Optical system, camera module and electronic equipment

Abstract

The invention discloses an optical system, a camera module and electronic equipment, the optical system comprises seven lenses with refractive power, and the optical system sequentially comprises 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 from an object side to an image side along an optical axis; wherein the object side surface of the first lens, the object side surface of the second lens, the object side surface of the third lens, the image side surface of the fourth lens, the object side surface of the fifth lens, the object side surface of the sixth lens and the object side surface of the seventh lens are convex surfaces near the optical axis; the image side surface of the first lens, the image side surface of the second lens, the image side surface of the third lens, the image side surface of the fifth lens, the image side surface of the sixth lens and the image side surface of the seventh lens are concave surfaces at the positions close to the optical axis. The optical system can satisfy miniaturization, and has a good imaging effect and a variable aperture characteristic.

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 in 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 purpose 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 purpose of the present invention, the following technical solutions are provided:

[0006] In a first aspect, the present invention provides an optical system, which has a total of 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 of view 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 gently transmit the 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 increasing 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 occurrence of an overly bent surface shape, 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, combined with the surface shape design where the object sides of the fifth to seventh lenses are convex at the optical axis and the image sides are concave at the optical axis, not only helps to eliminate the axial chromatic aberration but also shortens the axial focal length. While improving the imaging quality, it also realizes the miniaturization design; at least one inflection point exists on the object side and the image side of the seventh lens, which is beneficial to correct the off-axis aberration and suppress the incident angle of light on the imaging surface, improving both the imaging quality and the relative illumination.

[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 of view angle of the optical system is reasonably configured, which is beneficial to improving the resolution of the optical system in the full field of view and enhancing the imaging quality of the edge field of view; at the same time, it is also beneficial to make the optical system have a smaller overall optical length and realize the miniaturization characteristics.

[0010] By making the optical system satisfy 77deg < FOV < 86deg, the maximum field of view 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 miniaturization characteristics while obtaining sufficient field of view.

[0011] In the second aspect, the present invention further provides a camera module, which includes a photosensitive chip and the optical system described in any one of the embodiments of the first aspect, wherein the photosensitive chip is arranged on the image side of the optical system. Wherein, the photosensitive surface of the photosensitive chip is located on the imaging surface of the optical system, and the light of the object incident on the photosensitive surface through the lens can be converted into an electrical signal of the 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 in an electronic device, or it can be an independent lens. By adding the optical system provided by the present invention to the camera module, the surface shape and refractive power of each lens in the optical system can be reasonably designed, so that the camera module meets the characteristics of miniaturization, good imaging effect and variable aperture.

[0012] In a third aspect, the present invention further provides an electronic device, the electronic device comprising a housing and the camera module described in the second aspect, the camera module being disposed in the housing. The electronic device includes but is not limited to a smart phone, a computer, and a smart watch. By adding the camera module provided by the present invention to the electronic device, the electronic device satisfies the characteristics of miniaturization, good imaging effect, and variable aperture. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

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

[0015] Figure 1b Shows Figure 1a The longitudinal spherical aberration curve, astigmatism curve and distortion curve;

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

[0017] Figure 1d Shows Figure 1c The longitudinal spherical aberration curve, astigmatism curve and distortion curve;

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

[0019] Figure 1f Shows Figure 1e The longitudinal spherical aberration curve, astigmatism curve and distortion curve;

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

[0021] Figure 2b Shows Figure 2a The longitudinal spherical aberration curve, astigmatism curve and distortion curve;

[0022] Figure 2c is a longitudinal spherical aberration curve diagram, an astigmatism curve diagram and a distortion curve diagram of the second embodiment in the second aperture state;

[0023] Figure 2d 1 is a longitudinal spherical aberration curve diagram, an astigmatism curve diagram and a distortion curve diagram of the second embodiment in the third aperture state;

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

[0025] Figure 3b Shows Figure 3a The longitudinal spherical aberration curve, astigmatism curve and distortion curve;

[0026] Figure 3c 1. The longitudinal spherical aberration curve diagram, the astigmatism curve diagram and the distortion curve diagram of the third embodiment in the second aperture state;

