Optical System, Lens Module, and Electronic Device

Abstract

The present invention provides an optical system, a lens module, and an electronic device. The optical system includes: a first lens having a positive refractive power, the object side surface of the first lens being convex near the optical axis, and the image side surface of the first lens being concave near the optical axis; a second lens having a negative refractive power, the object side surface of the second lens being convex near the optical axis, and the image side surface of the second lens being concave; a third lens having a refractive power; a fourth lens having a positive refractive power; a fifth lens having a refractive power; a sixth lens having a refractive power, the object side surface of the sixth lens being concave near the optical axis; a seventh lens having a negative refractive power, the object side surface of the seventh lens being convex near the optical axis, and the image side surface of the seventh lens being concave near the optical axis; the optical system satisfies the conditional formula: TTL / Imgh < 1.32; TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis, and Imgh is half of the diagonal length of the effective pixel area of the imaging surface. The present invention meets the requirements of high pixels, large apertures, and good image quality while maintaining a small structure.

Description

Technical Field

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

[0002] In recent years, with the development of manufacturing technologies of electronic devices such as smart phones and tablets and the emergence of the development trend of diversified user demands, the market demand for miniaturized camera lenses has gradually increased. Currently, an electronic device is equipped with multiple cameras with different characteristics and application environments. Under the trend that the size and thickness of electronic products are maintained or even reduced, the electronic device has put forward more stringent requirements for the miniaturization of the lens. In addition, with the improvement of semiconductor process technology, the pixel size of the photosensitive element has also been reduced, and miniaturized lenses with good imaging quality have become the mainstream in the market.

[0003] In order to bring a better imaging experience to users, today's imaging devices are equipped with large photosensitive elements. At the same time, in order to achieve high imaging quality and large aperture effects, the number of lenses in the imaging device also needs to be increased. The increase in the number of lenses also causes difficulties in realizing the miniaturization of the lens. Therefore, the existing lenses cannot meet the requirements of large aperture, high pixels and miniaturization at the same time. Summary of the Invention

[0004] The purpose of the present application is to provide an optical system, a lens module and an electronic device to solve the above technical problems.

[0005] The present invention provides an optical system, which sequentially includes, from the object side to the image side along the optical axis direction:

[0006] The first lens has a positive refractive power. The object side of the first lens near the optical axis is convex, and the image side of the first lens near the optical axis is concave. The second lens has a negative refractive power. The object side of the second lens near the optical axis is convex, and the image side of the second lens near the optical axis is concave. The third lens has a refractive power. The fourth lens has a positive refractive power. The fifth lens has a refractive power. The sixth lens has a refractive power. The object side of the sixth lens near the optical axis is concave. The seventh lens has a negative refractive power. The object side of the seventh lens near the optical axis is convex, and the image side of the seventh lens near the optical axis is concave. The object side and the image side of any one of the first lens to the seventh lens are aspherical surfaces. The optical system satisfies the conditional formula: TTL / Imgh < 1.32; where TTL is the distance from the object side of the first lens to the imaging surface of the optical system on the optical axis, and Imgh is half of the diagonal length of the effective pixel area of the imaging surface. By reasonably configuring the surface types and refractive powers of the first lens to the seventh lens, the optical system can meet the requirements of high pixels, large aperture, and good image quality while maintaining a compact structure and miniaturization. When the optical system satisfies the above conditional formula and the image plane is fixed, it can ensure a small total length of the optical system and achieve the miniaturization requirement.

[0007] Wherein, the optical system satisfies the conditional formula: 2 < f / R14 < 3.5; where f is the effective focal length of the optical system, and R14 is the curvature radius of the image side of the seventh lens on the optical axis. When the optical system satisfies the above conditional formula, by reasonably distributing the value of R14, the main ray angle of the inner field of view of the chip can be better matched.

[0008] Wherein, the optical system satisfies the conditional formula: FNO ≤ 2; where FNO is the aperture number of the optical system. When the optical system satisfies the above conditional formula, when the effective focal length of the optical system is fixed, FNO ≤ 2 can ensure a large aperture, allowing the optical system to have sufficient light input, making the captured image clearer, and realizing the capture of object space scenes with low light brightness such as high-quality night scenes and starry skies.

[0009] Wherein, the optical system satisfies the conditional formula: TTL / f < 1.35; where TTL is the distance from the object side of the first lens to the imaging surface of the optical system on the optical axis, and f is the effective focal length of the optical system. When the optical system satisfies the above conditional formula, the miniaturization requirement of the optical system can be met when the effective focal length of the optical system is fixed.

[0010] Among them, the optical system satisfies the conditional formula: -0.31 ≤ f1 / f2 < -0.15; where f1 is the effective focal length of the first lens and f2 is the effective focal length of the second lens. When the optical system satisfies the above conditional formula, the first lens and the second lens are combined with positive and negative signs, which can effectively balance the chromatic aberration of the system. And by reasonably selecting the ratio of the above focal lengths, the sensitivity of the optical system can be reduced to a certain extent.

[0011] Among them, the optical system satisfies the conditional formula: sag1 / sag2 < 15; where sag1 is the sagitta at the effective aperture of the object side of the first lens and sag2 is the sagitta at the effective aperture of the image side of the first lens. When the optical system satisfies the above conditional formula, by reasonably selecting the ratio of sag1 / sag2, the manufacturability of the first lens can be ensured, which is beneficial to manufacturing, and at the same time, the sensitivity of the entire optical system can also be reduced. Among them, the optical system satisfies the conditional formula: (R2 + R1) / (R2 - R1) < 5; where R1 is the radius of curvature of the object side of the first lens and R2 is the radius of curvature of the image side of the first lens. When the optical system satisfies the above conditional formula, by reasonably selecting the ratio of (R2 + R1) / (R2 - R1), the optical power of the first lens can be enhanced, and the chromatic spherical aberration can be well corrected even under a large aperture, improving the overall performance.

