Optical imaging system, imaging module and electronic device

Abstract

The present application discloses an optical imaging system, an imaging module, and an electronic device. The optical imaging system sequentially includes, from the object side to the image side: a first lens; a second lens having a positive refractive power; a third lens having a negative refractive power; a fourth lens; a fifth lens having a positive refractive power, the image side surface of the fifth lens being convex near the optical axis; a sixth lens having a negative refractive power, at least one of the object side surface and the image side surface of the fifth lens and at least one of the object side surface and the image side surface of the sixth lens being an aspherical surface and having at least one critical point near the optical axis; the optical imaging system satisfies the following conditional expressions: 50 < V6 < 60, 2 < TTL / EPD < 3; V6 is the dispersion coefficient of the sixth lens, TTL is the distance on the optical axis from the object side surface of the first lens to the imaging surface of the optical imaging system, and EPD is the entrance pupil diameter of the optical imaging system. Through a compact spatial arrangement and a reasonable refractive power distribution, a thin and light design is achieved, which is beneficial to the application of miniaturized electronic products; the requirements for a large aperture, a wide viewing angle, and miniaturization can be satisfied.

Description

Technical Field

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

[0002] In recent years, with the rapid development of miniaturized camera lenses, users have increasingly demanded miniaturized optical imaging systems. With the advancement of semiconductor process technology, the pixel size of photosensitive components has been reduced, and the development trend of electronic products is to have good functions and a thin and light appearance. Therefore, miniaturized optical imaging systems with good imaging quality have become the mainstream in the current market.

[0003] Traditional optical imaging systems installed on portable electronic products generally need to be equipped with a sufficiently large aperture in order to obtain sufficient information in scenes such as night photography and dynamic photography. However, the volume of electronic products that can be installed with optical imaging systems is limited, so traditional camera modules often cannot achieve the requirements of maintaining a wide viewing angle while taking into account a large aperture. Summary of the invention

[0004] In view of the above, it is necessary to propose an optical imaging system, an imaging module and an electronic device to solve the above problems.

[0005] An embodiment of the present application provides an optical imaging system, which includes, from the object side to the image side, the following:

[0006] First lens;

[0007] The second lens has positive refractive power;

[0008] The third lens has negative refractive power;

[0009] The fourth lens;

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

[0011] a sixth lens having negative refractive power, wherein at least one of the object side surface and the image side surface of the fifth lens and the object side surface and the image side surface of the sixth lens is an aspherical surface and has at least one critical point near the optical axis;

[0012] The optical imaging system satisfies the following conditional formula:

[0013] 50 <V6<60,2<TTL / EPD<3;

[0014] Wherein, V6 is the dispersion coefficient of the sixth lens, TTL is the distance from the object side of the first lens to the imaging surface of the optical imaging system on the optical axis, and EPD is the entrance pupil diameter of the optical imaging system.

[0015] The above-mentioned optical imaging system realizes a lightweight design through compact spatial arrangement and reasonable distribution of refractive force, which is conducive to the application of miniaturized electronic products; when the above-mentioned conditions are met, the optical imaging system can meet the requirements of large aperture, wide viewing angle and miniaturization.

[0016] In some embodiments, the object side surface of the first lens is convex at the near optical axis, the image side surface of the fifth lens is convex at the near optical axis, and the object side surface of the sixth lens is concave at the near optical axis.

[0017] In some embodiments, the optical imaging system satisfies the following relationship:

[0018] 0.84 <Imgh / f<1.19;

[0019] Among them, Imgh is the image height corresponding to half of the maximum field angle of the optical imaging system, and f is the effective focal length of the optical imaging system.

[0020] In some embodiments, the optical imaging system satisfies the following relationship:

[0021] 1.41<(V2+V3+V5) / (V1+V4)<1.73;

[0022] Among them, V1 is the dispersion coefficient of the first lens, V2 is the dispersion coefficient of the second lens, V3 is the dispersion coefficient of the third lens, V4 is the dispersion coefficient of the fourth lens, and V5 is the dispersion coefficient of the fifth lens.

[0023] In some embodiments, the optical imaging system satisfies the following relationship:

[0024] 1.07 <TL1 / f<1.68;

[0025] Wherein, TL1 is the distance from the object side surface of the first lens to the imaging surface in the direction of the optical axis, and f is the effective focal length of the optical imaging system.

