Optical System, Lens Module and Electronic Device

Abstract

The present application provides an optical system, a lens module, and an electronic device. The optical system sequentially includes, from the object side to the image side along the optical axis direction: a first lens with positive refractive power, the object side surface of which is convex near the optical axis; a second lens with refractive power; a third lens with negative refractive power, the image side surface of which is concave near the optical axis; a fourth lens with negative refractive power; a fifth lens with positive refractive power, the object side surface and the image side surface of which are both convex near the optical axis, and there is at least one inflection point on the object side surface; a sixth lens with negative refractive power, the object side surface of which is convex near the optical axis, the image side surface of which is concave near the optical axis, and there is at least one inflection point on the image side surface. The optical system satisfies: CT1 / TTL>0.2; CT1 is the thickness of the first lens on the optical axis, and TTL is the distance from the object side surface of the first lens to the imaging surface on the optical axis. By reasonably configuring the surface shapes and optical powers of the first to sixth lenses, the optical system can have the characteristics of miniaturization while ensuring high resolution and high imaging quality.

Description

Technical Field

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

[0002] With the continuous development of camera-related technologies, taking pictures has become a standard function of smart electronic products. However, with the refinement of semiconductor manufacturing processes, the pixel size of photosensitive elements has gradually decreased, and the size of optical systems has also been correspondingly reduced. At the same time, optical systems are gradually moving towards the high-pixel field, and the requirements for imaging quality are increasing day by day, making the miniaturization characteristics of optical systems need to meet higher requirements. Therefore, how to be miniaturized while ensuring high resolution and high imaging quality is a technical problem that urgently needs to be solved. Summary of the Invention

[0003] The purpose of the present invention is to provide an optical system, a lens module, and an electronic device, which can be miniaturized while ensuring high resolution and high imaging quality.

[0004] To achieve the purpose of the present invention, the present invention provides the following technical solutions:

[0005] In a first aspect, the present invention provides an optical system, which sequentially includes, from the object side to the image side along the optical axis direction: a first lens having a positive refractive power, and the object side surface of the first lens near the optical axis is a convex surface; a second lens having a refractive power; a third lens having a negative refractive power, and the image side surface of the third lens near the optical axis is a concave surface; a fourth lens having a negative refractive power; a fifth lens having a positive refractive power, and both the object side surface and the image side surface of the fifth lens near the optical axis are convex surfaces, and at least one inflection point is provided on the object side surface of the fifth lens; a sixth lens having a negative refractive power, the object side surface of the sixth lens near the optical axis is a convex surface, the image side surface near the optical axis is a concave surface, and at least one inflection point is provided on the image side surface of the sixth lens; the optical system satisfies the conditional formula: CT1 / TTL>0.2; where CT1 is the thickness of the first lens on the optical axis, and TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis. By reasonably setting the value of CT1 / TTL, the optical system has the characteristics of a small aperture and a large depth, so that the optical system is miniaturized. At the same time, it is beneficial for the optical system to be mounted on high-end mobile phones such as full-screen mobile phones.

[0006] By reasonably configuring the surface types and refractive powers of the lenses from the first lens to the sixth lens, the optical system described in the present application can be miniaturized while ensuring high resolution and high imaging quality.

[0007] In one embodiment, the optical system satisfies the conditional formula: Y1 < 0.9 mm; where Y1 is the optical effective radius of the object side surface of the first lens. By reasonably setting the value of Y1, it helps to control the outer diameter of the object side surface of the first lens from increasing excessively, thereby ensuring the appearance of the small head of the optical system.

[0008] In one embodiment, the optical system satisfies the conditional formula: CT1 ≥ 1.0 mm; where CT1 is the thickness of the first lens on the optical axis. By reasonably setting the value of CT1, the depth of the optical system can be increased, which is beneficial for the optical system to be assembled on high-end models such as full-screen phones.

[0009] In one embodiment, the optical system satisfies the conditional formula: ET1 > 0.8 mm; where ET1 is the edge thickness of the first lens. By reasonably setting the value of ET1, it is beneficial to ensure that the first lens has sufficient edge thickness, causing the bearing part of the first lens to move towards the imaging surface, and thus enabling the miniaturization of the head of the optical system.

[0010] In one embodiment, the optical system satisfies the conditional formula: TTL / ImgH ≤ 1.7; 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 imaging area on the imaging surface of the optical system. By reasonably setting the value of TTL / ImgH, it can ensure that while the thickness of the first lens increases, the length of the entire optical system does not increase excessively.