[0012] Among them, the optical system satisfies the conditional formula: f1234 / f567 > -0.5; where f1234 is the combined focal length of the first lens to the fourth lens, and f567 is the combined focal length of the fifth lens to the seventh lens. The optical system of the present application can be regarded as two groups. The first lens to the fourth lens are the front group with a positive focal length, and the fifth lens to the seventh lens are the rear group with a negative focal length. The positive and negative combination can correct the chromatic spherical aberration of the entire optical system and improve the performance; when the optical system satisfies the above conditional formula, the absolute value of the front group focal length is less than that of the rear group, which can reduce the sensitivity of the rear group and improve the yield rate in the actual production process.

[0013] The present invention provides a lens module, including a lens barrel, an electronic photosensitive element, and the above optical system. The first lens to the seventh 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 the light of the object incident on the electronic photosensitive element through the first lens to the seventh lens into an electrical signal of an image. By installing the first lens to the seventh lens of the optical system in the lens module and reasonably configuring the surface types and refractive powers of the lenses of the first lens to the seventh lens, the lens module can meet the requirements of high pixel, large aperture, and good image quality while maintaining a compact structure and miniaturizing the lens module.

[0014] The present invention provides an electronic device, comprising a housing and the above-mentioned lens module, and the lens module is disposed within the housing. By providing the above-mentioned lens module in the electronic device, the electronic device can meet the requirements of high pixel, large aperture and good image quality while maintaining a compact structure and miniaturizing the electronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0016] Figure 1a is a schematic structural diagram of the optical system of the first embodiment;

[0017] Figure 1b is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the first embodiment;

[0018] Figure 2a is a schematic structural diagram of the optical system of the second embodiment;

[0019] Figure 2b is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the second embodiment;

[0020] Figure 3a is a schematic structural diagram of the optical system of the third embodiment;

[0021] Figure 3b is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the third embodiment;

[0022] Figure 4a is a schematic structural diagram of the optical system of the fourth embodiment;

[0023] Figure 4b is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the fourth embodiment;

[0024] Figure 5a is a schematic structural diagram of the optical system of the fifth embodiment;

[0025] Figure 5b is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the fifth embodiment;

[0026] Figure 6a is a schematic structural diagram of the optical system of the sixth embodiment;

[0027] Figure 6b is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the sixth embodiment.

[0028] Figure 7a It is a schematic structural diagram of the optical system of the seventh embodiment;

[0029] Figure 7b They are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the seventh embodiment. Specific Embodiments

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] The embodiment of the present application provides a lens module, which includes a lens barrel, an electronic photosensitive element and the optical system provided by the embodiment of the present invention. The first to seventh lenses 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 the light of the object incident on the electronic photosensitive element through the first to seventh lenses 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 on an electronic device such as a smart phone. By installing the first to seventh lenses of the optical system in the lens module and reasonably configuring the surface shapes and refractive powers of the lenses of the first to seventh lenses, the lens module can meet the requirements of high pixel, large aperture and good image quality while maintaining a compact structure and miniaturizing the lens module.

[0032] The embodiment of the present application provides an electronic device, which includes a housing and the lens module provided by the embodiment of the present application. 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 arranging the lens module in the electronic device, the electronic device can meet the requirements of high pixel, large aperture and good image quality while maintaining a compact structure and miniaturizing the electronic device.

[0033] An embodiment of the present application provides an optical system, which sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a seventh lens from the object side to the image side along the optical axis direction. There can be an air gap between any two adjacent lenses among the first lens to the seventh lens.

[0034] Specifically, the specific shapes and structures of the seven lenses are as follows:

[0035] The first lens has a positive refractive power. The object side surface of the first lens near the optical axis is convex, and the image side surface of the first lens near the optical axis is concave; the second lens has a negative refractive power. The object side surface of the second lens near the optical axis is convex, and the image side surface of the second lens near the optical axis is concave; the third lens has a refractive power; the fourth lens has a positive refractive power; the fifth lens has a refractive power; the sixth lens has a refractive power, and the object side surface of the sixth lens near the optical axis is concave; the seventh lens has a negative refractive power. The object side surface of the seventh lens near the optical axis is flat, and the image side surface of the seventh lens near the optical axis is concave; the object side surface and the image side surface of any one of the first lens to the seventh lens are aspherical surfaces; the optical system satisfies the conditional formula: TTL / Imgh < 1.32; where TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis, and Imgh is half of the diagonal length of the effective pixel area of the imaging surface. By reasonably configuring the surface types and refractive powers of the lenses from the first lens to the seventh lens in the present application, the optical system can meet the requirements of high pixels, large aperture, and good image quality while maintaining a compact structure and miniaturization. When the optical system satisfies the above conditional formula and the image plane is fixed, it can ensure a small total length of the optical system and achieve the miniaturization requirement.

[0036] In a specific embodiment, the optical system satisfies the conditional formula: 2 < f / R14 < 3.5; where f is the effective focal length of the optical system, and R14 is the curvature radius of the image side surface of the seventh lens on the optical axis. When the optical system satisfies the above conditional formula, by reasonably distributing the value of R14, the main ray angle of the inner field of view of the chip can be better matched.