[0026] In some embodiments, the optical imaging system satisfies the following condition:

[0027] 35.51° / mm <FOV / TL6<124.98° / mm;

[0028] Wherein, FOV is the maximum field of view of the optical imaging system, and TL6 is the distance from the object side surface of the fifth lens to the imaging surface in the direction of the optical axis.

[0029] In some embodiments, the optical imaging system satisfies the following condition:

[0030] 9.82° / mm <FOV / f<20.94° / mm。

[0031] Wherein, FOV is the maximum field of view of the optical imaging system, and f is the effective focal length of the optical imaging system.

[0032] In some embodiments, the optical imaging system satisfies the following condition:

[0033] 1.41 <TTL / Imgh<1.58;

[0034] Wherein, TTL is the distance from the object side of the first lens to the imaging surface of the optical imaging system on the optical axis, and Imgh is the image height corresponding to half of the maximum field of view of the optical imaging system.

[0035] An embodiment of the present application provides an imaging module, including:

[0036] The above optical imaging system; and

[0037] A photosensitive element is arranged on the image side of the optical imaging system.

[0038] An embodiment of the present application provides an electronic device, including:

[0039] housing; and

[0040] The above-mentioned imaging module is installed on the shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a structural diagram of the optical imaging system of the first embodiment of the present application.

[0042] Figure 2 It is the simulated MTF versus field angle performance data of the optical imaging system of the first embodiment of the present application.

[0043] Figure 3 It is a field curvature characteristic curve diagram of the optical imaging system of the first embodiment of the present application.

[0044] Figure 4 It is a distortion characteristic curve diagram of the optical imaging system of the first embodiment of the present application.

[0045] Figure 5 It is a structural diagram of the optical imaging system of the second embodiment of the present application.

[0046] Figure 6 This is the simulated MTF versus field angle performance data of the optical imaging system of the second embodiment of the present application.

[0047] Figure 7It is a field curvature characteristic curve diagram of the optical imaging system of the second embodiment of the present application.

[0048] Figure 8 It is a distortion characteristic curve diagram of the optical imaging system of the second embodiment of the present application.

[0049] Fig. 9 It is a structural diagram of the optical imaging system of the third embodiment of the present application.

[0050] Fig.10 This is the simulated MTF versus field angle performance data of the optical imaging system of the third embodiment of the present application.

[0051] Fig.11 It is a field curvature characteristic curve diagram of the optical imaging system of the third embodiment of the present application.

[0052] Fig.12 It is a distortion characteristic curve diagram of the optical imaging system of the third embodiment of the present application.

[0053] Fig.13 It is a structural diagram of the optical imaging system of the fourth embodiment of the present application.

[0054] Fig.14 This is the simulated MTF versus field angle performance data of the optical imaging system of the fourth embodiment of the present application.

[0055] Fig.15 It is a field curvature characteristic curve diagram of the optical imaging system of the fourth embodiment of the present application.

[0056] Fig.16 It is a distortion characteristic curve diagram of the optical imaging system of the fourth embodiment of the present application.

[0057] Fig.17 It is a structural schematic diagram of the imaging module of an embodiment of the present application.

[0058] Fig.18 It is a schematic diagram of the structure of an electronic device according to an embodiment of the present application.

[0059] Main component symbols

[0060] Image acquisition module 100

[0061] Optical imaging system 10

[0062] First lens L1

[0063] Second lens L2

[0064] The third lens L3

[0065] The fourth lens L4

[0066] Fifth lens L5

[0067] Sixth lens L6

[0068] Infrared filter L7

[0069] Aperture STO

[0070] Object side S1, S3, S5, S7, S9, S11, S13

[0071] Like side S2, S4, S6, S8, S10, S12, S14

[0072] Imaging Surface IMA

[0073] Photosensitive element 20

[0074] Electronic device 200

[0075] Housing 210 DETAILED DESCRIPTION

[0076] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0077] See also Figure 1 An embodiment of the present application proposes an optical imaging system 10, which includes, from the object side to the image side, a first lens L1, a second lens L2 with positive refractive power, a third lens L3 with negative refractive power, a fourth lens L4, a fifth lens L5 with positive refractive power, and a sixth lens L6 with negative refractive power.

