Optical systems, imaging modules and electronic equipment

Abstract

The present invention relates to an optical system, an imaging module and an electronic device. The optical system includes, in order from the object side to the image side along the optical axis: a first lens with positive refractive power, the object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis; a second lens with refractive power, the object side surface is convex at the near optical axis; a third lens with refractive power; a fourth lens with refractive power, the object side surface is convex at the near optical axis, and the image side surface is concave at the optical axis; a fifth lens with refractive power, the object side surface is concave at the near optical axis; a sixth lens with positive refractive power, the object side surface is convex at the near optical axis; a seventh lens with negative refractive power, the image side surface is concave at the near optical axis; and satisfying: |f(12) / f(67)|≤0.5; f(12) is the combined focal length of the first lens and the second lens, and f(67) is the combined focal length of the sixth lens and the seventh lens. The above optical system can meet the needs of miniaturized design.

Description

Technical Field

[0001] The present invention relates to the field of photography, and in particular to an optical system, an imaging module and electronic equipment. Background Art

[0002] With the rapid development of electronic devices such as smart phones and tablets, more and more electronic devices are equipped with imaging modules to realize the camera function. The imaging module mostly includes an optical system and a photosensitive element. The optical system is used to receive and adjust light so that the light can be imaged on the photosensitive element. The optical system occupies a certain space in the electronic device, which affects the size of the electronic device. At the same time, people have higher and higher requirements for electronic devices. Not only do they require electronic devices to have good camera functions, but they also hope that electronic devices can be miniaturized to reduce the size of the electronic device and facilitate carrying and use. However, the current size of the optical system needs to be reduced, otherwise it will be difficult to meet the needs of miniaturized design of electronic devices when used in electronic devices. Summary of the invention

[0003] Based on this, it is necessary to provide an optical system, an imaging module and an electronic device to address the problem that the current optical system is difficult to meet the needs of miniaturized design of electronic devices.

[0004] An optical system, comprising, in order from the object side to the image side along the optical axis:

[0005] A first lens having positive refractive power, wherein the object side surface of the first lens is convex at the near optical axis, and the image side surface of the first lens is concave at the near optical axis;

[0006] A second lens having refractive power, wherein the object side surface of the second lens is convex at a position close to the optical axis;

[0007] a third lens having refractive power;

[0008] a fourth lens having a refractive power, wherein the object side surface of the fourth lens is a convex surface near the optical axis, and the image side surface of the fourth lens is a concave surface at the optical axis;

[0009] a fifth lens having refractive power, wherein the object side surface of the fifth lens is concave at a position close to the optical axis;

[0010] a sixth lens element having positive refractive power, wherein the object side surface of the sixth lens element is convex near the optical axis;

[0011] a seventh lens element having negative refractive power, wherein the image side surface of the seventh lens element is concave at a near optical axis;

[0012] And the optical system satisfies the following conditional formula:

[0013] |f12 / f67|≤0.5;

[0014] Wherein, f12 is the combined focal length of the first lens and the second lens, and f67 is the combined focal length of the sixth lens and the seventh lens.

[0015] In the above optical system, the positive refractive power of the first lens and the surface shape of the convex surface on the object side and the concave surface on the image side are conducive to the incident light at a large angle to the optical axis entering the optical system and being effectively converged, thereby shortening the total length of the optical system and realizing a miniaturized design. The second lens and the third lens have refractive power, and the convex surface shape of the object side of the second lens is conducive to the smooth transmission of the light converged by the first lens to the rear lens, and the preliminary correction of the aberration of the object lens, so as to avoid a large number of aberrations that are difficult to correct and increase the correction burden of the rear lens. The surface shape of the convex surface on the object side and the concave surface on the image side of the fourth lens can cooperate with the object lens to further converge the incident light to shorten the total length of the optical system. The refractive power and the surface shape of the object side of the fifth lens can further balance the aberrations that are difficult to correct brought by each lens on the object side when converging the incident light. The positive refractive power of the sixth lens and the convex surface shape of the object side are conducive to offsetting the aberrations generated by the object lens. The seventh lens provides negative refractive power, which is matched with the positive refractive power of the sixth lens. The positive and negative refractive power lenses can offset each other's aberrations, and the convex surface of the object side of the sixth lens and the concave surface of the image side of the seventh lens are matched, which is conducive to correcting the off-axis coma and astigmatism of the optical system. The corresponding surface shapes of the second lens, the third lens, the fourth lens and the fifth lens are matched with each other, which is conducive to the smooth transition of light between the lenses and prevents the optical surfaces therein from causing excessive deflection of light.

[0016] When the above-mentioned conditional expression is further satisfied under the conditions of having the above-mentioned refractive power and surface design, the ratio of the combined focal length of the first lens and the second lens and the combined focal length of the sixth lens and the seventh lens can be reasonably set, so that the first lens and the second lens are conducive to collecting light in a larger angle range, and the sixth lens and the seventh lens are conducive to effectively converging the edge light of the center and the vicinity of the field of view, thereby making the structure of the optical system more compact, which is conducive to shortening the total length of the optical system and meeting the requirements of miniaturization design of electronic equipment; in addition, the sixth lens and the seventh lens as a whole can also effectively correct the aberrations generated by the first lens and the second lens, which is conducive to improving the imaging quality of the optical system.

[0017] In one embodiment, the optical system satisfies the following condition:

[0018] |(R51-R52) / (R51+R52)|≤100;

[0019] Wherein, R51 is the radius of curvature of the object side of the fifth lens at the optical axis, and R52 is the radius of curvature of the image side of the fifth lens at the optical axis. When the above conditional expression is met, the surface shapes of the object side and the image side of the fifth lens can be reasonably configured so that the surface shape of the fifth lens will not be too flat or overly curved, which is beneficial for the fifth lens to correct the aberration of the optical system and improve the imaging quality of the optical system. If the conditional expression is exceeded, the surface shape of the fifth lens will be too flat, which will result in too small light deflection, which is not conducive to the aberration correction of the optical system, or the surface shape of the fifth lens will be too curved, which will increase the difficulty of lens molding and increase the manufacturing cost of the optical system.

[0020] In one embodiment, the optical system satisfies the following condition:

[0021] |(R21-R22) / (R21+R22)|≤30;

[0022] Wherein, R21 is the radius of curvature of the object side of the second lens at the optical axis, and R22 is the radius of curvature of the image side of the second lens at the optical axis. When the above conditional expression is met, the surface shapes of the object side and the image side of the second lens can be reasonably configured so that the surface shape of the second lens is not too flat or overly curved, which is beneficial for the second lens to correct the aberration of the optical system and improve the imaging quality of the optical system. If the conditional expression is exceeded, the surface shape of the second lens will be too flat, which will result in too small light deflection, which is not conducive to the aberration correction of the optical system, or the surface shape of the second lens will be too curved, which will increase the difficulty of lens molding and increase the manufacturing cost of the optical system.

[0023] In one embodiment, the optical system satisfies the following condition:

[0024] |f / f2+f / f4|≤1.5;

[0025] Wherein, f is the effective focal length of the optical system, f2 is the effective focal length of the second lens, and f4 is the effective focal length of the fourth lens. When the above conditional formula is satisfied, the refractive power of the second lens and the fourth lens in the optical system can be reasonably configured, which is conducive to balancing the spherical aberration generated by the first lens and the second lens as a whole, thereby improving the overall resolution of the optical system, and is also conducive to correcting the aberration of the edge field of view of the optical system; in addition, the second lens and the fourth lens are used as central lenses, and the reasonable distribution of refractive power can provide sufficient light beam transmission space for the object side lens and the image side lens of the optical system, which is conducive to shortening the total length of the optical system and realizing miniaturization design. That is, satisfying the relationship can improve the resolution of the optical system, so that the optical system can have good imaging quality while being miniaturized.