[0037] In a specific embodiment, the optical system satisfies the conditional formula: FNO ≤ 2; where FNO is the aperture number of the optical system. When the optical system satisfies the above conditional formula and the effective focal length of the optical system is certain, FNO ≤ 2 can ensure a large aperture, allowing the optical system to have sufficient light input, making the captured image clearer, and realizing the capture of object space scenes with low light brightness such as high-quality night scenes and starry skies.

[0038] In a specific embodiment, the optical system satisfies the conditional formula: TTL / f < 1.35; where TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis, and f is the effective focal length of the optical system. When the optical system satisfies the above conditional formula, the miniaturization requirements of the optical system can be met when the effective focal length of the optical system is fixed. In this embodiment, an upper limit value can be set for TTL, for example, the upper limit value can be set to 7 mm.

[0039] In a specific embodiment, the optical system satisfies the conditional formula: -0.31 ≤ f1 / f2 < -0.15; where f1 is the effective focal length of the first lens, and f2 is the effective focal length of the second lens. When the optical system satisfies the above conditional formula, the first lens and the second lens are combined with positive and negative polarities, which can effectively balance the chromatic aberration of the system. Moreover, by reasonably selecting the ratio of the above focal lengths, the sensitivity of the optical system can be reduced to a certain extent.

[0040] In a specific embodiment, the optical system satisfies the conditional formula: sag1 / sag2 < 15; where sag1 is the sagitta at the effective aperture of the object side surface of the first lens, and sag2 is the sagitta at the effective aperture of the image side surface of the first lens. When the optical system satisfies the above conditional formula, by reasonably selecting the ratio of sag1 / sag2, the manufacturability of the first lens can be ensured, which is beneficial to manufacturing. At the same time, the sensitivity of the entire optical system can also be reduced.

[0041] In a specific embodiment, the optical system satisfies the conditional formula: (R2 + R1) / (R2 - R1) < 5; where R1 is the radius of curvature of the object side surface of the first lens, and R2 is the radius of curvature of the image side surface of the first lens. When the optical system satisfies the above conditional formula, by reasonably selecting the ratio of (R2 + R1) / (R2 - R1), the optical power of the first lens can be enhanced, and the chromatic spherical aberration can be well corrected even at a large aperture, thereby improving the overall performance.

[0042] In a specific embodiment, the optical system satisfies the conditional formula: f1234 / f567 > -0.5; where f1234 is the combined focal length of the first lens to the fourth lens, and f567 is the combined focal length of the fifth lens to the seventh lens. Specifically, the optical system of the present application can be regarded as two groups. The first lens to the fourth lens are the front group with a positive focal length, and the fifth lens to the seventh lens are the rear group with a negative focal length. The positive and negative polarities are combined to correct the chromatic spherical aberration of the entire optical system, which can improve the performance. When the optical system satisfies the above conditional formula, the absolute value of the focal length of the front group is less than that of the rear group, which can reduce the sensitivity of the rear group and improve the yield rate in the actual production process.

[0043] The first embodiment

[0044] Please refer to Figure 1a andFigure 1b The optical system of this embodiment sequentially includes, from the object side to the image side along the optical axis direction:

[0045] The first lens L1, having a positive refractive power. The object side surface S1 of the first lens is convex near the optical axis, and the image side surface S2 is concave near the optical axis; the object side surface S1 of the first lens is concave at the circumference, and the image side surface S2 is concave at the circumference.

[0046] The second lens L2, having a negative refractive power. The object side surface S3 of the second lens is convex near the optical axis, and the image side surface S4 is concave near the optical axis; the object side surface S3 of the second lens is convex at the circumference, and the image side surface S4 is convex at the circumference.

[0047] The third lens L3, having a negative refractive power. The object side surface S1 of the third lens is convex near the optical axis, and the image side surface S2 is concave near the optical axis; the object side surface S5 of the third lens is concave at the circumference, and the image side surface S6 is concave at the circumference.

[0048] The fourth lens L4, having a positive refractive power. The object side surface S7 of the fourth lens is convex near the optical axis, and the image side surface S8 is concave near the optical axis; the object side surface S7 of the fourth lens is convex at the circumference, and the image side surface S8 is concave at the circumference.

[0049] The fifth lens L5, having a negative refractive power. The object side surface S9 of the fifth lens is concave near the optical axis, and the image side surface S10 is convex near the optical axis; the object side surface S9 of the fifth lens is convex at the circumference, and the image side surface S10 is convex at the circumference.

[0050] The sixth lens L6, having a positive refractive power. The object side surface S11 of the sixth lens is convex near the optical axis, and the image side surface S12 is concave near the optical axis; the object side surface S11 of the sixth lens is convex at the circumference, and the image side surface S12 is concave at the circumference.

[0051] The seventh lens L7, having a negative refractive power. The object side surface S13 of the seventh lens is convex near the optical axis, and the image side surface S14 is concave near the optical axis; the object side surface S13 of the seventh lens is concave at the circumference, and the image side surface S14 is convex at the circumference.

[0052] The materials of the above-mentioned first lens L1 to seventh lens L7 are all plastics.

[0053] In addition, the optical system further includes a stop STO, an infrared filter L8, and an image plane S17. The stop STO is disposed on a side of the first lens L1 away from the second lens L2 and is used to control the amount of incident light. In other embodiments, the stop STO may also be disposed between two adjacent lenses or on other lenses. The infrared filter L8 is disposed on the image side of the seventh lens L7 and includes an object side surface S15 and an image side surface S16. The infrared filter L8 is used to filter out infrared light so that the light incident on the image plane S17 is visible light, and the wavelength of the visible light is 380 nm - 780 nm. The material of the infrared filter L8 is glass, and a film may be coated on the glass. The image plane S17 is the plane where the image of the light of the object to be photographed is formed after passing through the optical system.