[0027] Figure 3d 1 is a longitudinal spherical aberration curve diagram, an astigmatism curve diagram and a distortion curve diagram of the third embodiment in a third aperture state;

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

[0029] Figure 4b Shows Figure 4a The longitudinal spherical aberration curve, astigmatism curve and distortion curve;

[0030] Figure 4c 1. The longitudinal spherical aberration curve diagram, the astigmatism curve diagram and the distortion curve diagram of the fourth embodiment in the second aperture state;

[0031] Figure 4d 1 is a longitudinal spherical aberration curve diagram, an astigmatism curve diagram and a distortion curve diagram of the fourth embodiment in the third aperture state;

[0032] Figure 5ais a schematic structural diagram of the optical system of the fifth embodiment in the first aperture state;

[0033] Figure 5b Shows Figure 5a The longitudinal spherical aberration curve, astigmatism curve and distortion curve;

[0034] Figure 5c 1. The longitudinal spherical aberration curve diagram, the astigmatism curve diagram and the distortion curve diagram of the fifth embodiment in the second aperture state;

[0035] Figure 5d 1 is a longitudinal spherical aberration curve diagram, an astigmatism curve diagram and a distortion curve diagram of the fifth embodiment in the third aperture state;

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

[0037] Figure 7 A schematic structural diagram of an electronic device in an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In a first aspect, the present invention provides an optical system, which has a total of seven lenses with refractive power, and includes, in order from the object side to the image side along the optical axis: a first lens, which has positive refractive power, the object side surface of the first lens is convex at the near optical axis, and the image side surface of the first lens is concave at the near optical axis; a second lens, which has negative refractive power, the object side surface of the second lens is convex at the near optical axis, and the image side surface of the second lens is concave at the near optical axis; a third lens, which has negative refractive power, the object side surface of the third lens is convex at the near optical axis, and the image side surface of the third lens is concave at the near optical axis. The fourth lens has a positive refractive power, and the image side surface of the fourth lens is convex at the near optical axis; the fifth lens has a negative refractive power, the object side surface of the fifth lens is convex at the near optical axis, and the image side surface of the fifth lens is concave at the near optical axis; the sixth lens has a positive refractive power, the object side surface of the sixth lens is convex at the near optical axis, and the image side surface of the sixth lens is concave at the near optical axis; the seventh lens has a negative refractive power, the object side surface of the seventh lens is convex at the near optical axis, and the image side surface of the seventh lens is concave at the near optical axis. The optical system also includes an aperture, which is located on the object side of the first lens, and the size of the aperture can be changed.

[0040] The optical system satisfies the relation: 1.2 < TTL / ImgH < 1.55; further, the optical system satisfies the relation: 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 of view angle of the optical system.

[0041] The optical system satisfies the relation: 77deg < FOV < 86deg; further, the optical system satisfies the relation: 79deg < FOV < 84deg. Here, FOV is the maximum field of view 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 of view 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 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 surfaces 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 gently transmit the 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 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 increasing 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, combined with 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 the axial chromatic aberration but also shortens the axial focal length. While improving the imaging quality, it also realizes the miniaturization design; at least one inflection point exists on the object side surface and the image side surface of the seventh lens, which is beneficial to correct the 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 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 of view angle of the optical system is reasonably configured, which is beneficial to improving the resolution of the optical system in the full field of view and enhancing the imaging quality of the edge field of view; 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 of view 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 meet the characteristic of miniaturization while obtaining sufficient field of view.

[0045] In one embodiment, the optical system satisfies the relationship: 0.9 < f1 / f < 1.5; further, the optical system satisfies the relationship: 1 < f1 / f < 1.4. Wherein, f1 is the effective focal length of the first lens and f is the effective focal length of the optical system. Satisfying the above relationship is beneficial to the proper cooperation of the refractive power of the first lens in the optical system, the surface type design of the first lens is more simple and flexible, enabling the first lens to support a larger field of view 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 relationship: -4.5 < f2 / f < -2.5; further, the optical system satisfies the relationship: -4 < f2 / f < -3. Wherein, f2 is the effective focal length of the second lens. Satisfying the above relationship is beneficial to the proper cooperation of the refractive power of the second lens in the optical system, the surface type design of the second lens is more simple and flexible, reduces aberrations, and simplifies the overall aberration correction and imaging quality balance of the optical system.