[0078] The first lens L1 has an object-side surface S1 and an image-side surface S2; the second lens L2 has an object-side surface S3 and an image-side surface S4; the third lens L3 has an object-side surface S5 and an image-side surface S6; the fourth lens L4 has an object-side surface S7 and an image-side surface S8; the fifth lens L5 has an object-side surface S9 and an image-side surface S10, and the object-side surface S9 is a convex surface at the near optical axis; the sixth lens L6 has an object-side surface S11 and an image-side surface S12, and at least one of the object-side surface S9 and the image-side surface S10 of the fifth lens L5 and the object-side surface S11 and the image-side surface S12 of the sixth lens L6 is an aspherical surface and has at least one critical point at the near optical axis.

[0079] In this way, the optical imaging system 10 described above achieves a lightweight design through compact spatial arrangement and reasonable distribution of refractive force, which is beneficial to the application of miniaturized electronic products.

[0080] In some embodiments, the optical imaging system 10 satisfies the following conditional formula:

[0081] 50 <V6<60,2<TTL / EPD<3;

[0082] Wherein, V6 is the dispersion coefficient of the sixth lens L6, TTL is the distance from the object side surface S1 of the first lens L1 to the imaging surface of the optical imaging system 10 on the optical axis, and EPD is the entrance pupil diameter of the optical imaging system 10.

[0083] When the above conditions are met, the optical imaging system 10 can simultaneously meet the requirements of large aperture, wide viewing angle and miniaturization.

[0084] In some embodiments, the object-side surface S1 of the first lens L1 is convex at the near optical axis, the image-side surface S10 of the fifth lens L5 is convex at the near optical axis, and the object-side surface S11 of the sixth lens L6 is concave at the near optical axis.

[0085] In some embodiments, the optical imaging system 10 satisfies the following relationship:

[0086] 0.84 <Imgh / f<1.19;

[0087] Among them, Imgh is the image height corresponding to half of the maximum field angle of the optical imaging system 10, and f is the effective focal length of the optical imaging system 10. In this way, it is helpful to improve the optical imaging system 10 to obtain a larger viewing angle.

[0088] In some embodiments, the optical imaging system satisfies the following relationship:

[0089] 1.41<(V2+V3+V5) / (V1+V4)<1.73;

[0090] Wherein, V1 is the dispersion coefficient of the first lens L1, V2 is the dispersion coefficient of the second lens L2, V3 is the dispersion coefficient of the third lens L3, V4 is the dispersion coefficient of the fourth lens L4, and V5 is the dispersion coefficient of the fifth lens L5. In this way, a good balance can be achieved between chromatic aberration correction and astigmatism correction to improve the imaging quality of the optical imaging system 10.

[0091] In some embodiments, the optical imaging system satisfies the following relationship:

[0092] 1.07 <TL1 / f<1.68;

[0093] Wherein, TL1 is the distance from the object side surface S1 of the first lens L1 to the imaging surface in the optical axis direction, and f is the effective focal length of the optical imaging system 10. In this way, the total length of the optical imaging system 10 can be shortened, and the optical imaging system 10 has a larger viewing angle.

[0094] In some embodiments, the optical imaging system satisfies the following condition:

[0095] 35.51 <FOV / TL6<124.98;

[0096] Wherein, FOV is the maximum field of view of the optical imaging system 10, and TL6 is the distance from the object side surface of the fifth lens to the imaging surface in the optical axis direction. In this way, the optical imaging system 10 has a wide viewing angle.

[0097] In some embodiments, the optical imaging system 10 satisfies the following conditional formula:

[0098] 9.82 <FOV / f<20.94;

[0099] Wherein, FOV is the maximum field of view of the optical imaging system 10 , and f is the effective focal length of the optical imaging system 10 .

[0100] In this way, the optical imaging system 10 has a wide viewing angle and satisfies miniaturization.

[0101] In some embodiments, the optical imaging system 10 satisfies the following conditional formula:

[0102] 1.41 <TTL / Imgh<1.58;

[0103] Wherein, TTL is the distance on the optical axis from the object side surface S1 of the first lens L1 to the imaging surface of the optical imaging system 10. In this way, the camera module having the optical imaging system 10 can meet the requirements of miniaturization design.

