Optical system, camera module and electronic device

Abstract

The present invention relates to an optical system, a camera module and an electronic device. The optical system includes, from the object side to the image side, in sequence: a first lens with positive refractive power; a second lens with negative refractive power; a third lens with refractive power; a fourth lens with positive refractive power; a fifth lens with negative refractive power, the object side surface and the image side surface of the fifth lens are both aspherical surfaces, and at least one of the object side surface and the image side surface of the fifth lens has an inflection point; the optical system includes a stop arranged on the image side of the first lens; the optical system satisfies: 1.0<SD11 / tan(HFOV)+SAG11<1.5; SD11 is the maximum effective radius of the object side surface of the first lens, HFOV is half of the maximum field of view of the optical system, and SAG11 is the sagittal height of the object side surface of the first lens. Satisfying the above relationship can realize a miniaturized design of the head of the optical system.

Description

Technical Field

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

[0002] In recent years, full-screen mobile phones have gradually become popular in the market, and the key to achieving a higher screen-to-body ratio is to reduce the size of the lens head. Although traditional camera lenses mounted on portable electronic products can meet the requirements of miniaturization, such as reducing the axial size, the actual lens head is still large, resulting in a larger screen opening, making it difficult to achieve a full-screen design. Summary of the invention

[0003] Based on this, it is necessary to provide an optical system, a camera module and an electronic device to solve the problem of how to realize the small head design of the lens.

[0004] An optical system, comprising, from the object side to the image side, the following:

[0005] a first lens having positive refractive power;

[0006] a second lens element having negative refractive power;

[0007] a third lens having refractive power;

[0008] a fourth lens element having positive refractive power;

[0009] A fifth lens having negative refractive power, wherein both the object-side surface and the image-side surface of the fifth lens are aspherical surfaces, and at least one of the object-side surface and the image-side surface of the fifth lens has an inflection point;

[0010] The optical system further comprises an aperture, wherein the aperture is arranged on the image side of the first lens;

[0011] The optical system satisfies the following relationship:

[0012] 1.0<SD11 / tan(HFOV)+SAG11<1.5;

[0013] Among them, SD11 is the maximum effective radius of the object side surface of the first lens, HFOV is half of the maximum field of view angle of the optical system, SAG11 is the sagittal height of the object side surface of the first lens, that is, the horizontal displacement from the intersection of the object side surface of the first lens and the optical axis to the maximum effective radius of the object side surface on the optical axis (the horizontal displacement is defined as positive toward the image side and negative toward the object side), and the units of SD11 and SAG11 are both mm.

[0014] When the above-mentioned lens refractive power, surface shape and relationship conditions are met, the positive refractive power provided by the first lens and the negative refractive power provided by the second lens can promote the balance of the system's spherical aberration, and the positive refractive power setting of the fourth lens can further enhance the focusing ability of the system. In addition, when the above-mentioned relationship is met, the head of the optical system can also be miniaturized, and the optical system can also obtain a larger field of view, thereby improving the imaging quality.

[0015] In one embodiment, the optical system satisfies the following relationship:

[0016] 2.2≤FNO≤2.5;

[0017] Wherein, FNO is the aperture number of the optical system. When the above relationship is satisfied, it is not only conducive to the miniaturization design of the head of the optical system, but also can increase the luminous flux of the system per unit time and enhance the imaging effect in a dark environment.

[0018] In one embodiment, the optical system satisfies the following relationship:

[0019] 0.7<CT1 / CT4<2.0;

[0020] Wherein, CT1 is the thickness of the first lens at the optical axis, and CT4 is the thickness of the fourth lens at the optical axis. When the above relationship is satisfied, the thickness of the first lens and the fourth lens will be reasonably configured, so that the refractive power of the positive lens in the system can be reasonably distributed, thereby effectively correcting the spherical aberration of the system, and at the same time making the thickness of the first lens and the fourth lens relatively uniform, meeting the processing requirements.

[0021] In one embodiment, the optical system satisfies the following relationship:

[0022] 1.5<(CT2+CT3) / (T12+T23)<2.0;

[0023] Wherein, CT2 is the thickness of the second lens at the optical axis, CT3 is the thickness of the third lens at the optical axis, T12 is the spacing distance between the first lens and the second lens on the optical axis, and T23 is the spacing distance between the second lens and the third lens on the optical axis. When the above relationship is satisfied, there can be enough space for the first lens, the second lens and the third lens during assembly, thereby effectively avoiding collision between the first lens and the second lens or between the second lens and the third lens. In addition, when the above relationship is satisfied, the thickness of the second lens and the third lens at the optical axis can be reduced, which is beneficial to the miniaturization design of the optical system. At the same time, it can also prevent the thickness of the two lenses at the optical axis from being too small, avoiding the problem of inconvenient assembly and increased system sensitivity.

[0024] In one embodiment, the optical system satisfies the following relationship:

[0025] SD11 / ImgH<0.3;

[0026] Wherein, ImgH is half of the diagonal length of the effective pixel area on the imaging surface of the optical system. The smaller the optical aperture of the object side of the first lens, the more conducive it is to miniaturization of the head of the optical system. When the above relationship is met, the optical aperture of the object side of the first lens can form a reasonable configuration relationship with the size of the effective pixel area at the imaging surface of the system, so that when the optical system matches a high-pixel and large-size photosensitive element, it can still take into account the ultra-small head design.

[0027] In one embodiment, the optical system satisfies the following relationship:

[0028] -2.2<f5 / R52<-1.2;

[0029] Wherein, f5 is the effective focal length of the fifth lens, and R52 is the radius of curvature of the image side surface of the fifth lens at the optical axis. When the above relationship is satisfied, the deflection angle of the edge field light entering the system imaging surface can be effectively reduced, thereby increasing the matching degree between the optical system and the photosensitive element, and improving the astigmatism of the off-axis field of view.

[0030] In one embodiment, the optical system satisfies the following relationship:

[0031] 1.0<f12 / f4<2.5;

[0032] Wherein, f12 is the combined focal length of the first lens and the second lens, and f4 is the effective focal length of the fourth lens. When the above relationship is satisfied, the focusing ability of the optical system on light can be further enhanced, and it is also beneficial to correct the field curvature of the system and achieve good imaging quality; in addition, it is also beneficial to shorten the total length of the system, so that the optical system obtains a larger field angle.

