Optical systems, lens modules and electronic devices

Abstract

The present invention provides an optical system, a lens module and an electronic device, wherein the electronic device comprises, from the object side to the image side along the optical axis direction: a first lens having a positive refractive power, the object side surface of the first lens at the near optical axis and near the circumference is a convex surface, and the image side surface of the first lens at the near optical axis is a convex surface; a second lens having a negative refractive power, and the image side surface of the second lens at the near optical axis and near the circumference is a concave surface; a third lens; a fourth lens; a fifth lens having a negative refractive power; a sixth lens; the optical system satisfies the conditional formula: f14 / f≤1.5; TTL / f≤1; wherein f14 is the combined focal length of the first lens, the second lens, the third lens and the fourth lens, f is the effective focal length of the optical system, and TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis. Through the above arrangement, the light is smoothly transitioned, so that the optical system has a telephoto characteristic, and the overall length of the optical system is small, so that ultra-thinness is achieved.

Description

Technical Field

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

[0002] As the market demands for high-quality video, telephoto lenses have emerged. Telephoto lenses are characterized by a long focal length, which is conducive to capturing details of distant objects and achieving clear imaging. However, the barrel of telephoto lenses is long, which does not conform to the development trend of miniaturization and integration.

[0003] In the past, optical systems had too few lenses, making it difficult to achieve telephoto characteristics; and too many lenses, making it difficult to achieve miniaturization. Therefore, it is necessary to develop an optical system with a suitable lens layout that can achieve both telephoto characteristics and miniaturization. Summary of the invention

[0004] The object of the present invention is to provide an optical system which has a telephoto characteristic and is ultra-thin under a suitable total length of the optical system.

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

[0006] In the first aspect, the present invention provides an optical system, which comprises, in order from the object side to the image side along the optical axis: a first lens having positive refractive power, the object side surface of the first lens near the optical axis and near the circumference is convex, and the image side surface of the first lens near the optical axis is convex; a second lens having negative refractive power, the image side surface of the second lens near the optical axis and near the circumference is concave; a third lens having refractive power; a fourth lens having refractive power; a fifth lens having negative refractive power; and a sixth lens having refractive power; the optical system satisfies the conditional formula: f14 / f≤1.5; TTL / f≤1; wherein f14 is the combined focal length of the first lens, the second lens, the third lens and the fourth lens, f is the effective focal length of the optical system, and TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis. By reasonably configuring the surface shape and refractive power of each lens from the first lens to the sixth lens, the light is smoothly transitioned, and the f14 / f value is reasonably set so that the optical system has a telephoto characteristic. At the same time, the TTL / f value is reasonably set, so that the overall length of the optical system is short and ultra-thin.

[0007] In one embodiment, the optical system satisfies the conditional formula: T45 / f≤0.5; wherein T45 is the air interval between the fourth lens and the fifth lens on the optical axis. The value of T45 / f is reasonably set, and the spatial positions of the fourth lens and the fifth lens are arranged, so that the optical line transition is smoother, the field curvature of the optical system is corrected, and the dispersion and telephoto characteristics are balanced.

[0008] In one embodiment, the optical system satisfies the conditional formula: CT2 / R22≤0.5; wherein CT2 is the thickness of the second lens on the optical axis, and R22 is the radius of curvature of the image side surface of the second lens near the optical axis. Reasonable setting of the value of CT2 / R22 can reduce the incident light angle of the optical system, reduce the field of view angle within a reasonable range, achieve the telephoto function and balance the aberration of the optical system.

[0009] In one embodiment, the optical system satisfies the conditional formula: |SAG32|+|SAG42|≤1; wherein SAG32 is the sagittal height of the image side surface of the third lens, and SAG42 is the sagittal height of the image side surface of the fourth lens. Reasonable setting of the value of |SAG32|+|SAG42| can reasonably arrange the optical structure, which is conducive to compressing the length of the lens, and slowing down the change in direction of light after entering the optical system, which helps to reduce the intensity of stray light.

[0010] In one embodiment, the optical system satisfies the condition: SAG12 / CT1≤0.5; wherein SAG12 is the sagittal height of the image side of the first lens, and CT1 is the thickness of the first lens on the optical axis. The value of SAG12 / CT1 is reasonably set so that the light is smoothly transmitted to the second lens, the sensitivity of the optical system is reduced, and the production yield is improved.

[0011] In one embodiment, the optical system satisfies the condition: |V2-V1|>30; wherein V1 is the Abbe number of the first lens, and V2 is the Abbe number of the second lens. Reasonable setting of the value of |V2-V1| is conducive to correcting chromatic aberration, thereby improving imaging quality.

[0012] In one embodiment, the optical system satisfies the condition: 1≤(ET3+ET4) / (CT3+CT4)≤2; wherein ET3 is the thickness of the edge of the optically effective area of ​​the third lens, ET4 is the thickness of the edge of the optically effective area of ​​the fourth lens, CT3 is the thickness of the third lens on the optical axis, and CT4 is the thickness of the fourth lens on the optical axis. By reasonably setting the value of (ET3+ET4) / (CT3+CT4), the optical system has a better ability to balance field curvature, reduces the sensitivity of the third lens and the fourth lens, realizes ultra-thin optical system, and ensures the stability of production and processing.

