Optical systems, camera modules and electronic devices

Abstract

An optical system, camera module, and electronic device comprises seven lenses with refractive power. The optical system, along the optical axis from the object side to the image side, includes: a first lens, a fourth lens, and a sixth lens with positive refractive power; and a second lens, a third lens, a fifth lens, and a seventh lens with negative refractive power. The object-side surfaces of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are all convex near the optical axis, while the image-side surfaces of the first lens, the second lens, the third lens, the fifth lens, the sixth lens, and the seventh lens are all concave near the optical axis. Through the rational design of each lens in the optical system, miniaturization, good imaging performance, and variable aperture characteristics are achieved.

Description

Technical Field

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

[0002] In recent years, electronic devices equipped with cameras have developed rapidly, including portable information terminals such as smart phones, digital cameras, laptop computers, and tablet computers. People's requirements for imaging quality have also increased day by day. In order to enable users to have a better photo-taking experience and achieve shooting by the optical system under different scenarios and requirements, the optical system is required to have the function of variable aperture and good imaging effect.

[0003] However, the implementation of variable aperture and the combination of multiple lenses will result in a relatively large volume of the optical system, making it difficult to meet the development trend of miniaturization. Summary of the Invention

[0004] The object of the present invention is to provide an optical system, a camera module, and an electronic device to solve the problems that the optical system needs to meet miniaturization, have good imaging effects, and variable aperture.

[0005] To achieve the object of the present invention, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides an optical system, which has seven lenses with refractive power, and successively includes from the object side to the image side along the optical axis: a first lens with positive refractive power, the object side surface of the first lens is convex near the optical axis, and the image side surface of the first lens is concave near the optical axis; a second lens with negative refractive power, the object side surface of the second lens is convex near the optical axis, and the image side surface of the second lens is concave near the optical axis; a third lens with negative refractive power, the object side surface of the third lens is convex near the optical axis, and the image side surface of the third lens is concave near the optical axis; a fourth lens with positive refractive power, the image side surface of the fourth lens is convex near the optical axis; a fifth lens with negative refractive power, the object side surface of the fifth lens is convex near the optical axis, and the image side surface of the fifth lens is concave near the optical axis; a sixth lens with positive refractive power, the object side surface of the sixth lens is convex near the optical axis, and the image side surface of the sixth lens is concave near the optical axis; a seventh lens with negative refractive power, the object side surface of the seventh lens is convex near the optical axis, and the image side surface of the seventh lens is concave near the optical axis. The optical system further includes an aperture, and the aperture is located on the object side of the first lens, and the size of the aperture can change.

[0007] The optical system satisfies the relational expressions: 1.2 < TTL / ImgH < 1.55, and 77deg < FOV < 86deg.

[0008] By making the first lens have a positive refractive power, with the object side of the first lens being convex near the optical axis and the image side of the first lens being concave near the optical axis, it is beneficial to reduce the incident angle of light on the object side of the first lens, expand the field angle of the optical system, and avoid the too-fast convergence of light when it exits the first lens, gently transmitting the light, which helps with the miniaturization of the optical system; by making the second lens have a negative refractive power, with the object side of the second lens being convex near the optical axis and the image side of the second lens being concave near the optical axis, it is beneficial to correct the aberration generated by the first lens and improve the imaging quality; by making the third lens have a negative refractive power, with the object side of the third lens being convex near the optical axis and the image side of the third lens being concave near the optical axis, it is beneficial to soothe the transmission of light, gradually eliminate the aberration, and avoid the excessive bending of the second lens; by making the fourth lens have a positive refractive power, with the image side of the fourth lens being convex near the optical axis, it is beneficial to correct the distortion, spherical aberration, and astigmatism generated by the lens on the object side of the fourth lens, and reduce the incident angle of the gradually expanding light at the fourth lens, thereby improving the light transmittance; the above layout can make the first to fourth lenses have a double Gauss structure, reduce the workload of the fifth to seventh lenses, avoid the appearance of overly bent surface shapes, and improve the lens forming quality; the fifth lens, sixth lens, and seventh lens are arranged in a distribution of negative refractive power, positive refractive power, and negative refractive power. The above refractive power distribution method配合 the surface shape design where the object side and image side of the fifth to seventh lenses are convex at the optical axis and concave at the optical axis not only helps to eliminate axial chromatic aberration but also shortens the axial focal length. While improving the imaging quality, it also achieves a miniaturized design; at least one inflection point exists on the object side and image side of the seventh lens, which is beneficial to correct off-axis aberration and suppress the incident angle of light on the imaging surface, improving both the imaging quality and the relative illuminance.

[0009] By making the optical system satisfy 1.2 < TTL / ImgH < 1.55, the ratio of the distance from the object side of the first lens to the imaging surface of the optical system on the optical axis to half of the image height corresponding to the maximum field angle of the optical system is reasonably configured, which is beneficial to improving the resolution of the optical system in the full field and enhancing the imaging quality of the edge field; at the same time, it is also beneficial to make the optical system have a smaller overall optical length and achieve the characteristic of miniaturization.

[0010] By making the optical system satisfy 77deg < FOV < 86deg, the maximum field angle of the optical system is controlled within a reasonable range, which can avoid introducing excessive aberration and is beneficial to the optical system to meet the characteristic of miniaturization while obtaining sufficient vision.

[0011] Note: There seems to be an unclear part "配合" in the translation of , which might need further clarification in the original text for a more accurate translation.Secondly, the present invention also provides a camera module, which includes a photosensitive chip and an optical system as described in any embodiment of the first aspect, wherein the photosensitive chip is disposed on the image side of the optical system. The photosensitive surface of the photosensitive chip is located on the imaging surface of the optical system, and light rays from an object incident on the photosensitive surface through a lens can be converted into electrical signals for an image. The photosensitive chip can be a complementary metal-oxide-semiconductor (CMOS) or a charge-coupled device (CCD). The camera module can be an imaging module integrated into an electronic device or a standalone lens. By incorporating the optical system provided by the present invention into the camera module, the surface shape and refractive power of each lens in the optical system can be rationally designed, enabling the camera module to achieve miniaturization, good imaging performance, and variable aperture characteristics.

[0012] Thirdly, the present invention also provides an electronic device comprising a housing and the camera module described in the second aspect, wherein the camera module is disposed within the housing. This electronic device includes, but is not limited to, smartphones, computers, and smartwatches. By incorporating the camera module provided by the present invention into the electronic device, the device achieves miniaturization, good imaging performance, and variable aperture characteristics. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1a This is a schematic diagram of the optical system in the first aperture state according to the first embodiment;

[0015] Figure 1b It shows Figure 1a Longitudinal spherical aberration curve, astigmatism curve, and distortion curve;

[0016] Figure 1c This is a schematic diagram of the optical system in the second aperture state according to the first embodiment;

[0017] Figure 1d It shows Figure 1c Longitudinal spherical aberration curve, astigmatism curve, and distortion curve;

[0018] Figure 1e This is a schematic diagram of the optical system in the third aperture state according to the first embodiment;

[0019] Figure 1f It shows Figure 1e Longitudinal spherical aberration curve, astigmatism curve, and distortion curve;

[0020] Figure 2a This is a schematic diagram of the optical system in the first aperture state according to the second embodiment;

[0021] Figure 2b It shows Figure 2a Longitudinal spherical aberration curve, astigmatism curve, and distortion curve;

[0022] Figure 2c These are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the second embodiment under the second aperture state;

[0023] Figure 2d These are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the second embodiment under the third aperture condition;

[0024] Figure 3a This is a schematic diagram of the optical system in the first aperture state according to the third embodiment;

[0025] Figure 3b It shows Figure 3a Longitudinal spherical aberration curve, astigmatism curve, and distortion curve;

[0026] Figure 3c These are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the third embodiment under the second aperture state;

[0027] Figure 3d These are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the third embodiment under the third aperture state;

[0028] Figure 4a This is a schematic diagram of the optical system in the first aperture state according to the fourth embodiment;

[0029] Figure 4b It shows Figure 4a Longitudinal spherical aberration curve, astigmatism curve, and distortion curve;

[0030] Figure 4c These are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the fourth embodiment under the second aperture state;