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

[0048] In one embodiment, the optical system satisfies the relationship: 1.5 < f4 / f < 4; further, the optical system satisfies the relationship: 2 < f4 / f < 3.5. Wherein, f4 is the effective focal length of the fourth lens. Satisfying the above relationship 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 transmit smoothly to the subsequent lenses.

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

[0050] In one embodiment, the optical system satisfies the relationship: 0.4 < f6 / f < 1.2; further, the optical system satisfies the relationship: 0.6 < f6 / f < 1. Wherein, f6 is the effective focal length of the sixth lens. Satisfying the above relationship is beneficial for the sixth lens to balance the aberration of the foregoing lenses and improve the imaging quality.

[0051] In one embodiment, the optical system satisfies the relationship: -1.2 < f7 / f < -0.45; further, the optical system satisfies the relationship: -1 < f7 / f < -0.6. Wherein, f7 is the effective focal length of the seventh lens. Satisfying the above relationship is beneficial for the seventh lens to cooperate with the foregoing lenses to shorten the back focal length and realize the miniaturized 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 relationship: 0.3 < R11 / f < 0.7; further, the optical system satisfies the relationship: 0.4 < R11 / f < 0.6. In one embodiment, the optical system satisfies the relationship: 1.3 < R12 / f < 2.2; further, the optical system satisfies the relationship: 1.5 < R12 / f < 2. Satisfying at least one of the above relationships is beneficial for 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 relationship: 0.5 < R21 / f < 1.8; further, the optical system satisfies the relationship: 0.7 < R21 / f < 1.6. In one embodiment, the optical system satisfies the relationship: 0.5 < R22 / f < 1; further, the optical system satisfies the relationship: 0.6 < R22 / f < 0.9. Satisfying at least one of the above relationships is beneficial for 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 and facilitating the cooperation of 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, gently 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 beneficial to maintaining the surface shape of the seventh lens within a reasonable range, achieving 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 beneficial to a reasonable configuration of the ratio of the curvature radius of the object side surface of the first lens on the optical axis to the curvature radius of the image side surface 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 beneficial to a reasonable configuration of the ratio of the curvature radius of the object side surface of the second lens on the optical axis to the curvature radius of the image side surface 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 beneficial to a reasonable configuration of the ratio of the curvature radius of the object side surface of the third lens on the optical axis to the curvature radius of the image side surface 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 beneficial to a reasonable configuration of the ratio of the curvature radius of the object side surface of the fourth lens on the optical axis to the curvature radius of the image side surface 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 relationship: 1.5 < R51 / R52 < 2.6; further, the optical system satisfies the relationship: 1.7 < R51 / R52 < 2.4. Satisfying the above relationships is conducive to the 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 relationship: 0 < R61 / R62 < 0.35; further, the optical system satisfies the relationship: 0.15 < R61 / R62 < 0.3. Satisfying the above relationships is conducive to the 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 incident angle of light.

[0066] In one embodiment, the optical system satisfies the relationship: 3 < R71 / R72; further, the optical system satisfies the relationship: 4 < R71 / R72 < 17. Satisfying the above relationships is conducive to the 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 realizing a small-angle deflection of all-field light rays within the optical system.

[0067] In one embodiment, the optical system satisfies the relationship: 0.2 < |(R51 - R52) / (R51 + R52)| < 0.5; further, the optical system satisfies the relationship: 0.25 < |(R51 - R52) / (R51 + R52)| < 0.45. Satisfying the above relationships 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 incident angle of light on the two surfaces.