[0013] In one embodiment, the optical system satisfies the condition: 5° / mm≤FOV / f≤10° / mm; wherein FOV is the diagonal field of view of the optical system. The value of FOV / f is reasonably set to control the field of view within a reasonable range, so that the focal length reaches the telephoto distance and the telephoto function is realized.

[0014] In one embodiment, the optical system satisfies the condition: -3≤f6 / f≤-1; wherein f6 is the effective focal length of the sixth lens. Reasonable setting of the value of f6 / f is conducive to smooth convergence and divergence of light in the sixth lens, correcting the spherical aberration and chromatic aberration of the optical system, and improving molding stability.

[0015] In a second aspect, the present invention further provides a lens module, which includes a lens barrel and the optical system in any embodiment of the first aspect, wherein the first lens to the sixth lens of the optical system are installed in the lens barrel, and the electronic photosensitive element is arranged on the image side of the optical system, and is used to convert the light of the object that passes through the first lens to the sixth lens and is incident on the electronic photosensitive element into an electrical signal of an image. By installing the first lens to the sixth lens of the optical system in the lens module, the light is smoothly transitioned, so that the lens module has a telephoto characteristic, and the overall length of the lens module is small, so that it is ultra-thin.

[0016] In a third aspect, the present invention further provides an electronic device, the electronic device comprising a housing and the lens module of the second aspect, wherein the lens module is disposed in the housing. By disposing the lens module of the second aspect in the electronic device, light is smoothly transitioned, so that the electronic device has a telephoto characteristic, and the overall length of the electronic device is short, achieving ultra-thinness. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1a is a schematic structural diagram of the optical system of the first embodiment;

[0019] Figure 1b 7 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the first embodiment;

[0020] Figure 2a is a schematic structural diagram of an optical system of a second embodiment;

[0021] Figure 2b 7 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the second embodiment;

[0022] Figure 3a is a schematic structural diagram of an optical system of a third embodiment;

[0023] Figure 3b7 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the third embodiment;

[0024] Figure 4a is a schematic structural diagram of an optical system of a fourth embodiment;

[0025] Figure 4b 7 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the fourth embodiment;

[0026] Figure 5a is a schematic structural diagram of an optical system of a fifth embodiment;

[0027] Figure 5b 7 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the fifth embodiment;

[0028] Figure 6a is a schematic structural diagram of an optical system of a sixth embodiment;

[0029] Figure 6b 1 and 2 are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the sixth embodiment.

[0030] Figure 7a is a schematic structural diagram of an optical system of a seventh embodiment;

[0031] Figure 7b 7 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the seventh embodiment;

[0032] Figure 8a is a schematic structural diagram of an optical system of an eighth embodiment;

[0033] Figure 8b 7 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the eighth embodiment;

[0034] Figure 9a is a schematic structural diagram of an optical system of a ninth embodiment;

[0035] Figure 9b 1 and 2 are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the ninth embodiment. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] An embodiment of the present invention provides a lens module, which includes a lens barrel, an electronic photosensitive element and an optical system provided by an embodiment of the present invention, wherein the first lens to the sixth lens of the optical system are installed in the lens barrel, and the electronic photosensitive element is arranged on the image side of the optical system, and is used to convert the light of the object incident on the electronic photosensitive element through the first lens to the sixth lens into an electrical signal of an image. The electronic photosensitive element can be a complementary metal oxide semiconductor (CMOS) or a charge-coupled device (CCD). The lens module can be an independent lens of a digital camera, or an imaging module integrated in an electronic device such as a smart phone. By installing the first lens to the sixth lens of the optical system in the lens module, the light is smoothly transitioned, so that the lens module has a telephoto characteristic, and the overall length of the lens module is small, so that it can be ultra-thin.

[0038] An embodiment of the present invention provides an electronic device, which includes a housing and a lens module provided by an embodiment of the present invention. The lens module and the electronic photosensitive element are arranged in the housing. The electronic device can be a smart phone, a personal digital assistant (PDA), a tablet computer, a smart watch, a drone, an e-book reader, a driving recorder, a wearable device, etc. By setting the lens module of the second aspect in the electronic device, the light is smoothly transitioned, so that the electronic device has a telephoto characteristic, and the overall length of the electronic device is small, so that it is ultra-thin.

[0039] An embodiment of the present invention provides an optical system, which includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens in order from the object side to the image side along the optical axis. Among the first lens to the sixth lens, any two adjacent lenses may have an air gap between them.

[0040] Specifically, the specific shape and structure of the six lenses are as follows:

[0041] The first lens has positive refractive power, the object side surface of the first lens near the optical axis and near the circumference is convex, and the image side surface of the first lens near the optical axis is convex; the second lens has negative refractive power, and the image side surface of the second lens near the optical axis and near the circumference is concave; the third lens has refractive power; the fourth lens has refractive power; the fifth lens has negative refractive power; the sixth lens has refractive power;

[0042] The optical system further comprises an aperture stop, which can be arranged at any position between the first lens to the sixth lens, such as being arranged on the first lens.