[0031] Figure 4d These are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the fourth embodiment under the third aperture condition;

[0032] Figure 5aThis is a schematic diagram of the optical system in the first aperture state according to the fifth embodiment;

[0033] Figure 5b It shows Figure 5a Longitudinal spherical aberration curve, astigmatism curve, and distortion curve;

[0034] Figure 5c These are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the fifth embodiment in the second aperture state;

[0035] Figure 5d These are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the fifth embodiment in the third aperture state;

[0036] Figure 6 A schematic diagram of the camera module structure in one embodiment of the present invention is shown;

[0037] Figure 7 A schematic diagram of the structure of an electronic device according to one embodiment of the present invention is shown. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] In a first aspect, the present invention provides an optical system comprising seven refractive lenses, arranged sequentially along the optical axis from the object side to the image side: a first lens having positive refractive power, wherein the object side of the first lens is convex near the optical axis and the image side of the first lens is concave near the optical axis; a second lens having negative refractive power, wherein the object side of the second lens is convex near the optical axis and the image side of the second lens is concave near the optical axis; and a third lens having negative refractive power, wherein the object side of the third lens is convex near the optical axis and the image side of the third lens is concave near the optical axis. The first lens has a concave surface near the optical axis; the second lens has positive refractive power, and its image-side surface is convex near the optical axis; the third lens has negative refractive power, and its object-side surface is convex near the optical axis, while its image-side surface is concave near the optical axis; the fourth lens has positive refractive power, and its object-side surface is convex near the optical axis, while its image-side surface is concave near the optical axis; the fifth lens has negative refractive power, and its object-side surface is convex near the optical axis, while its image-side surface is concave near the optical axis. The optical system also includes an aperture located on the object side of the first lens, and the size of the aperture can be varied.

[0040] The optical system satisfies the relationship: 1.2 < TTL / ImgH < 1.55; further, the optical system satisfies the relationship: 1.3 < TTL / ImgH < 1.5. Here, TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis, and ImgH is half of the image height corresponding to the maximum field angle of the optical system.

[0041] The optical system satisfies the relationship: 77deg < FOV < 86deg; further, the optical system satisfies the relationship: 79deg < FOV < 84deg. Here, FOV is the maximum field angle of the optical system.

[0042] By making the first lens have a positive refractive power, with the object side surface of the first lens being convex near the optical axis and the image side surface of the first lens being concave near the optical axis, it is beneficial to reduce the incident angle of light on the object side surface of the first lens, expand the field angle of the optical system, and avoid the excessive convergence of light when it exits the first lens, gently transmitting the light, which helps with the miniaturization of the optical system; by making the second lens have a negative refractive power, with the object side surface of the second lens being convex near the optical axis and the image side surface of the second lens being concave near the optical axis, it is beneficial to correct the aberration generated by the first lens and improve the imaging quality; by making the third lens have a negative refractive power, with the object side surface of the third lens being convex near the optical axis and the image side surface of the third lens being concave near the optical axis, it is beneficial to soothe the transmission of light, gradually eliminate aberration, and avoid the excessive bending of the second lens; by making the fourth lens have a positive refractive power, with the image side surface of the fourth lens being convex near the optical axis, it is beneficial to correct the distortion, spherical aberration, and astigmatism generated by the lens on the object side of the fourth lens, and reduce the incident angle of the gradually expanding light at the fourth lens, thereby improving the light transmittance; the above layout can make the first to fourth lenses have a double Gauss structure, reduce the workload of the fifth to seventh lenses, avoid the appearance of overly bent surface shapes, and improve the lens forming quality; the fifth lens, the sixth lens, and the seventh lens are arranged in a distribution of negative refractive power, positive refractive power, and negative refractive power. The above refractive power distribution method配合 the surface shape design where the object side surfaces of the fifth to seventh lenses are convex at the optical axis and the image side surfaces are concave at the optical axis not only helps to eliminate axial chromatic aberration but also shortens the axial focal length. While improving the imaging quality, it also achieves a miniaturized design; the object side surface and the image side surface of the seventh lens have at least one anti - curvature point, which is beneficial to correct off - axis aberration and suppress the incident angle of light on the imaging surface, improving both the imaging quality and the relative illumination.

[0043] By making the optical system satisfy 1.2 < TTL / ImgH < 1.55, the ratio of the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis to half of the image height corresponding to the maximum field angle of the optical system is reasonably configured, which is beneficial to improving the resolution of the optical system in the full field and enhancing the imaging quality of the edge field; at the same time, it is also beneficial to make the optical system have a smaller overall optical length and achieve the characteristic of miniaturization.

[0044] By making the optical system satisfy 77deg < FOV < 86deg, the maximum field angle of the optical system is controlled within a reasonable range, which can avoid introducing excessive aberrations and is beneficial to the optical system to satisfy the characteristic of miniaturization while obtaining sufficient field of view.

[0045] In one embodiment, the optical system satisfies the relation: 0.9 < f1 / f < 1.5; further, the optical system satisfies the relation: 1 < f1 / f < 1.4. Where f1 is the effective focal length of the first lens and f is the effective focal length of the optical system. Satisfying the above relations is beneficial to the proper cooperation of the refractive power of the first lens in the optical system, and the surface type design of the first lens is more simple and flexible, enabling the first lens to support a larger field angle and large aperture; at the same time, it is also beneficial to converge the light rays incident from the first lens to the optical system, delay the incident angle of the light rays, reduce aberrations, and simplify the overall aberration correction and imaging quality balance of the optical system.

[0046] In one embodiment, the optical system satisfies the relation: -4.5 < f2 / f < -2.5; further, the optical system satisfies the relation: -4 < f2 / f < -3. Where f2 is the effective focal length of the second lens. Satisfying the above relations is beneficial to the proper cooperation of the refractive power of the second lens in the optical system, and the surface type design of the second lens is more simple and flexible, reducing aberrations, and simplifying the overall aberration correction and imaging quality balance of the optical system.

[0047] In one embodiment, the optical system satisfies the relation: f3 / f < -4; further, the optical system satisfies the relation: -10 < f3 / f < -5. Where f3 is the effective focal length of the third lens. Satisfying the above relations is beneficial to the proper cooperation of the refractive power of the third lens in the optical system, and the surface type design of the third lens is more simple and flexible, reducing aberrations, and simplifying the overall aberration correction and imaging quality balance of the optical system.

[0048] In one embodiment, the optical system satisfies the relation: 1.5 < f4 / f < 4; further, the optical system satisfies the relation: 2 < f4 / f < 3.5. Where f4 is the effective focal length of the fourth lens. Satisfying the above relations is beneficial to the fourth lens to form a double-Gauss structure in combination with the previous three lenses, eliminating aberrations and making the light rays transfer smoothly to the subsequent lenses.

[0049] In one embodiment, the optical system satisfies the relation: -3 < f5 / f < -1; further, the optical system satisfies the relation: -2.5 < f5 / f < -1.5. Here, f5 is the effective focal length of the fifth lens. Satisfying the above relations is conducive to the fifth lens gently diffusing the light beam, laying a foundation for subsequent large image plane imaging.

[0050] In one embodiment, the optical system satisfies the relation: 0.4 < f6 / f < 1.2; further, the optical system satisfies the relation: 0.6 < f6 / f < 1. Here, f6 is the effective focal length of the sixth lens. Satisfying the above relations is conducive to the sixth lens balancing the aberration of the foregoing lenses and improving the imaging quality.

[0051] In one embodiment, the optical system satisfies the relation: -1.2 < f7 / f < -0.45; further, the optical system satisfies the relation: -1 < f7 / f < -0.6. Here, f7 is the effective focal length of the seventh lens. Satisfying the above relations is conducive to the seventh lens cooperating with the foregoing lenses to shorten the back focal length and realizing the miniaturization design of the optical system.

[0052] Define Rxy as the curvature radius of the lens at the optical axis, where x takes any integer from 1 to 7, y takes 1 or 2, Rx1 is the curvature radius of the object side of the x-th lens at the optical axis, and Rx2 is the curvature radius of the image side of the x-th lens at the optical axis. Specifically, the curvature radius of the object side of the first lens at the optical axis is R11, and the curvature radius of the image side of the first lens at the optical axis is R12, and so on.