[0104] In some embodiments, the optical imaging system 10 further includes a stop STO. The stop STO can be disposed on the surface of any lens, or disposed before the first lens L1, or disposed between any two lenses, or disposed on the image side surface S12 of the sixth lens L6. Figure 1 In the embodiment, the stop STO is disposed on the object-side surface S3 of the second lens L2. The stop may be a glare stop or a field stop, etc., to reduce stray light and help improve image quality.

[0105] In some embodiments, the optical imaging system 10 further includes an infrared filter L7, and the infrared filter L7 has an object side surface S13 and an image side surface S14. The infrared filter L7 is disposed on the image side of the sixth lens L6 to filter out light of other wavelengths such as visible light and only allow infrared light to pass, so that the optical imaging system 10 can also form images in dim environments and other special application scenarios.

[0106] The above-mentioned optical imaging system 10 realizes a lightweight and miniaturized design through compact spatial arrangement and reasonable distribution of refractive force, which is conducive to the application of miniaturized electronic products; when the above-mentioned conditions are met, the optical imaging system 10 simultaneously meets the requirements of large aperture, wide viewing angle and miniaturization.

[0107] First embodiment

[0108] See also Figure 1 In the optical imaging system 10 in this embodiment, from the object side to the image side, it includes an aperture STO, a first lens L1 with refractive power, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with negative refractive power and an infrared filter L7.

[0109] The first lens L1 , the second lens L2 , the third lens L3 , the fourth lens L4 , the fifth lens L5 and the sixth lens L6 are all made of glass, and the infrared filter L7 is also made of glass.

[0110] The object-side surface S1 of the first lens L1 is convex at the near optical axis, the object-side surface S9 of the fifth lens L5 is convex at the near optical axis, the image-side surface S10 of the fifth lens L5 is convex at the near optical axis, and the object-side surface S11 of the sixth lens L6 is concave at the near optical axis.

[0111] When the optical imaging system 10 is used for imaging, the light emitted or reflected by the object enters the optical imaging system 10 from the object side, and passes through the aperture STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the infrared filter L7 in sequence, and finally converges on the imaging surface IMA.

[0112] Table 1 shows basic parameters of the optical imaging system 10 of this embodiment.

[0113] Table 1

[0114]

[0115]

[0116] Wherein, TL1 is the distance between the object side surface S1 of the first lens L1 and the imaging surface IMA of the optical imaging system 10 on the optical axis, TL2 is the distance between the object side surface S3 of the second lens L2 and the imaging surface IMA of the optical imaging system 10 on the optical axis, TL3 is the distance between the object side surface S5 of the third lens L3 and the imaging surface IMA of the optical imaging system 10 on the optical axis, TL4 is the distance between the object side surface S7 of the fourth lens L4 and the imaging surface IMA of the optical imaging system 10 on the optical axis, TL5 is the distance between the object side surface S9 of the fifth lens L5 and the imaging surface IMA of the optical imaging system 10 on the optical axis, and TL6 is the distance between the object side surface S11 of the sixth lens L6 and the imaging surface IMA of the optical imaging system 10 on the optical axis. To avoid repetition, the following embodiments are not described in detail.

[0117] Table 2 shows the characteristics of the optical imaging system 10 of this embodiment. The reference wavelength of the focal length, refractive index and Abbe number is 558 nm, and the units of the radius of curvature, thickness and semi-diameter are all millimeters (mm).

[0118] Table 2

[0119]

[0120]

[0121] Table 3 shows the aspheric coefficients of the optical imaging system 10 of this embodiment.

[0122] Table 3

[0123]

[0124] It should be noted that the surface of the lens of the optical imaging system 10 may be an aspherical surface. For these aspherical surfaces, the aspherical surface equation is:

[0125]

[0126] Wherein, Z is the distance between any point on the aspheric surface and the vertex of the surface parallel to the optical axis, r is the perpendicular distance from any point on the aspheric surface to the optical axis, c is the vertex curvature (the inverse of the radius of curvature), k is the cone constant, Ai is the correction coefficient of the i-th order aspheric surface, and Table 3 shows the high-order coefficients K, A2, A4, A6, A8, A10, A12 and A14 that can be used for each aspheric lens S1-S12 in the first embodiment.