[0043] The optical system satisfies the following conditions:

[0044] f14 / f≤1.5, preferably 0.697≤f14 / f≤1.310;

[0045] TTL / f≤1, preferably 0.9≤TTL / f≤1.0;

[0046] Wherein, f14 is the combined focal length of the first lens, the second lens, the third lens and the fourth lens, f is the effective focal length of the optical system, and TTL is the distance from the object side of the first lens to the imaging plane of the optical system on the optical axis.

[0047] By reasonably configuring the surface shape and refractive power of each lens from the first lens to the sixth lens, the light is smoothly transitioned, and the f14 / f value is reasonably set so that the optical system has a telephoto characteristic. At the same time, the TTL / f value is reasonably set, so that the overall length of the optical system is short and ultra-thin.

[0048] In one embodiment, the optical system satisfies the conditional formula: T45 / f≤0.5, preferably 0.094≤T45 / f≤0.230; wherein T45 is the air interval between the fourth lens and the fifth lens on the optical axis. The value of T45 / f is reasonably set, and the spatial positions of the fourth lens and the fifth lens are arranged, so that the optical line transition is smoother, the field curvature of the optical system is corrected, and the dispersion and telephoto characteristics are balanced.

[0049] In one embodiment, the optical system satisfies the conditional formula: CT2 / R22≤0.5, preferably 0.073≤CT2 / R22≤0.119; wherein CT2 is the thickness of the second lens on the optical axis, and R22 is the radius of curvature of the image side surface of the second lens near the optical axis. Reasonable setting of the value of CT2 / R22 can reduce the incident light angle of the optical system, reduce the field angle within a reasonable range, achieve the telephoto function and balance the aberration of the optical system.

[0050] In one embodiment, the optical system satisfies the conditional formula: |SAG32|+|SAG42|≤1, preferably 0.072≤|SAG32|+|SAG42|≤0.403; wherein SAG32 is the sagittal height of the image side surface of the third lens, and SAG42 is the sagittal height of the image side surface of the fourth lens. Reasonable setting of the value of |SAG32|+|SAG42|, thereby reasonably arranging the optical structure, is conducive to compressing the length of the lens, and slowing down the change in direction of light after entering the optical system, which helps to reduce the intensity of stray light.

[0051] In one embodiment, the optical system satisfies the conditional formula: SAG12 / CT1≤0.5, preferably -0.073≤SAG21 / f≤0.02; wherein SAG12 is the sagittal height of the image side of the first lens, and CT1 is the thickness of the first lens on the optical axis. The value of SAG12 / CT1 is reasonably set so that the light is smoothly transmitted to the second lens, the sensitivity of the optical system is reduced, and the production yield is improved.

[0052] In one embodiment, the optical system satisfies the condition: |V2-V1|>30, preferably 35.6≤|V2-V1|; wherein V1 is the Abbe number of the first lens, and V2 is the Abbe number of the second lens. Reasonable setting of the value of |V2-V1| is conducive to correcting chromatic aberration, thereby improving imaging quality.

[0053] In one embodiment, the optical system satisfies the conditional formula: 1≤(ET3+ET4) / (CT3+CT4)≤2, preferably 1.032≤(ET3+ET4) / (CT3+CT4)≤1.643; wherein ET3 is the thickness of the edge of the optically effective area of ​​the third lens, ET4 is the thickness of the edge of the optically effective area of ​​the fourth lens, CT3 is the thickness of the third lens on the optical axis, and CT4 is the thickness of the fourth lens on the optical axis. By reasonably setting the value of (ET3+ET4) / (CT3+CT4), the optical system has a better ability to balance field curvature, reduces the sensitivity of the third lens and the fourth lens, realizes ultra-thinness of the optical system, and ensures the stability of production and processing.

[0054] In one implementation, the optical system satisfies the conditional formula: 5° / mm≤FOV / f≤10° / mm, preferably 5.265° / mm≤FOV / f≤9.107° / mm; wherein FOV is the diagonal field of view of the optical system. The value of FOV / f is reasonably set to control the field of view within a reasonable range, so that the focal length reaches the telephoto distance and the telephoto function is realized.

[0055] In one embodiment, the optical system satisfies the condition: -3≤f6 / f≤-1, preferably -2.514≤f6 / f≤-1.315; wherein f6 is the effective focal length of the sixth lens. Reasonable setting of the value of f6 / f is conducive to smooth convergence and divergence of light in the sixth lens, correcting the spherical aberration and chromatic aberration of the optical system, and improving molding stability.

[0056] Specifically, the optical system satisfies the following conditions: 5.52≤f≤7.36; 2.29≤FNO≤3.12, where FNO is the aperture number of the optical system; 38.74≤FOV≤50.23; ImgH=2.62, where ImgH is the diagonal length of the photosensitive element on the imaging surface; 5.05≤TTL≤7.00.