[0026] In one embodiment, the optical system satisfies the following condition:

[0027] 15≤|f2 / SAG22|≤135;

[0028] Wherein, f2 is the effective focal length of the second lens, and SAG22 is the sag height of the image side surface of the second lens at the maximum effective aperture, that is, the distance from the intersection of the image side surface of the second lens and the optical axis to the maximum effective aperture of the image side surface of the second lens in the direction of the optical axis. When the above conditional formula is met, the refractive power of the second lens and the image side surface shape of the second lens can be reasonably configured, which is conducive to correcting the chromatic aberration and spherical aberration of the optical system, thereby improving the imaging quality of the optical system; at the same time, the surface shape of the second lens will not be too flat, which is conducive to improving the ability of the optical system to converge light, thereby shortening the total length of the optical system and realizing a miniaturized design.

[0029] In one embodiment, the optical system satisfies the following condition:

[0030] 50≤|f5 / SAG52|≤740;

[0031] Wherein, f5 is the effective focal length of the fifth lens, and SAG52 is the sagittal height of the image side surface of the fifth lens at the maximum effective aperture, that is, the distance from the intersection of the image side surface of the fifth lens and the optical axis to the maximum effective aperture of the image side surface of the fifth lens in the direction of the optical axis. When the above conditional formula is met, the refractive power of the fifth lens and the image side surface shape of the fifth lens can be reasonably configured, which is conducive to correcting the chromatic aberration and spherical aberration of the optical system, thereby improving the imaging quality of the optical system; at the same time, the surface shape of the fifth lens will not be too flat, which is conducive to improving the ability of the optical system to converge light, thereby shortening the total length of the optical system and realizing a miniaturized design.

[0032] In one embodiment, the optical system satisfies the following condition:

[0033] |SAG22 / SAG52|≤2;

[0034] Among them, SAG22 is the sagittal height of the image side of the second lens at the maximum effective aperture, and SAG52 is the sagittal height of the image side of the fifth lens at the maximum effective aperture. When the above conditional formula is met, the ratio of the sagittal heights of the second lens and the fifth lens can be reasonably configured, which is conducive to balancing the spherical aberration of the optical system and improving the overall resolution of the optical system; at the same time, the reasonable design of the surface shape of the second lens and the fifth lens is conducive to the sixth lens and the seventh lens on the image side to effectively correct the aberration of the edge field of view generated by the first lens and the second lens on the object side; in addition, the surface shape of the second lens and the fifth lens will not be excessively curved, which provides sufficient space for the arrangement between the lenses, thereby shortening the total length of the optical system and realizing a miniaturized design. That is, the relationship is satisfied, which is conducive to the optical system having good imaging quality while being miniaturized.

[0035] In one embodiment, at least one of the object-side surface and the image-side surface of the seventh lens has an inflection point, and the optical system satisfies the following conditional formula:

[0036] 1≤(|SAG71|+|SAG72|) / CT7≤2;

[0037] Among them, SAG71 is the sag height of the object side of the seventh lens at the maximum effective aperture, that is, the distance from the intersection of the object side of the seventh lens and the optical axis to the maximum effective aperture of the object side of the seventh lens in the direction of the optical axis, SAG72 is the sag height of the image side of the seventh lens at the maximum effective aperture, that is, the distance from the intersection of the image side of the seventh lens and the optical axis to the maximum effective aperture of the image side of the seventh lens in the direction of the optical axis, and CT7 is the thickness of the seventh lens on the optical axis. The seventh lens is provided with an inflection point. As the lens closest to the imaging surface of the optical system, it can make the deflection force of the light beam reaching the imaging surface of the optical system more uniform, which is conducive to correcting the distortion and field curvature generated by each lens on the object side of the seventh lens; when the above conditional formula is met, the thickness and surface shape of the seventh lens can be reasonably configured, so that the seventh lens will not be too thin or too thick, and the surface shape of the seventh lens will not be too flat or overly curved, which is conducive to reducing the incident angle of light on the image plane and reducing the sensitivity of the optical system. If the thickness exceeds the upper limit of the above conditional expression, the edge of the seventh lens is too thick, which may increase the field curvature aberration and cause the image plane to bend. If the thickness is below the lower limit of the above conditional expression, the edge of the seventh lens is too thin, and it is impossible to effectively deflect and converge the edge field light, making it difficult to reduce the incident angle of the light at the edge of the image plane, thereby increasing the vignetting phenomenon.

[0038] An imaging module comprises a photosensitive element and the optical system described in any one of the above embodiments, wherein the photosensitive element is arranged on the image side of the optical system. The above optical system is adopted in the imaging module, and the optical system has a compact structure, which can meet the requirements of miniaturization design of the imaging module.

[0039] An electronic device comprises a housing and the above-mentioned imaging module, wherein the imaging module is arranged in the housing. When the imaging module is used in the electronic device, the structure of the optical system is compact, which can meet the requirements of miniaturization design of the electronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a schematic structural diagram of an optical system in the first embodiment of the present application;

[0041] Figure 2 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the first embodiment of the present application;

[0042] Figure 3 is a schematic structural diagram of an optical system in a second embodiment of the present application;

[0043] Figure 4 The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the second embodiment of the present application;

[0044] Figure 5 is a schematic structural diagram of an optical system in a third embodiment of the present application;

[0045] Figure 6 A longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram of the optical system in the third embodiment of the present application;

[0046] Figure 7 is a schematic structural diagram of an optical system in a fourth embodiment of the present application;

[0047] Figure 8 A longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram of the optical system in the fourth embodiment of the present application;

[0048] Fig. 9 is a schematic structural diagram of an optical system in a fifth embodiment of the present application;

[0049] Fig.10 A longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram of the optical system in the fifth embodiment of the present application;

[0050] Fig.11 is a schematic diagram of an imaging module in an embodiment of the present application;

[0051] Fig.12 It is a schematic diagram of an electronic device in an embodiment of the present application. DETAILED DESCRIPTION

[0052] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0053] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0054] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0055] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0057] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0058] See also Figure 1 In some embodiments of the present application, the optical system 100 includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7 in order from the object side to the image side along the optical axis 110. Specifically, the first lens L1 includes an object-side surface S1 and an image-side surface S2, the second lens L2 includes an object-side surface S3 and an image-side surface S4, the third lens L3 includes an object-side surface S5 and an image-side surface S6, the fourth lens L4 includes an object-side surface S7 and an image-side surface S8, the fifth lens L5 includes an object-side surface S9 and an image-side surface S10, the sixth lens L6 includes an object-side surface S11 and an image-side surface S12, and the seventh lens L7 includes an object-side surface S13 and an image-side surface S14. The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are coaxially arranged, and the common axis of each lens in the optical system 100 is the optical axis 110 of the optical system 100.

[0059] Among them, the first lens L1 has positive refractive power, the object side surface S1 is convex at the near optical axis 110, and the image side surface S2 is concave at the near optical axis 110. The second lens L2, the third lens L3 and the fourth lens L4 all have refractive power. The object side surface S3 of the second lens L2 is convex at the near optical axis 110. The object side surface S7 of the fourth lens L4 is convex at the near optical axis 110, and the image side surface S8 is concave at the near optical axis 110. The fifth lens L5 has refractive power, and the object side surface S9 is concave at the near optical axis 110. The sixth lens L6 has positive refractive power, and the object side surface S11 is convex at the near optical axis 110. The seventh lens L7 has negative refractive power. The image side surface S14 is concave at the near optical axis 110.