[0033] In one embodiment, the optical system satisfies the following relationship:

[0034] 0<(nd2-nd3)<0.2;

[0035] Wherein, nd2 is the refractive index of the second lens, and nd3 is the refractive index of the third lens. When the above relationship is satisfied, the chromatic aberration of the optical system can be effectively corrected, the imaging clarity can be improved, and thus the imaging quality can be improved.

[0036] In one embodiment, the optical system satisfies the following relationship:

[0037] 1<CT4 / |SAG41|<15;

[0038] Wherein, CT4 is the thickness of the fourth lens at the optical axis, and SAG41 is the sagittal height of the object side surface of the fourth lens, i.e., the horizontal displacement from the intersection of the object side surface of the fourth lens and the optical axis to the maximum effective radius of the object side surface on the optical axis (the horizontal displacement is defined as positive toward the image side and negative toward the object side). When the above relationship is satisfied, the shape of the fourth lens is conducive to manufacturing and molding, and can reduce the defects of poor molding; at the same time, it can also effectively correct the field curvature generated by the front lens group (the first lens, the second lens and the third lens), ensure the balance of the field curvature of the system, and improve the imaging quality of the optical system.

[0039] A camera 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 fifth lens. By adopting the above optical system, the head of the camera module can also be miniaturized, and a larger field of view can be obtained, thereby improving the imaging quality.

[0040] An electronic device comprises a housing and the above-mentioned camera module, wherein the camera module is arranged in the housing. By adopting the above-mentioned camera module with a small head characteristic, not only can the camera quality of the electronic device be improved, but also the under-screen packaging of the module is facilitated, and at the same time, the size of the light entrance hole corresponding to the camera module on the screen module of the electronic device can be made small, thereby improving the screen-to-body ratio of the electronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of an optical system provided in accordance with the first embodiment of the present application;

[0042] Figure 2 : are the longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) of the optical system in the first embodiment;

[0043] Figure 3 A schematic diagram of an optical system provided for a second embodiment of the present application;

[0044] Figure 4 : are longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) of the optical system in the second embodiment;

[0045] Figure 5 A schematic diagram of an optical system provided in accordance with a third embodiment of the present application;

[0046] Figure 6 : are longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) of the optical system in the third embodiment;

[0047] Figure 7 A schematic diagram of an optical system provided in accordance with a fourth embodiment of the present application;

[0048] Figure 8 : are longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) of the optical system in the fourth embodiment;

[0049] Fig. 9 A schematic diagram of an optical system provided in accordance with a fifth embodiment of the present application;

[0050] Fig.10 : are longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) of the optical system in the fifth embodiment;

[0051] Fig.11 A schematic diagram of an optical system provided in accordance with a sixth embodiment of the present application;

[0052] Fig.12 : are longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) of the optical system in the sixth embodiment;

[0053] Fig.13 A schematic diagram of a camera module provided in one embodiment of the present application;

[0054] Fig.14 A schematic diagram of an electronic device provided in accordance with an embodiment of the present application. DETAILED DESCRIPTION

[0055] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0056] It should be noted that when an element is referred to as being "fixed to" another original, it may be directly on another element or may also have a centered element. When an element is considered to be "connected" to another original, it may be directly connected to another element or may simultaneously have a centered element. On the contrary, when an element is referred to as being "directly on" another original, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for illustrative purposes.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0058] In recent years, full-screen mobile phones have become increasingly popular in the market, and the key to achieving a higher screen-to-body ratio is to reduce the size of the lens head. Although traditional camera lenses mounted on portable electronic products can meet the requirements of miniaturization, such as reducing the axial size, the actual lens head is still relatively large, resulting in a larger screen opening, making it difficult to achieve a full-screen design. To this end, some embodiments of the present application provide an optical system with a small head characteristic to solve the above problem.

[0059] refer to Figure 1 In some embodiments of the present application, the optical system 10 includes, from the object side to the image side, a first lens L1, an aperture (not shown in the figure), a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5. Among them, the first lens L1 has a positive refractive power, the second lens L2 has a negative refractive power, the fourth lens L4 has a positive refractive power, and the fifth lens L5 has a negative refractive power. The first lens L1 to the fifth lens L5 each include only one lens, and each lens in the optical system 10 is coaxially arranged with the aperture, that is, the optical axis of each lens and the center of the aperture are located on the same straight line, and the straight line can be called the optical axis of the optical system 10.

[0060] In the above embodiment, the aperture is disposed on the image side surface S2 of the first lens L1. The aperture at this time can be called a central aperture, and the aperture of the aperture is equal to the maximum effective radius of the image side surface S2 of the first lens L1. At this time, the image side surface S2 of the first lens L1 can also be regarded as an aperture. However, it should be noted that in other embodiments, the aperture can be disposed at any reasonable position on the image side of the first lens L1, for example, between any two adjacent lenses from the first lens L1 to the fifth lens L5.

[0061] 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, and the fifth lens L5 includes an object side surface S9 and an image side surface S10. In addition, the optical system 10 also has an imaging surface S13, which is located on the image side of the fifth lens L5. The incident light can be imaged on the imaging surface S13 after being adjusted by the lenses of the optical system 10. For ease of understanding, the imaging surface S13 can be regarded as the photosensitive surface of the photosensitive element. The optical system 10 also has an object surface, and the object located on the object surface can form a clear image on the imaging surface S13 of the optical system 10.

[0062] In the above embodiment, the object-side surface and the image-side surface of the first lens L1 to the fifth lens L5 are all aspherical surfaces, and at least one of the object-side surface S9 and the image-side surface S10 has an inflection point, that is, both the object-side surface S9 and the image-side surface S10 may have an inflection point or only one of the surfaces may have an inflection point.

[0063] The aspheric surface setting can effectively help the optical system 10 eliminate aberrations and solve the problem of visual distortion. It is also beneficial to the miniaturized design of the optical system 10, so that the optical system 10 can have excellent optical effects while maintaining a miniaturized design. Of course, in other embodiments, the object side surface of any one of the first lens L1 to the fifth lens L5 can be a spherical surface or an aspherical surface; the image side surface of any one of the first lens L1 to the fifth lens L5 can be a spherical surface or an aspherical surface. The coordination of the spherical surface and the aspherical surface can also effectively eliminate the aberration problem, so that the optical system 10 has an excellent imaging effect, while improving the flexibility of lens design and assembly. In particular, when the fifth lens L5 is an aspherical lens, it will be beneficial to finally correct the aberrations generated by the front lenses, thereby improving the imaging quality.