[0011] In one embodiment, the optical system satisfies the conditional formula: -8.1 < R51 / R52 < -2.2; where R51 is the curvature radius of the object side surface of the fifth lens on the optical axis, and R52 is the curvature radius of the image side surface of the fifth lens on the optical axis. By reasonably setting the value of R51 / R52, it is more beneficial for the fifth lens to cooperate with the first lens for imaging and further control the length of the entire optical system from increasing excessively.

[0012] In one embodiment, the optical system satisfies the conditional formula: 0.58 < f1 / f < 0.93; where f1 is the effective focal length of the first lens, and f is the effective focal length of the optical system. By reasonably setting the value of f1 / f, it is beneficial to control the length of the optical system and correct the field curvature to a certain extent.

[0013] In one embodiment, the optical system satisfies the conditional formula: 0.48 < f3 / f < 0.6; where f3 is the effective focal length of the third lens, and f is the effective focal length of the optical system. By reasonably setting the value of f3 / f, the spherical aberration can be effectively corrected to ensure that the optical system has high imaging quality.

[0014] In one embodiment, the optical system satisfies the conditional expressions: 1.63 < n3 < 1.67 and 1.56 < n4 < 1.64; where n3 is the refractive index of the third lens, n4 is the refractive index of the fourth lens, and the reference wavelength of the refractive index is 587.56 nm. By reasonably setting the values of n3 and n4, chromatic aberration can be effectively corrected and the resolution of the optical system can be improved.

[0015] In one embodiment, the optical system satisfies the conditional expression G5 / CT5 > 0.4; where G5 is the thickness at the thinnest part of the fifth lens along the optical axis direction, and CT5 is the thickness of the fifth lens on the optical axis. By reasonably setting the value of G5 / CT5, the distortion of the optical system can be effectively corrected, while the sensitivity of the fifth lens can be reduced and the yield can be improved.

[0016] In a second aspect, the present invention also provides a lens module, which includes a lens barrel and the optical system according to any one of the embodiments in the first aspect. The first lens to the sixth lens of the optical system are installed in the lens barrel, and the electronic photosensitive chip is arranged on the image side of the optical system for converting the light of the object incident on the electronic photosensitive chip through the first lens to the sixth lens into an electrical signal of an image. By installing the first lens to the sixth lens of the optical system in the lens module, the lens module of the present application has a high imaging quality, can be adapted to an electronic photosensitive chip with a higher pixel, and at the same time, the overall length of the lens module is small, realizing miniaturization.

[0017] In a third aspect, the present invention also provides an electronic device, which includes a housing and the lens module according to the second aspect, and the lens module is arranged in the housing. By arranging the lens module according to the second aspect in the electronic device, the electronic device has a high imaging quality, and at the same time, the overall length of the electronic device is small, realizing miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1a It is a schematic structural diagram of the optical system of the first embodiment;

[0020] Figure 1b It is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the first embodiment;

[0021] Figure 2a is a schematic structural diagram of the optical system of the second embodiment;

[0022] Figure 2b are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the second embodiment;

[0023] Figure 3a is a schematic structural diagram of the optical system of the third embodiment;

[0024] Figure 3b are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the third embodiment;

[0025] Figure 4a is a schematic structural diagram of the optical system of the fourth embodiment;

[0026] Figure 4b are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the fourth embodiment;

[0027] Figure 5a is a schematic structural diagram of the optical system of the fifth embodiment;

[0028] Figure 5b are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the fifth embodiment;

[0029] Figure 6a is a schematic structural diagram of the optical system of the sixth embodiment;

[0030] Figure 6b are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the sixth embodiment;

[0031] Figure 7a is a schematic structural diagram of the optical system of the seventh embodiment;

[0032] Figure 7b are the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the seventh embodiment. Detailed implementation manners

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with 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 making creative efforts shall fall within the protection scope of the present invention.

[0034] An embodiment of the present invention provides a lens module, which includes a lens barrel, an electronic photosensitive chip, and an optical system provided by the embodiment of the present invention. The first lens to the fifth lens of the optical system are installed in the lens barrel. The electronic photosensitive chip is arranged on the image side of the optical system and is used to convert the light of an object incident on the electronic photosensitive chip through the first lens to the fifth lens into an electrical signal of an image. The electronic photosensitive chip can be a Complementary Metal Oxide Semiconductor (CMOS). 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 lens to the sixth lens of the optical system in the lens module, the lens module provided by the embodiment of the present application can be miniaturized while ensuring high resolution and high imaging quality.

[0035] An embodiment of the present invention provides an electronic device, which includes a housing and the lens module provided by the embodiment of the present invention. The lens module and the electronic photosensitive chip 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 dash cam, a wearable device, etc. By arranging the lens module of the second aspect in the electronic device, the electronic device provided by the embodiment of the present application can be miniaturized while ensuring high resolution and high imaging quality.