[0054] Table 1a shows a table of the characteristics of the optical system of this embodiment, where 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).

[0055] Table 1a

[0056]

[0057]

[0058] Among them, f is the effective focal length of the optical system, FNO is the f-number of the optical system, FOV is the field of view angle of the optical system, and TTL is the distance from the object side surface of the first lens to the imaging plane of the optical system on the optical axis.

[0059] In this embodiment, the object side surface and the image side surface of any one of the first lens L1 to the seventh lens L7 are aspherical surfaces, and the surface profile x of each aspherical lens can be defined by, but not limited to, the following aspherical formula:

[0060]

[0061] Among them, x is the sagitta, the distance from the vertex of the aspherical surface at the position where the height is h along the optical axis direction; c is the paraxial curvature of the aspherical surface, c = 1 / R (that is, the paraxial curvature c is the reciprocal of the Y radius R in Table 1a above); k is the conic coefficient; Ai is the correction coefficient of the i-th order of the aspherical surface. Table 1b gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for each aspherical mirror surface S1 - S16 in the first embodiment.

[0062] Table 1b

[0063]

[0064]

[0065] Figure 1b The longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the first embodiment are shown. Among them, the longitudinal spherical aberration curve represents the deviation of the focusing points of light rays of different wavelengths after passing through each lens of the optical system; the astigmatism curve represents the curvature of the meridional image plane and the sagittal image plane; the distortion curve represents the distortion magnitude values corresponding to different field angles. According to Figure 1b it can be known that the optical system given in the first embodiment can achieve good imaging quality.

[0066] Second Embodiment

[0067] Please refer to Figure 2a and Figure 2b , the optical system of this embodiment sequentially includes, from the object side to the image side along the optical axis direction:

[0068] The first lens L1 has a positive refractive power. The object side surface S1 of the first lens is convex near the optical axis, and the image side surface S2 is concave near the optical axis; the object side surface S1 of the first lens is concave at the circumference, and the image side surface S2 is convex at the circumference.

[0069] The second lens L2 has a negative refractive power. The object side surface S3 of the second lens is convex near the optical axis, and the image side surface S4 is concave near the optical axis; the object side surface S3 of the second lens is convex at the circumference, and the image side surface S4 is convex at the circumference.

[0070] The third lens L3 has a positive refractive power. The object side surface S1 of the third lens is concave near the optical axis, and the image side surface S2 is convex near the optical axis; the object side surface S5 of the third lens is concave at the circumference, and the image side surface S6 is concave at the circumference.

[0071] The fourth lens L4 has a positive refractive power. The object side surface S7 of the fourth lens is convex near the optical axis, and the image side surface S8 is convex near the optical axis; the object side surface S7 of the fourth lens is convex at the circumference, and the image side surface S8 is concave at the circumference.

[0072] The fifth lens L5 has a negative refractive power. The object side surface S9 of the fifth lens is concave near the optical axis, and the image side surface S10 is convex near the optical axis; the object side surface S9 of the fifth lens is convex at the circumference, and the image side surface S10 is concave at the circumference.

[0073] The sixth lens L6 has a positive refractive power. The object side surface S11 of the sixth lens is convex near the optical axis, and the image side surface S12 is concave near the optical axis; the object side surface S11 of the sixth lens is convex at the circumference, and the image side surface S12 is concave at the circumference.

[0074] The seventh lens L7 has a negative refractive power. The object side surface S13 of the seventh lens is convex near the optical axis, and the image side surface S14 is concave near the optical axis; the object side surface S13 of the seventh lens is concave at the circumference, and the image side surface S14 is convex at the circumference.

[0075] The other structures of the second embodiment are the same as those of the first embodiment, and can be referred to.

[0076] Table 2a shows a table of the characteristics of the optical system of this embodiment, where the data is obtained using light with a wavelength of 587 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0077] Table 2a

[0078]

[0079] Among them, the meanings of the parameters in Table 2a are the same as those of the parameters in the first embodiment.

[0080] Table 2b gives the high-order term coefficients of the aspherical mirror surfaces that can be used in the second embodiment. Among them, the aspherical surface types can be defined by the formulas given in the first embodiment.

[0081] Table 2b

[0082] Surface number K A4 A6 A8 A10 S1 -0.4790 0.0031 0.0120 -0.0224 0.0286 S2 -6.5209 -0.0158 0.0018 -0.0009 0.0086 S3 10.0000 -0.0359 0.0198 -0.0117 0.0308 S4 1.8169 -0.0190 0.0201 -0.0311 0.0893 S5 0.0000 -0.0127 -0.0115 -0.0136 0.0533 S6 -18.0000 -0.0071 -0.0618 0.1233 -0.1714 S7 3.8640 -0.0251 -0.0254 0.0203 0.0115 S8 -10.2850 -0.0215 -0.0020 0.0026 -0.0150 S9 2.0000 -0.0068 -0.0112 0.0029 0.0054 S10 -18.0000 -0.0018 -0.0539 0.0562 -0.0354 S11 -2.1235 0.0070 -0.0524 0.0448 -0.0268 S12 -7.8596 -0.0083 0.0059 -0.0059 0.0022 S13 -2.4290 -0.1016 0.0333 -0.0083 0.0015 S14 -1.4674 -0.0856 0.0271 -0.0067 0.0011 Surface number A12 A14 A16 A18 A20 S1 -0.0226 0.0112 -0.0034 0.0006 0.0000 S2 -0.0134 0.0106 -0.0048 0.0012 -0.0001 S3 -0.0428 0.0318 -0.0136 0.0031 -0.0003 S4 -0.1406 0.1266 -0.0670 0.0194 -0.0024 S5 -0.0890 0.0864 -0.0497 0.0156 -0.0020 S6 0.1636 -0.0999 0.0370 -0.0075 0.0006 S7 -0.0364 0.0341 -0.0167 0.0042 -0.0004 S8 0.0220 -0.0165 0.0069 -0.0015 0.0001 S9 -0.0089 0.0055 -0.0017 0.0003 0.0000 S10 0.0137 -0.0032 0.0004 0.0000 0.0000 S11 0.0102 -0.0024 0.0003 0.0000 0.0000 S12 -0.0004 0.0001 0.0000 0.0000 0.0000 S13 -0.0002 0.0000 0.0000 0.0000 0.0000 S14 -0.0001 0.0000 0.0000 0.0000 0.0000