[0068] In one embodiment, the optical system satisfies the relationship: 0.8 < DL / TTL < 0.9; further, the optical system satisfies the relationship: 0.83 < DL / TTL < 0.87. Wherein, 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 relationships is conducive to the 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 realizing the miniaturization of 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 relation: 1.15 < TTL / f < 1.55; further, the optical system satisfies the relation: 1.22 < TTL / f < 1.5. Satisfying the above relations is beneficial to the reasonable configuration of 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 the effective focal length of the optical system, enabling the optical system to have a smaller overall optical length, realizing 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 relation: 0.8 < ImgH / f < 1.2; further, the optical system satisfies the relation: 0.9 < ImgH / f < 1.1. Wherein, ImgH is half of the image height corresponding to the maximum field of view angle of the optical system. Satisfying the above relations 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 relation: 1.4 < f123 / f < 2.4; further, the optical system satisfies the relation: 1.4 < f123 / f < 2.4. Wherein, f123 is the combined effective focal length of the first lens, the second lens and the third lens. Satisfying the above relations 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 relation: FOV / (FNOmax - FNOmin) < 35 deg; further, the optical system satisfies the relation: 28 deg < FOV / (FNOmax - FNOmin) < 33 deg. Wherein, FOV is the maximum field of view angle of the optical system, FNOmax is the maximum aperture number of the optical system, and FNOmin is the minimum aperture number of the optical system. Satisfying the above relations enables the optical system to have a larger field of view angle, and the aperture number of the optical system is maintained within a reasonable range, realizing the combined effect of a larger field of view angle and a large aperture of the optical system, the optical system has a reasonable light input amount, improving the overall illuminance of the imaging picture, and making the optical system applicable to different lighting environments.

[0073] In one embodiment, the optical system satisfies the relation: 3.5 < |f7 / SAG71|; further, the optical system satisfies the relation: 4 < |f7 / SAG71| < 7. In one embodiment, the optical system satisfies the relation: 3 < |f7 / SAG72|; further, the optical system satisfies the relation: 4.5 < |f7 / SAG72| < 7.5. Wherein, 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. Satisfying at least one of the above relations 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 realize miniaturization of the optical system.

[0074] In one embodiment, the optical system satisfies the relation: 2 < (|SAG71| + |SAG72|) / CT7 < 14; further, the optical system satisfies the relation: 2.7 < (|SAG71| + |SAG72|) / CT7 < 13. Wherein, CT7 is the thickness of the seventh lens on the optical axis. Satisfying the above relation is beneficial to reasonably controlling the refractive power and thickness of the seventh lens at each point in the direction 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 relation: 0.5 < Yc62 / SD62 < 0.75; further, the optical system satisfies the relation: 0.55 < Yc62 / SD62 < 0.7. Wherein, 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. Satisfying the above relation is beneficial to reasonably controlling the refractive power and thickness of the sixth lens at each point in the direction 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. Wherein, Yc72 is the off-axis vertex vertical height 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. Satisfying the above relation is beneficial to reasonably control the refractive power and thickness of each part of the seventh lens in the direction 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. Wherein, 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. Wherein, 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, enable the first lens and the third lens to mutually regulate and reduce aberration, reduce the aberration correction pressure of the lens on the image side of the third lens, simplify the processing technology of the first lens and the third lens, and reduce 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. Wherein, 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 from the image side surface of the second lens to the object side surface of the third lens on the optical axis. Satisfying the above relationship is conducive to reasonably controlling the lens gap, improving the imaging 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 relationship is conducive to controlling the ratio of lens spacing to thickness and 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 from the image side surface of the sixth lens to the object side surface of the seventh lens on the optical axis. Satisfying the above relationship is beneficial to the spacing between the sixth lens and the seventh lens, ensuring sufficient spatial spacing for aberration correction.

[0083] In some embodiments, the optical system further includes a filter, which may be an infrared cutoff filter or an infrared bandpass filter. The infrared cutoff filter is used to filter out infrared light, and the infrared bandpass filter only allows infrared light to pass through. In the present application, the filter is an infrared cutoff filter, which is fixedly arranged 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 a part of the optical system. In other embodiments, the filter can also be an independent element outside the optical system. The filter can be installed between the optical system and the photosensitive chip when the optical system and the photosensitive chip are assembled. It can be understood that the filter can be made of optical glass coating, or it can be made of colored glass, or a filter of other materials, which can be selected according to actual needs and is not specifically limited in this embodiment. In other embodiments, a filter coating can be set on at least one lens from the first lens to the seventh lens to achieve the effect of filtering out infrared light.