[0057] First embodiment

[0058] Please refer to Figure 1a and Figure 1b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0059] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 is convex near the optical axis and near the circumference, and the image side surface S2 of the first lens L1 is convex near the optical axis and near the circumference;

[0060] The second lens L2 has negative refractive power, the object side surface S3 of the second lens L2 near the optical axis is concave, the object side surface S3 near the circumference is convex, and the image side surface S4 of the second lens L2 near the optical axis and near the circumference is concave;

[0061] The third lens L3 has negative refractive power. The object side surface S5 of the third lens L3 near the optical axis is concave, and the object side surface S5 near the circumference is convex. The image side surface S6 of the third lens L3 near the optical axis is convex, and the image side surface S6 near the circumference is concave.

[0062] The fourth lens L4 has a positive refractive power, the object side surface S7 of the fourth lens L4 near the optical axis is a concave surface, the object side surface S7 near the circumference is a convex surface, the image side surface S8 of the fourth lens L4 near the optical axis is a convex surface, and the image side surface S8 near the circumference is a concave surface;

[0063] The fifth lens L5 has negative refractive power. The object side surface S9 of the fifth lens L5 near the optical axis and near the circumference is concave. The image side surface S10 of the fifth lens L5 near the optical axis is concave, and the image side surface S10 near the circumference is convex.

[0064] The sixth lens L6 has positive refractive power. The object side surface S11 of the sixth lens L6 near the optical axis is convex, and the object side surface S11 near the circumference is concave. The image side surface S12 of the sixth lens L6 near the optical axis and near the circumference is convex.

[0065] The materials of the first lens L1 to the sixth lens L6 are all plastic.

[0066] In addition, the optical system also includes an aperture STO, an infrared cutoff filter L7 and an imaging surface S15. The aperture STO is arranged on the side of the first lens L1 away from the second lens L2, and is used to control the amount of light entering. In other embodiments, the aperture STO can also be arranged between two adjacent lenses, or on other lenses. The infrared cutoff filter L7 is arranged on the image side of the sixth lens L6, and includes an object side surface S13 and an image side surface S14. The infrared cutoff filter L7 is used to filter out infrared light, so that the light incident on the imaging surface S15 is visible light, and the wavelength of visible light is 380nm-780nm. The material of the infrared cutoff filter L7 is glass (Glass), and a film can be coated on the glass. The imaging surface S15 is an effective pixel area of ​​the electronic photosensitive element.

[0067] Table 1a shows a table of characteristics of the optical system of this embodiment, wherein the data are obtained using light with a wavelength of 587 nm, and the units of Y radius, thickness and focal length are all millimeters (mm).

[0068] Table 1a

[0069]

[0070]

[0071] Wherein, f is the effective focal length of the optical system, FNO is the aperture number of the optical system, FOV is the field of view of the optical system, and TTL is the distance from the object side of the first lens to the imaging plane of the optical system on the optical axis.

[0072] In this embodiment, the object side surface and the image side surface of any lens of the first lens L1 to the sixth lens L6 are both aspherical surfaces, and the surface shape x of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0073]

[0074] Wherein, x is the distance vector height from the vertex of the aspherical surface when the aspherical surface is at a height of h along the optical axis; c is the paraxial curvature of the aspherical surface, c=1 / R (i.e., the paraxial curvature c is the reciprocal of the Y radius R in the above Table 1a); k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspherical surface. Table 1b shows the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for each aspherical mirror surface S1-S10 in the first embodiment.

[0075] Table 1b

[0076]

[0077]

[0078] Figure 1b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the first embodiment are shown. The longitudinal spherical aberration curve indicates the deviation of the focal point of light of different wavelengths after passing through each lens of the optical system; the astigmatism curve indicates the meridional image curvature and sagittal image curvature; and the distortion curve indicates the distortion magnitude value corresponding to different field angles. Figure 1b It can be seen that the optical system provided in the first embodiment can achieve good imaging quality.

[0079] Second embodiment

[0080] Please refer to Figure 2a and Figure 2b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0081] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 near the optical axis and near the circumference is a convex surface, and the image side surface S2 of the first lens L1 near the optical axis and near the circumference is a convex surface;

[0082] The second lens L2 has negative refractive power, the object side surface S3 of the second lens L2 near the optical axis and near the circumference is a convex surface, and the image side surface S4 of the second lens L2 near the optical axis and near the circumference is a concave surface;

[0083] The third lens L3 has negative refractive power, the object side surface S5 of the third lens L3 near the optical axis is concave, the object side surface S5 near the circumference is convex, and the image side surface S6 of the third lens L3 near the optical axis and near the circumference is convex;

[0084] The fourth lens L4 has negative refractive power. The object side surface S7 of the fourth lens L4 near the optical axis is concave, and the object side surface S7 near the circumference is convex. The image side surface S8 of the fourth lens L4 near the optical axis is convex, and the image side surface S8 near the circumference is concave.

[0085] The fifth lens L5 has negative refractive power. The object side surface S9 of the fifth lens L5 near the optical axis and near the circumference is concave. The image side surface S10 of the fifth lens L5 near the optical axis is concave, and the image side surface S10 near the circumference is convex.

[0086] The sixth lens L6 has positive refractive power. The object side surface S11 of the sixth lens L6 near the optical axis is convex, and the object side surface S11 near the circumference is concave. The image side surface S12 of the sixth lens L6 near the optical axis and near the circumference is convex.

[0087] The other structures of the second embodiment are the same as those of the first embodiment, and can be used as a reference.