[0036] An embodiment of the present invention provides an optical system, which sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens from the object side to the image side along the optical axis direction. Among the first lens to the sixth lens, there can be an air gap between any two adjacent lenses.

[0037] Specifically, the specific shapes and structures of the six lenses are as follows: the first lens has a positive refractive power, and the object side surface of the first lens is convex near the optical axis; the second lens has a refractive power; the third lens has a negative refractive power, and the image side surface of the third lens is concave near the optical axis; the fourth lens has a negative refractive power; the fifth lens has a positive refractive power, and both the object side surface and the image side surface of the fifth lens are convex near the optical axis, and at least one inflection point is provided on the object side surface of the fifth lens; the sixth lens has a negative refractive power, the object side surface of the sixth lens is convex near the optical axis, the image side surface is concave near the optical axis, and at least one inflection point is provided on the image side surface of the sixth lens; the optical system satisfies the conditional formula: CT1 / TTL>0.2; where CT1 is the thickness of the first lens on the optical axis, and TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis. The optical system further includes a diaphragm, and the diaphragm can be arranged at any position between the first lens and the sixth lens, such as on the first lens.

[0038] By reasonably setting the value of CT1 / TTL, the optical system has the characteristics of a small head aperture and a large depth. Among them, by thickening the thickness of the first lens and using the image-side edge of the first lens to abut against the lens barrel, the space for abutting against the lens barrel can be saved at the object side end of the first lens, thereby enabling the miniaturization of the optical system. At the same time, the optical system shows a change in which the opening size decreases while the depth increases, which is more conducive to the optical system being mounted on high-end mobile phones such as full-screen mobile phones.

[0039] By reasonably configuring the surface shapes and refractive powers of the lenses from the first lens to the sixth lens, the optical system can be miniaturized while ensuring high resolution and high imaging quality.

[0040] In one embodiment, the optical system satisfies the conditional formula: Y1 < 0.9 mm; where Y1 is the optical effective radius of the object side surface of the first lens. By reasonably setting the value of Y1, it helps to control the outer diameter of the object side surface of the first lens from increasing excessively, thereby ensuring the small-head shape of the optical system.

[0041] In one embodiment, the optical system satisfies the conditional formula: CT1 ≥ 1.0 mm; where CT1 is the thickness of the first lens on the optical axis. By reasonably setting the value of CT1, the depth of the optical system can be increased, which is conducive to the optical system being assembled on high-end models such as full-screen mobile phones.

[0042] In one embodiment, the optical system satisfies the conditional formula: ET1 > 0.8 mm; where ET1 is the edge thickness of the first lens. By reasonably setting the value of ET1, it is beneficial to ensure that the first lens has sufficient edge thickness, move the abutting part of the first lens towards the imaging surface direction, and thus enable the miniaturization of the head of the optical system.

[0043] In one embodiment, the optical system satisfies the conditional formula: TTL / ImgH ≤ 1.7; 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 imaging area on the imaging surface of the optical system. By reasonably setting the value of TTL / ImgH, it can ensure that while the thickness of the first lens increases, the length of the entire optical system will not increase excessively.

[0044] In one embodiment, the optical system satisfies the conditional formula: -8.1 < R51 / R52 < -2.2; where R51 is the curvature radius of the object side surface of the fifth lens on the optical axis, and R52 is the curvature radius of the image side surface of the fifth lens on the optical axis. Among them, the fifth lens provides positive refractive power and is double-convex at the optical axis. By reasonably setting the value of R51 / R52, it is more conducive to the fifth lens cooperating with the first lens for imaging and further controlling the length of the entire optical system from increasing excessively.

[0045] In one embodiment, the optical system satisfies the conditional formula: 0.58 < f1 / f < 0.93; where f1 is the effective focal length of the first lens, and f is the effective focal length of the optical system. The first lens provides most of the positive refractive power and converges light rays for imaging in the optical system. By reasonably setting the value of f1 / f, it is beneficial to control the length of the optical system and correct the field curvature to a certain extent.

[0046] In one embodiment, the optical system satisfies the conditional formula: 0.48 < f3 / f < 0.6; where f3 is the effective focal length of the third lens, and f is the effective focal length of the optical system. The third lens provides negative refractive power. By reasonably setting the value of f3 / f, spherical aberration can be effectively corrected, ensuring that the optical system has high imaging quality.