[0083] Figure 2b Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the second embodiment. According to Figure 2b It can be seen that the optical system given in the second embodiment can achieve good imaging quality.

[0084] The third embodiment

[0085] 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 direction:

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

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

[0088] The third lens L3 has a negative refractive power. The object side surface S1 of the third lens is convex near the optical axis, and the image side surface S2 is concave near the optical axis. The object side surface S5 of the third lens is concave at the circumference, and the image side surface S6 is concave at the circumference.

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

[0090] The fifth lens L5 has a positive refractive power. The object side surface S9 of the fifth lens is convex near the optical axis, and the image side surface S10 is concave near the optical axis. The object side surface S9 of the fifth lens is convex at the circumference, and the image side surface S10 is convex at the circumference.

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

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

[0093] The other structures of the third embodiment are the same as those of the first embodiment, and can be referred to.

[0094] Table 3a shows a table of the characteristics of the optical system of this embodiment, where the data is obtained with light of a wavelength of 587 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0095] Table 3a

[0096]

[0097]

[0098] Among them, the meanings of the parameters in Table 3a are the same as those of the parameters in the first embodiment.

[0099] Table 3b gives the high-order term coefficients available for each aspherical mirror surface in the third embodiment. Among them, each aspherical surface type can be defined by the formula given in the first embodiment.

[0100] Table 3b

[0101]

[0102]

[0103] Figure 3b Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the third embodiment. According to Figure 3b It can be seen that the optical system given in the third embodiment can achieve good imaging quality.

[0104] Fourth Embodiment

[0105] Please refer to Figure 4a and Figure 4b , the optical system of this embodiment sequentially includes, from the object side to the image side along the optical axis direction:

[0106] The first lens L1, having a positive refractive power, the object side surface S1 of the first lens is convex near the optical axis, and the image side surface S2 is concave near the optical axis; the object side surface S1 of the first lens is concave at the circumference, and the image side surface S2 is convex at the circumference.

[0107] The second lens L2, having a negative refractive power, the object side surface S3 of the second lens is convex near the optical axis, and the image side surface S4 is concave near the optical axis; the object side surface S3 of the second lens is convex at the circumference, and the image side surface S4 is convex at the circumference.

[0108] The third lens L3, having a negative refractive power, the object side surface S1 of the third lens is convex near the optical axis, and the image side surface S2 is concave near the optical axis; the object side surface S5 of the third lens is concave at the circumference, and the image side surface S6 is concave at the circumference.

[0109] The fourth lens L4, having a positive refractive power, the object side surface S7 of the fourth lens is convex near the optical axis, and the image side surface S8 is concave near the optical axis; the object side surface S7 of the fourth lens is convex at the circumference, and the image side surface S8 is concave at the circumference.

[0110] The fifth lens L5, having a positive refractive power, the object side surface S9 of the fifth lens is convex near the optical axis, and the image side surface S10 is concave near the optical axis; the object side surface S9 of the fifth lens is concave at the circumference, and the image side surface S10 is convex at the circumference.

[0111] The sixth lens L6, having a negative refractive power, the object side surface S11 of the sixth lens is concave near the optical axis, and the image side surface S12 is concave near the optical axis; the object side surface S11 of the sixth lens is convex at the circumference, and the image side surface S12 is concave at the circumference.

[0112] The seventh lens L7, having a negative refractive power, the object side surface S13 of the seventh lens is convex near the optical axis, and the image side surface S14 is concave near the optical axis; the object side surface S13 of the seventh lens is concave at the circumference, and the image side surface S14 is convex at the circumference.

[0113] The other structures of the fourth embodiment are the same as those of the first embodiment, and can be referred to directly.

[0114] Table 4a shows a table of the characteristics of the optical system of this embodiment, in which the data are obtained with light rays having a wavelength of 587 nm. The units of the Y radius, thickness, and focal length are all millimeters (mm).

[0115] Table 4a

[0116]

[0117] Among them, the meanings of the parameters in Table 4a are the same as those of the parameters in the first embodiment.

[0118] Table 4b gives the high-order term coefficients of the aspherical mirrors that can be used in the fourth embodiment. Among them, each aspherical surface type can be defined by the formula given in the first embodiment.