[0053] In one embodiment, the optical system satisfies the relation: 0.3 < R11 / f < 0.7; further, the optical system satisfies the relation: 0.4 < R11 / f < 0.6. In one embodiment, the optical system satisfies the relation: 1.3 < R12 / f < 2.2; further, the optical system satisfies the relation: 1.5 < R12 / f < 2. Satisfying at least one of the above relations is conducive to maintaining the astigmatism of the first lens within a reasonable range, enabling the optical system to have good imaging quality.

[0054] In one embodiment, the optical system satisfies the relation: 0.5 < R21 / f < 1.8; further, the optical system satisfies the relation: 0.7 < R21 / f < 1.6. In one embodiment, the optical system satisfies the relation: 0.5 < R22 / f < 1; further, the optical system satisfies the relation: 0.6 < R22 / f < 0.9. Satisfying at least one of the above relations is conducive to maintaining the astigmatism of the second lens within a reasonable range and effectively balancing the astigmatism generated by the first lens, enabling the optical system to have good imaging quality.

[0055] In one embodiment, the optical system satisfies the relation: 1.2 < R31 / f < 2.4; further, the optical system satisfies the relation: 1.4 < R31 / f < 2.2. In one embodiment, the optical system satisfies the relation: 0.9 < R32 / f < 1.7; further, the optical system satisfies the relation: 1.1 < R32 / f < 1.5. Satisfying at least one of the above relations is beneficial to maintaining the surface shape of the third lens within a reasonable range and effectively balancing the aberrations generated by the first lens and the second lens, so that the optical system has good imaging quality.

[0056] In one embodiment, the optical system satisfies the relation: 2.5 < R41 / f; further, the optical system satisfies the relation: 3.5 < R41 / f < 8. In one embodiment, the optical system satisfies the relation: -4 < R42 / f < -1; further, the optical system satisfies the relation: -3 < R42 / f < -1.25. Satisfying at least one of the above relations is beneficial to maintaining the surface shape of the fourth lens within a reasonable range, facilitating the cooperation with the first lens to the third lens to form a double-Gauss structure, so that the optical system has good imaging quality.

[0057] In one embodiment, the optical system satisfies the relation: 0.9 < R51 / f < 1.6; further, the optical system satisfies the relation: 1 < R51 / f < 1.5. In one embodiment, the optical system satisfies the relation: 0.4 < R52 / f < 0.8; further, the optical system satisfies the relation: 0.5 < R52 / f < 0.7. Satisfying at least one of the above relations is beneficial to maintaining the refractive power of the fifth lens within a reasonable range, avoiding excessive refractive power of the fifth lens, smoothly receiving the light from the object side, so that the optical system has good imaging quality.

[0058] In one embodiment, the optical system satisfies the relation: 0.25 < R61 / f < 0.5; further, the optical system satisfies the relation: 0.3 < R61 / f < 0.45. In one embodiment, the optical system satisfies the relation: 1 < R62 / f < 2.2; further, the optical system satisfies the relation: 1.25 < R62 / f < 2. Satisfying at least one of the above relations is beneficial to maintaining the surface shape of the sixth lens within a reasonable range, achieving balance in overall performance with the seventh lens, having a surface shape similar to that of the seventh lens and correcting aberrations, so that the optical system has good imaging quality.

[0059] In one embodiment, the optical system satisfies the relation: 1.4 < R71 / f; further, the optical system satisfies the relation: 1.6 < R71 / f < 7. In one embodiment, the optical system satisfies the relation: 0.2 < R72 / f < 0.6; further, the optical system satisfies the relation: 0.3 < R72 / f < 0.5. Satisfying at least one of the above relations is conducive to maintaining the surface shape of the seventh lens within a reasonable range, achieving a balance in the overall performance with the sixth lens, having a surface shape similar to that of the sixth lens and correcting aberrations in combination, so that the optical system has good imaging quality.

[0060] In one embodiment, the optical system satisfies the relation: 0 < R11 / R12 < 0.4; further, the optical system satisfies the relation: 0.2 < R11 / R12 < 0.35. Satisfying the above relation is conducive to reasonably configuring the ratio of the curvature radius of the object side of the first lens on the optical axis to the curvature radius of the image side of the first lens on the optical axis, adjusting the refractive power within a reasonable range, and controlling the generation and correction of aberrations.

[0061] In one embodiment, the optical system satisfies the relation: 1 < R21 / R22 < 2; further, the optical system satisfies the relation: 1.2 < R21 / R22 < 1.8. Satisfying the above relation is conducive to reasonably configuring the ratio of the curvature radius of the object side of the second lens on the optical axis to the curvature radius of the image side of the second lens on the optical axis, adjusting the refractive power within a reasonable range, and controlling the generation and correction of aberrations.

[0062] In one embodiment, the optical system satisfies the relation: 1 < R31 / R32 < 1.9; further, the optical system satisfies the relation: 1.1 < R31 / R32 < 1.7. Satisfying the above relation is conducive to reasonably configuring the ratio of the curvature radius of the object side of the third lens on the optical axis to the curvature radius of the image side of the third lens on the optical axis, adjusting the refractive power within a reasonable range, and controlling the generation and correction of aberrations.

[0063] In one embodiment, the optical system satisfies the relation: R41 / R42 < -1.4; further, the optical system satisfies the relation: -6 < R41 / R42 < -1.5. Satisfying the above relation is conducive to reasonably configuring the ratio of the curvature radius of the object side of the fourth lens on the optical axis to the curvature radius of the image side of the fourth lens on the optical axis, adjusting the refractive power within a reasonable range, and controlling the generation and correction of aberrations.

[0064] In one embodiment, the optical system satisfies the relation: 1.5 < R51 / R52 < 2.6; further, the optical system satisfies the relation: 1.7 < R51 / R52 < 2.4. Satisfying the above relations is conducive to a reasonable configuration of the ratio of the curvature radius of the object side of the fifth lens on the optical axis to the curvature radius of the image side of the fifth lens on the optical axis, adjusting the refractive power within a reasonable range, and controlling the generation and correction of aberrations.

[0065] In one embodiment, the optical system satisfies the relation: 0 < R61 / R62 < 0.35; further, the optical system satisfies the relation: 0.15 < R61 / R62 < 0.3. Satisfying the above relations is conducive to a reasonable configuration of the ratio of the curvature radius of the object side of the sixth lens on the optical axis to the curvature radius of the image side of the sixth lens on the optical axis, adjusting the refractive power within a reasonable range, making the surface shapes of the sixth lens and the seventh lens similar, and reducing the light incident angle.

[0066] In one embodiment, the optical system satisfies the relation: 3 < R71 / R72; further, the optical system satisfies the relation: 4 < R71 / R72 < 17. Satisfying the above relations is conducive to a reasonable configuration of the ratio of the curvature radius of the object side of the seventh lens on the optical axis to the curvature radius of the image side of the seventh lens on the optical axis, reasonably setting the difference between the curvature radius of the object side of the seventh lens and the curvature radius of the image side of the seventh lens, adjusting the refractive power within a reasonable range, controlling the generation and correction of aberrations, and achieving a small-angle deflection of all-field light rays within the optical system.

[0067] In one embodiment, the optical system satisfies the relation: 0.2 < |(R51 - R52) / (R51 + R52)| < 0.5; further, the optical system satisfies the relation: 0.25 < |(R51 - R52) / (R51 + R52)| < 0.45. Satisfying the above relations is conducive to effectively correcting the astigmatism of the optical system, the difference in surface shapes between the two will not be too large, and reducing the light incident angles on the two surfaces.

[0068] In one embodiment, the optical system satisfies the relation: 0.8 < DL / TTL < 0.9; further, the optical system satisfies the relation: 0.83 < DL / TTL < 0.87. Here, 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 of the optical system on the optical axis. Satisfying the above relations is conducive to a reasonable configuration of the ratio of the distance from the object side of the first lens to the image side of the seventh lens on the optical axis to the distance from the object side of the first lens to the imaging surface of the optical system on the optical axis. On the premise of miniaturizing the optical system, increasing the distance from the image side of the seventh lens to the imaging surface of the optical system on the optical axis, and further increasing the layout space at the module structure end.