[0047] In one embodiment, the optical system satisfies the conditional formulas: 1.63 < n3 < 1.67 and 1.56 < n4 < 1.64; where n3 is the refractive index of the third lens, n4 is the refractive index of the fourth lens, and the reference wavelength of the refractive index is 587.56 nm. By reasonably setting the values of n3 and n4, that is, by reasonably using lens materials with medium and high refractive indices, chromatic aberration can be effectively corrected and the resolution of the optical system can be improved.

[0048] In one embodiment, the optical system satisfies the conditional formula G5 / CT5 > 0.4; where G5 is the thickness at the thinnest part of the fifth lens along the optical axis direction, and CT5 is the thickness of the fifth lens on the optical axis. The object side surface of the fifth lens has a changing trend from convex to concave from the center to the edge. This structure can correct the distortion of the optical system, and this changing trend will result in a thinnest position of the fifth lens. If G5 / CT5 < 0.4, the thickness ratio of the fifth lens is too large, which will lead to poor molding processability and high lens sensitivity, and further reduce the production yield, which is not conducive to actual mass production. By reasonably configuring the value of G5 / CT5, the sensitivity of the fifth lens can be reduced and the yield can be improved.

[0049] First Embodiment

[0050] Please refer to Figure 1a and Figure 1b , the optical system of this embodiment includes, in order from the object side to the image side along the optical axis direction:

[0051] The first lens L1 has positive refractive power. The near-optical-axis part and the near-circumference part of the object side surface S1 of the first lens L1 are convex surfaces, and the near-optical-axis part and the near-circumference part of the image side surface S2 of the first lens L1 are convex surfaces;

[0052] The second lens L2 has positive refractive power. The near-optical-axis part and the near-circumference part of the object side surface S3 of the second lens L2 are concave surfaces, and the near-optical-axis part and the near-circumference part of the image side surface S4 of the second lens L2 are convex surfaces;

[0053] The third lens L3 has a negative refractive power. The near optical axis and near the circumference of the object side surface S5 of the third lens L3 are concave surfaces, and the near optical axis and near the circumference of the image side surface S6 of the third lens L3 are concave surfaces.

[0054] The fourth lens L4 has a negative refractive power. The near optical axis and near the circumference of the object side surface S7 of the fourth lens L4 are concave surfaces, the near optical axis of the image side surface S8 of the fourth lens L4 is a concave surface, and the near circumference of the image side surface S8 is a convex surface.

[0055] The fifth lens L5 has a positive refractive power. The near optical axis of the object side surface S9 of the fifth lens L5 is a convex surface, the near circumference of the object side surface S9 is a concave surface, and the near optical axis and near the circumference of the image side surface S10 of the fifth lens L5 are convex surfaces.

[0056] The sixth lens L6 has a negative refractive power. The near optical axis of the object side surface S11 of the sixth lens L6 is a convex surface, the near circumference of the object side surface S11 is a concave surface, the near optical axis of the image side surface S12 of the sixth lens L6 is a concave surface, and the near circumference of the image side surface S12 is a convex surface.

[0057] The materials of the above-mentioned first lens L1 to sixth lens L6 are all plastic.

[0058] In addition, the optical system further includes a diaphragm STO, an infrared filter L7, and an imaging surface S15. The diaphragm STO is arranged on the side of the first lens L1 away from the second lens L2 and is used to control the amount of incident light. In other embodiments, the diaphragm STO can also be arranged between two adjacent lenses or on other lenses. The infrared filter L7 is arranged on the image side of the sixth lens L6, and it includes an object side surface S13 and an image side surface S14. The infrared filter L7 is used to filter out infrared light so that the light incident on the imaging surface S15 is visible light, and the wavelength of the visible light is 380nm - 780nm. The material of the infrared filter L7 is glass and can be coated with a film on the glass. The imaging surface S15 is the effective pixel area of the electronic photosensitive chip.

[0059] Table 1a shows a table of the characteristics of the optical system of this embodiment, and the data therein are obtained using light with a wavelength of 587.6nm. The units of the Y radius, thickness, and focal length are all millimeters (mm).

[0060] Table 1a

[0061]

[0062]

[0063] 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 surface of the optical system on the optical axis.

[0064] In this embodiment, the object side and the image side of any one of the first lens L1 to the sixth lens L6 are aspherical surfaces. The surface profile x of each aspherical lens can be defined by, but not limited to, the following aspherical formula:

[0065]

[0066] Where x is the sagitta, the distance from the vertex of the aspherical surface along the optical axis at a position with a height of h; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the Y radius R in 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 of the aspherical mirrors S1 - S12 in the first embodiment.