[0088] Table 2a shows a table of the characteristics of the optical system of this embodiment, wherein the data are obtained using light with a wavelength of 587 nm, and the units of the Y radius, thickness and focal length are all millimeters (mm).

[0089] Table 2a

[0090]

[0091] The meanings of the parameters in Table 2a are the same as those in the first embodiment.

[0092] Table 2b gives the coefficients of the higher-order terms that can be used for each aspherical mirror surface in the second embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0093] Table 2b

[0094]

[0095]

[0096] Figure 2b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the second embodiment are shown. Figure 2b It can be seen that the optical system provided in the second embodiment can achieve good imaging quality.

[0097] Third embodiment

[0098] Please refer to Figure 3a and Figure 3b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0099] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 near the optical axis and near the circumference is a convex surface, and the image side surface S2 of the first lens L1 near the optical axis and near the circumference is a convex surface;

[0100] The second lens L2 has negative refractive power, the object side surface S3 of the second lens L2 near the optical axis and near the circumference is a convex surface, and the image side surface S4 of the second lens L2 near the optical axis and near the circumference is a concave surface;

[0101] The third lens L3 has negative refractive power, the object side surface S5 of the third lens L3 near the optical axis and near the circumference is a concave surface, and the image side surface S6 of the third lens L3 near the optical axis and near the circumference is a convex surface;

[0102] The fourth lens L4 has a positive refractive power, the object side surface S7 of the fourth lens L4 near the optical axis is a concave surface, the object side surface S7 near the circumference is a convex surface, the image side surface S8 of the fourth lens L4 near the optical axis is a convex surface, and the image side surface S8 near the circumference is a concave surface;

[0103] The fifth lens L5 has negative refractive power. The object side surface S9 of the fifth lens L5 near the optical axis and near the circumference is concave. The image side surface S10 of the fifth lens L5 near the optical axis is concave, and the image side surface S10 near the circumference is convex.

[0104] The sixth lens L6 has negative refractive power. The object side surface S11 of the sixth lens L6 near the optical axis is convex, and the object side surface S11 near the circumference is concave. The image side surface S12 of the sixth lens L6 near the optical axis is concave, and the image side surface S12 near the circumference is convex.

[0105] The other structures of the third embodiment are the same as those of the first embodiment, and can be used as a reference.

[0106] Table 3a shows a table of the characteristics of the optical system of this embodiment, wherein the data are obtained using light with a wavelength of 587 nm, and the units of Y radius, thickness and focal length are all millimeters (mm).

[0107] Table 3a

[0108]

[0109] The meanings of the parameters in Table 3a are the same as those in the first embodiment.

[0110] Table 3b gives the coefficients of the higher-order terms that can be used for each aspherical mirror surface in the third embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0111] Table 3b

[0112]

[0113]

[0114] Figure 3b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the third embodiment are shown. Figure 3b It can be seen that the optical system provided in the third embodiment can achieve good imaging quality.

[0115] Fourth embodiment

[0116] Please refer to Figure 4a and Figure 4b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0117] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 near the optical axis and near the circumference is a convex surface, and the image side surface S2 of the first lens L1 near the optical axis and near the circumference is a convex surface;

[0118] The second lens L2 has negative refractive power, the object side surface S3 of the second lens L2 near the optical axis and near the circumference is a convex surface, and the image side surface S4 of the second lens L2 near the optical axis and near the circumference is a concave surface;

[0119] The third lens L3 has negative refractive power. The object side surface S5 of the third lens L3 near the optical axis is concave, and the object side surface S5 near the circumference is convex. The image side surface S6 of the third lens L3 near the optical axis is convex, and the image side surface S6 near the circumference is concave.

[0120] The fourth lens L4 has a positive refractive power, the object side surface S7 of the fourth lens L4 near the optical axis and near the circumference is a convex surface, the image side surface S8 of the fourth lens L4 near the optical axis is a convex surface, and the image side surface S8 near the circumference is a concave surface;

[0121] The fifth lens L5 has negative refractive power. The object side surface S9 of the fifth lens L5 near the optical axis and near the circumference is concave. The image side surface S10 of the fifth lens L5 near the optical axis is concave, and the image side surface S10 near the circumference is convex.

[0122] The sixth lens L6 has positive refractive power. The object side surface S11 of the sixth lens L6 near the optical axis is convex, and the object side surface S11 near the circumference is concave. The image side surface S12 of the sixth lens L6 near the optical axis and near the circumference is convex.

[0123] The other structures of the fourth embodiment are the same as those of the first embodiment, and can be referred to herein.

[0124] Table 4a shows a table of the characteristics of the optical system of this embodiment, wherein the data are obtained using light with a wavelength of 587 nm, and the units of Y radius, thickness and focal length are all millimeters (mm).

[0125] Table 4a

[0126]

[0127] The meanings of the parameters in Table 4a are the same as those in the first embodiment.

[0128] Table 4b gives the coefficients of the higher-order terms that can be used for each aspherical mirror surface in the fourth embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0129] Table 4b

[0130]

[0131]

[0132] Figure 4b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the fourth embodiment are shown. Figure 4b It can be seen that the optical system provided in the fourth embodiment can achieve good imaging quality.