[0060] The positive refractive power of the first lens L1 and the surface shape of the object side surface S1 being convex and the image side surface S2 being concave are conducive to the incident light at a large angle to the optical axis 110 entering the optical system 100 and being effectively converged, thereby being conducive to shortening the total length of the optical system 100 and realizing a miniaturized design. The second lens L2 and the third lens L3 have refractive power, and the convex surface shape of the object side surface S3 of the second lens L2 are conducive to the smooth transmission of the light converged by the first lens L1 to the rear lens, and the preliminary correction of the aberration of the object side lens, so as to avoid a large number of difficult-to-correct aberrations and increase the correction burden of the rear lens. The surface shape of the fourth lens L4 having the convex surface S7 of the object side surface and the concave surface S8 of the image side surface can cooperate with the object side lens to further converge the incident light, so as to shorten the total length of the optical system 100. The refractive power of the fifth lens L5 and the surface shape of the object side surface S9 can further balance the difficult-to-correct aberrations brought by the object side lenses when converging the incident light. The positive refractive power of the sixth lens L6 and the convex surface of the object side S11 are conducive to offsetting the aberrations generated by the object lens. The seventh lens L7 provides negative refractive power, and is matched with the positive refractive power of the sixth lens L6. The combination of positive and negative refractive power lenses can offset the aberrations generated by each other, and the convex surface of the object side S11 of the sixth lens L6 and the concave surface of the image side S14 of the seventh lens L7 are matched, which is conducive to correcting the off-axis coma and astigmatism of the optical system 100. The corresponding surface shapes of the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 are matched with each other, which is conducive to the smooth transition of light between the lenses and prevents the optical surfaces therein from causing excessive deflection of light.

[0061] In addition, in some embodiments, the optical system 100 is provided with a stop STO, which can be provided on the object side of the first lens L1, or on the object side surface S1 of the first lens L1. In some embodiments, the optical system 100 further includes an infrared filter L8 provided on the image side of the seventh lens L7, and the infrared filter L8 includes an object side surface S15 and an image side surface S16. Further, the optical system 100 further includes an image plane S17 located on the image side of the seventh lens L7, and the image plane S17 is the imaging plane of the optical system 100. The incident light can be imaged on the image plane S17 after being adjusted by the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7. It is worth noting that the infrared filter L8 can be an infrared cut-off filter, which is used to filter out interference light and prevent the interference light from reaching the image plane S17 of the optical system 100 and affecting normal imaging.

[0062] In some embodiments, the object side and image side of each lens of the optical system 100 are both aspherical. The use of aspherical structures can improve the flexibility of lens design, effectively correct spherical aberration, and improve imaging quality. In other embodiments, the object side and image side of each lens of the optical system 100 can also be spherical. It should be noted that the above embodiments are only examples of some embodiments of the present application. In some embodiments, the surface of each lens in the optical system 100 can be any combination of aspherical or spherical surfaces.

[0063] In some embodiments, the material of each lens in the optical system 100 can be glass or plastic. The use of plastic lenses can reduce the weight of the optical system 100 and reduce production costs, and the small size of the optical system 100 can be used to achieve a lightweight design of the optical system 100. The use of glass lenses enables the optical system 100 to have excellent optical properties and high temperature resistance. It should be noted that the material of each lens in the optical system 100 can also be any combination of glass and plastic, and does not necessarily have to be glass or plastic. In some embodiments, at least two lenses in the optical system 100 are made of plastic materials with different optical properties, which is conducive to correcting the dispersion of the optical system 100 and improving the imaging quality of the optical system 100.

[0064] It should be noted that the first lens L1 does not mean that there is only one lens. In some embodiments, there may be two or more lenses in the first lens L1. The two or more lenses can form a cemented lens. The surface of the cemented lens closest to the object side can be regarded as the object side surface S1, and the surface closest to the image side can be regarded as the image side surface S2. Alternatively, the lenses in the first lens L1 do not form a cemented lens, but the distances between the lenses are relatively fixed. In this case, the object side surface of the lens closest to the object side is the object side surface S1, and the image side surface of the lens closest to the image side is the image side surface S2. In addition, in some embodiments, the number of lenses in the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, or the seventh lens L7 may be greater than or equal to two, and any adjacent lenses may form a cemented lens or a non-cemented lens.

[0065] Further, in some embodiments, the optical system 100 satisfies the condition: |f12 / f67|≤0.5, wherein f12 is the combined focal length of the first lens L1 and the second lens L2, and f67 is the combined focal length of the sixth lens L6 and the seventh lens L7. Specifically, |f(12) / f(67)| may be: 0.037, 0.088, 0.129, 0.145, 0.178, 0.207, 0.234, 0.258, 0.357 or 0.479. When the above conditional expression is satisfied, the ratio of the combined focal length of the first lens L1 and the second lens L2 and the combined focal length of the sixth lens L6 and the seventh lens L7 can be reasonably set, so that the first lens L1 and the second lens L2 can collect light in a larger angle range, and the sixth lens L6 and the seventh lens L7 can effectively converge the edge light of the center and the vicinity of the field of view, thereby making the structure of the optical system 100 more compact, which is conducive to shortening the total length of the optical system 100 and meeting the requirements of miniaturization design of electronic equipment; in addition, the sixth lens L6 and the seventh lens L7 as a whole can also effectively correct the aberrations generated by the first lens L1 and the second lens L2, so as to improve the imaging quality of the optical system 100.

[0066] In some embodiments, the optical system 100 satisfies the conditional formula: |(R51-R52) / (R51+R52)|≤100; wherein R51 is the radius of curvature of the object-side surface S9 of the fifth lens L5 at the optical axis 110, and R52 is the radius of curvature of the image-side surface S10 of the fifth lens L5 at the optical axis 110. Specifically, |(R51-R52) / (R51+R52)| may be: 0.044, 0.098, 0.139, 0.155, 0.181, 0.201, 0.222, 0.315, 0.952, or 97.825. When the above conditional expression is satisfied, the surface of the object side surface S9 and the image side surface S10 of the fifth lens L5 can be reasonably configured, so that the surface of the fifth lens L5 will not be too flat or too curved, which is conducive to the fifth lens L5 correcting the aberration of the optical system 100 and improving the imaging quality of the optical system 100. Beyond the range of the conditional expression, the surface of the fifth lens L5 will be too flat, which will cause the light deflection to be too small, which is not conducive to the aberration correction of the optical system 100, or the surface of the fifth lens L5 will be too curved, resulting in increased difficulty in lens molding and increased manufacturing cost of the optical system 100. Further, in some embodiments, the optical system 100 satisfies the conditional expression: 0.04≤|(R51-R52) / (R51+R52)|≤0.23. When the above conditional expression is satisfied, the aberration correction effect of the fifth lens L5 on the optical system 100 can be better.

[0067] In some embodiments, the optical system 100 satisfies the conditional formula: |(R21-R22) / (R21+R22)|≤30, wherein R21 is the radius of curvature of the object-side surface S3 of the second lens L2 at the optical axis 110, and R22 is the radius of curvature of the image-side surface S4 of the second lens L2 at the optical axis 110. Specifically, |(R21-R22) / (R21+R22)| may be: 0.271, 0.451, 0.656, 1.337, 5.628, 13.010, 15.369, 24.530, 25.012, or 28.576. When the above conditional expression is satisfied, the surface shapes of the object-side surface S3 and the image-side surface S4 of the second lens L2 can be reasonably configured, so that the surface shape of the second lens L2 will not be too flat or too curved, which is beneficial for the second lens L2 to correct the aberration of the optical system 100 and improve the imaging quality of the optical system 100. If the conditional expression is exceeded, the surface shape of the second lens L2 will be too flat, which will result in too small light deflection, which is not conducive to the aberration correction of the optical system 100, or the surface shape of the second lens L2 will be too curved, which will increase the difficulty of lens molding and increase the manufacturing cost of the optical system 100.