[0064] The calculation of the aspheric surface can refer to the aspheric surface formula:

[0065]

[0066] Among them, Z is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, r is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the aspherical vertex, k is the cone coefficient, and Ai is the coefficient corresponding to the i-th high-order term in the aspherical surface shape formula.

[0067] On the other hand, in some embodiments, when the object side or image side of a lens is an aspheric surface, the surface may be a structure that is convex as a whole or concave as a whole; or the surface may be designed to have a structure with an inflection point, in which case the surface shape of the surface from the center to the edge will change, for example, the surface is convex at the center and concave at the edge. It should be noted that when the embodiments of the present application describe a side surface of a lens as convex at the optical axis (the central area of ​​the side surface), it can be understood that the area of ​​the side surface of the lens near the optical axis is convex, and therefore the side surface can also be considered to be convex at the near axis; when describing a side surface of a lens as concave at the circumference, it can be understood that the area of ​​the side surface near the maximum effective semi-aperture is concave. For example, when the side surface is convex at the optical axis and is also convex at the circumference, the shape of the side surface from the center (optical axis) to the edge direction may be a pure convex surface; or it may first transition from a convex shape at the center to a concave shape, and then become convex when approaching the maximum effective semi-aperture. This is only an example to illustrate the relationship between the optical axis and the circumference. The various shape structures (concave and convex relationships) of the side are not fully reflected, but other situations can be deduced based on the above examples and should also be regarded as the content recorded in this application.

[0068] On the other hand, in the above embodiments, the materials of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 are all plastic. In other embodiments, the material of the first lens L1 is glass, and the material of the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 are all plastic. At this time, since the material of the lens located on the object side in the optical system 10 is glass, these glass lenses located on the object side have a good tolerance effect on extreme environments and are not easily affected by the object side environment and aging, etc., so when the optical system 10 is in an extreme environment such as exposure to high temperature, this structure can effectively prevent the optical system 10 from having a decrease in imaging quality and a reduction in service life. The lens made of plastic can reduce the weight of the optical system 10 and reduce the production cost, while the lens made of glass can withstand higher temperatures and have excellent optical properties. Of course, the material configuration of each lens in the optical system 10 is not limited to the above embodiments, and the material of any lens can be plastic or glass.

[0069] In the above embodiment, the optical system 10 includes an infrared filter L6, and the infrared filter L6 is arranged on the image side of the fifth lens L5. The infrared filter L6 includes an object side surface S11 and an image side surface S12. The infrared filter L6 can be an infrared cut-off filter. In this case, the infrared filter L6 is used to filter out infrared light to prevent infrared light from reaching the imaging surface S13, thereby preventing infrared light from interfering with normal imaging. The infrared filter L6 can be assembled together with each lens as a part of the optical system 10. In other embodiments, the infrared filter L6 does not belong to the components of the optical system 10. In this case, the infrared filter L6 can be installed between the optical system 10 and the photosensitive element when the optical system 10 and the photosensitive element are assembled into a camera module. In some embodiments, the infrared filter L6 can also be arranged on the object side of the first lens L1. In addition, in some embodiments, the infrared filter L6 may not be arranged, but a filter coating is arranged on any lens from the first lens L1 to the fifth lens L5 to achieve the effect of filtering out infrared light. Correspondingly, the infrared filter L6 in some embodiments can also be an infrared bandpass filter. In this case, the infrared filter L6 can be used to filter out visible light through infrared light. The camera module equipped with the infrared bandpass filter can be used as a recognition module and applied to electronic devices together with the corresponding infrared emission module (such as TOF time of flight or 3D structured light). This type of camera module can be specifically used to identify facial contours, pupils, fingerprints, palm prints, etc.

[0070] In some other embodiments, the first lens L1 may also include two or more lenses, the object-side surface of the lens closest to the object side is the object-side surface of the first lens L1, and the object-side surface of the lens closest to the image side is the image-side surface S2 of the first lens L1. Accordingly, in some embodiments, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 are not limited to the case of including only one lens.

[0071] In some embodiments, the optical system 10 may include not only a lens and an aperture having refractive power, but also an infrared filter, a protective glass, a photosensitive element, a reflector for changing the incident light path, and other elements.

[0072] In the above embodiment, the optical system 10 also satisfies the following relationships:

[0073] 1.0<SD11 / tan(HFOV)+SAG11<1.5;

[0074] Wherein, SD11 is the maximum effective radius of the object side surface S1 of the first lens L1, HFOV is half of the maximum field of view of the optical system 10, SAG11 is the sag of the object side surface S1 of the first lens L1, that is, the horizontal displacement from the intersection of the object side surface S1 and the optical axis to the maximum effective radius of the object side surface S1 on the optical axis (the horizontal displacement is defined as positive toward the image side and negative toward the object side), and the units of SD11 and SAG11 are both mm. Specifically, SD11 / tan(HFOV)+SAG11 can be 1.050mm, 1.070mm, 1.100mm, 1.150mm, 1.200mm, 1.250mm, 1.300mm, 1.320mm, 1.330mm or 1.350mm. When the above-mentioned lens refractive power, surface shape and relationship conditions are met, the positive refractive power provided by the first lens L1 and the negative refractive power provided by the second lens L2 can promote the balance of the spherical aberration of the system, and the positive refractive power setting of the fourth lens L4 can further enhance the focusing ability of the system. In addition, when the above-mentioned relationship is met, the head of the optical system 10 can also be miniaturized, and the optical system 10 can also obtain a larger field of view, thereby improving the imaging quality.

[0075] 2.2≤FNO≤2.5;

[0076] Wherein, FNO is the aperture number of the optical system 10. Specifically, FNO can be 2.27, 2.30, 2.35, 2.40, 2.43, 2.46 or 2.48. When the above relationship is satisfied, it is not only conducive to the miniaturization design of the head of the optical system 10, but also can improve the luminous flux of the system per unit time and enhance the imaging effect in a dark environment.

