

The second lens L2 has a negative refractive power and is made of plastic material, the object side S3 is convex at the near optical axis and the circumference, and the image side S4 is concave at the near optical axis and the circumference, and both are non- spherical.

The third lens L3 has negative refractive power and is made of plastic material, its object side S5 is concave at the near optical axis and at the circumference, and its image side S6 is convex at the near optical axis and at the circumference, and both are non- spherical.

The fourth lens L4 has a positive refractive power and is a plastic material, and its object side surface S7 is convex at the near optical axis and at the circumference, and its image side S8 is convex at the near optical axis and at the circumference, and both are non-convex. spherical.

The fifth lens L5 has a negative refractive power and is made of plastic material, and its object side surface S9 is concave at the near optical axis and at the circumference, and its image side S10 is convex at the near optical axis and at the circumference, and both are non-concave. spherical.

The sixth lens L6 has a positive refractive power and is made of plastic material. Its object side S11 is convex at the near optical axis, its object side S11 is concave at the circumference, and its image side S12 is at the near optical axis and at the circumference. Convex, and both are aspherical.

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

The diaphragm STO may be located on the object side of the first lens L1 or between any two adjacent lenses, and the diaphragm STO in this embodiment is arranged on the object side of the first lens L1.

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

The imaging plane S17 is the plane where the image formed by the light of the subject passing through the optical system is located.

Table 5a 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.

Table 5a

where 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 surface of the optical system on the optical axis, and ImgH is The image height corresponding to the maximum angle of view of the optical system, DL is the distance on the optical axis from the object side of the first lens to the image side of the seventh lens.

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, and the combined focal length f45 of the fourth lens L4 and the fifth lens L5 is 24.4426mm, the combined focal length f56 of the fifth lens L5 and the sixth lens L6 is 10.3997mm, and the combined focal length f67 of the sixth lens L6 and the seventh lens L7 is -12.1354mm.

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

Table 5b

face 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

face 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

FIG. 10 shows longitudinal spherical aberration curves, astigmatism curves, and distortion curves of the optical system of the fifth embodiment. Among them, the longitudinal spherical aberration curve represents the deviation of the focusing point of light of different wavelengths after passing through each lens of the optical system, and the reference wavelengths of the longitudinal spherical aberration curve are 650.0000nm, 610.0000nm, 555.0000nm, 510.0000nm, 470.0000nm; the astigmatism curve represents Meridional image surface curvature and sagittal image surface curvature, where S represents the sagittal direction, T represents the meridional direction, and the reference wavelength of the astigmatism curve is 555.0000 nm; the distortion curve represents the distortion value corresponding to different field angles. The reference wavelength is 555.0000nm. It can be seen from FIG. 10 that the optical system provided in the fifth embodiment can achieve good imaging quality.

Table 6 shows the 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, (|SAG71|+SAG72)/CT7.

Table 6

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.

Referring to FIG. 11 , the optical system involved in the present application is applied to the camera module 20 in the terminal device 30 . The terminal device 30 may be a mobile phone, a tablet computer, a drone, a computer, or other devices. 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 .

The present application provides a camera module, including a photosensitive element and the optical system provided by the embodiments of the present application. The photosensitive element is located on the image side of the optical system, and is used to pass through the first lens to the seventh lens and be incident on the electronic photosensitive element. The light is converted into an electrical signal of the image. The electronic photosensitive element can be a complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, CMOS) or a charge-coupled device (Charge-coupled Device, CCD). By installing the optical system in the camera module, the camera module can meet the requirements of high pixel, large aperture and miniaturization at the same time.

The present application further provides a terminal device, where the terminal device includes the camera module provided by the embodiment of the present application. The terminal device may be a mobile phone, a tablet computer, a drone, a computer, and the like. By installing the camera module in the terminal device, the terminal device can meet the requirements of high pixel, large aperture and miniaturization at the same time.

The above are the preferred embodiments of the present application. It should be pointed out that for those of ordinary skill in the art, without departing from the principles of the present application, several improvements and modifications can also be made, and these improvements and modifications may also be regarded as The protection scope of this application.

Claims (18)

1. An optical system, characterized in that it includes a plurality of lenses, and the plurality of lenses include:

   The first lens has a 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;

   The second lens has a negative refractive power, the object side of the second lens is convex at the near optical axis, and the image side of the second lens is concave at the near optical axis;

   The third lens has negative refractive power;

   the fourth lens has a positive refractive power; the image side surface of the fourth lens is convex at the near optical axis;

   the fifth lens, with negative refractive power;

   The sixth lens has a positive refractive power, the object side of the sixth lens is convex at the near optical axis, and the image side of the sixth lens is convex at the near optical axis;

   The seventh lens has a negative refractive power, the object side of the seventh lens is convex at the near optical axis, and the image side 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 on the optical axis from the off-axis point within the effective diameter of the object side of the seventh lens to the on-axis vertex of the object side of the seventh lens, and SAG72 is the effective diameter of the image side of the seventh lens The maximum distance from the inner off-axis point to the on-axis vertex of the image side surface of the seventh lens on the optical axis, CT7 is the thickness of the seventh lens on the optical axis.
2. The optical system according to claim 1, wherein the optical system satisfies the conditional expression:

   |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, wherein the optical system satisfies the conditional expression:

   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, wherein the optical system satisfies the conditional expression:

   f23<0mm,

   f23 is the combined focal length of the second lens and the third lens.
5. The optical system according to claim 1, wherein the optical system satisfies the conditional expression:

   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 thickness of the optical system. The distance from the object side of the first lens to the imaging plane on the optical axis.
6. The optical system according to claim 1, wherein the optical system satisfies the conditional expression:

   (|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, wherein the optical system satisfies the conditional expression:

   (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, wherein the optical system satisfies the conditional expression:

   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, wherein the optical system satisfies the conditional expression:

   |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, wherein the optical system satisfies the conditional expression:

    0<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, wherein the optical system satisfies the conditional expression:

    0<Yc72/SD72<0.5,

    Yc72 is the vertical 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 axis direction.
12. The optical system according to claim 1, wherein the optical system satisfies the conditional expression:

    0.6<TTL/(ImgH*2)<0.8,

    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 angle of view of the optical system.
13. The optical system according to claim 1, wherein the optical system satisfies the conditional expression:

    38°<HFOV<45°,

    HFOV is half the maximum field of view of the optical system.
14. The optical system according to claim 1, wherein the optical system satisfies the conditional expression:

    0.75<DL/TTL<1,

    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 plane on the optical axis in the optical system .
15. The optical system according to claim 1, wherein the optical system satisfies the conditional expression:

    1.0<TTL/f<1.4,

    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.
16. The optical system according to claim 1, wherein the optical system satisfies the conditional expression:

    1.5 < FNO < 2.0,

    FNO is the aperture number of the optical system.
17. A camera module, comprising a photosensitive element and the optical system according to 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, comprising the camera module according to claim 17 .

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