[0068] In some embodiments, the optical system 100 satisfies the condition: |f / f2+f / f4|≤1.5, wherein f is the effective focal length of the optical system 100, f2 is the effective focal length of the second lens L2, and f4 is the effective focal length of the fourth lens L4. Specifically, |f / f2+f / f4| may be: 0.125, 0.235, 0.329, 0.422, 0.510, 0.632, 0.835, 0.993, 1.097, or 1.098. When the above conditional formula is satisfied, the refractive power of the second lens L2 and the fourth lens L4 in the optical system 100 can be reasonably configured, which is beneficial to balancing the spherical aberration generated by the first lens L1 and the second lens L2 as a whole, thereby improving the overall resolution of the optical system 100, and is also beneficial to correcting the aberration of the edge field of view of the optical system 100; in addition, the second lens L2 and the fourth lens L4 are used as central lenses, and the reasonable distribution of refractive power can provide sufficient light beam transmission space for the object side lens and the image side lens of the optical system 100, thereby shortening the total length of the optical system 100 and realizing a miniaturized design. That is, when the relationship is satisfied, the resolution of the optical system 100 can be improved, so that the optical system 100 can have good imaging quality while being miniaturized.

[0069] In some embodiments, the optical system 100 satisfies the condition: 15≤|f2 / SAG22|≤135; wherein f2 is the effective focal length of the second lens L2, and SAG22 is the sag height of the image side surface S4 of the second lens L2 at the maximum effective aperture. Specifically, |f2 / SAG22| may be: 17.718, 18.653, 19.204, 21.058, 35.364, 55.151, 70.154, 99.552, 102.285, or 130.559. When the above conditional formula is met, the refractive power of the second lens L2 and the surface shape of the image-side surface S4 of the second lens L2 can be reasonably configured, which is beneficial to correcting the chromatic aberration and spherical aberration of the optical system 100, thereby improving the imaging quality of the optical system 100; at the same time, the surface shape of the second lens L2 will not be too flat, which is beneficial to improving the ability of the optical system 100 to converge light, thereby shortening the total length of the optical system 100 and realizing a miniaturized design.

[0070] In some embodiments, the optical system 100 satisfies the condition: 50≤|f5 / SAG52|≤740; wherein f5 is the effective focal length of the fifth lens L5, and SAG52 is the sag height of the image side surface S10 of the fifth lens L5 at the maximum effective aperture. Specifically, |f5 / SAG52| may be: 64.860, 100.258, 242.862, 263.147, 300.364, 421.213, 637.808, 666.154, 680.367, or 735.050. When the above conditional formula is met, the refractive power of the fifth lens L5 and the surface shape of the image-side surface S10 of the fifth lens L5 can be reasonably configured, which is beneficial to correcting the chromatic aberration and spherical aberration of the optical system 100, thereby improving the imaging quality of the optical system 100; at the same time, the surface shape of the fifth lens L5 will not be too flat, which is beneficial to improving the ability of the optical system 100 to converge light, thereby facilitating shortening the total length of the optical system 100 and realizing a miniaturized design.

[0071] In some embodiments, the optical system 100 satisfies the condition: |SAG22 / SAG52|≤2; wherein SAG22 is the sag of the image side surface S4 of the second lens L2 at the maximum effective aperture, and SAG52 is the sag of the image side surface S10 of the fifth lens L5 at the maximum effective aperture. Specifically, |SAG22 / SAG52| may be: 0.433, 0.465, 0.495, 0.551, 0.688, 0.842, 1.132, 1.366, 1.391 or 1.420. When the above conditional formula is satisfied, the ratio of the sagittal height of the second lens L2 to the fifth lens L5 can be reasonably configured, which is beneficial to balancing the spherical aberration of the optical system 100 and improving the overall resolution of the optical system 100; at the same time, the reasonable design of the surface shape of the second lens L2 and the fifth lens L5 is also beneficial to the sixth lens L6 and the seventh lens L7 on the image side to effectively correct the aberration of the edge field of view generated by the first lens L1 and the second lens L2 on the object side; in addition, the surface shape of the second lens L2 and the fifth lens L5 will not be excessively curved, which provides sufficient space for the arrangement between the lenses, thereby shortening the total length of the optical system 100 and realizing a miniaturized design. That is, the relationship is satisfied, which is beneficial for the optical system 100 to have good imaging quality while being miniaturized.

[0072] In some embodiments, at least one of the object-side surface S13 and the image-side surface S14 of the seventh lens L7 has an inflection point, and the optical system 100 satisfies the conditional formula: 1≤(|SAG71|+|SAG72|) / CT7≤2; wherein SAG71 is the sag height of the object-side surface S13 of the seventh lens L7 at the maximum effective aperture, SAG72 is the sag height of the image-side surface S14 of the seventh lens L7 at the maximum effective aperture, and CT7 is the thickness of the seventh lens L7 on the optical axis 110. Specifically, (|SAG71|+|SAG72|) / CT7 may be: 1.038, 1.050, 1.079, 1.332, 1.501, 1.753, 1.767, 1.816, 1.874, or 1.909. The seventh lens L7 is provided with an inflection point. As the lens closest to the imaging surface of the optical system 100, it can make the deflection force of the light beam reaching the imaging surface of the optical system 100 more uniform, which is beneficial to correct the distortion and field curvature generated by each lens on the object side of the seventh lens L7. When the above conditional expression is met, the thickness and surface shape of the seventh lens L7 can be reasonably configured, so that the seventh lens L7 will not be too thin or too thick, and the surface shape of the seventh lens L7 will not be too flat or overly curved, which is beneficial to reduce the incident angle of the light on the image plane and reduce the sensitivity of the optical system 100. If the upper limit of the above conditional expression is exceeded, the edge of the seventh lens L7 is too thick, which is easy to increase the field curvature aberration and cause the image plane to bend. If the lower limit of the above conditional expression is lower than the lower limit of the above conditional expression, the edge of the seventh lens L7 is too thin, and it is impossible to effectively deflect and converge the edge field light, so it is difficult to reduce the incident angle of the light at the edge of the image plane S17, thereby increasing the dark angle phenomenon.

[0073] In some embodiments, the optical system 100 satisfies the conditional expression: 3.7 mm ≤ f ≤ 4.6 mm, where f is the effective focal length of the optical system 100. By satisfying the above conditional expression, the optical system 100 has a longer focal length and can meet the shooting requirements of more scenes.

[0074] In some embodiments, the optical system 100 satisfies the conditional expression: 4.6 mm ≤ TTL ≤ 5.4 mm, where TTL is the distance from the object-side surface S1 of the first lens L1 to the image-side surface S14 of the seventh lens L7 on the optical axis 110. When the conditional expression is satisfied, the total optical length of the optical system 100 is short, which is conducive to the realization of a miniaturized design.

[0075] In some embodiments, the optical system 100 satisfies the conditional formula: 1.6≤FNO≤2.2, where FNO is the aperture number of the optical system 100. When the above conditional formula is satisfied, the optical system 100 has a relatively large aperture and can have good imaging quality even in a weak light environment.

[0076] In some embodiments, the optical system 100 satisfies the conditional expression: 76°≤FOV≤88°, where FVO is the maximum field of view of the optical system 100. When the above conditional expression is satisfied, the optical system 100 has a larger field of view and can acquire more scene information.

[0077] In some embodiments, the optical system 100 satisfies the conditional formula: ImgH=3.59 mm, where ImgH is half of the image height corresponding to the maximum field angle of the optical system 100. By satisfying the above conditional formula, the optical system 100 has a larger image surface, can match a large-sized photosensitive element, and achieve high-pixel imaging, thereby being able to meet the shooting requirements of more scenes.

[0078] The reference wavelength for the above effective focal length and combined focal length values ​​is 555nm.

[0079] Based on the description of the above embodiments, more specific embodiments and drawings are presented below for detailed description.

[0080] First embodiment

[0081] See also Figure 1 and Figure 2 , Figure 1 : is a schematic diagram of the structure of the optical system 100 in the first embodiment. The optical system 100 includes, from the object side to the image side, an aperture STO, a first lens L1 with positive refractive power, a second lens L2 with positive refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with positive refractive power and a seventh lens L7 with negative refractive power. Figure 2 From left to right are graphs of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the first embodiment, wherein the reference wavelength of the astigmatism graph and the distortion graph is 555 nm, which is the same as in other embodiments.