[0127] Figures 2 to 4 The simulated MTF versus field angle performance data, the field curvature characteristic curve, and the distortion characteristic curve of the optical imaging system 10 of the first embodiment are respectively shown. Figure 2The horizontal axis represents the Y field offset angle, that is, the angle of the field of view of the optical imaging system 10 relative to the optical axis, in degrees; the vertical axis represents the OTF coefficient; the curve at a lower frequency can reflect the contrast characteristics of the optical imaging system 10, and the curve at a higher frequency can reflect the resolution characteristics of the optical imaging system 10, and other embodiments are the same. Figure 3 The field curvature curve represents the meridional field curvature and sagittal field curvature, in which the maximum values ​​of sagittal field curvature and meridional field curvature are both less than 0.05mm, which is well compensated. Figure 4 The medium distortion curve represents the distortion values ​​corresponding to different field angles, wherein the maximum distortion is less than 2%, and the distortion is also well corrected. It can be seen that the optical imaging system 10 provided in the first embodiment can meet the requirements of large aperture, wide viewing angle and miniaturization.

[0128] Second embodiment

[0129] See also Figure 5 In the optical imaging system 10 in this embodiment, from the object side to the image side, it includes an aperture STO, a first lens L1 with refractive power, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with negative refractive power and an infrared filter L7.

[0130] The first lens L1 , the second lens L2 , the third lens L3 , the fourth lens L4 , the fifth lens L5 and the sixth lens L6 are all made of glass, and the infrared filter L7 is also made of glass.

[0131] The object-side surface S1 of the first lens L1 is convex at the near optical axis, the object-side surface S9 of the fifth lens L5 is convex at the near optical axis, the image-side surface S10 of the fifth lens L5 is convex at the near optical axis, and the object-side surface S11 of the sixth lens L6 is concave at the near optical axis.

[0132] When the optical imaging system 10 is used for imaging, the light emitted or reflected by the object enters the optical imaging system 10 from the object side, and passes through the aperture STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the infrared filter L7 in sequence, and finally converges on the imaging surface IMA.

[0133] Table 4 shows basic parameters of the optical imaging system 10 of this embodiment.

[0134] Table 4

[0135] Imgh (unit: mm) 3.4 TTL (unit: mm) 5.128247 FOV(unit:°) 40.057 TL1(Unit: mm) 4.281509 TL2(Unit: mm) 4.031124 TL3(Unit: mm) 3.280001 TL4 (unit: mm) 2.750077 TL5(Unit: mm) 1.627851 TL6 (unit: mm) 0.643684 V1 55.9512 V2 23.52887 V3 55.9512 V4 23.52887 V5 55.9512 V6 55.59355 EPD (unit: mm) 1.9 f(unit: mm) 3.9659

[0136] Table 5 shows the characteristics of the optical imaging system 10 of this embodiment. The reference wavelength of the focal length, refractive index and Abbe number is 558 nm, and the units of the radius of curvature, thickness and semi-diameter are all millimeters (mm).

[0137] Table 5

[0138]

[0139] Table 6 shows the aspheric coefficients of the optical imaging system 10 of this embodiment.

[0140] Table 6

[0141]

[0142] It should be noted that the surface of the lens of the optical imaging system 10 may be an aspherical surface. For these aspherical surfaces, the aspherical surface equation is:

[0143]

[0144] Wherein, Z is the distance between any point on the aspheric surface and the vertex of the surface parallel to the optical axis, r is the perpendicular distance from any point on the aspheric surface to the optical axis, c is the vertex curvature (the inverse of the radius of curvature), k is the cone constant, Ai is the correction coefficient of the i-th order aspheric surface, and Table 3 shows the high-order coefficients K, A2, A4, A6, A8, A10, A12 and A14 that can be used for each aspheric lens S1-S12 in the first embodiment.