[0069] In one embodiment, the optical system satisfies the relationship: 1.15 < TTL / f < 1.55; further, the optical system satisfies the relationship: 1.22 < TTL / f < 1.5. Satisfying the above relationships is beneficial to reasonably configure the ratio of the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis to the effective focal length of the optical system, enabling the optical system to have a smaller overall optical length, achieving the characteristic of miniaturization, and also enabling the optical system to have a better telephoto effect.

[0070] In one embodiment, the optical system satisfies the relationship: 0.8 < ImgH / f < 1.2; further, the optical system satisfies the relationship: 0.9 < ImgH / f < 1.1. Here, ImgH is half of the image height corresponding to the maximum field angle of the optical system. Satisfying the above relationships enables the refractive power of the optical system to match the image plane size, improving the imaging quality of the optical system.

[0071] In one embodiment, the optical system satisfies the relationship: 1.4 < f123 / f < 2.4; further, the optical system satisfies the relationship: 1.4 < f123 / f < 2.4. Here, f123 is the combined effective focal length of the first lens, the second lens, and the third lens. Satisfying the above relationships enables the focal lengths of the first lens to the third lens to be reasonably configured, which is beneficial for the first lens to the third lens to mutually regulate and reduce aberrations, and simplifies the processing manufacturability of the first lens to the third lens, reducing its tolerance sensitivity.

[0072] In one embodiment, the optical system satisfies the relationship: FOV / (FNOmax - FNOmin) < 35 deg; further, the optical system satisfies the relationship: 28 deg < FOV / (FNOmax - FNOmin) < 33 deg. Here, FOV is the maximum field angle of the optical system, FNOmax is the maximum f-number of the optical system, and FNOmin is the minimum f-number of the optical system. Satisfying the above relationships enables the optical system to have a larger field angle, and the f-number of the optical system is maintained within a reasonable range, achieving the combined effect of a larger field angle and a large aperture for the optical system. The optical system has a reasonable light input amount, improving the overall illuminance of the imaging picture, making the optical system suitable for different lighting environments.

[0073] In one embodiment, the optical system satisfies the relationship: 3.5 < |f7 / SAG71|; further, the optical system satisfies the relationship: 4 < |f7 / SAG71| < 7. In one embodiment, the optical system satisfies the relationship: 3 < |f7 / SAG72|; further, the optical system satisfies the relationship: 4.5 < |f7 / SAG72| < 7.5. Here, SAG71 is the sagitta at the maximum effective aperture of the object side surface of the seventh lens, and SAG72 is the sagitta at the maximum effective aperture of the image side surface of the seventh lens. Meeting at least one of the above relationships enables reasonable setting of the effective focal length of the seventh lens and the surface shape of the object side surface of the seventh lens, which is beneficial to minimizing chromatic aberration and spherical aberration to the greatest extent and improving the imaging quality of the optical system; at the same time, it is also beneficial to reasonably distribute the refractive power of the seventh lens, strengthen the light-gathering ability of the optical system, reduce the total length of the optical system, and achieve miniaturization of the optical system.

[0074] In one embodiment, the optical system satisfies the relationship: 2 < (|SAG71| + |SAG72|) / CT7 < 14; further, the optical system satisfies the relationship: 2.7 < (|SAG71| + |SAG72|) / CT7 < 13. Here, CT7 is the thickness of the seventh lens on the optical axis. Meeting the above relationship is beneficial to reasonably controlling the refractive power and thickness of the seventh lens at various positions perpendicular to the optical axis, avoiding the seventh lens being too thick or too thin, reducing the incident angle of light on the object side surface of the seventh lens, and reducing the tolerance sensitivity of the optical system; at the same time, the seventh lens has multiple inflection points, which is beneficial to correcting the distortion and field curvature generated by the object side lens of the seventh lens and evenly distributing the refractive power of multiple lenses near the imaging surface of the optical system.

[0075] In one embodiment, the optical system satisfies the relationship: 0.5 < Yc62 / SD62 < 0.75; further, the optical system satisfies the relationship: 0.55 < Yc62 / SD62 < 0.7. Here, Yc62 is the vertical height from the off-axis vertex of the image side surface of the sixth lens to the optical axis, and SD62 is the maximum effective aperture of the image side surface of the sixth lens. Meeting the above relationship is beneficial to reasonably controlling the refractive power and thickness of the sixth lens at various positions perpendicular to the optical axis, avoiding the sixth lens being too thick or too thin, reducing the incident angle of light on the object side surface of the sixth lens, and reducing the tolerance sensitivity of the optical system.

[0076] In one embodiment, the optical system satisfies the relation: 0.25 < Yc72 / SD72 < 0.5; further, the optical system satisfies the relation: 0.3 < Yc72 / SD72 < 0.45. Here, Yc72 is the off-axis vertex vertical height 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. Satisfying the above relation is beneficial to reasonably control the refractive power and thickness of the seventh lens at various positions perpendicular to the optical axis, avoid the seventh lens being too thick or too thin, reduce the incident angle of light on the object side of the seventh lens, and reduce the tolerance sensitivity of the optical system.

[0077] In one embodiment, the optical system satisfies the relation: 0.4 < (AT34 + CT5) / (AT45 + AT56) < 2; further, the optical system satisfies the relation: 0.5 < (AT34 + CT5) / (AT45 + AT56) < 1.9. Here, AT34 is the distance on the optical axis from the image side of the third lens to the object side of the fourth lens, CT5 is the thickness of the fifth lens on the optical axis, AT45 is the distance on the optical axis from the image side of the fourth lens to the object side of the fifth lens, and AT56 is the distance on the optical axis from the image side of the fifth lens to the object side of the sixth lens. Satisfying the above relation is beneficial to reducing the sensitivity of the optical system, making the fifth lens effectively diverge the outgoing angle of light, and making the optical system adapt to an imaging surface with a larger area.

[0078] In one embodiment, the optical system satisfies the relation: 0.8 < (CT1 + CT3) / (CT4 + CT5) < 1.3; further, the optical system satisfies the relation: 0.9 < (CT1 + CT3) / (CT4 + CT5) < 1.2. Here, CT1 is the thickness of the first lens on the optical axis, CT3 is the thickness of the third lens on the optical axis, CT4 is the thickness of the fourth lens on the optical axis, and CT5 is the thickness of the fifth lens on the optical axis. Satisfying the above relation is beneficial to reducing the sensitivity of the optical system, delaying the incident angle of light entering the optical system, and maintaining the miniaturization characteristics of the optical system; at the same time, it is also beneficial to simplify the surface shape setting of the first lens and the third lens, make the first lens and the third lens mutually regulate and reduce aberration, reduce the aberration correction pressure of the lens on the image side of the third lens, and simplify the processing technology of the first lens and the third lens, reducing their tolerance sensitivity.

[0079] In one embodiment, the optical system satisfies the relation: 0.8 < (CT1 + CT2) / (CT3 + CT4) < 1.5; further, the optical system satisfies the relation: 0.9 < (CT1 + CT2) / (CT3 + CT4) < 1.4. Here, CT2 is the thickness of the second lens on the optical axis. Satisfying the above relation is beneficial to forming a double Gauss structure.

[0080] In one embodiment, the optical system satisfies the relationship: 0.7 < (AT34 + AT23) / (AT45 + AT56) < 1.1; further, the optical system satisfies the relationship: 0.8 < (AT34 + AT23) / (AT45 + AT56) < 1. Wherein, AT23 is the distance along the optical axis from the image-side surface of the second lens to the object-side surface of the third lens. Satisfying the above relationships facilitates reasonable control of lens gaps, improving image quality and assemblability.

[0081] In one embodiment, the optical system satisfies the relationship: 2.5 < (CT1 + CT2 + CT3 + CT4) / AT23 < 5; further, the optical system satisfies the relationship: 3 < (CT1 + CT2 + CT3 + CT4) / AT23 < 4.4. Satisfying the above relationships is beneficial for controlling the ratio of lens spacing to thickness, and is conducive to forming a double Gaussian structure.