[0067] Table 1b

[0068]

[0069]

[0070] Figure 1b Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the first embodiment. Among them, the longitudinal spherical aberration curve represents the deviation of the convergence points of light rays of different wavelengths after passing through each lens of the optical system; the astigmatism curve represents the meridional image plane curvature and sagittal image plane curvature; the distortion curve represents the distortion magnitude values corresponding to different field angles. According to Figure 1b It can be seen that the optical system given in the first embodiment can achieve good imaging quality.

[0071] Second Embodiment

[0072] 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:

[0073] The first lens L1, having a positive refractive power. The near-optical-axis and near-periphery of the object side S1 of the first lens L1 are convex surfaces, and the near-optical-axis and near-periphery of the image side S2 of the first lens L1 are convex surfaces;

[0074] The second lens L2, having a positive refractive power. The near-optical-axis and near-periphery of the object side S3 of the second lens L2 are concave surfaces, and the near-optical-axis and near-periphery of the image side S4 of the second lens L2 are convex surfaces;

[0075] The third lens L3 has a negative refractive power. The near optical axis and near circumference of the object side surface S5 of the third lens L3 are concave surfaces, and the near optical axis and near circumference of the image side surface S6 of the third lens L3 are concave surfaces;

[0076] The fourth lens L4 has a negative refractive power. The near optical axis and near circumference of the object side surface S7 of the fourth lens L4 are concave surfaces, the near optical axis of the image side surface S8 of the fourth lens L4 is a concave surface, and the near circumference of the image side surface S8 is a convex surface;

[0077] The fifth lens L5 has a positive refractive power. The near optical axis of the object side surface S9 of the fifth lens L5 is a convex surface, the near circumference of the object side surface S9 is a concave surface, and the near optical axis and near circumference of the image side surface S10 of the fifth lens L5 are convex surfaces.

[0078] The sixth lens L6 has a negative refractive power. The near optical axis of the object side surface S11 of the sixth lens L6 is a convex surface, the near circumference of the object side surface S11 is a concave surface, the near optical axis of the image side surface S12 of the sixth lens L6 is a concave surface, and the near circumference of the image side surface S12 is a convex surface.

[0079] The other structures of the second embodiment are the same as those of the first embodiment and can be referred to.

[0080] Table 2a shows a table of the characteristics of the optical system of this embodiment, where the data are obtained with light rays of a wavelength of 587.6 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0081] Table 2a

[0082]

[0083] Among them, the meanings of the parameters in Table 2a are the same as those of the parameters in the first embodiment.

[0084] 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.

[0085] Table 2b

[0086]

[0087]

[0088] 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.

[0089] Third Embodiment

[0090] Please refer toFigure 3a and Figure 3b For the optical system of this embodiment, along the optical axis direction from the object side to the image side, it successively includes:

[0091] The first lens L1 has a positive refractive power. At the near-optical axis and near-circumference of the object side surface S1 of the first lens L1, it is convex, and at the near-optical axis and near-circumference of the image side surface S2 of the first lens L1, it is concave;

[0092] The second lens L2 has a positive refractive power. At the near-optical axis of the object side surface S3 of the second lens L2, it is convex, at the near-circumference of the object side surface S3, it is concave, and at the near-optical axis and near-circumference of the image side surface S4 of the second lens L2, it is convex;

[0093] The third lens L3 has a negative refractive power. At the near-optical axis and near-circumference of the object side surface S5 of the third lens L3, it is concave, and at the near-optical axis and near-circumference of the image side surface S6 of the third lens L3, it is concave;

[0094] The fourth lens L4 has a negative refractive power. At the near-optical axis and near-circumference of the object side surface S7 of the fourth lens L4, it is concave, at the near-optical axis of the image side surface S8 of the fourth lens L4, it is concave, and at the near-circumference of the image side surface S8, it is convex;

[0095] The fifth lens L5 has a positive refractive power. At the near-optical axis of the object side surface S9 of the fifth lens L5, it is convex, at the near-circumference of the object side surface S9, it is concave, and at the near-optical axis and near-circumference of the image side surface S10 of the fifth lens L5, it is convex.

[0096] The sixth lens L6 has a negative refractive power. At the near-optical axis and near-circumference of the object side surface S11 of the sixth lens L6, it is convex, at the near-optical axis of the image side surface S12 of the sixth lens L6, it is concave, and at the near-circumference of the image side surface S12, it is convex.

[0097] The other structures of the third embodiment are the same as those of the first embodiment, and can be referred to.

[0098] 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 587.6 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0099] Table 3a

[0100]

[0101] Among them, the meanings of the parameters in Table 3a are the same as those of the parameters in the first embodiment.

[0102] 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.

[0103] Table 3b

[0104]

[0105]

[0106] 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 by the third embodiment can achieve good imaging quality.