[0084] First embodiment

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

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

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

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

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

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

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

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

[0093] In addition, the optical system 10 further includes an aperture STO, a filter IR and an imaging surface IMG, and a variable aperture is also provided on the object side of the optical system 10. In this embodiment, the aperture STO is provided on the object side of the first lens of the optical system 10 to control the amount of light entering. Figure 1a , Figure 1c and Figure 1e Schematic diagrams of the optical system 10 are shown in which the aperture STO is in three different states. When the aperture STO is in three different states, the optical system 10 can have different aperture numbers. Based on this, in order to facilitate the description of the three states of the aperture STO, Figure 1a The aperture STO in the state shown is referred to as the aperture STO of the optical system 10 in the first aperture state. Figure 1c The aperture STO in the state shown is referred to as the aperture STO of the optical system 10 in the second aperture state. Figure 1e The aperture STO in the state shown is referred to as the aperture STO in the first aperture state of the optical system 10. It can be understood that the aperture STO includes but is not limited to these three states, and 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 obtains aperture numbers of different sizes.

[0094] The filter IR is arranged between the seventh lens L7 and the imaging surface IMG, and includes an object side surface S15 and an image side surface S16. The filter IR includes an infrared cut-off filter for filtering out infrared light so that the light incident on the imaging surface IMG is only visible light, and the wavelength of visible light is 380nm-780nm. The material of the infrared cut-off filter IR can be glass (GLASS) or plastic (Plastic), and a film can be coated on its surface. The material of the first lens L1 to the seventh lens L7 can be glass (GLASS) or plastic (Plastic). The effective pixel area of ​​the photosensitive chip is located on the imaging surface, and an infrared photosensitive chip is arranged at the imaging surface IMG. The photosensitive chip captures different band information of the object for subsequent processing.

[0095] Table 1a shows various parameters of the optical system 10 of the present embodiment, wherein the Y radius is the radius of curvature of the object side or image side of the corresponding surface number at the optical axis. Surface number S1 and surface number S2 are the object side S1 and image side S2 of the first lens L1, respectively, that is, in the same lens, the surface with a smaller surface number is the object side, and the surface with a larger surface number is the image side. The first value in the "thickness" parameter column of the first lens L1 is the thickness of the lens on the optical axis, and the second value is the distance from the image side of the lens to the next surface on the optical axis in the image side direction. The focal length, material refractive index and Abbe number are all obtained using visible light with a reference wavelength of 587.6nm, and the units of the Y radius, thickness and focal length are all millimeters (mm). Table 1b is the supplementary data of 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] Wherein, f is the focal length of the optical system 10, FNO is the aperture number of the optical system 10, FOV is the maximum field angle of the optical system 10, TTL is the distance from the object side surface of the first lens to the imaging surface on the optical axis, that is, the total optical length, and A is the distance from the aperture STO to the object side surface S1 of the first lens L1 in a direction parallel to the optical axis.

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

[0103]

[0104] Wherein, x is the distance from the corresponding point on the aspheric surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the vertex of the aspheric surface, k is the cone coefficient, and Ai is the coefficient corresponding to the i-th high-order term in the aspheric surface shape formula. Table 1c gives the high-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, A30 of the aspheric mirror surfaces 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 state), Figure 1d (Second aperture state) and Figure 1f (Third aperture state) (a) respectively 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, wherein the horizontal axis along the X-axis direction represents the focus offset, that is, the distance from the imaging plane to the intersection of the light and the optical axis (in mm), the vertical axis along the Y-axis direction represents the normalized field of view, and the longitudinal spherical aberration curve represents the deviation of the convergent focus of light of different wavelengths after passing through each lens of the optical system 10. Figure 1b , Figure 1d and Figure 1f It can be seen from (a) that the degree of deviation of the convergence focus of the light of each wavelength in the first embodiment tends to be consistent, and the dispersion spots or color halo in the imaging picture 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 (b) shows the astigmatism curves of the optical system 10 at different focal lengths in the first embodiment at a wavelength of 555.0000nm, wherein the abscissa along the X-axis represents the focus offset, and the ordinate along the Y-axis represents the image height, and the unit is mm. The S curve in the astigmatism curve represents the sagittal field curvature at 555.0000nm, and the T curve represents the meridian field curvature at 555.0000nm. Figure 1b , Figure 1d and Figure 1fAs can be seen in (b), the field curvature of the optical system 10 is small, the field curvature and astigmatism of each field of view are well corrected, and the center and edge of the field of view have clear images.