[0082] In one embodiment, the optical system satisfies the relationship: 0.8 < (CT5 + CT6 + CT7) / AT67 < 2.2; further, the optical system satisfies the relationship: 0.9 < (CT5 + CT6 + CT7) / AT67 < 2.1. Wherein, CT6 is the thickness of the sixth lens on the optical axis, CT7 is the thickness of the seventh lens on the optical axis, and AT67 is the distance on the optical axis from the image-side surface of the sixth lens to the object-side surface of the seventh lens. Satisfying the above relationships facilitates the spacing between the sixth and seventh lenses, ensuring sufficient spatial spacing for aberration correction.

[0083] In some embodiments, the optical system further includes a filter, which can be an infrared cut-off filter or an infrared bandpass filter. The infrared cut-off filter is used to filter out infrared light, while the infrared bandpass filter only allows infrared light to pass through. In this application, the filter is an infrared cut-off filter, which is fixedly disposed relative to each lens in the optical system to prevent infrared light from reaching the imaging surface of the optical system and interfering with normal imaging. The filter can be assembled together with each lens as part of the optical system. In other embodiments, the filter can also be a component independent of the optical system, and the filter can be installed between the optical system and the photosensitive chip during the assembly of the optical system and the photosensitive chip. It is understood that the filter can be made of optical glass coating, colored glass, or other materials, and can be selected according to actual needs. This embodiment does not impose specific limitations. In other embodiments, the function of filtering out infrared light can also be achieved by providing a filter coating on at least one of the first to seventh lenses.

[0084] First Embodiment

[0085] Please refer to Figure 1a , Figure 1c and Figure 1eThe optical system 10 of this embodiment includes, from the object side to the image side along the optical axis:

[0086] The first lens L1 has positive refractive power, the object side S1 is convex near the optical axis, and the image side S2 is concave near the optical axis.

[0087] The second lens L2 has a negative refractive power, the object-side surface S3 is convex near the optical axis, and the image-side surface S4 is concave near the optical axis.

[0088] The third lens L3 has a negative refractive power, the object-side surface S5 is convex near the optical axis, and the image-side surface S6 is concave near the optical axis.

[0089] The fourth lens L4 has positive refractive power. The object-side surface S7 is convex near the optical axis, and the image-side surface S8 is convex near the optical axis.

[0090] The fifth lens L5 has a negative refractive power. The object-side surface S9 is convex near the optical axis, and the image-side surface S10 is concave near the optical axis.

[0091] The sixth lens L6 has positive refractive power. The object-side surface S11 is convex near the optical axis, and the image-side surface S12 is concave near the optical axis.

[0092] The seventh lens L7 has a negative refractive power. The object-side surface S13 is convex near the optical axis, and the image-side surface S14 is concave near the optical axis.

[0093] In addition, the optical system 10 also includes an aperture STO, an IR filter, and an imaging plane IMG. A variable aperture is also provided on the object side of the optical system 10. In this embodiment, the aperture STO is located on the object side of the first lens of the optical system 10 and is used to control the amount of light entering the system. Figure 1a , Figure 1c and Figure 1e Schematic diagrams of the optical system 10 with the aperture STO in three different states are shown. When the aperture STO is in three different states, the optical system 10 can have different aperture numbers. Therefore, for ease of description of the three states of the aperture STO, [the diagrams are then presented]. Figure 1a The aperture STO in the state shown is called the aperture STO of the optical system 10 in the first aperture state. Figure 1c The aperture STO in the state shown is called the aperture STO of the optical system 10 in the second aperture state. Figure 1e The aperture STO in the shown state is called the aperture STO of the optical system 10 in the first aperture state. It can be understood that the aperture STO includes, but is not limited to, these three states. By adjusting the distance A from the aperture STO to the object side surface S1 of the first lens L1 and the opening size of the aperture STO, the aperture STO can also have other different states so that the optical system 10 can obtain different aperture numbers.

[0094] An infrared filter IR is positioned between the seventh lens L7 and the imaging surface IMG. It includes an object-side surface S15 and an image-side surface S16. The filter IR includes an infrared cut-off filter to filter out infrared light, ensuring that only visible light (wavelength 380nm-780nm) enters the imaging surface IMG. The infrared cut-off filter IR can be made of glass or plastic, and a coating can be applied to its surface. The first lens L1 to the seventh lens L7 can also be made of glass or plastic. The effective pixel area of ​​the photosensitive chip is located on the imaging surface IMG. An infrared photosensitive chip is positioned on the imaging surface IMG, capturing different wavelengths of information about the object for subsequent processing.

[0095] Table 1a shows the parameters of the optical system 10 in this embodiment, where the Y-radius is the radius of curvature of the object-side or image-side surface of the corresponding surface number at the optical axis. Surface numbers S1 and S2 are the object-side surface S1 and image-side surface S2 of the first lens L1, respectively; that is, in the same lens, the surface with the smaller surface number is the object-side surface, and the surface with the larger surface number is the image-side surface. The first value in the "thickness" parameter column of the first lens L1 is the thickness of the lens along the optical axis, and the second value is the distance along the optical axis from the image-side surface to the next surface in the image-side direction. Focal length, material refractive index, and Abbe number are all obtained using visible light with a reference wavelength of 587.6 nm. The units for Y-radius, thickness, and focal length are all millimeters (mm). Table 1b is supplementary data to Table 1a.

[0096] Table 1a

[0097]

[0098]

[0099] Table 1b

[0100] f(mm) FNO FOV(deg) TTL(mm) A(mm) First aperture 6.98 1.4 82.13 8.9 -0.38 Second aperture 6.98 2.0 82.13 8.9 0.07 Third aperture 6.98 4.0 82.13 8.9 0.07

[0101] Where f is the focal length of optical system 10, FNO is the aperture number of optical system 10, FOV is the maximum field of view of optical system 10, TTL is the distance from the object side of the first lens to the imaging surface on the optical axis, i.e., the total optical length, and A is the distance from the aperture stop STO to the object side S1 of the first lens L1 in the direction parallel to the optical axis.

[0102] In this embodiment, the object-side surface and image-side surface of the first lens L1 to the seventh lens L7 are both aspherical surfaces. The surface shape x of the aspherical surface can be defined using, but is not limited to, the following aspherical surface formula:

[0103]

[0104] Where x is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the vertex of the aspherical surface, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspherical surface shape formula. Table 1c gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 of the aspherical mirrors S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, and S14 that can be used in the first embodiment.

[0105] Table 1c

[0106]

[0107]

[0108] Figure 1b (First aperture setting) Figure 1d (Second aperture state) and Figure 1f (Third aperture state) (a) shows the longitudinal spherical aberration curves of the optical system 10 at different focal lengths in the first embodiment at wavelengths of 650.0000nm, 610.0000nm, 555.0000nm, 510.0000nm, 470.0000nm, and 435.0000nm. The horizontal axis along the X-axis represents the focal point shift, i.e., the distance from the imaging plane to the intersection of the light ray and the optical axis (in mm). The vertical axis along the Y-axis represents the normalized field of view. The longitudinal spherical aberration curves represent the deviation of the converging focal point of light rays of different wavelengths after passing through the lenses of the optical system 10. Figure 1b , Figure 1d and Figure 1f As can be seen in (a), the convergence focus of each wavelength of light in the first embodiment tends to be consistent, and the blur spots or color halos in the image are effectively suppressed, indicating that the imaging quality of the optical system 10 in this embodiment is good.

[0109] Figure 1b , Figure 1d and Figure 1f Figure (b) shows the astigmatism curves of the optical system 10 at different focal lengths in the first embodiment at a wavelength of 555.0000 nm. The horizontal axis along the X-axis represents the focus shift, and the vertical axis along the Y-axis represents the image height, both in mm. The S-curve in the astigmatism curves represents the sagittal field curvature at 555.0000 nm, and the T-curve represents the meridional field curvature at 555.0000 nm. Figure 1b , Figure 1d and Figure 1fAs can be seen in (b), the field curvature of the optical system 10 is small, and the field curvature and astigmatism of each field of view are well corrected, with clear imaging at both the center and edge of the field of view.