[0107] Fourth Embodiment

[0108] Please refer to Figure 4a and Figure 4b , the optical system of this embodiment successively includes, from the object side to the image side along the optical axis direction:

[0109] The first lens L1, having a positive refractive power, the near-optical axis and near-circumference of the object side surface S1 of the first lens L1 are convex surfaces, and the near-optical axis and near-circumference of the image side surface S2 of the first lens L1 are convex surfaces;

[0110] The second lens L2, having a negative refractive power, the near-optical axis and near-circumference of the object side surface S3 of the second lens L2 are concave surfaces, the near-optical axis of the image side surface S4 of the second lens L2 is a convex surface, and the near-circumference of the image side surface S4 is a concave surface;

[0111] The third lens L3, having a negative refractive power, the near-optical axis and near-circumference of the object side surface S5 of the third lens L3 are convex surfaces, and the near-optical axis and near-circumference of the image side surface S6 of the third lens L3 are concave surfaces;

[0112] The fourth lens L4, having a negative refractive power, the near-optical axis of the object side surface S7 of the fourth lens L4 is a convex surface, the near-circumference of the object side surface S7 is a concave surface, the near-optical axis of the image side surface S8 of the fourth lens L4 is a concave surface, and the near-circumference of the image side surface S8 is a convex surface;

[0113] The fifth lens L5, having a positive refractive power, the near-optical axis of the object side surface S9 of the fifth lens L5 is a convex surface, the near-circumference of the object side surface S9 is a concave surface, and the near-optical axis and near-circumference of the image side surface S10 of the fifth lens L5 are convex surfaces.

[0114] The sixth lens L6, having a negative refractive power, the near-optical axis of the object side surface S11 of the sixth lens L6 is a convex surface, the near-circumference of the object side surface S11 is a concave surface, the near-optical axis of the image side surface S12 of the sixth lens L6 is a concave surface, and the near-circumference of the image side surface S12 is a convex surface.

[0115] The other structures of the fourth embodiment are the same as those of the first embodiment, and can be referred to.

[0116] Table 4a shows a table of the characteristics of the optical system of this embodiment, where the data is obtained using light with a wavelength of 587.6 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0117] Table 4a

[0118]

[0119] Among them, the meanings of the parameters in Table 4a are the same as those of the parameters in the first embodiment.

[0120] Table 4b gives the higher-order term coefficients of the aspherical mirrors that can be used in the fourth embodiment. Among them, the aspherical surface types can be defined by the formulas given in the first embodiment.

[0121] Table 4b

[0122]

[0123]

[0124] 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 seen that the optical system given in the fourth embodiment can achieve good imaging quality.

[0125] Fifth Embodiment

[0126] 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:

[0127] The first lens L1 has a positive refractive power. The near-optical-axis and near-periphery of the object side surface S1 of the first lens L1 are convex surfaces, and the near-optical-axis and near-periphery of the image side surface S2 of the first lens L1 are convex surfaces;

[0128] The second lens L2 has a negative refractive power. The near-optical-axis of the object side surface S3 of the second lens L2 is a concave surface, the near-periphery of the object side surface S3 is a convex surface, the near-optical-axis of the image side surface S4 of the second lens L2 is a convex surface, and the near-periphery of the image side surface S4 is a concave surface;

[0129] The third lens L3 has a negative refractive power. The near-optical-axis and near-periphery of the object side surface S5 of the third lens L3 are convex surfaces, and the near-optical-axis and near-periphery of the image side surface S6 of the third lens L3 are concave surfaces;

[0130] The fourth lens L4 has a negative refractive power. The near-optical-axis of the object side surface S7 of the fourth lens L4 is a convex surface, the near-periphery of the object side surface S7 is a concave surface, the near-optical-axis of the image side surface S8 of the fourth lens L4 is a concave surface, and the near-periphery of the image side surface S8 is a convex surface;

[0131] The fifth lens L5 has a positive refractive power. The near optical axis of the object side S9 of the fifth lens L5 is convex, and the near circumference of the object side S9 is concave. The near optical axis and the near circumference of the image side S10 of the fifth lens L5 are convex.

[0132] The sixth lens L6 has a negative refractive power. The near optical axis of the object side S11 of the sixth lens L6 is convex, and the near circumference of the object side S11 is concave. The near optical axis of the image side S12 of the sixth lens L6 is concave, and the near circumference of the image side S12 is convex.

[0133] The other structures of the fifth embodiment are the same as those of the first embodiment, and can be referred to.

[0134] Table 5a shows a table of the characteristics of the optical system of this embodiment, where the data are obtained with light of a wavelength of 587.6 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0135] Table 5a

[0136]

[0137] Among them, the meanings of the parameters in Table 5a are the same as those of the parameters in the first embodiment.