[0110] Figure 1b , Figure 1d and Figure 1f (c) shows the distortion curves of the optical system 10 at different focal lengths in the first embodiment at a wavelength of 555.0000nm. The horizontal axis along the X-axis represents the distortion value, with the symbol %, and the vertical axis along the Y-axis represents the image height, with the unit being mm. The distortion curve represents the distortion magnitude value corresponding to different field angles. Figure 1b , Figure 1d and Figure 1f It can be seen from (c) that at a wavelength of 555.0000nm, the image deformation 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 It can be seen from (a), (b) and (c) that the optical system 10 of this embodiment has small aberration, good imaging quality and excellent imaging quality.

[0112] Second embodiment

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

[0114] Table 2a shows various parameters of the optical system 10 of this embodiment, wherein 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 of the Y radius, thickness and focal length are all millimeters (mm), and the meanings of other parameters are the same as those of the first embodiment. Table 2b is the supplementary data of 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 coefficients of the higher-order terms that can be used for each aspherical mirror surface 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 state), Figure 2c (Second aperture state) and Figure 2d (A), (B), and (C) in (Third Aperture State) 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, wherein the longitudinal spherical aberration curve indicates the deviation of the convergence focus of light of different wavelengths after passing through each lens of the optical system 10; the astigmatism curve indicates the meridian field curvature and sagittal field curvature; and the distortion curve indicates the distortion magnitude value corresponding to different field angles. Figure 2b , Figure 2c and Figure 2d As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 10 are all well controlled, so that the optical system 10 of this embodiment has good imaging quality.

[0125] Third embodiment

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

[0127] Table 3a shows various parameters of the optical system 10 of this embodiment, wherein 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 of the Y radius, thickness and focal length are all millimeters (mm), and the meanings of other parameters are the same as those of the first embodiment. Table 3b is the supplementary data of 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 coefficients of the higher-order terms that can be used for each aspherical mirror surface 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 state), Figure 3c (Second aperture state) and Figure 3d (A), (B), and (C) in (Third Aperture State) respectively show the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system 10 at different focal lengths in the third embodiment, wherein the longitudinal spherical aberration curve indicates the deviation of the convergence focus of light of different wavelengths after passing through each lens of the optical system 10; the astigmatism curve indicates the meridian field curvature and sagittal field curvature; and the distortion curve indicates the distortion magnitude value corresponding to different field angles. Figure 3b , Figure 3c and Figure 3d As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 10 are all well controlled, so that the optical system 10 of this embodiment has good imaging quality.

[0138] Fourth embodiment

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

[0140] Table 4a shows various parameters of the optical system 10 of this embodiment, wherein 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 of the Y radius, thickness and focal length are all millimeters (mm), and the meanings of other parameters are the same as those of the first embodiment. Table 4b is the supplementary data of Table 4a.

[0141] Table 4a

[0142]

[0143] Table 4b

[0144]

[0145]

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

[0147] Table 4c

[0148] Surface 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 Surface 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 Surface 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 state), Figure 4c (Second aperture state) and Figure 4d(A), (B), and (C) in (Third Aperture State) respectively show the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system 10 at different focal lengths in the fourth embodiment, wherein the longitudinal spherical aberration curve indicates the deviation of the convergent focus of light of different wavelengths after passing through each lens of the optical system 10; the astigmatism curve indicates the meridian field curvature and sagittal field curvature; and the distortion curve indicates the distortion magnitude value corresponding to different field angles. Figure 4b , Figure 4c and Figure 4d As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 10 are all well controlled, so that the optical system 10 of this embodiment has good imaging quality.