[0133] Fifth embodiment

[0134] Please refer to Figure 5a and Figure 5b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0135] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 near the optical axis and near the circumference is a convex surface, the image side surface S2 of the first lens L1 near the optical axis is a convex surface, and the image side surface S2 near the circumference is a concave surface;

[0136] The second lens L2 has negative refractive power, the object side surface S3 of the second lens L2 near the optical axis and near the circumference is a convex surface, and the image side surface S4 of the second lens L2 near the optical axis and near the circumference is a concave surface;

[0137] The third lens L3 has negative refractive power, the object side surface S5 of the third lens L3 near the optical axis and near the circumference is a convex surface, and the image side surface S6 of the third lens L3 near the optical axis and near the circumference is a concave surface;

[0138] The fourth lens L4 has a positive refractive power, the object side surface S7 of the fourth lens L4 near the optical axis and near the circumference is a convex surface, the image side surface S8 of the fourth lens L4 near the optical axis is a convex surface, and the image side surface S8 near the circumference is a concave surface;

[0139] The fifth lens L5 has negative refractive power. The object side surface S9 of the fifth lens L5 near the optical axis is concave, and the object side surface S9 near the circumference is convex. The image side surface S10 of the fifth lens L5 near the optical axis is concave, and the image side surface S10 near the circumference is convex.

[0140] The sixth lens L6 has positive refractive power. The object side surface S11 of the sixth lens L6 near the optical axis is convex, and the object side surface S11 near the circumference is concave. The image side surface S12 of the sixth lens L6 near the optical axis and near the circumference is convex.

[0141] The other structures of the fifth embodiment are the same as those of the first embodiment, and can be referred to herein.

[0142] Table 5a shows a table of the characteristics of the optical system of this embodiment, wherein the data are obtained using light with a wavelength of 587 nm, and the units of Y radius, thickness and focal length are all millimeters (mm).

[0143] Table 5a

[0144]

[0145] The meanings of the parameters in Table 5a are the same as those in the first embodiment.

[0146] Table 5b gives the coefficients of the higher-order terms that can be used for each aspherical mirror surface in the fifth embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0147] Table 5b

[0148]

[0149] Figure 5b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the fifth embodiment are shown. Figure 5b It can be seen that the optical system provided in the fifth embodiment can achieve good imaging quality.

[0150] Sixth embodiment

[0151] Please refer to Figure 6a and Figure 6b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0152] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 near the optical axis and near the circumference is a convex surface, and the image side surface S2 of the first lens L1 near the optical axis and near the circumference is a convex surface;

[0153] The second lens L2 has negative refractive power, the object side surface S3 of the second lens L2 near the optical axis is concave, the object side surface S3 near the circumference is convex, and the image side surface S4 of the second lens L2 near the optical axis and near the circumference is concave;

[0154] The third lens L3 has negative refractive power, the object side surface S5 of the third lens L3 near the optical axis is concave, the object side surface S5 near the circumference is convex, and the image side surface S6 of the third lens L3 near the optical axis and near the circumference is concave;

[0155] The fourth lens L4 has negative refractive power, the object side surface S7 of the fourth lens L4 near the optical axis and near the circumference is a concave surface, and the image side surface S8 of the fourth lens L4 near the optical axis and near the circumference is a concave surface;

[0156] The fifth lens L5 has negative refractive power. The object side surface S9 of the fifth lens L5 near the optical axis and near the circumference is concave. The image side surface S10 of the fifth lens L5 near the optical axis is concave, and the image side surface S10 near the circumference is convex.

[0157] The sixth lens L6 has positive refractive power. The object side surface S11 of the sixth lens L6 near the optical axis is convex, and the object side surface S11 near the circumference is concave. The image side surface S12 of the sixth lens L6 near the optical axis and near the circumference is convex.

[0158] The other structures of the sixth embodiment are the same as those of the first embodiment, and can be referred to herein.

[0159] Table 6a shows a table of the characteristics of the optical system of this embodiment, wherein the data are obtained using light with a wavelength of 587 nm, and the units of Y radius, thickness and focal length are all millimeters (mm).

[0160] Table 6a

[0161]

[0162] The meanings of the parameters in Table 6a are the same as those in the first embodiment.

[0163] Table 6b gives the coefficients of the higher-order terms that can be used for each aspherical mirror surface in the sixth embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0164] Table 6b

[0165]

[0166] Figure 6b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the sixth embodiment are shown. Figure 6b It can be seen that the optical system provided in the sixth embodiment can achieve good imaging quality.