[0082] The object side surface S1 of the first lens L1 is convex at the near optical axis 110 and is convex at the circumference;

[0083] The image side surface S2 of the first lens L1 is concave at the near optical axis 110 and is concave at the circumference;

[0084] The object side surface S3 of the second lens L2 is convex at the near optical axis 110 and is convex at the circumference;

[0085] The image side surface S4 of the second lens L2 is convex at the near optical axis 110 and is convex at the circumference;

[0086] The object side surface S5 of the third lens L3 is convex at the near optical axis 110 and concave at the circumference;

[0087] The image-side surface S6 of the third lens L3 is concave at the near optical axis 110 and is concave at the circumference;

[0088] The object-side surface S7 of the fourth lens L4 is convex at the near optical axis 110 and concave at the circumference;

[0089] The image-side surface S8 of the fourth lens L4 is concave at the near optical axis 110 and is convex at the circumference;

[0090] The object side surface S9 of the fifth lens L5 is concave at the near optical axis 110 and is concave at the circumference;

[0091] The image-side surface S10 of the fifth lens L5 is convex at the near optical axis 110 and is convex at the circumference;

[0092] The object-side surface S11 of the sixth lens L6 is convex at the near optical axis 110 and concave at the circumference;

[0093] The image-side surface S12 of the sixth lens L6 is concave at the near optical axis 110 and is convex at the circumference;

[0094] The object-side surface S13 of the seventh lens L7 is convex near the optical axis 110 and is convex at the circumference;

[0095] The image-side surface S14 of the seventh lens L7 is concave at the near optical axis 110 and is convex at the circumference.

[0096] The object-side surfaces and image-side surfaces of the first lens L1 , the second lens L2 , the third lens L3 , the fourth lens L4 , the fifth lens L5 , the sixth lens L6 and the seventh lens L7 are all aspherical surfaces.

[0097] It should be noted that in the present application, when a surface of a lens is described as convex at the near optical axis 110 (the central area of ​​the surface), it can be understood that the area of ​​the surface of the lens near the optical axis 110 is convex. When a surface of a lens is described as concave at the circumference, it can be understood that the area of ​​the surface close to the maximum effective radius is concave. For example, when the surface is convex at the near optical axis 110 and is also convex at the circumference, the shape of the surface from the center (the intersection of the surface and the optical axis 110) to the edge direction can be a pure convex surface; or it first transitions from a convex shape at the center to a concave shape, and then becomes convex when close to the maximum effective radius. This is only an example made to illustrate the relationship between the optical axis 110 and the circumference, and the various shape structures (convex-concave relationship) of the surface are not fully reflected, but other situations can be derived based on the above examples.

[0098] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all made of plastic.

[0099] Further, the optical system 100 satisfies the conditional formula: |f12 / f67|=0.037; wherein f12 is the combined focal length of the first lens L1 and the second lens L2, and f67 is the combined focal length of the sixth lens L6 and the seventh lens L7. When the above conditional formula is satisfied, the ratio of the combined focal length of the first lens L1 and the second lens L2 and the combined focal length of the sixth lens L6 and the seventh lens L7 can be reasonably set, so that the first lens L1 and the second lens L2 can collect light in a larger angle range, and the sixth lens L6 and the seventh lens L7 can effectively converge the edge light of the center and the vicinity of the field of view, thereby making the structure of the optical system 100 more compact, which is conducive to shortening the total length of the optical system 100 and meeting the requirements of miniaturization design of electronic equipment; in addition, the sixth lens L6 and the seventh lens L7 as a whole can also effectively correct the aberrations generated by the first lens L1 and the second lens L2, so as to improve the imaging quality of the optical system 100.

[0100] The optical system 100 satisfies the conditional formula: |(R51-R52) / (R51+R52)|=0.139; wherein R51 is the radius of curvature of the object-side surface S9 of the fifth lens L5 at the optical axis 110, and R52 is the radius of curvature of the image-side surface S10 of the fifth lens L5 at the optical axis 110. When the above conditional formula is satisfied, the surface shapes of the object-side surface S9 and the image-side surface S10 of the fifth lens L5 can be reasonably configured, so that the surface shape of the fifth lens L5 is not too flat or overly curved, which is beneficial for the fifth lens L5 to correct the aberration of the optical system 100 and improve the imaging quality of the optical system 100.

[0101] The optical system 100 satisfies the conditional formula: |(R21-R22) / (R21+R22)|=24.530; wherein R21 is the radius of curvature of the object-side surface S3 of the second lens L2 at the optical axis 110, and R22 is the radius of curvature of the image-side surface S4 of the second lens L2 at the optical axis 110. When the above conditional formula is satisfied, the surface shapes of the object-side surface S3 and the image-side surface S4 of the second lens L2 can be reasonably configured, so that the surface shape of the second lens L2 is not too flat or too curved, which is beneficial for the second lens L2 to correct the aberration of the optical system 100 and improve the imaging quality of the optical system 100.

[0102] The optical system 100 satisfies the conditional formula: |f / f2+f / f4|=1.097; wherein f is the effective focal length of the optical system 100, f2 is the effective focal length of the second lens L2, and f4 is the effective focal length of the fourth lens L4. When the above conditional formula is satisfied, the refractive power of the second lens L2 and the fourth lens L4 in the optical system 100 can be reasonably configured, which is conducive to balancing the spherical aberration generated by the first lens L1 and the second lens L2 as a whole, thereby improving the overall resolution of the optical system 100, and is also conducive to correcting the aberration of the edge field of view of the optical system 100; in addition, the second lens L2 and the fourth lens L4 are used as central lenses, and the reasonable refractive power distribution can provide sufficient light beam transmission space for the object side lens and the image side lens of the optical system 100, thereby shortening the total length of the optical system 100 and realizing a miniaturized design. That is, the relationship is satisfied, the resolution of the optical system 100 can be improved, so that the optical system 100 can have good imaging quality while being miniaturized.

[0103] The optical system 100 satisfies the conditional formula: |f2 / SAG22|=17.718; wherein f2 is the effective focal length of the second lens L2, and SAG22 is the sagittal height of the image side surface S4 of the second lens L2 at the maximum effective aperture. When the above conditional formula is satisfied, the refractive power of the second lens L2 and the surface shape of the image side surface S4 of the second lens L2 can be reasonably configured, which is beneficial to correcting the chromatic aberration and spherical aberration of the optical system 100, thereby improving the imaging quality of the optical system 100; at the same time, the surface shape of the second lens L2 will not be too flat, which is beneficial to improving the ability of the optical system 100 to converge light, thereby shortening the total length of the optical system 100 and realizing a miniaturized design.

[0104] The optical system 100 satisfies the conditional formula: |f5 / SAG52|=637.809; wherein f5 is the effective focal length of the fifth lens L5, and SAG52 is the sagittal height of the image side surface S10 of the fifth lens L5 at the maximum effective aperture. When the above conditional formula is satisfied, the refractive power of the fifth lens L5 and the surface shape of the image side surface S10 of the fifth lens L5 can be reasonably configured, which is beneficial to correcting the chromatic aberration and spherical aberration of the optical system 100, thereby improving the imaging quality of the optical system 100; at the same time, the surface shape of the fifth lens L5 will not be too flat, which is beneficial to improving the ability of the optical system 100 to converge light, thereby shortening the total length of the optical system 100 and realizing a miniaturized design.