[0145] Figures 6 to 8 The simulated MTF versus field angle performance data, the field curvature characteristic curve, and the distortion characteristic curve of the optical imaging system 10 of the second embodiment are respectively shown. Figure 6 The horizontal axis represents the Y field offset angle, that is, the angle of the field of view of the optical imaging system 10 relative to the optical axis, in degrees; the vertical axis represents the OTF coefficient; the curve at a lower frequency can reflect the contrast characteristics of the optical imaging system 10, and the curve at a higher frequency can reflect the resolution characteristics of the optical imaging system 10, and other embodiments are the same. Figure 6 The field curvature curve represents the meridional field curvature and sagittal field curvature, in which the maximum values ​​of sagittal field curvature and meridional field curvature are both less than 0.1mm, which is well compensated. Figure 8 The medium distortion curve represents the distortion values ​​corresponding to different field angles, wherein the maximum distortion is less than 5%, and the distortion is also well corrected. It can be seen that the optical imaging system 10 provided in the second embodiment can meet the requirements of large aperture, wide viewing angle and miniaturization.

[0146] Third embodiment

[0147] See also Fig. 9In the optical imaging system 10 in this embodiment, from the object side to the image side, it includes an aperture STO, a first lens L1 with refractive power, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with negative refractive power and an infrared filter L7.

[0148] The first lens L1 , the second lens L2 , the third lens L3 , the fourth lens L4 , the fifth lens L5 and the sixth lens L6 are all made of glass, and the infrared filter L7 is also made of glass.

[0149] The object-side surface S1 of the first lens L1 is convex at the near optical axis, the object-side surface S9 of the fifth lens L5 is convex at the near optical axis, the image-side surface S10 of the fifth lens L5 is convex at the near optical axis, and the object-side surface S11 of the sixth lens L6 is concave at the near optical axis.

[0150] When the optical imaging system 10 is used for imaging, the light emitted or reflected by the object enters the optical imaging system 10 from the object side, and passes through the aperture STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the infrared filter L7 in sequence, and finally converges on the imaging surface IMA.

[0151] Table 7 shows basic parameters of the optical imaging system 10 of this embodiment.

[0152] Table 7

[0153]

[0154]

[0155] Table 8 shows the characteristics of the optical imaging system 10 of this embodiment. The reference wavelength of the focal length, refractive index and Abbe number is 558 nm, and the units of the radius of curvature, thickness and semi-diameter are all millimeters (mm).

[0156] Table 8

[0157]

[0158] Table 9 shows the aspheric coefficients of the optical imaging system 10 of this embodiment.

[0159] Form 9

[0160]

[0161]

[0162] It should be noted that the surface of the lens of the optical imaging system 10 may be an aspherical surface. For these aspherical surfaces, the aspherical surface equation is:

[0163]

[0164] Wherein, Z is the distance between any point on the aspheric surface and the surface vertex parallel to the optical axis, r is the perpendicular distance from any point on the aspheric surface to the optical axis, c is the vertex curvature (the inverse of the radius of curvature), k is the cone constant, Ai is the correction coefficient of the i-th order aspheric surface, and Table 9 shows the high-order coefficients K, A2, A4, A6 and A8 that can be used for each aspheric lens S1-S12 in the third embodiment.

[0165] Figures 10 to 12 The simulated MTF versus field angle performance data, the field curvature characteristic curve, and the distortion characteristic curve of the optical imaging system 10 of the third embodiment are respectively shown. Fig.10 The horizontal axis represents the Y field offset angle, that is, the angle of the field of view of the optical imaging system 10 relative to the optical axis, in degrees; the vertical axis represents the OTF coefficient; the curve at a lower frequency can reflect the contrast characteristics of the optical imaging system 10, and the curve at a higher frequency can reflect the resolution characteristics of the optical imaging system 10, and other embodiments are the same. Fig.11 The field curvature curve represents the meridional field curvature and sagittal field curvature, in which the maximum values ​​of sagittal field curvature and meridional field curvature are both less than 0.2mm, which is well compensated. Fig.12 The medium distortion curve represents the distortion values ​​corresponding to different field angles, wherein the maximum distortion is less than 10%, and the distortion is also well corrected. It can be seen that the optical imaging system 10 provided in the third embodiment can meet the requirements of large aperture, wide viewing angle and miniaturization.

[0166] Fourth embodiment

[0167] See also Fig.13 In the optical imaging system 10 in this embodiment, from the object side to the image side, it includes an aperture STO, a first lens L1 with refractive power, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with negative refractive power and an infrared filter L7.

[0168] The first lens L1 , the second lens L2 , the third lens L3 , the fourth lens L4 , the fifth lens L5 and the sixth lens L6 are all made of glass, and the infrared filter L7 is also made of glass.