[0077] 0.7<CT1 / CT4<2.0;

[0078] Wherein, CT1 is the thickness of the first lens L1 at the optical axis, CT4 is the thickness of the fourth lens L4 at the optical axis, and in the embodiment of the present application, the thickness of the lens at the optical axis is the thickness of the lens on its own optical axis. Specifically, CT1 / CT4 can be 0.900, 0.950, 1.000, 1.050, 1.100, 1.300, 1.500, 1.700, 1.750, 1.800, 1.850 or 1.900. When the above relationship is satisfied, the thickness of the first lens L1 and the fourth lens L4 will be reasonably configured, so that the refractive power of the positive lens in the system can be reasonably distributed, thereby effectively correcting the spherical aberration of the system, and at the same time making the thickness of the first lens L1 and the fourth lens L4 relatively uniform, meeting the processing technology requirements.

[0079] 1.5<(CT2+CT3) / (T12+T23)<2.0;

[0080] Wherein, CT2 is the thickness of the second lens L2 at the optical axis, CT3 is the thickness of the third lens L3 at the optical axis, T12 is the distance between the first lens L1 and the second lens L2 on the optical axis, and T23 is the distance between the second lens L2 and the third lens L3 on the optical axis. Specifically, (CT2+CT3) / (T12+T23) can be 1.550, 1.600, 1.650, 1.700, 1.850, 1.900, 1.930, 1.950 or 1.960. When the above relationship is satisfied, there is enough space for the first lens L1, the second lens L2 and the third lens L3 during assembly, thereby effectively avoiding collision between the first lens L1 and the second lens L2 or between the second lens L2 and the third lens L3. In addition, when the above relationship is satisfied, the thickness of the second lens L2 and the third lens L3 at the optical axis can be reduced, which is beneficial to the miniaturization design of the optical system 10. At the same time, it can also prevent the thickness of the two at the optical axis from being too small, avoiding the problems of inconvenience in assembly and increased system sensitivity.

[0081] SD11 / ImgH<0.3;

[0082] Among them, ImgH is half of the diagonal length of the effective pixel area on the imaging surface S13 of the optical system 10. SD11 / ImgH can be 0.230, 0.235, 0.240, 0.250, 0.260, 0.270 or 0.280. The smaller the optical aperture of the object side surface S1 of the first lens L1, the more conducive to the miniaturization of the head of the optical system 10. When the above relationship is satisfied, the optical aperture of the object side surface S1 of the first lens L1 can form a reasonable configuration relationship with the size of the effective pixel area at the imaging surface S13 of the system, so that when the optical system 10 matches a high-pixel and large-size photosensitive element, it can still take into account the ultra-small head design.

[0083] -2.2<f5 / R52<-1.2;

[0084] Wherein, f5 is the effective focal length of the fifth lens L5, and R52 is the radius of curvature of the image side surface S10 of the fifth lens L5 at the optical axis. Specifically, f5 / R52 can be -1.470, -1.500, -1.550, -1.700, -1.800, -1.850, -1.900 or -1.920. When the above relationship is satisfied, the deflection angle of the edge field light entering the system imaging surface S13 can be effectively reduced, thereby increasing the matching degree between the optical system 10 and the photosensitive element, and improving the astigmatism of the off-axis field of view.

[0085] 1.0<f12 / f4<2.5;

[0086] Wherein, f12 is the combined focal length of the first lens L1 and the second lens L2, and f4 is the effective focal length of the fourth lens L4. Specifically, f12 / f4 can be 1.300, 1.320, 1.350, 1.400, 1.600, 1.800, 1.900, 2.000, 2.100, 2.150, 2.200 or 2.250. When the above relationship is satisfied, the focusing ability of the optical system 10 on light can be further enhanced, and it is also beneficial to correct the field curvature of the system and achieve good imaging quality; in addition, it is also beneficial to shorten the total length of the system, so that the optical system 10 can obtain a larger field angle.

[0087] 0<(nd2-nd3)<0.2;

[0088] Wherein, nd2 is the refractive index of the second lens L2, and nd3 is the refractive index of the third lens L3. Specifically, (nd2-nd3) can be 0.03, 0.04, 0.06, 0.08, 0.10, 0.12, 0.125 or 0.130. When the above relationship is satisfied, the chromatic aberration of the optical system 10 can be effectively corrected, the imaging clarity can be improved, and thus the imaging quality can be improved.

[0089] 1<CT4 / |SAG41|<15;

[0090] Among them, CT4 is the thickness of the fourth lens L4 at the optical axis, and SAG41 is the vector height of the object side surface S7 of the fourth lens L4, that is, the horizontal displacement from the intersection of the object side surface S7 and the optical axis to the maximum effective radius of the object side surface S7 on the optical axis (the horizontal displacement is defined as positive toward the image side and negative toward the object side). Specifically, CT4 / |SAG41| can be 1.100, 1.300, 1.500, 2.000, 2.500, 8.000, 9.000, 9.500, 13.000, 13.500 or 13.800. When the above relationship is met, the shape of the fourth lens L4 is conducive to manufacturing and molding, which can reduce the defects of poor molding; at the same time, it can also effectively correct the field curvature generated by the front lens group (the first lens L1, the second lens L2 and the third lens L3), ensure the balance of the system field curvature, and improve the imaging quality of the optical system 10.

[0091] Next, the optical system 10 of the present application is described with more specific and detailed embodiments:

[0092] First embodiment

[0093] refer to Figure 1 and Figure 2In the first embodiment, the optical system 10 includes, from the object side to the image side, a first lens L1 with positive refractive power, a stop disposed on the image side surface S2, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, and a fifth lens L5 with negative refractive power. Figure 2 It includes a longitudinal spherical aberration diagram (mm), an astigmatism diagram (mm) and a distortion diagram (%) of the optical system 10 in the first embodiment, wherein the astigmatism diagram and the distortion diagram are curve diagrams at a wavelength of 555 nm.

[0094] The object-side surface S1 of the first lens L1 is convex at the optical axis, and the image-side surface S2 is concave at the optical axis; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is concave at the circumference.

[0095] The object-side surface S3 of the second lens L2 is convex at the optical axis, and the image-side surface S4 is concave at the optical axis; the object-side surface S3 is convex at the circumference, and the image-side surface S4 is concave at the circumference.

[0096] The object-side surface S5 of the third lens L3 is concave at the optical axis, and the image-side surface S6 is convex at the optical axis; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is concave at the circumference.

[0097] The object-side surface S7 of the fourth lens L4 is concave at the optical axis, and the image-side surface S8 is convex at the optical axis; the object-side surface S7 is concave at the circumference, and the image-side surface S8 is concave at the circumference.