[0110] Figure 1b , Figure 1d and Figure 1f Image (c) shows the distortion curves of the optical system 10 at different focal lengths in the first embodiment at a wavelength of 555.0000 nm. The horizontal axis along the X-axis represents the distortion value (%), and the vertical axis along the Y-axis represents the image height in mm. The distortion curves represent the distortion magnitude corresponding to different field of view angles. Figure 1b , Figure 1d and Figure 1f As can be seen in (c), at a wavelength of 555.0000nm, the image distortion caused by the main beam is small, and the imaging quality of the system is excellent.

[0111] Depend on Figure 1b , Figure 1d and Figure 1f As can be seen from (a), (b) and (c), the optical system 10 of this embodiment has small aberrations, good imaging quality, and excellent imaging performance.

[0112] Second Embodiment

[0113] Please refer to Figure 2a The lens structure of the optical system 10 in this embodiment is the same as that in the first embodiment, and can be referred to accordingly.

[0114] Table 2a shows the parameters of the optical system 10 in this embodiment. The focal length, material refractive index, and Abbe number are obtained using visible light with a reference wavelength of 587.6 nm. The units for Y radius, thickness, and focal length are millimeters (mm). The meanings of the other parameters are the same as those in the first embodiment. Table 2b is supplementary data to Table 2a.

[0115] Table 2a

[0116]

[0117]

[0118] Table 2b

[0119] f(mm) FNO FOV (deg) TTL(mm) A(mm) First aperture 7.145 1.4 80.908 9.1 -0.38 Second aperture 7.145 2.0 80.908 9.1 0.07 Third aperture 7.145 4.0 80.908 9.1 0.07

[0120] Table 2c gives the higher-order coefficients that can be used for each aspherical mirror in the second embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0121] Table 2c

[0122]

[0123]

[0124] Figure 2b (First aperture setting) Figure 2c (Second aperture state) and Figure 2d (Third aperture state) Images (a), (b), and (c) respectively show the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system 10 at different focal lengths in the second embodiment. The longitudinal spherical aberration curve represents the deviation of the converging focal point of light rays of different wavelengths after passing through the lenses of the optical system 10; the astigmatism curve represents the meridional field curvature and sagittal field curvature; and the distortion curve represents the distortion magnitude corresponding to different field of view angles. Figure 2b , Figure 2c and Figure 2d As can be seen from the aberration diagram, the longitudinal spherical aberration, field curvature, and distortion of the optical system 10 are all well controlled, thus the optical system 10 of this embodiment has good imaging quality.

[0125] Third Embodiment

[0126] Please refer to Figure 3a The lens structure of the optical system 10 in this embodiment is the same as that in the first embodiment, and can be referred to accordingly.

[0127] Table 3a shows the parameters of the optical system 10 in this embodiment. The focal length, material refractive index, and Abbe number are all obtained using visible light with a reference wavelength of 587.6 nm. The units for Y radius, thickness, and focal length are millimeters (mm). The meanings of the other parameters are the same as those in the first embodiment. Table 3b is supplementary data to Table 3a.

[0128] Table 3a

[0129]

[0130]

[0131] Table 3b

[0132] f(mm) FNO FOV(deg) TTL(mm) A(mm) First aperture 6.99 1.4 82.34 8.9 -0.29 Second aperture 6.99 2.0 82.34 8.9 0.03 Third aperture 6.99 4.0 82.34 8.9 0.03

[0133] Table 3c gives the higher-order coefficients that can be used for each aspherical mirror in the third embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0134] Table 3c

[0135]

[0136]

[0137] Figure 3b (First aperture setting) Figure 3c (Second aperture state) and Figure 3d In the third aperture state, (a), (b), and (c) show the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system 10 at different focal lengths in the third embodiment, respectively. The longitudinal spherical aberration curve represents the deviation of the converging focal point of light rays of different wavelengths after passing through the lenses of the optical system 10; the astigmatism curve represents the meridional field curvature and sagittal field curvature; and the distortion curve represents the distortion magnitude corresponding to different field of view angles. Figure 3b , Figure 3c and Figure 3d As can be seen from the aberration diagram, the longitudinal spherical aberration, field curvature, and distortion of the optical system 10 are all well controlled, thus the optical system 10 of this embodiment has good imaging quality.

[0138] Fourth embodiment

[0139] Please refer to Figure 4a The lens structure of the optical system 10 in this embodiment is the same as that in the first embodiment, and can be referred to accordingly.

[0140] Table 4a shows the parameters of the optical system 10 in this embodiment. The focal length, material refractive index, and Abbe number are obtained using visible light with a reference wavelength of 587.6 nm. The units for Y radius, thickness, and focal length are millimeters (mm). The meanings of the other parameters are the same as those in the first embodiment. Table 4b is supplementary data to Table 4a.

[0141] Table 4a

[0142]

[0143] Table 4b

[0144]

[0145]

[0146] Table 4c gives the higher-order coefficients that can be used for each aspherical mirror in the fourth embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0147] Table 4c

[0148] Face number k A4 A6 A8 A10 S1 0.0000E+00 1.7560E-03 -2.8212E-03 2.6913E-03 -1.5033E-03 S2 0.0000E+00 -1.3670E-02 9.1262E-03 -5.3408E-03 2.2141E-03 S3 0.0000E+00 -2.1740E-02 9.7784E-03 -8.9662E-04 -1.7365E-03 S4 0.0000E+00 -1.3086E-02 8.8608E-03 -4.2183E-03 2.4678E-03 S5 0.0000E+00 -1.8987E-02 1.0216E-02 -1.9308E-02 1.6864E-02 S6 0.0000E+00 -2.7437E-02 3.0315E-02 -3.7575E-02 2.4685E-02 S7 0.0000E+00 -1.0557E+00 1.4492E+01 -1.4221E+02 9.6523E+02 S8 0.0000E+00 -6.8152E-01 2.0028E+00 -1.4011E+01 9.2488E+01 S9 0.0000E+00 -4.4598E-02 3.4962E-02 -1.3604E-02 -8.1129E-03 S10 0.0000E+00 -1.4408E-01 1.3083E-01 -9.8315E-02 5.3364E-02 S11 -2.7234E+00 -8.5493E-02 8.3086E-02 -5.8906E-02 2.9439E-02 S12 0.0000E+00 3.7644E-03 6.1252E-03 -4.2959E-03 1.3387E-03 S13 0.0000E+00 -7.5157E-02 2.6543E-02 -7.9722E-03 1.8355E-03 S14 -7.2544E+00 -4.0623E-02 1.5284E-02 -4.6596E-03 1.0513E-03 Face number A12 A14 A16 A18 A20 S1 4.9746E-04 -9.6195E-05 9.8176E-06 -3.7227E-07 -5.5067E-09 S2 -5.4982E-04 6.4538E-05 6.3981E-07 -8.9832E-07 6.0122E-08 S3 1.3630E-03 -5.0080E-04 1.0201E-04 -1.0952E-05 4.8066E-07 S4 -1.2784E-03 4.8707E-04 -1.1946E-04 1.6617E-05 -9.8388E-07 S5 -9.2489E-03 3.1953E-03 -6.7479E-04 7.9822E-05 -4.0459E-06 S6 -1.0075E-02 2.6457E-03 -4.3637E-04 4.1306E-05 -1.7102E-06 S7 -4.7898E+03 1.7536E+04 -4.7190E+04 9.3014E+04 -1.3353E+05 S8 -5.3717E+02 2.4318E+03 -7.9365E+03 1.8328E+04 -2.9864E+04 S9 1.4130E-02 -9.3379E-03 3.7771E-03 -1.0299E-03 1.9509E-04 S10 -2.1033E-02 6.0745E-03 -1.2946E-03 2.0426E-04 -2.3791E-05 S11 -1.0695E-02 2.8364E-03 -5.5028E-04 7.8020E-05 -8.0289E-06 S12 -2.7061E-04 3.9082E-05 -4.1333E-06 3.1906E-07 -1.7663E-08 S13 -2.8560E-04 2.9816E-05 -2.1259E-06 1.0423E-07 -3.4530E-09 S14 -1.7263E-04 2.0779E-05 -1.8507E-06 1.2247E-07 -5.9939E-09 Face number A22 A24 A26 A28 A30 S7 1.3781E+05 -9.9514E+04 4.7715E+04 -1.3647E+04 1.7622E+03 S8 3.4040E+04 -2.6502E+04 1.3399E+04 -3.9545E+03 5.1563E+02 S9 -2.5715E-05 2.3098E-06 -1.3442E-07 4.5512E-09 -6.7708E-11 S10 2.0203E-06 -1.2168E-07 4.9271E-09 -1.2031E-10 1.3382E-12 S11 5.9069E-07 -3.0192E-08 1.0166E-09 -2.0253E-11 1.8070E-13 S12 6.7903E-10 -1.7100E-11 2.5005E-13 -1.4997E-15 -2.5347E-18 S13 7.2501E-11 -7.7535E-13 -1.1682E-15 1.2554E-16 -9.8266E-19 S14 2.1368E-10 -5.3825E-12 9.0604E-14 -9.1272E-16 4.1544E-18