[0138] Table 5b gives the higher-order term coefficients available for each aspherical mirror surface in the fifth embodiment. Among them, each aspherical surface type can be defined by the formula given in the first embodiment.

[0139] Table 5b

[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 sequentially includes, from the object side to the image side along the optical axis direction:

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

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

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

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

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

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

[0150] The other structures of the sixth embodiment are the same as those of the first embodiment, and can be referred to.

[0151] Table 6a shows a table of the characteristics of the optical system of this embodiment, where the data are obtained with light rays of a wavelength of 587.6 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0152] Table 6a

[0153]

[0154] Among them, the meanings of the parameters in Table 6a are the same as those of the parameters in the first embodiment.

[0155] Table 6b gives the higher-order term coefficients of the aspherical mirror surfaces 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.

[0156] Table 6b

[0157]

[0158] 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.

[0159] The Seventh Embodiment

[0160] 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:

[0161] The first lens L1 has a positive refractive power. The near-optical axis and near-periphery of the object side surface S1 of the first lens L1 are convex surfaces, and the near-optical axis and near-periphery of the image side surface S2 of the first lens L1 are convex surfaces;

[0162] The second lens L2 has a negative refractive power. The near-optical axis and near-periphery of the object side surface S3 of the second lens L2 are concave surfaces, the near-optical axis of the image side surface S4 of the second lens L2 is a concave surface, and the near-periphery of the image side surface S4 is a convex surface;

[0163] The third lens L3 has a negative refractive power. The near-optical axis of the object side surface S5 of the third lens L3 is a convex surface, the near-periphery of the object side surface S5 is a concave surface, and the near-optical axis and near-periphery of the image side surface S6 of the third lens L3 are concave surfaces;

[0164] The fourth lens L4 has a negative refractive power. The near-optical axis of the object side surface S7 of the fourth lens L4 is a convex surface, the near-periphery of the object side surface S7 is a concave surface, the near-optical axis of the image side surface S8 of the fourth lens L4 is a concave surface, and the near-periphery of the image side surface S8 is a convex surface;

[0165] The fifth lens L5 has a positive refractive power. The near-optical axis of the object side surface S9 of the fifth lens L5 is a convex surface, the near-periphery of the object side surface S9 is a concave surface; the near-optical axis and near-periphery of the image side surface S10 of the fifth lens L5 are convex surfaces.

[0166] The sixth lens L6 has a negative refractive power. The near-optical axis of the object side surface S11 of the sixth lens L6 is a convex surface, the near-periphery of the object side surface S11 is a concave surface, the near-optical axis of the image side surface S12 of the sixth lens L6 is a concave surface, and the near-periphery of the image side surface S12 is a convex surface.

[0167] The other structures of the seventh embodiment are the same as those of the first embodiment, and can be referred to accordingly.

[0168] 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 587.6 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0169] Table 7a

[0170]

[0171]

[0172] Among them, the meanings of the parameters in Table 7a are the same as those of the parameters in the first embodiment.

[0173] Table 7b gives the higher-order term coefficients of the aspherical mirrors that can be used in the sixth embodiment. Among them, each aspherical surface type can be defined by the formula given in the first embodiment.

[0174] Table 7b

[0175]

[0176] 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.

[0177] Table 8 shows the values of CT1 / TTL, Y1, CT1, ET1, TTL / ImgH, R51 / R52, f1 / f, f3 / f, n3, n4, and G5 / CT5 of the optical systems of the first to seventh embodiments.

[0178] Table 8

[0179] CT1 / TTL Y1 / mm CT1 / mm ET1mm TTL / ImgH First Embodiment 0.203 0.800 1 0.819 1.68 Second Embodiment 0.208 0.770 1 0.81 1.64 Third Embodiment 0.209 0.793 1 0.826 1.63 Fourth Embodiment 0.261 0.744 1.2 0.991 1.57 Fifth Embodiment 0.281 0.740 1.3 1.0845 1.58 Sixth Embodiment 0.277 0.803 1.322 0.998 1.63 Seventh Embodiment 0.261 0.873 1.36 1.1 1.70 R51 / R52 f1 / f f3 / f n3, n4 G5 / CT5 First Embodiment -2.423 0.857 -2.253 1.661、1.626 0.724 Second Embodiment -2.204 0.827 -2.169 1.661、1.623 0.653 Third Embodiment -2.746 0.923 -1.791 1.661、1.634 0.650 Fourth Embodiment -4.102 0.752 -4.655 1.661、1.564 0.498 Fifth Embodiment -3.181 0.733 -4.082 1.661、1.568 0.502 Sixth Embodiment -2.153 0.581 -5.044 1.633、1.622 0.462 Seventh Embodiment -8.078 0.683 -10.377 1.654、1.574 0.508

[0180] As can be seen from Table 8, each embodiment can satisfy: CT1 / TTL > 0.2, Y1 < 0.9 mm, CT1 ≥ 1.0 mm, ET1 > 0.8 mm, TTL / ImgH ≤ 1.7, -8.1 < R51 / R52 < -2.2, 0.58 < f1 / f < 0.93, 0.48 < f3 / f < 0.6, 1.63 < n3 < 1.67, 1.56 < n4 < 1.64, and G5 / CT5 > 0.4.