[0098] The object-side surface S9 of the fifth lens L5 is concave at the optical axis, and the image-side surface S10 is concave at the optical axis; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is convex at the circumference.

[0099] When the first lens L1 has a positive refractive power, it will be helpful to shorten the total length of the optical system 10 and further achieve an ultra-thin design.

[0100] The object side surface and image side surface of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 are all aspherical surfaces. By matching the aspherical surface of each lens in the optical system 10, the problem of field distortion of the optical system 10 can be effectively solved, and the lens can achieve excellent optical effects in a smaller and thinner case, thereby making the optical system 10 have a smaller volume, which is conducive to the miniaturization design of the optical system 10.

[0101] The first lens L1 , the second lens L2 , the third lens L3 , the fourth lens L4 and the fifth lens L5 are all made of plastic. The use of plastic lenses can reduce the manufacturing cost of the optical system 10 and reduce the weight of the optical system 10 .

[0102] The image side of the fifth lens L5 is also provided with an infrared filter L6 for filtering infrared light. In some embodiments, the infrared filter L6 is a part of the optical system 10, for example, the infrared filter L6 is assembled to the lens barrel together with each lens. In other embodiments, the infrared filter L6 can also be installed between the optical system 10 and the photosensitive element when the optical system 10 and the photosensitive element are assembled into a camera module.

[0103] In the first embodiment, the optical system 10 satisfies the following relationships:

[0104] SD11 / tan(HFOV)+SAG11=1.357mm; wherein SD11 is the maximum effective radius of the object side surface S1 of the first lens L1, HFOV is half of the maximum field of view of the optical system 10, SAG11 is the horizontal displacement from the intersection of the object side surface S1 of the first lens L1 and the optical axis to the maximum effective radius of the object side surface S1 on the optical axis (the horizontal displacement is defined as positive toward the image side and negative toward the object side), that is, SAG11 is the sagittal height of the object side surface S1, and the units of SD11 and SAG11 are both mm. When the above-mentioned lens refractive power, surface shape and relationship conditions are met, the positive refractive power provided by the first lens L1 and the negative refractive power provided by the second lens L2 can promote the balance of the spherical aberration of the system, and the positive refractive power setting of the fourth lens L4 can further enhance the focusing ability of the system. In addition, when the above-mentioned relationship is met, the head of the optical system 10 can also be miniaturized, and the optical system 10 can also obtain a larger field of view, thereby improving the imaging quality.

[0105] FNO=2.25, where FNO is the aperture number of the optical system 10. When the above relationship is satisfied, it is not only conducive to miniaturization of the head of the optical system 10, but also can increase the luminous flux per unit time of the system and enhance the imaging effect in a dark environment.

[0106] CT1 / CT4=1.397; where CT1 is the thickness of the first lens L1 at the optical axis, and CT4 is the thickness of the fourth lens L4 at the optical axis. When the above relationship is satisfied, the thickness of the first lens L1 and the fourth lens L4 will be reasonably configured, so that the refractive power of the positive lens in the system can be reasonably distributed, thereby effectively correcting the spherical aberration of the system, and at the same time making the thickness of the first lens L1 and the fourth lens L4 relatively uniform, meeting the processing requirements.

[0107] (CT2+CT3) / (T12+T23)=1.955; wherein CT2 is the thickness of the second lens L2 at the optical axis, CT3 is the thickness of the third lens L3 at the optical axis, T12 is the distance between the first lens L1 and the second lens L2 on the optical axis, and T23 is the distance between the second lens L2 and the third lens L3 on the optical axis. When the above relationship is satisfied, there is enough space for the first lens L1, the second lens L2, and the third lens L3 during assembly, thereby effectively avoiding collision between the first lens L1 and the second lens L2 or between the second lens L2 and the third lens L3. In addition, when the above relationship is satisfied, the thickness of the second lens L2 and the third lens L3 at the optical axis can be reduced, which is beneficial to the miniaturization design of the optical system 10. At the same time, it can also prevent the thickness of the two lenses at the optical axis from being too small, thereby avoiding the problems of inconvenience in assembly and increased system sensitivity.

[0108] SD11 / ImgH<0.262; wherein ImgH is half of the diagonal length of the effective pixel area on the imaging surface S13 of the optical system 10. The smaller the optical aperture of the object side surface S1 of the first lens L1, the more conducive it is to miniaturization of the head of the optical system 10. When the above relationship is satisfied, the optical aperture of the object side surface S1 of the first lens L1 can form a reasonable configuration relationship with the size of the effective pixel area at the imaging surface S13 of the system, so that when the optical system 10 matches a high-pixel and large-size photosensitive element, the ultra-small head design can still be taken into account.

[0109] f5 / R52=-1.455; wherein f5 is the effective focal length of the fifth lens L5, and R52 is the radius of curvature of the image side surface S10 of the fifth lens L5 at the optical axis. When the above relationship is satisfied, the deflection angle of the edge field light entering the system imaging surface S13 can be effectively reduced, thereby increasing the matching degree between the optical system 10 and the photosensitive element, and improving the astigmatism of the off-axis field of view.

[0110] f12 / f4=1.253; where f12 is the combined focal length of the first lens L1 and the second lens L2, and f4 is the effective focal length of the fourth lens L4. When the above relationship is satisfied, the focusing ability of the optical system 10 on light can be further enhanced, and it is also beneficial to correct the field curvature of the system and achieve good imaging quality; in addition, it is also beneficial to shorten the total length of the system, so that the optical system 10 obtains a larger field angle.

[0111] (nd2-nd3)=0.132; wherein nd2 is the refractive index of the second lens L2, and nd3 is the refractive index of the third lens L3. When the above relationship is satisfied, the chromatic aberration of the optical system 10 can be effectively corrected, the imaging clarity can be improved, and thus the imaging quality can be improved.

[0112] CT4 / |SAG41|=1.036; wherein CT4 is the thickness of the fourth lens L4 at the optical axis, SAG41 is the horizontal displacement from the intersection of the object side surface S7 of the fourth lens L4 and the optical axis to the maximum effective radius of the object side surface S7 on the optical axis (the horizontal displacement is defined as positive toward the image side and negative toward the object side), that is, SAG41 is the sagittal height of the object side surface S7. When the above relationship is satisfied, the shape of the fourth lens L4 is conducive to manufacturing and molding, and can reduce the defects of poor molding; at the same time, it can also effectively correct the field curvature generated by the front lens group (the first lens L1, the second lens L2 and the third lens L3), ensure the balance of the system field curvature, and improve the imaging quality of the optical system 10.