[0149] Figure 4b (First aperture setting) Figure 4c (Second aperture state) and Figure 4d(In the third aperture state) (a), (b), and (c) show the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system 10 at different focal lengths in the fourth embodiment, respectively. The longitudinal spherical aberration curve represents the deviation of the converging focal point of light rays of different wavelengths after passing through the lenses of the optical system 10; the astigmatism curve represents the meridional field curvature and sagittal field curvature; and the distortion curve represents the distortion magnitude corresponding to different field of view angles. Figure 4b , Figure 4c and Figure 4d As can be seen from the aberration diagram, the longitudinal spherical aberration, field curvature, and distortion of the optical system 10 are all well controlled, thus the optical system 10 of this embodiment has good imaging quality.

[0150] Fifth embodiment

[0151] Please refer to Figure 5a In this embodiment, the object-side surface S7 of the fourth lens L4 is concave near the optical axis, and the object-side surface S9 of the fifth lens L5 is concave near the optical axis. The other structures of this embodiment are the same as those of the first embodiment, and can be referred to accordingly.

[0152] Table 5a shows the parameters of the optical system 10 in this embodiment. The focal length, material refractive index, and Abbe number are obtained using visible light with a reference wavelength of 587.6 nm. The units for Y radius, thickness, and focal length are millimeters (mm). The meanings of the other parameters are the same as those in the first embodiment. Table 5b is supplementary data to Table 5a.

[0153] Table 5a

[0154]

[0155] Table 5b

[0156] f(mm) FNO FOV (deg) TTL(mm) A(mm) First aperture 6.96 1.4 82.25 8.9 -0.29 Second aperture 6.96 2.0 82.25 8.9 0.03 Third aperture 6.96 4.0 82.25 8.9 0.03

[0157] Table 5c gives the higher-order coefficients that can be used for each aspherical mirror in the fifth embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0158] Table 5c

[0159]

[0160]

[0161] Figure 5b (First aperture setting) Figure 5c (Second aperture state) and Figure 5d(In the third aperture state) (a), (b), and (c) show the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system 10 at different focal lengths in the fifth embodiment, respectively. The longitudinal spherical aberration curve represents the deviation of the converging focal point of light rays of different wavelengths after passing through the lenses of the optical system 10; the astigmatism curve represents the meridional field curvature and sagittal field curvature; and the distortion curve represents the distortion magnitude corresponding to different field of view angles. Figure 5b , Figure 5c and Figure 5d As can be seen from the aberration diagram, the longitudinal spherical aberration, field curvature, and distortion of the optical system 10 are all well controlled, thus the optical system 10 of this embodiment has good imaging quality.

[0162] Table 6 shows the values ​​of several relationships in the optical systems of the first to fifth embodiments.

[0163] Table 6

[0164]

[0165]

[0166] As can be seen from Table 6, the optical systems of the first to fifth embodiments all satisfy the following relational expressions: 1.2 < TTL / ImgH < 1.55, 77deg < FOV < 86deg, 0.9 < f1 / f < 1.5, -4.5 < f2 / f < -2.5, f3 / f < -4, 1.5 < f4 / f < 4, -3 < f5 / f < -1, 0.4 < f6 / f < 1.2, -1.2 < f7 / f < -0.45, 0.3 < R11 / f < 0.7, 1.3 < R12 / f < 2.2, 0.5 < R21 / f < 1.8, 0.5 < R22 / f < 1, 1.2 < R31 / f < 2.4, 0.9 < R32 / f < 1.7, 2.5 < R41 / f, -4 < R42 / f < -1, 0.9 < R51 / f < 1.6, 0.4 < R52 / f < 0.8, 0.25 < R61 / f < 0.5, 1 < R62 / f < 2.2, 1.4 < R71 / f, 0.2 < R72 / f < 0.6, 0 < R11 / R12 < 0.4, 1 < R21 / R22 < 2, 1 < R31 / R32 < 1.9, R41 / R42 < -1.4, 1.5 < R51 / R52 < 2.6, 0 < R61 / R62 < 0.35, 3 < R71 / R72, 0.2 < |(R51 - R52) / (R51 + R52)| < 0.5, 0.8 < DL / TTL < 0.9, 1.15 < TTL / f < 1.55, 0.8 < ImgH / f < 1.2, 1.4 < f123 / f < 2.4, FOV / (FNOmax - FNOmin) < 35deg, 3.5 < |f7 / SAG71|, 3 < |f7 / SAG72|, 2 < (|SAG71| + |SAG72|) / CT7 < 14, 0.5 < Yc62 / SD62 < 0.75, 0.25 < Yc72 / SD72 < 0.5, 0.4 < (AT34 + CT5) / (AT45 + AT56) < 2, 0.8 < (CT1 + CT3) / (CT4 + CT5) < 1.3, 0.8 < (CT1 + CT2) / (CT3 + CT4) < 1.5, 0.7 < (AT34 + AT23) / (AT45 + AT56) < 1.1, 2.5 < (CT1 + CT2 + CT3 + CT4) / AT23 < 5, 0.8 < (CT5 + CT6 + CT7) / AT67 < 2.2.

[0167] Please refer to Figure 6The present invention also provides a camera module 20, which includes a photosensitive chip 21 and an optical system 10 as described in any embodiment of the first aspect. The photosensitive chip 21 is disposed on the image side of the optical system 10. The photosensitive surface of the photosensitive chip 21 is located on the imaging surface of the optical system 10, and light rays from an object incident on the photosensitive surface through a lens can be converted into electrical signals for an image. The photosensitive chip 21 can be a complementary metal-oxide-semiconductor (CMOS) or a charge-coupled device (CCD). The camera module 20 can be an imaging module integrated into an electronic device 30 or a separate lens. By incorporating the optical system 10 provided by the present invention into the camera module 20, the camera module 20 can achieve miniaturization, good imaging performance, and variable aperture characteristics through reasonable design of the surface shape and refractive power of each lens in the optical system 10.

[0168] Please see Figure 7 The present invention also provides an electronic device 30, which includes a housing 31 and the aforementioned camera module 20, wherein the camera module 20 is disposed within the housing 31. This electronic device 30 includes, but is not limited to, smartphones, computers, and smartwatches. By incorporating the camera module 20 provided by the present invention into the electronic device 30, the electronic device 30 achieves miniaturization, good imaging performance, and variable aperture characteristics.

[0169] The above description discloses only some preferred embodiments of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art can understand that implementing all or part of the above embodiments and making equivalent changes in accordance with the claims of the present invention still fall within the scope of the present invention.