[0150] Fifth embodiment

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

[0152] Table 5a shows various parameters of the optical system 10 of this embodiment, wherein 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 of the Y radius, thickness and focal length are all millimeters (mm), and the meanings of other parameters are the same as those of the first embodiment. Table 5b is the supplementary data of 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 coefficients of the higher-order terms that can be used for each aspherical mirror surface 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 state), Figure 5c (Second aperture state) and Figure 5d(A), (B), and (C) in (Third Aperture State) respectively show the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system 10 at different focal lengths in the fifth embodiment, wherein the longitudinal spherical aberration curve indicates the deviation of the convergent focus of light of different wavelengths after passing through each lens of the optical system 10; the astigmatism curve indicates the meridian field curvature and sagittal field curvature; and the distortion curve indicates the distortion magnitude value corresponding to different field angles. Figure 5b , Figure 5c and Figure 5d As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 10 are all well controlled, so that the optical system 10 of this embodiment has good imaging quality.

[0162] Table 6 shows the values ​​of a plurality of relational expressions 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 relationships: 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 the optical system 10 described in any one of the embodiments of the first aspect, wherein the photosensitive chip 21 is arranged 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 the light of the object incident on the photosensitive surface through the lens can be converted into an electrical signal of the 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 on the electronic device 30, or it can be an independent lens. By adding the optical system 10 provided by the present invention to the camera module 20, the surface shape and refractive power of each lens in the optical system 10 can be reasonably designed, so that the camera module 20 meets the characteristics of miniaturization, good imaging effect and variable aperture.

[0168] See also Figure 7 The present invention further provides an electronic device 30, which includes a housing 31 and the camera module 20, wherein the camera module 20 is disposed in the housing 31. The electronic device 30 includes but is not limited to a smart phone, a computer, and a smart watch. By adding the camera module 20 provided by the present invention to the electronic device 30, the electronic device 30 satisfies the characteristics of miniaturization, good imaging effect, and variable aperture.

[0169] The above disclosures are only some preferred embodiments of the present invention, which certainly cannot be used to limit the scope of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention are still 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: 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 satisfies the relational expressions: 1.2 < TTL / ImgH < 1.55, and 77deg < FOV < 86deg; Wherein, 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 of view angle of the optical system, and FOV is the maximum field of view angle of the optical system.

2. The optical system according to claim 1, wherein: The optical system satisfies the relational expressions: 0.9 < f1 / f < 1.5, and / or -4.5 < f2 / f < -2.5, and / or f3 / f < -4, and / or 1.5 < f4 / f < 4, and / or -3 < f5 / f < -1, and / or 0.4 < f6 / f < 1.2, and / or -1.2 < f7 / f < -0.45; Wherein, 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 according to claim 1, wherein: The optical system satisfies the relational expressions: 0.3 < R11 / f < 0.7, and / or 1.3 < R12 / f < 2.2, and / or 0.5 < R21 / f < 1.8, and / or 0.5 < R22 / f < 1, and / or 1.2 < R31 / f < 2.4, and / or 0.9 < R32 / f < 1.7, and / or 2.5 < R41 / f, and / or -4 < R42 / f < -1, and / or 0.9 < R51 / f < 1.6, and / or 0.4 < R52 / f < 0.8, and / or 0.25 < R61 / f < 0.5, and / or 1 < R62 / f < 2.2, and / or 1.4 < R71 / f, and / or 0.2 < R72 / f < 0.6; Wherein, R11 is the curvature radius of the object side of the first lens on the optical axis, R12 is the curvature radius of the image side of the first lens on the optical axis, R21 is the curvature radius of the object side of the second lens on the optical axis, R22 is the curvature radius of the image side of the second lens on the optical axis, R31 is the curvature radius of the object side of the third lens on the optical axis, R32 is the curvature radius of the image side of the third lens on the optical axis, R41 is the curvature radius of the object side of the fourth lens on the optical axis, R42 is the curvature radius of the image side of the fourth lens on the optical axis, R51 is the curvature radius of the object side of the fifth lens on the optical axis, R52 is the curvature radius of the image side of the fifth lens on the optical axis, R61 is the curvature radius of the object side of the sixth lens on the optical axis, R62 is the curvature radius of the image side of the sixth lens on the optical axis, R71 is the curvature radius of the object side of the seventh lens on the optical axis, R72 is the curvature radius of the image side of the seventh lens on the optical axis, and f is the effective focal length of the optical system.