[0113] In addition, the lens parameters of the optical system 10 are given in Table 1 and Table 2, where K in Table 2 is the cone coefficient, and Ai is the coefficient corresponding to the i-th high-order term in the aspheric surface formula. The elements from the object plane to the image plane (imaging plane S13) are arranged in the order of the elements from top to bottom in Table 1, wherein the subject located on the object plane can form a clear image on the imaging plane S13 of the optical system 10. The surface numbers 1 and 2 respectively represent the object side surface S1 and the image side surface S2 of the first lens L1, 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 Y radius in Table 1 is the radius of curvature of the object side surface or the image side surface of the corresponding surface number at the paraxial position (or understood as on the optical axis). The first value of the lens in the "thickness" parameter column is the thickness of the lens on the optical axis, and the second value is the distance from the image side surface of the lens to the object side surface of the next lens on the optical axis. The optical axes of the lenses in the embodiment of the present application are on the same straight line, and the straight line serves as the optical axis of the optical system 10. The "thickness" parameter value in the surface serial number 10 is the distance on the optical axis from the image side surface S10 of the fifth lens L5 to the object side surface S11 of the infrared filter L6. The "thickness" parameter value corresponding to the surface serial number 12 of the infrared filter L6 is the distance on the optical axis from the image side surface S12 of the infrared filter L6 to the image plane (imaging surface S13) of the optical system 10. In addition, in this embodiment and the following second embodiment, third embodiment, fourth embodiment, fifth embodiment and sixth embodiment, the aperture is set on the image side surface S2 of the first lens L1. At this time, the aperture can be understood as a spacer ring that abuts against the image side surface S2 of the first lens L1 and the object side surface S3 of the second lens L2, respectively, or as a clamping member that is only used to clamp the first lens L1. The aperture is not shown in the figures of the corresponding embodiments.

[0114] In the first embodiment, the effective focal length f of the optical system 10 is 3.80 mm, the aperture number FNO is 2.25, half of the maximum field angle (i.e., half of the diagonal viewing angle) HFOV is 40.8°, and the total optical length TTL is 4.4 mm. The total optical length TTL is the distance on the optical axis from the object-side surface S1 of the first lens L1 to the imaging surface S13 of the optical system 10.

[0115] In addition, in the following embodiments (the first embodiment, the second embodiment, the third embodiment, the fourth embodiment, the fifth embodiment and the sixth embodiment), the refractive index, the Abbe number and the focal length of each lens are values ​​at a wavelength of 555 nm. In addition, the relationship calculation and lens structure of each embodiment shall be based on the lens parameters (such as Table 1, Table 2, Table 3, Table 4, etc.).

[0116] Table 1

[0117]

[0118] Table 2

[0119]

[0120]

[0121] Second embodiment

[0122] refer to Figure 3 and Figure 4 In the second embodiment, the optical system 10 includes, from the object side to the image side, a first lens L1 with positive refractive power, an aperture, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, and a fifth lens L5 with negative refractive power. Figure 4 It includes a longitudinal spherical aberration diagram (mm), an astigmatism diagram (mm) and a distortion diagram (%) of the optical system 10 in the second embodiment, wherein the astigmatism diagram and the distortion diagram are curve diagrams at a wavelength of 555 nm.

[0123] The ordinates of the astigmatism diagram and the distortion diagram can be understood as half of the diagonal length of the effective pixel area on the imaging surface S13 of the optical system 10 , and the unit of the ordinate is mm.

[0124] The object-side surface S1 of the first lens L1 is convex at the optical axis, and the image-side surface S2 is concave at the optical axis; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is concave at the circumference.

[0125] The object-side surface S3 of the second lens L2 is convex at the optical axis, and the image-side surface S4 is concave at the optical axis; the object-side surface S3 is convex at the circumference, and the image-side surface S4 is concave at the circumference.

[0126] The object-side surface S5 of the third lens L3 is concave at the optical axis, and the image-side surface S6 is convex at the optical axis; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is concave at the circumference.

[0127] The object-side surface S7 of the fourth lens L4 is concave at the optical axis, and the image-side surface S8 is convex at the optical axis; the object-side surface S7 is concave at the circumference, and the image-side surface S8 is concave at the circumference.

[0128] The object-side surface S9 of the fifth lens L5 is concave at the optical axis, and the image-side surface S10 is concave at the optical axis; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is convex at the circumference.

[0129] In addition, the lens parameters of the optical system 10 in the second embodiment are given in Table 3 and Table 4, wherein the definitions of the structures and parameters can be obtained from the first embodiment and are not described in detail here.

[0130] Table 3

[0131]

[0132]

[0133] Table 4

[0134]

[0135] The optical system 10 of this embodiment satisfies the following relationship:

[0136]

[0137]

[0138] Third embodiment

[0139] refer to Figure 5 and Figure 6 In the third embodiment, the optical system 10 includes, from the object side to the image side, a first lens L1 with positive refractive power, an aperture, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, and a fifth lens L5 with negative refractive power. Figure 6 It includes a longitudinal spherical aberration diagram (mm), an astigmatism diagram (mm) and a distortion diagram (%) of the optical system 10 in the third embodiment, wherein the astigmatism diagram and the distortion diagram are curve diagrams at a wavelength of 555 nm.

[0140] The ordinates of the astigmatism diagram and the distortion diagram can be understood as half of the diagonal length of the effective pixel area on the imaging surface S13 of the optical system 10 , and the unit of the ordinate is mm.

[0141] The object-side surface S1 of the first lens L1 is convex at the optical axis, and the image-side surface S2 is concave at the optical axis; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is concave at the circumference.

[0142] The object-side surface S3 of the second lens L2 is convex at the optical axis, and the image-side surface S4 is concave at the optical axis; the object-side surface S3 is convex at the circumference, and the image-side surface S4 is concave at the circumference.

[0143] The object-side surface S5 of the third lens L3 is concave at the optical axis, and the image-side surface S6 is convex at the optical axis; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is concave at the circumference.

[0144] The object-side surface S7 of the fourth lens L4 is concave at the optical axis, and the image-side surface S8 is convex at the optical axis; the object-side surface S7 is concave at the circumference, and the image-side surface S8 is concave at the circumference.