Claims

1. An optical system, characterized in that, There are a total of seven lenses with refractive power, which successively include, from the object side to the image side along the optical axis: The first lens, having positive refractive power, the object side surface of the first lens is convex near the optical axis, and the image side surface of the first lens is concave near the optical axis; The second lens, having negative refractive power, the object side surface of the second lens is convex near the optical axis, and the image side surface of the second lens is concave near the optical axis; The third lens, having negative refractive power, the object side surface of the third lens is convex near the optical axis, and the image side surface of the third lens is concave near the optical axis; The fourth lens, having positive refractive power, the image side surface of the fourth lens is convex near the optical axis; The fifth lens, having negative refractive power, the object side surface of the fifth lens is convex near the optical axis, and the image side surface of the fifth lens is concave near the optical axis; The sixth lens, having positive refractive power, the object side surface of the sixth lens is convex near the optical axis, and the image side surface of the sixth lens is concave near the optical axis; The seventh lens, having negative refractive power, the object side surface of the seventh lens is convex near the optical axis, and the image side surface of the seventh lens is concave near the optical axis; The optical system satisfies the relational expressions: 1.2 < TTL / ImgH < 1.55, and 77deg < FOV < 86deg, and 0.5 < Yc62 / SD62 < 0.75, and 0.25 < Yc72 / SD72 < 0.5; Where, TTL is the distance on the optical axis from the object side surface of the first lens to the imaging surface of the optical system, ImgH is half of the image height corresponding to the maximum field angle of the optical system, FOV is the maximum field angle of the optical system, Yc62 is the vertical height from the off-axis vertex of the image side surface of the sixth lens to the optical axis, SD62 is the maximum effective aperture of the image side surface of the sixth lens, Yc72 is the vertical height from the off-axis vertex of 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.

2. The optical system as described in claim 1, characterized in that, The optical system satisfies the relational expressions: 1 < f1 / f < 1.4, and / or -4 < f2 / f < -3, and / or -10 < f3 / f < -5, and / or 2 < f4 / f < 3.5, and / or -2.5 < f5 / f < -1.5, and / or 0.6 < f6 / f < 1, and / or -1 < f7 / f < -0.6; Where, f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, f7 is the effective focal length of the seventh lens, and f is the effective focal length of the optical system.

3. The optical system as described in claim 1, characterized in that, The optical system satisfies the relational expressions: ​ ​ ​ ​ ​ ​ ​ -3 < R42 / f < -1.25, and / or 1 < R51 / f < 1.5, and / or 0.5 < R52 / f < 0.7, and / or 0.3 < R61 / f < 0.45, and / or 1.25 < R62 / f < 2, and / or 1.6 < R71 / f < 7, and / or 0.3 < R72 / f < 0.5; where, R11 is the radius of curvature of the object side surface of the first lens at the optical axis, R12 is the radius of curvature of the image side surface of the first lens at the optical axis, R21 is the radius of curvature of the object side surface of the second lens at the optical axis, R22 is the radius of curvature of the image side surface of the second lens at the optical axis, R31 is the radius of curvature of the object side surface of the third lens at the optical axis, R32 is the radius of curvature of the image side surface of the third lens at the optical axis, R41 is the radius of curvature of the object side surface of the fourth lens at the optical axis, R42 is the radius of curvature of the image side surface of the fourth lens at the optical axis, R51 is the radius of curvature of the object side surface of the fifth lens at the optical axis, R52 is the radius of curvature of the image side surface of the fifth lens at the optical axis, R61 is the radius of curvature of the object side surface of the sixth lens at the optical axis, R62 is the radius of curvature of the image side surface of the sixth lens at the optical axis, R71 is the radius of curvature of the object side surface of the seventh lens at the optical axis, R72 is the radius of curvature of the image side surface of the seventh lens at the optical axis, and f is the effective focal length of the optical system.

4. The optical system as claimed in claim 1, characterized in that, The optical system satisfies the relationship: 0.2 < R11 / R12 < 0.35, and / or 1.2 < R21 / R22 < 1.8, and / or 1.1 < R31 / R32 < 1.7, and / or -6 < R41 / R42 < -1.5, and / or 1.7 < R51 / R52 < 2.4, and / or 0.1 < R + 1 / R < 0.3, and / or 4 < R71 / R72 < 17, and / or 0.25 < |(R51 - R52) / (R51 + R52)| < 0.45; where, R11 is the radius of curvature of the object side surface of the first lens at the optical axis, R12 is the radius of curvature of the image side surface of the first lens at the optical axis, R21 is the radius of curvature of the object side surface of the second lens at the optical axis, R22 is the radius of curvature of the image side surface of the second lens at the optical axis, R31 is the radius of curvature of the object side surface of the third lens at the optical axis, R32 is the radius of curvature of the image side surface of the third lens at the optical axis, R41 is the radius of curvature of the object side surface of the fourth lens at the optical axis, R42 is the radius of curvature of the image side surface of the fourth lens at the optical axis, R51 is the radius of curvature of the object side surface of the fifth lens at the optical axis, R52 is the radius of curvature of the image side surface of the fifth lens at the optical axis, R61 is the radius of curvature of the object side surface of the sixth lens at the optical axis, R62 is the radius of curvature of the image side surface of the sixth lens at the optical axis, R71 is the radius of curvature of the object side surface of the seventh lens at the optical axis, R72 is the radius of curvature of the image side surface of the seventh lens at the optical axis.

5. The optical system as claimed in claim 1, characterized in that, The optical system satisfies the relationship: It should be noted that there seems to be an error in the original text for item . It should probably be "0.15 < R61 / R62 < 0.3" instead of "0.1 < R + 1 / R < 0.3". The above translation is based on the corrected understanding. 0.83 < DL / TTL < 0.87, and / or 1.22 < TTL / f < 1.5, and / or 0.9 < ImgH / f < 1.1, and / or 1.6 < f123 / f < 2.4, and / or 28 deg < FOV / (FNOmax - FNOmin) < 33 deg; 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, f is the effective focal length of the optical system, f123 is the combined effective focal length of the first lens, the second lens and the third lens, FNOmax is the maximum f-number of the optical system, and FNOmin is the minimum f-number of the optical system.

6. The optical system as claimed in claim 1, characterized in that, The optical system satisfies the relationship: 4 < |f7 / SAG71| < 7, and / or 4.5 < |f7 / SAG72| < 7.5, and / or 2.7 < (|SAG71| + |SAG72|) / CT7 < 13; where, f7 is the effective focal length of the seventh lens, SAG71 is the sagitta at the maximum effective aperture of the object side of the seventh lens, SAG72 is the sagitta at the maximum effective aperture of the image side of the seventh lens, and CT7 is the thickness of the seventh lens on the optical axis.

7. The optical system as claimed in claim 1, characterized in that, The optical system satisfies the relationship: 0.55 < Yc62 / SD62 < 0.7, and / or 0.3 < Yc72 / SD72 < 0.45; where, Yc62 is the vertical height from the off-axis vertex of the image side of the sixth lens to the optical axis, SD62 is the maximum effective aperture of the image side of the sixth lens, Yc72 is the vertical height from the off-axis vertex of 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.

8. The optical system as claimed in claim 1, characterized in that, The optical system satisfies the relationship: 0.5 < (AT34 + CT5) / (AT45 + AT56) < 1.9, and / or 0.9 < (CT1 + CT3) / (CT4 + CT5) < 1.2, and / or 0.9 < (CT1 + CT2) / (CT3 + CT4) < 1.4, and / or 0.8 < (AT34 + AT23) / (AT45 + AT56) < 1, and / or 3 < (CT1 + CT2 + CT3 + CT4) / AT23 < 4.4, and / or 0.9 < (CT5 + CT6 + CT7) / AT67 < 2.1; Wherein, AT23 is the distance on the optical axis from the image side of the second lens to the object side of the third lens, AT34 is the distance on the optical axis from the image side of the third lens to the object side of the fourth lens, AT45 is the distance on the optical axis from the image side of the fourth lens to the object side of the fifth lens, AT56 is the distance on the optical axis from the image side of the fifth lens to the object side of the sixth lens, AT67 is the distance on the optical axis from the image side of the sixth lens to the object side of the seventh lens, 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, CT4 is the thickness of the fourth lens on the optical axis, CT5 is the thickness of the fifth lens on the optical axis, CT6 is the thickness of the sixth lens on the optical axis, and CT7 is the thickness of the seventh lens on the optical axis.

9. A camera module, characterized in that, The optical system and photosensitive chip according to any one of claims 1 to 8 are included, wherein the photosensitive chip is located on the image side of the optical system.

10. An electronic device, characterized in that, The electronic device includes a housing and the camera module as described in claim 9, wherein the camera module is disposed within the housing.

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