[0119] Table 4b

[0120] Surface number K A4 A6 A8 A10 S1 -0.4893 0.0019 0.0150 -0.0281 0.0346 S2 -8.0854 -0.0170 0.0046 -0.0089 0.0206 S3 5.8805 -0.0323 0.0194 -0.0209 0.0426 S4 3.7165 -0.0151 0.0186 -0.0305 0.0811 S5 0.0000 -0.0325 0.0380 -0.0801 0.0972 S6 -12.5796 -0.0533 0.0488 -0.0351 -0.0167 S7 -5.6570 -0.0631 0.0453 -0.0398 0.0257 S8 -10.2850 -0.0332 0.0137 -0.0236 0.0241 S9 2.0000 -0.0362 0.0495 -0.0793 0.0774 S10 -18.0000 -0.0222 0.0064 -0.0110 0.0070 S11 -12.8810 0.0317 -0.0470 0.0282 -0.0163 S12 1.6104 0.0154 -0.0090 -0.0004 0.0008 S13 -2.3616 -0.0953 0.0320 -0.0080 0.0014 S14 -1.4139 -0.0918 0.0298 -0.0075 0.0013 Surface number A12 A14 A16 A18 A20 S1 -0.0262 0.0124 -0.0036 0.0006 0.0000 S2 -0.0246 0.0169 -0.0069 0.0015 -0.0001 S3 -0.0508 0.0351 -0.0142 0.0031 -0.0003 S4 -0.1243 0.1105 -0.0577 0.0164 -0.0020 S5 -0.0838 0.0514 -0.0223 0.0062 -0.0008 S6 0.0563 -0.0509 0.0234 -0.0055 0.0005 S7 -0.0164 0.0108 -0.0055 0.0016 -0.0002 S8 -0.0164 0.0067 -0.0015 0.0001 0.0000 S9 -0.0494 0.0202 -0.0051 0.0007 0.0000 S10 -0.0022 0.0005 -0.0001 0.0000 0.0000 S11 0.0068 -0.0018 0.0003 0.0000 0.0000 S12 -0.0002 0.0000 0.0000 0.0000 0.0000 S13 -0.0002 0.0000 0.0000 0.0000 0.0000 S14 -0.0001 0.0000 0.0000 0.0000 0.0000

[0121] Figure 4b shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the fourth embodiment. According to Figure 4b it can be known that the optical system given in the fourth embodiment can achieve good imaging quality.

[0122] Fifth Embodiment

[0123] Please refer to Figure 5a and Figure 5b , the optical system of this embodiment sequentially includes, from the object side to the image side along the optical axis direction:

[0124] The first lens L1 has a positive refractive power. The object surface S1 of the first lens is convex near the optical axis, and the image surface S2 is concave near the optical axis; the object surface S1 of the first lens is concave at the circumference, and the image surface S2 is convex at the circumference.

[0125] The second lens L2 has a negative refractive power. The object surface S3 of the second lens is convex near the optical axis, and the image surface S4 is concave near the optical axis; the object surface S3 of the second lens is convex at the circumference, and the image surface S4 is convex at the circumference.

[0126] The third lens L3 has a negative refractive power. The object surface S1 of the third lens is convex near the optical axis, and the image surface S2 is concave near the optical axis; the object surface S5 of the third lens is concave at the circumference, and the image surface S6 is concave at the circumference.

[0127] The fourth lens L4 has a positive refractive power. The object side S7 of the fourth lens is convex near the optical axis, and the image side S8 is convex near the optical axis. The object side S7 of the fourth lens is convex at the circumference, and the image side S8 is concave at the circumference.

[0128] The fifth lens L5 has a negative refractive power. The object side S9 of the fifth lens is concave near the optical axis, and the image side S10 is convex near the optical axis. The object side S9 of the fifth lens is convex at the circumference, and the image side S10 is concave at the circumference.

[0129] The sixth lens L6 has a positive refractive power. The object side S11 of the sixth lens is convex near the optical axis, and the image side S12 is convex near the optical axis. The object side S11 of the sixth lens is convex at the circumference, and the image side S12 is concave at the circumference.

[0130] The seventh lens L7 has a negative refractive power. The object side S13 of the seventh lens is convex near the optical axis, and the image side S14 is concave near the optical axis. The object side S13 of the seventh lens is concave at the circumference, and the image side S14 is convex at the circumference.

[0131] The other structures of the fifth embodiment are the same as those of the first embodiment, and can be referred to.

[0132] Table 5a shows a table of the characteristics of the optical system of this embodiment, where the data is obtained with light of a wavelength of 587 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0133] Table 5a

[0134]

[0135]

[0136] Among them, the meanings of the parameters in Table 5a are the same as those of the parameters in the first embodiment.

[0137] Table 5b gives the high-order term coefficients of the aspherical mirror surfaces that can be used in the fifth embodiment. Among them, the aspherical surface types can be defined by the formulas given in the first embodiment.

[0138] Table 5b

[0139]

[0140]

[0141] Figure 5b Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the fifth embodiment. According to Figure 5b It can be seen that the optical system given in the fifth embodiment can achieve good imaging quality.

[0142] Sixth Embodiment

[0143] 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 direction:

[0144] The first lens L1 has a positive refractive power. The object side surface S1 of the first lens is convex near the optical axis, and the image side surface S2 is concave near the optical axis; the object side surface S1 of the first lens is concave at the circumference, and the image side surface S2 is concave at the circumference.

[0145] The second lens L2 has a negative refractive power. The object side surface S3 of the second lens is convex near the optical axis, and the image side surface S4 is concave near the optical axis; the object side surface S3 of the second lens is convex at the circumference, and the image side surface S4 is convex at the circumference.

[0146] The third lens L3 has a positive refractive power. The object side surface S1 of the third lens is convex near the optical axis, and the image side surface S2 is concave near the optical axis; the object side surface S5 of the third lens is concave at the circumference, and the image side surface S6 is concave at the circumference.

[0147] The fourth lens L4 has a positive refractive power. The object side surface S7 of the fourth lens is concave near the optical axis, and the image side surface S8 is convex near the optical axis; the object side surface S7 of the fourth lens is convex at the circumference, and the image side surface S8 is concave at the circumference.