[0105] The optical system 100 satisfies the conditional formula: |SAG22 / SAG52|=1.366; wherein SAG22 is the sagittal height of the image side surface S4 of the second lens L2 at the maximum effective aperture, and SAG52 is the sagittal height of the image side surface S10 of the fifth lens L5 at the maximum effective aperture. When the above conditional formula is satisfied, the ratio of the sagittal heights of the second lens L2 and the fifth lens L5 can be reasonably configured, which is beneficial to balancing the spherical aberration of the optical system 100 and improving the overall resolution of the optical system 100; at the same time, the reasonable design of the surface shape of the second lens L2 and the fifth lens L5 is also beneficial to the sixth lens L6 and the seventh lens L7 on the image side to effectively correct the aberration of the edge field of view generated by the first lens L1 and the second lens L2 on the object side; in addition, the surface shapes of the second lens L2 and the fifth lens L5 will not be excessively curved, providing sufficient space for the arrangement between the lenses, thereby facilitating shortening the total length of the optical system 100 and realizing a miniaturized design. That is, the relationship is satisfied, which is beneficial for the optical system 100 to have good imaging quality while being miniaturized.

[0106] At least one of the object-side surface S13 and the image-side surface S14 of the seventh lens L7 has an inflection point, and the optical system 100 satisfies the conditional equation: (|SAG71|+|SAG72|) / CT7=1.038; wherein SAG71 is the sag of the object-side surface S13 of the seventh lens L7 at the maximum effective aperture, SAG72 is the sag of the image-side surface S14 of the seventh lens L7 at the maximum effective aperture, and CT7 is the thickness of the seventh lens L7 on the optical axis 110. The seventh lens L7 is provided with an inflection point. As the lens closest to the imaging surface of the optical system 100, the deflection force of the light beam reaching the imaging surface of the optical system 100 can be made more uniform, which is beneficial to correcting the distortion and field curvature produced by the lenses on the object side of the seventh lens L7. When the above conditional formula is met, the thickness and surface shape of the seventh lens L7 can be reasonably configured, so that the seventh lens L7 is not too thin or too thick, and the surface shape of the seventh lens L7 is not too flat or too curved, which is beneficial to reducing the incident angle of the light on the image plane and reducing the sensitivity of the optical system 100.

[0107] In addition, various parameters of the optical system 100 are given in Table 1. Among them, the image plane S17 in Table 1 can be understood as the imaging plane of the optical system 100. The elements from the object plane (not shown) to the image plane S17 are arranged in the order of the elements from top to bottom in Table 1. The Y radius in Table 1 is the radius of curvature of the object side surface or image side surface of the corresponding surface number at the optical axis 110. The surface number S1 and the surface number S2 are the object side surface S1 and the image side surface S2 of the first lens L1, respectively, that is, in the same lens, the surface with a smaller surface number is the object side surface, and the surface with a 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 on the optical axis 110, and the second value is the distance from the image side surface of the lens to the next surface in the image side direction on the optical axis 110.

[0108] It should be noted that, in this embodiment and the following embodiments, the optical system 100 may not be provided with the infrared filter L8, but in this case the distance from the image side surface S14 to the image plane S17 of the seventh lens L7 remains unchanged.

[0109] In the first embodiment, the effective focal length f of the optical system 100 is 4.01 mm, the aperture number FNO is 1.68, the maximum field angle FOV is 83°, the total optical length TTL is 5.38 mm, the half of the image height corresponding to the maximum field angle ImgH is 3.594 mm, and the distance DL from the object side surface S1 of the first lens L1 to the image side surface S14 of the seventh lens L7 on the optical axis 110 is 4.32 mm. In the first embodiment and other embodiments, the aperture number of the optical system 100 satisfies FNO≤2.2, and it can be seen that the optical system 100 has the characteristic of a large aperture.

[0110] It should be noted that, in some embodiments, the optical system 100 can match a photosensitive element having a rectangular photosensitive surface, and the imaging surface of the optical system 100 coincides with the photosensitive surface of the photosensitive element. In this case, the effective pixel area on the imaging surface of the optical system 100 has a horizontal direction and a diagonal direction, and the FOV can be understood as the maximum field of view angle of the optical system 100 in the diagonal direction, and ImgH can be understood as half of the length of the effective pixel area in the diagonal direction on the imaging surface of the optical system 100.

[0111] The reference wavelength of the focal length of each lens is 555 nm, and the reference wavelength of the refractive index and Abbe number of each lens is 587.56 nm (d-line), which is the same for other embodiments.

[0112] Table 1

[0113]

[0114] Further, the aspheric coefficients of the image side or object side of each lens of the optical system 100 are given in Table 2. Among them, the surface numbers S1-S14 represent the image side or object side S1-S14 respectively. And K-A20 from top to bottom represent the types of aspheric coefficients respectively, among which K represents the cone coefficient, A4 represents the fourth-order aspheric coefficient, A6 represents the sixth-order aspheric coefficient, A8 represents the eighth-order aspheric coefficient, and so on. In addition, the formula of the aspheric coefficient is as follows:

[0115]

[0116] Among them, Z is the distance from the corresponding point on the aspherical surface to the plane tangent to the surface vertex, r is the distance from the corresponding point on the aspherical surface to the optical axis 110, c is the curvature of the aspherical vertex, k is the cone coefficient, and Ai is the coefficient corresponding to the i-th high-order term in the aspherical surface shape formula.

[0117] Table 2

[0118]

[0119]

[0120] in addition, Figure 2 The optical system 100 includes a longitudinal spherical aberration diagram (Longitudinal Spherical Aberration), which indicates the deviation of the convergence focus of light of different wavelengths after passing through the lens. The ordinate of the longitudinal spherical aberration diagram indicates the normalized pupil coordinate (Normalized Pupil Coordinator) from the center of the pupil to the edge of the pupil, and the abscissa indicates the distance (in mm) from the imaging plane to the intersection of the light and the optical axis 110. It can be seen from the longitudinal spherical aberration diagram that the degree of deviation of the convergence focus of light of each wavelength in the first embodiment tends to be consistent, and the diffuse spots or color halos in the imaging picture are effectively suppressed. Figure 2 Also included is a field curvature diagram (ASTIGMATIC FIELD CURVES) of the optical system 100, where the S curve represents the sagittal field curvature at 555nm, and the T curve represents the meridian field curvature at 555nm. As can be seen from the figure, the field curvature of the optical system 100 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 imaging. Figure 2 The optical system 100 also includes a distortion diagram (DISTORTION). It can be seen from the diagram that the image deformation caused by the main light beam is small and the imaging quality of the system is excellent.

[0121] Second embodiment

[0122] See also Figure 3 and Figure 4 , Figure 3 : is a schematic diagram of the structure of the optical system 100 in the second embodiment. The optical system 100 includes, from the object side to the image side, an aperture STO, a first lens L1 with positive refractive power, a second lens L2 with positive refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with positive refractive power and a seventh lens L7 with negative refractive power. Figure 4 From left to right are graphs of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the second embodiment.

[0123] The object side surface S1 of the first lens L1 is convex at the near optical axis 110 and is convex at the circumference;

[0124] The image side surface S2 of the first lens L1 is concave at the near optical axis 110 and is concave at the circumference;

[0125] The object side surface S3 of the second lens L2 is convex at the near optical axis 110 and is convex at the circumference;

[0126] The image side surface S4 of the second lens L2 is convex at the near optical axis 110 and is convex at the circumference;

[0127] The object side surface S5 of the third lens L3 is convex at the near optical axis 110 and concave at the circumference;

[0128] The image-side surface S6 of the third lens L3 is concave at the near optical axis 110 and is concave at the circumference;

[0129] The object-side surface S7 of the fourth lens L4 is convex at the near optical axis 110 and concave at the circumference;

[0130] The image-side surface S8 of the fourth lens L4 is concave at the near optical axis 110 and is convex at the circumference;

[0131] The object side surface S9 of the fifth lens L5 is concave at the near optical axis 110 and is concave at the circumference;

[0132] The image-side surface S10 of the fifth lens L5 is convex at the near optical axis 110 and is convex at the circumference;

[0133] The object-side surface S11 of the sixth lens L6 is convex at the near optical axis 110 and concave at the circumference;

[0134] The image-side surface S12 of the sixth lens L6 is concave at the near optical axis 110 and is convex at the circumference;

[0135] The object-side surface S13 of the seventh lens L7 is convex near the optical axis 110 and is convex at the circumference;

[0136] The image-side surface S14 of the seventh lens L7 is concave at the near optical axis 110 and is convex at the circumference.