4. The optical system according to claim 1, wherein: The optical system satisfies the relationship: 0 < R11 / R12 < 0.4, and / or 1 < R21 / R22 < 2, and / or 1 < R31 / R32 < 1.9, and / or R41 / R42 < -1.4, and / or 1.5 < R51 / R52 < 2.6, and / or 0 < R61 / R62 < 0.35, and / or 3 < R71 / R72, and / or 0.2 < |(R51 - R52) / (R51 + R52)| < 0.5; Wherein, R11 is the curvature radius of the object side of the first lens on the optical axis, R12 is the curvature radius of the image side of the first lens on the optical axis, R21 is the curvature radius of the object side of the second lens on the optical axis, R22 is the curvature radius of the image side of the second lens on the optical axis, R31 is the curvature radius of the object side of the third lens on the optical axis, R32 is the curvature radius of the image side of the third lens on the optical axis, R41 is the curvature radius of the object side of the fourth lens on the optical axis, R42 is the curvature radius of the image side of the fourth lens on the optical axis, R51 is the curvature radius of the object side of the fifth lens on the optical axis, R52 is the curvature radius of the image side of the fifth lens on the optical axis, R61 is the curvature radius of the object side of the sixth lens on the optical axis, R62 is the curvature radius of the image side of the sixth lens on the optical axis, R71 is the curvature radius of the object side of the seventh lens on the optical axis, R72 is the curvature radius of the image side of the seventh lens on the optical axis.

5. The optical system according to claim 1, wherein: The optical system satisfies the relationship: 0.8 < DL / TTL < 0.9, and / or 1.15 < TTL / f < 1.55, and / or 0.8 < ImgH / f < 1.2, and / or 1.4 < f123 / f < 2.4, and / or FOV / (FNOmax - FNOmin) < 35deg; Wherein, DL is the distance on the optical axis from the object side surface of the first lens to the image side surface of the seventh lens, 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 aperture number of the optical system, and FNOmin is the minimum aperture number of the optical system.

6. The optical system according to claim 1, wherein: The optical system satisfies the relational expressions: 3.5 < |f7 / SAG71|, and / or 3 < |f7 / SAG72|, and / or 2 < (|SAG71| + |SAG72|) / CT7 < 14; Wherein, f7 is the effective focal length of the seventh lens, SAG71 is the sagitta at the maximum effective aperture of the object side surface of the seventh lens, SAG72 is the sagitta at the maximum effective aperture of the image side surface of the seventh lens, and CT7 is the thickness of the seventh lens on the optical axis.

7. The optical system according to claim 1, wherein: The optical system satisfies the relational expressions: 0.5 < Yc62 / SD62 < 0.75, and / or 0.25 < Yc72 / SD72 < 0.5; Wherein, 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.

8. The optical system according to claim 1, wherein: The optical system satisfies the relational expressions: 0.4 < (AT34 + CT5) / (AT45 + AT56) < 2, and / or 0.8 < (CT1 + CT3) / (CT4 + CT5) < 1.3, and / or 0.8 < (CT1 + CT2) / (CT3 + CT4) < 1.5, and / or 0.7 < (AT34 + AT23) / (AT45 + AT56) < 1.1, and / or 2.5 < (CT1 + CT2 + CT3 + CT4) / AT23 < 5, and / or 0.8 < (CT5 + CT6 + CT7) / AT67 < 2.2; Wherein, AT23 is the distance on the optical axis from the image side surface of the second lens to the object side surface of the third lens, AT34 is the distance on the optical axis from the image side surface of the third lens to the object side surface of the fourth lens, AT45 is the distance on the optical axis from the image side surface of the fourth lens to the object side surface of the fifth lens, AT56 is the distance on the optical axis from the image side surface of the fifth lens to the object side surface of the sixth lens, 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, 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: Comprising the optical system according to any one of claims 1 to 8 and a photosensitive chip, the photosensitive chip being 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 according to claim 9, and the camera module is arranged in the housing.

Images