[0148] The fifth lens L5 has a negative refractive power. The object side surface S9 of the fifth lens is concave near the optical axis, and the image side surface S10 is convex near the optical axis; the object side surface S9 of the fifth lens is convex at the circumference, and the image side surface S10 is convex at the circumference.

[0149] The sixth lens L6 has a positive refractive power. The object side surface S11 of the sixth lens is convex near the optical axis, and the image side surface S12 is concave near the optical axis; the object side surface S11 of the sixth lens is convex at the circumference, and the image side surface S12 is concave at the circumference.

[0150] The seventh lens L7 has a negative refractive power. The object side surface S13 of the seventh lens is convex near the optical axis, and the image side surface S14 is concave near the optical axis; the object side surface S13 of the seventh lens is concave at the circumference, and the image side surface S14 is convex at the circumference.

[0151] The other structures of the sixth embodiment are the same as those of the first embodiment, and can be referred to accordingly.

[0152] Table 6a shows a table of the characteristics of the optical system of this embodiment, where the data is obtained with light rays of a wavelength of 587 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0153] Table 6a

[0154]

[0155] Among them, the meanings of the parameters in Table 6a are the same as those of the parameters in the first embodiment.

[0156] Table 6b gives the higher-order term coefficients of the aspherical mirrors that can be used in the sixth embodiment. Among them, the aspherical surface types can be defined by the formulas given in the first embodiment.

[0157] Table 6b

[0158] Surface number K A4 A6 A8 A10 S1 -0.4930 0.0033 0.0084 -0.0130 0.0139 S2 -8.1952 -0.0241 0.0048 0.0073 -0.0063 S3 10.0000 -0.0365 0.0224 -0.0033 0.0062 S4 2.9573 -0.0164 0.0274 -0.0465 0.1119 S5 0.0000 -0.0354 0.0151 -0.0474 0.0842 S6 -2.8665 -0.0267 -0.0143 0.0453 -0.0889 S7 3.8640 -0.0210 -0.0067 0.0005 0.0079 S8 -7.0454 -0.0245 0.0101 -0.0209 0.0157 S9 -18.0000 -0.0111 0.0156 -0.0304 0.0300 S10 2.0000 -0.0115 -0.0138 0.0161 -0.0106 S11 -2.8207 -0.0054 -0.0265 0.0208 -0.0118 S12 -7.3236 -0.0066 0.0024 -0.0032 0.0011 S13 -2.4607 -0.0966 0.0291 -0.0068 0.0012 S14 -1.4448 -0.0842 0.0255 -0.0060 0.0009 Surface number A12 A14 A16 A18 A20 S1 -0.0090 0.0035 -0.0008 0.0001 0.0000 S2 0.0007 0.0019 -0.0014 0.0004 -0.0001 S3 -0.0142 0.0128 -0.0059 0.0014 -0.0001 S4 -0.1701 0.1520 -0.0798 0.0228 -0.0028 S5 -0.1054 0.0877 -0.0461 0.0138 -0.0018 S6 0.1021 -0.0692 0.0275 -0.0058 0.0005 S7 -0.0179 0.0190 -0.0105 0.0030 -0.0003 S8 -0.0052 -0.0007 0.0013 -0.0004 0.0001 S9 -0.0200 0.0083 -0.0021 0.0003 0.0000 S10 0.0037 -0.0007 0.0001 0.0000 0.0000 S11 0.0041 -0.0009 0.0001 0.0000 0.0000 S12 -0.0002 0.0000 0.0000 0.0000 0.0000 S13 -0.0001 0.0000 0.0000 0.0000 0.0000 S14 -0.0001 0.0000 0.0000 0.0000 0.0000

[0159] Figure 6b shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the sixth embodiment. According to Figure 6b it can be seen that the optical system given in the sixth embodiment can achieve good imaging quality.

[0160] Seventh Embodiment

[0161] Please refer to Figure 7a and Figure 7b , the optical system of this embodiment sequentially includes, from the object side to the image side along the optical axis direction:

[0162] The first lens L1 has a positive refractive power. The object side surface S1 of the first lens is convex near the optical axis, and the image side surface S2 is concave near the optical axis; the object side surface S1 of the first lens is convex, and the image side surface S2 is concave.

[0163] The second lens L2 has a negative refractive power. The object side surface S3 of the second lens is convex near the optical axis, and the image side surface S4 is concave near the optical axis; the object side surface S3 of the second lens is convex at the circumference, and the image side surface S4 is convex at the circumference.

[0164] The third lens L3 has a negative refractive power. The object side surface S1 of the third lens is concave near the optical axis, and the image side surface S2 is concave near the optical axis; the object side surface S5 of the third lens is concave at the circumference, and the image side surface S6 is concave at the circumference.

[0165] The fourth lens L4 has a positive refractive power. The object side surface S7 of the fourth lens is convex near the optical axis, and the image side surface S8 is concave near the optical axis; the object side surface S7 of the fourth lens is convex at the circumference, and the image side surface S8 is convex at the circumference.

[0166] The fifth lens L5 has a negative refractive power. The object side S9 of the fifth lens is concave near the optical axis, and the image side S10 is concave near the optical axis. The object side S9 of the fifth lens is concave at the circumference, and the image side S10 is convex at the circumference.

[0167] The sixth lens L6 has a positive refractive power. The object side S11 of the sixth lens is convex near the optical axis, and the image side S12 is concave near the optical axis. The object side S11 of the sixth lens is convex at the circumference, and the image side S12 is concave at the circumference.