[0181] The technical features of the above embodiments can be combined arbitrarily. For the sake of brief description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should be considered as the scope described in this specification.

[0182] The above embodiments only represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limiting 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 six 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 a positive refractive power, has a convex surface near the optical axis on the object side surface of the first lens, and a convex surface near the optical axis on the image side surface of the first lens; The second lens, which has a negative refractive power, has a concave surface near the optical axis on the object side surface of the second lens; The third lens, which has a negative refractive power, has a convex surface near the optical axis on the object side surface of the third lens, and a concave surface near the optical axis on the image side surface of the third lens; The fourth lens, which has a negative refractive power, has a concave surface near the optical axis on the image side surface of the fourth lens; The fifth lens, which has a positive refractive power, has convex surfaces near the optical axis on both the object side surface and the image side surface, and at least one inflection point is provided on the object side surface of the fifth lens; The sixth lens, which has a negative refractive power, has a convex surface near the optical axis on the object side surface, a concave surface near the optical axis on the image side surface, and at least one inflection point is provided on the image side surface of the sixth lens; The optical system satisfies the conditional formula: 0.281 ≥ CT1 / TTL ≥ 0.261; TTL / ImgH ≤ 1.7; 0.508 ≥ G5 / CT5 > 0.4; Wherein, CT1 is the thickness of the first lens on the optical axis, TTL is the distance on the optical axis from the object side surface of the first lens to the imaging surface of the optical system, ImgH is half of the diagonal length of the effective imaging area on the imaging surface of the optical system, G5 is the thickness of the thinnest part of the fifth lens along the optical axis direction, and CT5 is the thickness of the fifth lens on the optical axis.

2. The optical system according to claim 1, wherein The optical system satisfies the conditional formula: 0.744mm ≤ Y1 < 0.9mm; Wherein, Y1 is the optical effective radius of the object side surface of the first lens.

3. The optical system according to claim 1, characterized in that, The optical system satisfies the conditional formula: 1.36mm ≥ CT1 ≥ 1.2mm; Wherein, CT1 is the thickness of the first lens on the optical axis.

4. The optical system according to claim 1, characterized in that, The optical system satisfies the conditional formula: 1.1mm ≥ ET1 > 0.991mm; Wherein, ET1 is the edge thickness of the first lens.

5. The optical system according to claim 1, wherein The optical system satisfies the conditional formula: 1.57 ≤ TTL / ImgH ≤ 1.7; Wherein, TTL is the distance on the optical axis from the object side surface of the first lens to the imaging surface of the optical system, and ImgH is half of the diagonal length of the effective imaging area on the imaging surface of the optical system.

6. The optical system according to claim 1, wherein The optical system satisfies the conditional formula: -8.1 < R51 / R52 < -2.2; Wherein, R51 is the curvature radius of the object side surface of the fifth lens at the optical axis, and R52 is the curvature radius of the image side surface of the fifth lens at the optical axis.

7. The optical system according to claim 1, characterized in that, The optical system satisfies the conditional formula: 0.58 < f1 / f ≤ 0.752; Wherein, f1 is the effective focal length of the first lens, and f is the effective focal length of the optical system.

8. The optical system according to claim 1, characterized in that, The optical system satisfies the conditional formula: 1.63<n3<1.67； 1.56<n4<1.64； Wherein, n3 is the refractive index of the third lens, n4 is the refractive index of the fourth lens, and the reference wavelength of the refractive index is 587.56nm.

9. A lens module, characterized in that, Comprising a lens barrel, an electronic photosensitive chip, and an optical system according to any one of claims 1 to 8, wherein the first lens to the sixth lens of the optical system are mounted in the lens barrel, and the electronic photosensitive chip is disposed on the image side of the optical system for converting the light of an object incident on the electronic photosensitive chip through the first lens to the sixth lens into an electrical signal of an image.

10. An electronic device, characterized in that, Comprising a housing and a lens module according to claim 9, wherein the lens module is disposed in the housing.

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