[0145] The object-side surface S9 of the fifth lens L5 is convex at the optical axis, and the image-side surface S10 is concave at the optical axis; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is convex at the circumference.

[0146] In addition, the lens parameters of the optical system 10 in the third embodiment are given in Table 5 and Table 6, wherein the definitions of the structures and parameters can be obtained from the first embodiment and are not elaborated here.

[0147] Table 5

[0148]

[0149] Table 6

[0150]

[0151]

[0152] The optical system 10 of this embodiment satisfies the following relationship:

[0153]

[0154] Fourth embodiment

[0155] refer to Figure 7 and Figure 8 In the fourth embodiment, the optical system 10 includes, from the object side to the image side, a first lens L1 with positive refractive power, an aperture, a second lens L2 with negative refractive power, a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, and a fifth lens L5 with negative refractive power. Figure 8It includes a longitudinal spherical aberration diagram (mm), an astigmatism diagram (mm) and a distortion diagram (%) of the optical system 10 in the fourth embodiment, wherein the astigmatism diagram and the distortion diagram are curve diagrams at a wavelength of 555 nm.

[0156] The ordinates of the astigmatism diagram and the distortion diagram can be understood as half of the diagonal length of the effective pixel area on the imaging surface S13 of the optical system 10 , and the unit of the ordinate is mm.

[0157] The object-side surface S1 of the first lens L1 is convex at the optical axis, and the image-side surface S2 is concave at the optical axis; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is concave at the circumference.

[0158] The object-side surface S3 of the second lens L2 is convex at the optical axis, and the image-side surface S4 is concave at the optical axis; the object-side surface S3 is concave at the circumference, and the image-side surface S4 is concave at the circumference.

[0159] The object-side surface S5 of the third lens L3 is concave at the optical axis, and the image-side surface S6 is convex at the optical axis; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is concave at the circumference.

[0160] The object-side surface S7 of the fourth lens L4 is convex at the optical axis, and the image-side surface S8 is convex at the optical axis; the object-side surface S7 is concave at the circumference, and the image-side surface S8 is concave at the circumference.

[0161] The object-side surface S9 of the fifth lens L5 is concave at the optical axis, and the image-side surface S10 is concave at the optical axis; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is convex at the circumference.

[0162] In addition, the lens parameters of the optical system 10 in the fourth embodiment are given in Table 7 and Table 8, wherein the definitions of the structures and parameters can be obtained from the first embodiment and will not be repeated here.

[0163] Table 7

[0164]

[0165] Table 8

[0166]

[0167]

[0168] The optical system 10 of this embodiment satisfies the following relationship:

[0169]

[0170] Fifth embodiment

[0171] refer to Fig. 9 and Fig.10In the fifth embodiment, the optical system 10 includes, from the object side to the image side, a first lens L1 with positive refractive power, an aperture, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, and a fifth lens L5 with negative refractive power. Fig.10 It includes a longitudinal spherical aberration diagram (mm), an astigmatism diagram (mm) and a distortion diagram (%) of the optical system 10 in the fifth embodiment, wherein the astigmatism diagram and the distortion diagram are curve diagrams at a wavelength of 555 nm.

[0172] The ordinates of the astigmatism diagram and the distortion diagram can be understood as half of the diagonal length of the effective pixel area on the imaging surface S13 of the optical system 10 , and the unit of the ordinate is mm.

[0173] The object-side surface S1 of the first lens L1 is convex at the optical axis, and the image-side surface S2 is concave at the optical axis; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is convex at the circumference.

[0174] The object-side surface S3 of the second lens L2 is concave at the optical axis, and the image-side surface S4 is convex at the optical axis; the object-side surface S3 is concave at the circumference, and the image-side surface S4 is concave at the circumference.

[0175] The object-side surface S5 of the third lens L3 is concave at the optical axis, and the image-side surface S6 is concave at the optical axis; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is convex at the circumference.

[0176] The object-side surface S7 of the fourth lens L4 is convex at the optical axis, and the image-side surface S8 is convex at the optical axis; the object-side surface S7 is concave at the circumference, and the image-side surface S8 is convex at the circumference.

[0177] The object-side surface S9 of the fifth lens L5 is convex at the optical axis, and the image-side surface S10 is concave at the optical axis; the object-side surface S9 is concave at the circumference, and the image-side surface S10 is convex at the circumference.

[0178] In addition, the lens parameters of the optical system 10 in the fifth embodiment are given in Tables 9 and 10, wherein the definitions of the structures and parameters can be obtained from the first embodiment and will not be elaborated here.

[0179] Table 9

[0180]

[0181]

[0182] Table 10

[0183]

[0184] The optical system 10 of this embodiment satisfies the following relationship:

[0185]

[0186] Sixth embodiment

[0187] refer to Fig.11 and Fig.12 In the sixth embodiment, the optical system 10 includes, from the object side to the image side, a first lens L1 with positive refractive power, an aperture, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, and a fifth lens L5 with negative refractive power. Fig.12 It includes the longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) of the optical system 10 in the sixth embodiment, wherein the astigmatism diagram and the distortion diagram are curve diagrams at a wavelength of 555nm.

[0188] The ordinates of the astigmatism diagram and the distortion diagram can be understood as half of the diagonal length of the effective pixel area on the imaging surface S13 of the optical system 10 , and the unit of the ordinate is mm.

[0189] The object-side surface S1 of the first lens L1 is convex at the optical axis, and the image-side surface S2 is concave at the optical axis; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is convex at the circumference.

[0190] The object-side surface S3 of the second lens L2 is convex at the optical axis, and the image-side surface S4 is concave at the optical axis; the object-side surface S3 is concave at the circumference, and the image-side surface S4 is concave at the circumference.

[0191] The object-side surface S5 of the third lens L3 is convex at the optical axis, and the image-side surface S6 is concave at the optical axis; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is convex at the circumference.

[0192] The object-side surface S7 of the fourth lens L4 is convex at the optical axis, and the image-side surface S8 is convex at the optical axis; the object-side surface S7 is concave at the circumference, and the image-side surface S8 is convex at the circumference.

[0193] The object-side surface S9 of the fifth lens L5 is concave at the optical axis, and the image-side surface S10 is concave at the optical axis; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is convex at the circumference.