[0137] The object-side surfaces and image-side surfaces of the first lens L1 , the second lens L2 , the third lens L3 , the fourth lens L4 , the fifth lens L5 , the sixth lens L6 and the seventh lens L7 are all aspherical surfaces.

[0138] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all made of plastic.

[0139] In addition, various parameters of the optical system 100 are given in Table 3, and the definition of each parameter can be obtained from the first embodiment, which will not be repeated here.

[0140] Table 3

[0141]

[0142] Furthermore, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are given in Table 4, and the definition of each parameter therein can be obtained from the first embodiment, which will not be elaborated here.

[0143] Table 4

[0144]

[0145]

[0146] Based on the above parameter information, the following data can be derived:

[0147] |f12 / f67| 0.129 |f2 / SAG22| 19.204 |(R51-R52) / (R51+R52)| 0.222 |f5 / SAG52| 421.213 |(R21-R22) / (R21+R22)| 13.010 |SAG22 / SAG52| 1.420 |f / f2+f / f4| 1.098 (|SAG71|+|SAG72|) / CT7 1.079

[0148] In addition, by Figure 4 As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 100 are all well controlled, so that the optical system 100 of this embodiment has good imaging quality.

[0149] Third embodiment

[0150] See also Figure 5 and Figure 6 , Figure 5 : is a schematic diagram of the structure of the optical system 100 in the third embodiment. The optical system 100 includes, from the object side to the image side, an aperture STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with positive refractive power and a seventh lens L7 with negative refractive power. Figure 6 From left to right are graphs of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the third embodiment.

[0151] The object side surface S1 of the first lens L1 is convex at the near optical axis 110 and is convex at the circumference;

[0152] The image side surface S2 of the first lens L1 is concave at the near optical axis 110 and is convex at the circumference;

[0153] The object side surface S3 of the second lens L2 is convex at the near optical axis 110 and is convex at the circumference;

[0154] The image side surface S4 of the second lens L2 is concave at the near optical axis 110 and is concave at the circumference;

[0155] The object side surface S5 of the third lens L3 is concave at the near optical axis 110 and is concave at the circumference;

[0156] The image-side surface S6 of the third lens L3 is convex at the near optical axis 110 and is convex at the circumference;

[0157] The object-side surface S7 of the fourth lens L4 is convex at the near optical axis 110 and concave at the circumference;

[0158] The image-side surface S8 of the fourth lens L4 is concave at the near optical axis 110 and is convex at the circumference;

[0159] The object side surface S9 of the fifth lens L5 is concave at the near optical axis 110 and is concave at the circumference;

[0160] The image-side surface S10 of the fifth lens L5 is convex at the near optical axis 110 and is convex at the circumference;

[0161] The object-side surface S11 of the sixth lens L6 is convex at the near optical axis 110 and concave at the circumference;

[0162] The image-side surface S12 of the sixth lens L6 is convex at the near optical axis 110 and is convex at the circumference;

[0163] The object-side surface S13 of the seventh lens L7 is concave at the near optical axis 110 and is convex at the circumference;

[0164] The image-side surface S14 of the seventh lens L7 is concave at the near optical axis 110 and is convex at the circumference.

[0165] The object-side surfaces and image-side surfaces of the first lens L1 , the second lens L2 , the third lens L3 , the fourth lens L4 , the fifth lens L5 , the sixth lens L6 and the seventh lens L7 are all aspherical surfaces.

[0166] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all made of plastic.

[0167] In addition, various parameters of the optical system 100 are given in Table 5, and the definition of each parameter can be obtained from the first embodiment, which will not be repeated here.

[0168] Table 5

[0169]

[0170]

[0171] Furthermore, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are given in Table 6, and the definition of each parameter therein can be obtained from the first embodiment, which will not be repeated here.

[0172] Table 6

[0173]

[0174] Furthermore, based on the above-mentioned parameter information, the following data can be derived:

[0175]

[0176]

[0177] In addition, by Figure 6 As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 100 are all well controlled, so that the optical system 100 of this embodiment has good imaging quality.

[0178] Fourth embodiment

[0179] See also Figure 7 and Figure 8 , Figure 7 : is a schematic structural diagram of the optical system 100 in the fourth embodiment. The optical system 100 includes, from the object side to the image side, an aperture STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with positive refractive power and a seventh lens L7 with negative refractive power. Figure 8 From left to right are graphs of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the fourth embodiment.

[0180] The object side surface S1 of the first lens L1 is convex at the near optical axis 110 and is convex at the circumference;

[0181] The image side surface S2 of the first lens L1 is concave at the near optical axis 110 and is convex at the circumference;

[0182] The object side surface S3 of the second lens L2 is convex at the near optical axis 110 and is convex at the circumference;

[0183] The image side surface S4 of the second lens L2 is concave at the near optical axis 110 and is concave at the circumference;

[0184] The object side surface S5 of the third lens L3 is convex at the near optical axis 110 and concave at the circumference;

[0185] The image-side surface S6 of the third lens L3 is concave at the near optical axis 110 and is convex at the circumference;

[0186] The object-side surface S7 of the fourth lens L4 is convex at the near optical axis 110 and concave at the circumference;

[0187] The image-side surface S8 of the fourth lens L4 is concave at the near optical axis 110 and is convex at the circumference;

[0188] The object side surface S9 of the fifth lens L5 is concave at the near optical axis 110 and is concave at the circumference;

[0189] The image-side surface S10 of the fifth lens L5 is convex at the near optical axis 110 and is convex at the circumference;

[0190] The object-side surface S11 of the sixth lens L6 is convex at the near optical axis 110 and concave at the circumference;

[0191] The image-side surface S12 of the sixth lens L6 is concave at the near optical axis 110 and is convex at the circumference;

[0192] The object-side surface S13 of the seventh lens L7 is convex near the optical axis 110 and is convex at the circumference;

[0193] The image-side surface S14 of the seventh lens L7 is concave at the near optical axis 110 and is convex at the circumference.

[0194] The object-side surfaces and image-side surfaces of the first lens L1 , the second lens L2 , the third lens L3 , the fourth lens L4 , the fifth lens L5 , the sixth lens L6 and the seventh lens L7 are all aspherical surfaces.

[0195] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all made of plastic.

[0196] In addition, various parameters of the optical system 100 are given in Table 7, and the definition of each parameter can be obtained from the first embodiment, which will not be repeated here.

[0197] Table 7

[0198]

[0199]

[0200] Furthermore, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are given in Table 8, and the definition of each parameter therein can be obtained from the first embodiment, which will not be repeated here.

[0201] Table 8

[0202]

[0203] Furthermore, based on the above-mentioned parameter information, the following data can be derived:

[0204] |f12 / f67| 0.478548 |f2 / SAG22| 99.55188 |(R51-R52) / (R51+R52)| 0.1808 |f5 / SAG52| 242.8625 |(R21-R22) / (R21+R22)| 28.57595 |SAG22 / SAG52| 0.495098 |f / f2+f / f4| 0.632268 (|SAG71|+|SAG72|) / CT7 1.816302

[0205] In addition, by Figure 8As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 100 are all well controlled, so that the optical system 100 of this embodiment has good imaging quality.

[0206] Fifth embodiment

[0207] See also Fig. 9 and Fig.10 , Fig. 9 : is a schematic diagram of the structure of the optical system 100 in the fifth embodiment. The optical system 100 includes, from the object side to the image side, an aperture STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, a fifth lens L5 with negative refractive power, a sixth lens L6 with positive refractive power, and a seventh lens L7 with negative refractive power. Fig.10 From left to right are graphs of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the fifth embodiment.