[0167] Seventh embodiment

[0168] Please refer to Figure 7a and Figure 7b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0169] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 near the optical axis and near the circumference is a convex surface, and the image side surface S2 of the first lens L1 near the optical axis and near the circumference is a convex surface;

[0170] The second lens L2 has negative refractive power, the object side surface S3 of the second lens L2 near the optical axis and near the circumference is a convex surface, and the image side surface S4 of the second lens L2 near the optical axis and near the circumference is a concave surface;

[0171] The third lens L3 has negative refractive power, the object side surface S5 of the third lens L3 near the optical axis and near the circumference is a convex surface, and the image side surface S6 of the third lens L3 near the optical axis and near the circumference is a concave surface;

[0172] The fourth lens L4 has a positive refractive power, the object side surface S7 of the fourth lens L4 near the optical axis is a concave surface, the object side surface S7 near the circumference is a convex surface, the image side surface S8 of the fourth lens L4 near the optical axis is a convex surface, and the image side surface S8 is a concave surface;

[0173] The fifth lens L5 has negative refractive power, and the object side surface S9 of the fifth lens L5 near the optical axis and near the circumference is a concave surface; the image side surface S10 of the fifth lens L5 near the optical axis is a concave surface, and the image side surface S10 near the circumference is a convex surface;

[0174] The sixth lens L6 has positive refractive power. The object side surface S11 of the sixth lens L6 near the optical axis is convex, and the object side surface S11 near the circumference is concave. The image side surface S12 of the sixth lens L6 near the optical axis and near the circumference is convex.

[0175] The other structures of the seventh embodiment are the same as those of the first embodiment, and can be referred to herein.

[0176] Table 7a shows a table of the characteristics of the optical system of this embodiment, wherein the data are obtained using light with a wavelength of 587 nm, and the units of Y radius, thickness and focal length are all millimeters (mm).

[0177] Table 7a

[0178]

[0179] The meanings of the parameters in Table 7a are the same as those in the first embodiment.

[0180] Table 7b gives the coefficients of the higher-order terms that can be used for each aspherical mirror surface in the seventh embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0181] Table 7b

[0182]

[0183] Figure 7b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the seventh embodiment are shown. Figure 7b It can be seen that the optical system provided in the seventh embodiment can achieve good imaging quality.

[0184] Eighth embodiment

[0185] Please refer to Figure 8a and Figure 8b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0186] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 near the optical axis and near the circumference is a convex surface, and the image side surface S2 of the first lens L1 near the optical axis and near the circumference is a convex surface;

[0187] The second lens L2 has negative refractive power, the object side surface S3 of the second lens L2 near the optical axis and near the circumference is a convex surface, and the image side surface S4 of the second lens L2 near the optical axis and near the circumference is a concave surface;

[0188] The third lens L3 has negative refractive power, the object side surface S5 of the third lens L3 near the optical axis and near the circumference is a concave surface, and the image side surface S6 of the third lens L3 near the optical axis and near the circumference is a convex surface;

[0189] The fourth lens L4 has a positive refractive power, the object side surface S7 of the fourth lens L4 near the optical axis and near the circumference is a concave surface, the image side surface S8 of the fourth lens L4 near the optical axis is a convex surface, and the image side surface S8 near the circumference is a concave surface;

[0190] The fifth lens L5 has negative refractive power. The object side surface S9 of the fifth lens L5 near the optical axis is convex, and the object side surface S9 near the circumference is concave. The image side surface S10 of the fifth lens L5 near the optical axis is concave, and the image side surface S10 near the circumference is convex.

[0191] The sixth lens L6 has negative refractive power. The object-side surface S11 of the sixth lens L6 near the optical axis and near the circumference is a concave surface. The image-side surface S12 of the sixth lens L6 near the optical axis and near the circumference is a convex surface.

[0192] The other structures of the eighth embodiment are the same as those of the first embodiment, and can be referred to herein.

[0193] Table 8a shows a table of the characteristics of the optical system of this embodiment, wherein the data is obtained using light with a wavelength of 587 nm, and the units of Y radius, thickness and focal length are all millimeters (mm).

[0194] Table 8a

[0195]

[0196] The meanings of the parameters in Table 8a are the same as those in the first embodiment.

[0197] Table 8b gives the coefficients of the higher-order terms that can be used for each aspherical mirror surface in the eighth embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0198] Table 8b

[0199]

[0200] Figure 8b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the eighth embodiment are shown. Figure 8b It can be seen that the optical system provided in the eighth embodiment can achieve good imaging quality.

[0201] Ninth embodiment

[0202] Please refer to Figure 9a and Figure 9b The optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0203] The first lens L1 has positive refractive power, the object side surface S1 of the first lens L1 near the optical axis and near the circumference is a convex surface, and the image side surface S2 of the first lens L1 near the optical axis and near the circumference is a convex surface;

[0204] The second lens L2 has negative refractive power, the object side surface S3 of the second lens L2 near the optical axis and near the circumference is a convex surface, and the image side surface S4 of the second lens L2 near the optical axis and near the circumference is a concave surface;

[0205] The third lens L3 has negative refractive power, the object side surface S5 of the third lens L3 near the optical axis and near the circumference is a convex surface, and the image side surface S6 of the third lens L3 near the optical axis and near the circumference is a concave surface;

[0206] The fourth lens L4 has a positive refractive power, the object side surface S7 of the fourth lens L4 near the optical axis is a concave surface, the object side surface S7 near the circumference is a convex surface, the image side surface S8 of the fourth lens L4 near the optical axis is a convex surface, and the image side surface S8 near the circumference is a concave surface;

[0207] The fifth lens L5 has negative refractive power. The object side surface S9 of the fifth lens L5 near the optical axis is convex, and the object side surface S9 near the circumference is concave. The image side surface S10 of the fifth lens L5 near the optical axis and near the circumference is convex.