[0194] In addition, the lens parameters of the optical system 10 in the sixth embodiment are given in Table 11 and Table 12, wherein the definitions of the structures and parameters can be obtained from the first embodiment and will not be repeated here.

[0195] Table 11

[0196]

[0197] Table 12

[0198]

[0199]

[0200] The optical system 10 of this embodiment satisfies the following relationship:

[0201]

[0202] In the above embodiment, the optical system 10 has the characteristic of a small head, which not only has high imaging quality, but also is conducive to the under-screen packaging of the module, reducing the size of the screen opening on the device, thereby achieving a high screen-to-body ratio design.

[0203] refer to Fig.13 In one embodiment provided in the present application, the optical system 10 is assembled with a photosensitive element 210 to form a camera module 20, and the photosensitive element 210 is arranged on the image side of the fifth lens L5, that is, on the image side of the optical system 10. An infrared filter L6 is also arranged between the fifth lens L5 and the photosensitive element 210 in this embodiment. The photosensitive element 210 can be a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). By adopting the above-mentioned optical system 10, the camera module 20 not only has a large field of view, but also can realize a small head design, which is conducive to under-screen packaging and reduces the size of the screen opening, thereby realizing a high screen-to-body ratio design.

[0204] In some embodiments, the distance between the photosensitive element 210 and each lens in the optical system 10 is relatively fixed. In this case, the camera module 20 is a fixed focus module. In other embodiments, a driving mechanism such as a voice coil motor can be provided to enable the photosensitive element 210 to move relative to each lens in the optical system 10, thereby achieving a focusing effect. Specifically, a coil electrically connected to a driving chip is provided on the lens barrel on which the above-mentioned lenses are assembled. At the same time, the camera module 20 is also provided with a magnet. The magnetic force between the coil and the magnet after power is applied is used to drive the lens barrel to move relative to the photosensitive element 210, thereby achieving a focusing effect. In other embodiments, a similar driving mechanism can also be provided to drive some lenses in the optical system 10 to move, thereby achieving an optical zoom effect.

[0205] refer to Fig.14Some embodiments of the present application also provide an electronic device 30, and the camera module 20 is applied to the electronic device 30 so that the electronic device 30 has a camera function. Specifically, the electronic device 30 includes a housing 310, and the camera module 20 is installed in the housing 310. The housing 310 can be a circuit board, a middle frame and other components. The electronic device 30 can be but not limited to a smart phone, a smart watch, an e-book reader, a vehicle-mounted camera device, a monitoring device, a medical device (such as an endoscope), a tablet computer, a biometric device (such as a fingerprint recognition device or a pupil recognition device, etc.), a PDA (Personal Digital Assistant), a drone, etc. Specifically, in some embodiments, the electronic device 30 is a smart phone, and the smart phone includes a middle frame and a circuit board, the circuit board is arranged in the middle frame, the camera module 20 is installed in the middle frame of the smart phone, and the photosensitive element 210 therein is electrically connected to the circuit board. The camera module 20 can be used as a front camera module or a rear camera module of a smart phone. By adopting a camera module 20 with a small head feature, not only can the camera quality of the electronic device 30 be improved, but it is also beneficial to the under-screen packaging of the module. At the same time, the size of the light entrance hole on the screen module of the electronic device 30 corresponding to the camera module 20 can be made smaller, thereby increasing the screen-to-body ratio of the electronic device and realizing a full-screen design.

[0206] 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.

[0207] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it 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, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. An optical system, characterized in that: The total number of lenses with refractive power is five, including from the object side to the image side: a first lens having positive refractive power; a second lens element having negative refractive power; a third lens having refractive power; a fourth lens element having positive refractive power; A fifth lens having negative refractive power, wherein both the object-side surface and the image-side surface of the fifth lens are aspherical surfaces, and at least one of the object-side surface and the image-side surface of the fifth lens has an inflection point; The optical system further comprises an aperture, wherein the aperture is arranged on the image side of the first lens; The optical system satisfies the following relationship: 1.0<SD11 / tan(HFOV)+SAG11<1.5; Among them, SD11 is the maximum effective radius of the object side of the first lens, HFOV is half of the maximum field of view angle of the optical system, SAG11 is the sag of the object side of the first lens, and the units of SD11 and SAG11 are both mm.

2. The optical system according to claim 1, characterized in that The following relations are satisfied: 2.2≤FNO≤2.5; Wherein, FNO is the aperture number of the optical system.

3. The optical system according to claim 1, characterized in that The following relations are satisfied: 0.7<CT1 / CT4<2.0; Wherein, CT1 is the thickness of the first lens at the optical axis, and CT4 is the thickness of the fourth lens at the optical axis.

4. The optical system according to claim 1, characterized in that The following relations are satisfied: 1.5<(CT2+CT3) / (T12+T23)<2.0; Wherein, CT2 is the thickness of the second lens at the optical axis, CT3 is the thickness of the third lens at the optical axis, T12 is the spacing distance between the first lens and the second lens on the optical axis, and T23 is the spacing distance between the second lens and the third lens on the optical axis.

5. The optical system according to claim 1, characterized in that The following relations are satisfied: 0.226≤SD11 / ImgH<0.3; Wherein, ImgH is half of the diagonal length of the effective pixel area on the imaging plane of the optical system.

6. The optical system according to claim 1, characterized in that The following relations are satisfied: -2.2<f5 / R52<-1.2; Wherein, f5 is the effective focal length of the fifth lens, and R52 is the radius of curvature of the image side surface of the fifth lens at the optical axis.

7. The optical system according to claim 1, characterized in that The following relations are satisfied: 1.0<f12 / f4<2.5; Wherein, f12 is the combined focal length of the first lens and the second lens, and f4 is the effective focal length of the fourth lens.

8. The optical system according to claim 1, characterized in that The following relations are satisfied: 0<(nd2-nd3)<0.2; Wherein, nd2 is the refractive index of the second lens, and nd3 is the refractive index of the third lens.

9. The optical system according to claim 1, characterized in that The following relations are satisfied: 1<CT4 / |SAG41|<15; Wherein, CT4 is the thickness of the fourth lens at the optical axis, and SAG41 is the sagittal height of the object side surface of the fourth lens.

10. A camera module, characterized in that: An optical system comprising a photosensitive element and any one of claims 1 to 9, wherein the photosensitive element is arranged on the image side of the fifth lens.

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

Images