[0168] The seventh lens L7 has a negative refractive power. The object side S13 of the seventh lens is convex near the optical axis, and the image side S14 is concave near the optical axis. The object side S13 of the seventh lens is concave at the circumference, and the image side S14 is convex at the circumference.

[0169] The other structures of the seventh embodiment are the same as those of the first embodiment, and can be referred to.

[0170] Table 7a shows a table of the characteristics of the optical system of this embodiment, where the data is obtained with light of a wavelength of 587 nm. The units of the Y radius, thickness, and focal length are all millimeters (mm).

[0171] Table 7a

[0172]

[0173]

[0174] Among them, the meanings of the parameters in Table 7a are the same as those of the parameters in the first embodiment.

[0175] Table 7b gives the higher-order term coefficients of the aspherical mirrors that can be used in the seventh embodiment. Among them, the aspherical surface types can be defined by the formulas given in the first embodiment.

[0176] Table 7b

[0177]

[0178]

[0179] Figure 7b Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the seventh embodiment. According to Figure 7b It can be seen that the optical system given in the seventh embodiment can achieve good imaging quality.

[0180] Table 8 shows the values of TTL / Imgh, f / R14, FNO, TTL / f, f1 / f2, sag1 / sag2, (R2+R1) / (R2-R1), and f1234 / f567 for the optical systems of the first to seventh embodiments.

[0181] Table 8

[0182] TTL / Imgh f / R14 FNO TTL / f First embodiment 1.27 2.63 1.75 1.18 Second embodiment 1.27 2.57 1.78 1.19 Third embodiment 1.27 2.61 1.75 1.19 Fourth embodiment 1.27 2.67 1.75 1.19 Fifth embodiment 1.27 2.76 1.75 1.19 Sixth embodiment 1.27 2.56 1.75 1.19 Seventh embodiment 1.28 2.67 1.69 1.20 f1 / f2 sag1 / sag2 (R2+R1) / (R2-R1) f1234 / f567 First embodiment -0.26 7.18 2.00 -0.26 Second embodiment -0.31 7.61 1.87 -0.31 Third embodiment -0.27 7.40 1.94 -0.27 Fourth embodiment -0.25 7.31 1.98 -0.25 Fifth embodiment -0.29 7.90 1.87 -0.29 Sixth embodiment -0.29 8.11 1.87 -0.29 Seventh embodiment -0.25 7.15 1.97 -0.25

[0183] As can be seen from Table 8, each embodiment satisfies the following conditional expressions: TTL / Imgh < 1.32, 2 < f / R14 < 3.5, FNO ≤ 2, TTL / f < 1.35, -0.31 ≤ f1 / f2 < -0.15, sag1 / sag2 < 15, (R2+R1) / (R2-R1) < 5, and f1234 / f567 > -0.5.

[0184] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.

[0185] The above embodiments only represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed. However, it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. An optical system, characterized in that, There are a total of seven lenses with refractive power, which successively include, from the object side to the image side along the optical axis direction: The first lens, which has positive refractive power. The object side surface of the first lens is convex near the optical axis, and the image side surface of the first lens is concave near the optical axis. The second lens, which has negative refractive power. The object side surface of the second lens is convex near the optical axis, and the image side surface of the second lens is concave near the optical axis. The third lens, which has refractive power. The fourth lens, which has positive refractive power. The fifth lens, which has refractive power. The sixth lens, which has refractive power. The image side surface of the sixth lens is concave near the optical axis. The seventh lens, which has negative refractive power. The object side surface of the seventh lens is convex near the optical axis, and the image side surface of the seventh lens is concave near the optical axis. The object side surface and the image side surface of any one of the first lens to the seventh lens are aspherical surfaces. The optical system satisfies the conditional expressions: TTL / Imgh < 1.32, -0.31 ≤ f1 / f2 < -0.15, 1.18 ≤ TTL / f < 1.35; where 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, Imgh is half of the diagonal length of the effective pixel area of the imaging surface, f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, and f is the effective focal length of the optical system.

2. The optical system according to claim 1, wherein The optical system satisfies the conditional expression: 2 < f / R14 < 3.5; where f is the effective focal length of the optical system, and R14 is the curvature radius of the image side surface of the seventh lens on the optical axis.

3. The optical system according to claim 1, wherein The optical system satisfies the conditional expression: 1.69 ≤ FNO ≤ 2; where FNO is the f-number of the optical system.

4. The optical system according to claim 1, characterized in that, The optical system satisfies the conditional expression: 7.18 ≤ sag1 / sag2 < 15; where sag1 is the sagitta at the effective aperture of the object side surface of the first lens, and sag2 is the sagitta at the effective aperture of the image side surface of the first lens.

5. The optical system according to claim 1, characterized in that The optical system satisfies the conditional expression: 1.87 ≤ (R2 + R1) / (R2 - R1) < 5; where R1 is the curvature radius of the object side surface of the first lens, and R2 is the curvature radius of the image side surface of the first lens.

6. The optical system according to claim 1, characterized in that, The optical system satisfies the conditional expression: f1234 / f567 > -0.5; where f1234 is the combined focal length of the first lens to the fourth lens, and f567 is the combined focal length of the fifth lens to the seventh lens.

7. A lens module, characterized in that, It includes a lens barrel, an electronic photosensitive element, and the optical system according to any one of claims 1 to 6. The first lens to the seventh 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 the light of the object incident on the electronic photosensitive element through the first lens to the seventh lens into an electrical signal of an image.

8. An electronic device, characterized in that, It includes a housing and the lens module according to claim 7. The lens module is arranged in the housing.

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