[0169] The object-side surface S1 of the first lens L1 is convex at the near optical axis, the object-side surface S9 of the fifth lens L5 is convex at the near optical axis, the image-side surface S10 of the fifth lens L5 is convex at the near optical axis, and the object-side surface S11 of the sixth lens L6 is concave at the near optical axis.

[0170] When the optical imaging system 10 is used for imaging, the light emitted or reflected by the object enters the optical imaging system 10 from the object side, and passes through the aperture STO, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the infrared filter L7 in sequence, and finally converges on the imaging surface IMA.

[0171] Table 10 shows basic parameters of the optical imaging system 10 of this embodiment.

[0172] Table 10

[0173] Imgh (unit: mm) 3.35 TTL (unit: mm) 5.2797 FOV(unit:°) 84 TL1(Unit: mm) 4.4267 TL2(Unit: mm) 4.1873 TL3(Unit: mm) 3.3579 TL4 (unit: mm) 2.8859 TL5(Unit: mm) 1.7622 TL6 (unit: mm) 0.6721 V1 55.951198 V2 20.372904 V3 55.951198 V4 20.372904 V5 55.951198 V6 55.951198 EPD (unit: mm) 1.916 f(unit: mm) 4.011

[0174] Wherein, TL1 is the distance between the image side surface S2 of the first lens L1 and the imaging surface IMA of the optical imaging system 10 on the optical axis, TL2 is the distance between the image side surface S4 of the second lens L2 and the imaging surface IMA of the optical imaging system 10 on the optical axis, TL3 is the distance between the image side surface S6 of the third lens L3 and the imaging surface IMA of the optical imaging system 10 on the optical axis, TL4 is the distance between the image side surface S8 of the fourth lens L4 and the imaging surface IMA of the optical imaging system 10 on the optical axis, TL5 is the distance between the image side surface S10 of the fifth lens L5 and the imaging surface IMA of the optical imaging system 10 on the optical axis, and TL6 is the distance between the image side surface S12 of the sixth lens L6 and the imaging surface IMA of the optical imaging system 10 on the optical axis. To avoid repetition, the following embodiments are not described in detail.

[0175] Table 11 shows the characteristics of the optical imaging system 10 of this embodiment. The reference wavelength of the focal length, refractive index and Abbe number is 558 nm, and the units of the radius of curvature, thickness and semi-diameter are all millimeters (mm).

[0176] Table 11

[0177]

[0178]

[0179] Table 12 shows the aspheric coefficients of the optical imaging system 10 of this embodiment.

[0180] Table 12

[0181]

[0182] It should be noted that the surface of the lens of the optical imaging system 10 may be an aspherical surface. For these aspherical surfaces, the aspherical surface equation is:

[0183]

[0184] Wherein, Z is the distance between any point on the aspheric surface and the vertex of the surface parallel to the optical axis, r is the perpendicular distance from any point on the aspheric surface to the optical axis, c is the vertex curvature (the inverse of the radius of curvature), k is the cone constant, Ai is the correction coefficient of the i-th order aspheric surface, and Table 12 shows the high-order coefficients K, A2, A4, A6, A8, A10, A12 and A14 that can be used for each aspheric lens S1-S12 in the fourth embodiment.

[0185] Figures 14 to 16 The simulated MTF versus field angle performance data, the field curvature characteristic curve, and the distortion characteristic curve of the optical imaging system 10 of the fourth embodiment are respectively shown. Fig.14 The horizontal axis represents the Y field offset angle, that is, the angle of the field of view of the optical imaging system 10 relative to the optical axis, in degrees; the vertical axis represents the OTF coefficient; the curve at a lower frequency can reflect the contrast characteristics of the optical imaging system 10, and the curve at a higher frequency can reflect the resolution characteristics of the optical imaging system 10, and other embodiments are the same. Fig.16 The field curvature curve represents the meridional field curvature and sagittal field curvature, in which the maximum values ​​of sagittal field curvature and meridional field curvature are both less than 0.05mm, which is well compensated. Fig.17 The medium distortion curve represents the distortion values ​​corresponding to different field angles, wherein the maximum distortion is less than 10%, and the distortion is also well corrected. It can be seen that the optical imaging system 10 provided in the fourth embodiment can meet the requirements of large aperture, wide viewing angle and miniaturization.