[0208] The object side surface S1 of the first lens L1 is convex at the near optical axis 110 and is convex at the circumference;

[0209] The image side surface S2 of the first lens L1 is concave at the near optical axis 110 and is concave at the circumference;

[0210] The object side surface S3 of the second lens L2 is convex at the near optical axis 110 and is convex at the circumference;

[0211] The image side surface S4 of the second lens L2 is concave at the near optical axis 110 and is concave at the circumference;

[0212] The object side surface S5 of the third lens L3 is convex at the near optical axis 110 and concave at the circumference;

[0213] The image-side surface S6 of the third lens L3 is concave at the near optical axis 110 and is convex at the circumference;

[0214] The object-side surface S7 of the fourth lens L4 is convex at the near optical axis 110 and concave at the circumference;

[0215] The image-side surface S8 of the fourth lens L4 is concave at the near optical axis 110 and is convex at the circumference;

[0216] The object side surface S9 of the fifth lens L5 is concave at the near optical axis 110 and is concave at the circumference;

[0217] The image-side surface S10 of the fifth lens L5 is concave at the near optical axis 110 and is convex at the circumference;

[0218] The object-side surface S11 of the sixth lens L6 is convex at the near optical axis 110 and concave at the circumference;

[0219] The image-side surface S12 of the sixth lens L6 is convex at the near optical axis 110 and is convex at the circumference;

[0220] The object-side surface S13 of the seventh lens L7 is concave at the near optical axis 110 and is convex at the circumference;

[0221] The image-side surface S14 of the seventh lens L7 is concave at the near optical axis 110 and is convex at the circumference.

[0222] The object-side surfaces and image-side surfaces of the first lens L1 , the second lens L2 , the third lens L3 , the fourth lens L4 , the fifth lens L5 , the sixth lens L6 and the seventh lens L7 are all aspherical surfaces.

[0223] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all made of plastic.

[0224] In addition, various parameters of the optical system 100 are given in Table 9, and the definition of each parameter can be obtained from the first embodiment, which will not be repeated here.

[0225] Table 9

[0226]

[0227] Furthermore, the aspheric coefficients of the image-side surface or the object-side surface of each lens of the optical system 100 are given in Table 10, and the definition of each parameter therein can be obtained from the first embodiment, which will not be repeated here.

[0228] Table 10

[0229]

[0230] Furthermore, based on the above-mentioned parameter information, the following data can be derived:

[0231] |f12 / f67| 0.207 |f2 / SAG22| 55.151 |(R51-R52) / (R51+R52)| 97.825 |f5 / SAG52| 64.860 |(R21-R22) / (R21+R22)| 0.656 |SAG22 / SAG52| 0.433 |f / f2+f / f4| 0.329 (|SAG71|+|SAG72|) / CT7 1.909

[0232] In addition, by Fig.10 As can be seen from the aberration diagram in , the longitudinal spherical aberration, field curvature and distortion of the optical system 100 are all well controlled, so that the optical system 100 of this embodiment has good imaging quality.

[0233] See also Fig.11In some embodiments, the optical system 100 can be assembled with the photosensitive element 210 to form an imaging module 200. At this time, the photosensitive surface of the photosensitive element 210 can be regarded as the image plane S17 of the optical system 100. The imaging module 200 can also be provided with an infrared filter L8, and the infrared filter L8 is arranged between the image side surface S14 of the seventh lens L7 and the image plane S17. Specifically, the photosensitive element 210 can be a charge coupled device (CCD) or a complementary metal oxide semiconductor device (CMOS Sensor). The above optical system 100 is used in the imaging module 200, and the optical system 100 has a compact structure and can meet the requirements of the miniaturized design of the imaging module 200.

[0234] See also Fig.11 and Fig.12 In some embodiments, the imaging module 200 can be applied to an electronic device 300, and the electronic device includes a housing 310, and the imaging module 200 is disposed in the housing 310. Specifically, the electronic device 300 can be, but is not limited to, a portable phone, a video phone, a smart phone, an e-book reader, a driving recorder, or other vehicle-mounted imaging devices or a wearable device such as a smart watch. When the electronic device 300 is a smart phone, the housing 310 can be the middle frame of the electronic device 300. By adopting the above-mentioned imaging module 200 in the electronic device 300, the structure of the optical system 100 is compact, which can meet the requirements of the miniaturized design of the electronic device 300.

[0235] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0236] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An optical system, characterized in that: Along the optical axis from the object side to the image side, it includes: A first lens having positive refractive power, wherein the object side surface of the first lens is convex at the near optical axis, and the image side surface of the first lens is concave at the near optical axis; A second lens having refractive power, wherein the object side surface of the second lens is convex at a position close to the optical axis; a third lens having refractive power; a fourth lens having a refractive power, wherein the object side surface of the fourth lens is a convex surface near the optical axis, and the image side surface of the fourth lens is a concave surface at the optical axis; a fifth lens having refractive power, wherein the object side surface of the fifth lens is concave at a position close to the optical axis; a sixth lens element having positive refractive power, wherein the object side surface of the sixth lens element is convex near the optical axis; a seventh lens element having negative refractive power, wherein the image side surface of the seventh lens element is concave at a near optical axis; There are seven lenses with refractive power; The object side surface and the image side surface of each lens of the optical system are both aspherical surfaces; And the optical system satisfies the following conditional formula: |f12 / f67|≤0.5;1≤(|SAG71|+|SAG72|) / CT7≤2; Among them, f12 is the combined focal length of the first lens and the second lens, f67 is the combined focal length of the sixth lens and the seventh lens, SAG71 is the sag of the object side of the seventh lens at the maximum effective aperture, SAG72 is the sag of the image side of the seventh lens at the maximum effective aperture, and CT7 is the thickness of the seventh lens on the optical axis.

2. The optical system according to claim 1, characterized in that The following conditions are met: |(R51-R52) / (R51+R52)|≤100; Wherein, R51 is the curvature radius of the object side surface of the fifth lens at the optical axis, and R52 is the curvature radius of the image side surface of the fifth lens at the optical axis.

3. The optical system according to claim 1, characterized in that The following conditions are met: |(R21-R22) / (R21+R22)|≤30; Wherein, R21 is the curvature radius of the object side surface of the second lens at the optical axis, and R22 is the curvature radius of the image side surface of the second lens at the optical axis.

4. The optical system according to claim 1, characterized in that The following conditions are met: |f / f2+f / f4|≤1.5; Among them, f is the effective focal length of the optical system, f2 is the effective focal length of the second lens, and f4 is the effective focal length of the fourth lens.

5. The optical system according to claim 1, characterized in that The following conditions are met: 15≤|f2 / SAG22|≤135; Wherein, f2 is the effective focal length of the second lens, and SAG22 is the sag of the image side of the second lens at the maximum effective aperture.

6. The optical system according to claim 1, characterized in that The following conditions are met: 50≤|f5 / SAG52|≤740; Wherein, f5 is the effective focal length of the fifth lens, and SAG52 is the sag height of the image side surface of the fifth lens at the maximum effective aperture.

7. The optical system according to claim 1, characterized in that The following conditions are met: |SAG22 / SAG52|≤2; Among them, SAG22 is the sag of the image side surface of the second lens at the maximum effective aperture, and SAG52 is the sag of the image side surface of the fifth lens at the maximum effective aperture.

8. The optical system according to claim 1, characterized in that At least one of the object-side surface and the image-side surface of the seventh lens has an inflection point.

9. An imaging module, characterized in that: The optical system comprises a photosensitive element and any one of claims 1 to 8, wherein the photosensitive element is arranged on the image side of the optical system.

10. An electronic device, characterized in that: It comprises a shell and the imaging module as claimed in claim 9, wherein the imaging module is arranged in the shell.

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