[0208] The sixth lens L6 has positive refractive power, and the object-side surface S11 of the sixth lens L6 near the optical axis and near the circumference is a concave surface; the image-side surface S12 of the sixth lens L6 near the optical axis and near the circumference is a convex surface.

[0209] The other structures of the ninth embodiment are the same as those of the first embodiment, and can be referred to herein.

[0210] Table 9a shows a table of the characteristics of the optical system of this embodiment, wherein the data is obtained using light with a wavelength of 587 nm, and the units of Y radius, thickness and focal length are all millimeters (mm).

[0211] Table 9a

[0212]

[0213] The meanings of the parameters in Table 9a are the same as those in the first embodiment.

[0214] Table 9b gives the coefficients of the higher-order terms that can be used for each aspherical mirror surface in the ninth embodiment, wherein each aspherical surface shape can be defined by the formula given in the first embodiment.

[0215] Table 9b

[0216]

[0217]

[0218] Figure 9b The longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the ninth embodiment are shown. Figure 9b It can be seen that the optical system provided in the ninth embodiment can achieve good imaging quality.

[0219] Table 10 shows the values ​​of f14 / f, TTL / f, T45 / f, CT2 / R22, |SAG32|+|SAG42|, SAG12 / CT1, |V2-V1|, (ET3+ET4) / (CT3+CT4), FOV / f, and f6 / f of the optical systems of the first to ninth embodiments.

[0220] Table 10

[0221]

[0222]

[0223] It can be seen from Table 10 that all embodiments can satisfy the following requirements: f14 / f≤1.5, TTL / f≤1, T45 / f≤0.5, CT2 / R22≤0.5, |SAG32|+|SAG42|≤1, SAG12 / CT1≤0.5, |V2-V1|>30, 1≤(ET3+ET4) / (CT3+CT4)≤2, 5° / mm≤FOV / f≤10° / mm, -3≤f6 / f≤-1.

[0224] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of implementing the above-mentioned embodiment and making equivalent changes according to the claims of the present invention still fall within the scope of the invention.

Claims

1. An optical system, characterized in that: The optical system has six lenses with refractive power, which include the following from the object side to the image side along the optical axis: A first lens has positive refractive power, the object side surface of the first lens near the optical axis and near the circumference is a convex surface, and the image side surface of the first lens near the optical axis is a convex surface; A second lens has negative refractive power, and the image side surface of the second lens near the optical axis and near the circumference is concave; The third lens has negative refractive power; The fourth lens has a refracting power; A fifth lens having negative refractive power; The sixth lens has a refracting power; The optical system satisfies the condition: f14 / f≤1.5; TTL / f≤1; SAG12 / CT1≤0.5; Wherein, f14 is the combined focal length of the first lens, the second lens, the third lens and the fourth lens, f is the effective focal length of the optical system, TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis; SAG12 is the sagittal height of the image side surface of the first lens, and CT1 is the thickness of the first lens on the optical axis.

2. The optical system according to claim 1, wherein: The optical system satisfies the condition: T45 / f≤0.5; Wherein, T45 is an air gap between the fourth lens and the fifth lens on the optical axis.

3. The optical system according to claim 1, wherein: The optical system satisfies the condition: CT2 / R22≤0.5; Wherein, CT2 is the thickness of the second lens on the optical axis, and R22 is the radius of curvature of the image side surface of the second lens near the optical axis.

4. The optical system according to claim 1, wherein: The optical system satisfies the condition: |SAG32|+|SAG42|≤1; Among them, SAG32 is the sagittal height of the image side surface of the third lens, and SAG42 is the sagittal height of the image side surface of the fourth lens.

5. The optical system according to claim 1, wherein: The optical system satisfies the condition: |V2-V1|>30; Wherein, V1 is the Abbe number of the first lens, and V2 is the Abbe number of the second lens.

6. The optical system according to claim 1, wherein: The optical system satisfies the condition: 1≤(ET3+ET4) / (CT3+CT4)≤2; Among them, ET3 is the thickness of the edge of the optically effective area of ​​the third lens, ET4 is the thickness of the edge of the optically effective area of ​​the fourth lens, CT3 is the thickness of the third lens on the optical axis, and CT4 is the thickness of the fourth lens on the optical axis.

7. The optical system according to claim 1, wherein: The optical system satisfies the condition: 5° / mm≤FOV / f≤10° / mm; Wherein, FOV is the diagonal field of view of the optical system.

8. The optical system according to claim 1, wherein: The optical system satisfies the condition: -3≤f6 / f≤-1; Wherein, f6 is the effective focal length of the sixth lens.

9. A lens module, characterized in that: The optical system comprises a lens barrel, an electronic photosensitive element and the optical system as claimed in any one of claims 1 to 8, wherein the first lens to the sixth lens of the optical system are installed in the lens barrel, and the electronic photosensitive element is arranged on the image side of the optical system for converting light of an object passing through the first lens to the sixth lens and incident on the electronic photosensitive element into an electrical signal of an image.

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

Images