[0186] See also Fig.17 The optical imaging system 10 of the embodiment of the present application can be applied to the imaging module 100 of the embodiment of the present application. The imaging module 100 includes a photosensitive element 20 and the optical imaging system 10 of any of the above embodiments. The photosensitive element 20 is disposed on the image side of the optical imaging system 10.

[0187] The photosensitive element 20 may be a complementary metal oxide semiconductor (CMOS) image sensor or a charge-coupled device (CCD).

[0188] See also Fig.18The imaging module 100 of the embodiment of the present application can be applied to the electronic device 200 of the embodiment of the present application. The electronic device 200 includes a housing 210 and the imaging module 100 , and the imaging module 100 is mounted on the housing 210 .

[0189] The electronic device 200 of the embodiment of the present application includes but is not limited to a driving recorder, a smart phone, a tablet computer, a laptop computer, an e-book reader, a portable multimedia player (PMP), a portable phone, a video phone, a digital still camera, a mobile medical device, a wearable device, and other electronic devices that support imaging.

[0190] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the preferred embodiments, a person of ordinary skill in the art should understand that the technical solution of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present application.

Claims

1. An optical imaging system, characterized in that: From the object side to the image side, it includes: First lens; The second lens has positive refractive power; The third lens has negative refractive power; The fourth lens; a fifth lens element having positive refractive power, wherein the image side surface of the fifth lens element is convex at the near optical axis; a sixth lens having negative refractive power, wherein at least one of the object side surface and the image side surface of the fifth lens and the object side surface and the image side surface of the sixth lens is an aspherical surface and has at least one critical point near the optical axis; The optical imaging system satisfies the following conditional formula: 1.41<(V2+V3+V5) / (V1+V4)<1.73, 50 <V6<60,2<TTL / EPD<3; Among them, V1 is the dispersion coefficient of the first lens, V2 is the dispersion coefficient of the second lens, V3 is the dispersion coefficient of the third lens, V4 is the dispersion coefficient of the fourth lens, V5 is the dispersion coefficient of the fifth lens, V6 is the dispersion coefficient of the sixth lens, TTL is the distance from the object side of the first lens to the imaging surface of the optical imaging system on the optical axis, and EPD is the entrance pupil diameter of the optical imaging system.

2. The optical imaging system according to claim 1, wherein: The object side surface of the first lens is convex at the near optical axis, the image side surface of the fifth lens is convex at the near optical axis, and the object side surface of the sixth lens is concave at the near optical axis.

3. The optical imaging system according to claim 1, wherein: The optical imaging system satisfies the following relationship: 0.84 <Imgh / f<1.19; Among them, Imgh is the image height corresponding to half of the maximum field angle of the optical imaging system, and f is the effective focal length of the optical imaging system.

4. The optical imaging system according to claim 1, wherein: The optical imaging system satisfies the following relationship: 1.07 <TL1 / f<1.68; Wherein, TL1 is the distance from the object side surface of the first lens to the imaging surface in the direction of the optical axis, and f is the effective focal length of the optical imaging system.

5. The optical imaging system according to claim 1, wherein: The optical imaging system satisfies the following conditional formula: 35.51° / mm <FOV / TL6<124.98° / mm; Wherein, FOV is the maximum field of view of the optical imaging system, and TL6 is the distance from the object side surface of the fifth lens to the imaging surface in the direction of the optical axis.

6. The optical imaging system according to claim 1, wherein: The optical imaging system satisfies the following conditional formula: 9.82° / mm <FOV / f<20.94° / mm; Wherein, FOV is the maximum field of view of the optical imaging system, and f is the effective focal length of the optical imaging system.

7. The optical imaging system according to claim 1, wherein: The optical imaging system satisfies the following conditional formula: 1.41 <TTL / Imgh<1.58; Wherein, TTL is the distance from the object side of the first lens to the imaging surface of the optical imaging system on the optical axis, and Imgh is the image height corresponding to half of the maximum field of view of the optical imaging system.

8. An imaging module, characterized in that: include: The optical imaging system according to any one of claims 1 to 7; and A photosensitive element is arranged on the image side of the optical imaging system.

9. An electronic device, characterized in that: include: case; and The imaging module as described in claim 8 is mounted on the housing.

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