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 sequentially includes, from the object side to the image side: a first lens having a positive refractive power, the object side surface of the first lens being convex at the optical axis, and the image side surface of the first lens being concave both at the optical axis and at the circumference; a second lens having a refractive power, the object side surface of the second lens being convex at the optical axis, and the image side surface of the second lens being concave both at the optical axis and at the circumference; a third lens, a fourth lens, a fifth lens and a sixth lens having refractive powers; a seventh lens having a negative refractive power, the image side surface of the seventh lens being concave at the optical axis and having at least one inflection point; the optical system satisfies the conditional formula: f / EPD < 1.7. For the optical system provided by the present invention, through the above settings, the optical system has a larger light entrance aperture, so that it has a larger light entrance amount, can improve the shooting effect under dark conditions, and has a better imaging effect.

Description

Technical Field

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

[0002] Nowadays, with the rapid development of technology, consumers have higher and higher requirements for the imaging quality of mobile electronic products. At present, the five-piece optical system is relatively mature, but the resolution can no longer meet the needs of consumers. Compared with them, the seven-piece optical system has obvious advantages, can obtain higher resolving power, can be used for high-end mobile electronic products, thereby improving the picture quality of shooting, increasing the resolution and clarity.

[0003] However, the current seven-piece optical system is not yet perfect, and the shooting effects in low-light environments such as night scenes, rainy days, and starry skies are still not satisfactory. Therefore, how to further improve the seven-piece optical system to make it overcome the low-light environment and have better shooting effects has become the key. Summary of the Invention

[0004] The purpose of the present invention is to provide an optical system that still has better shooting effects under low-light conditions.

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

[0006] In a first aspect, the present invention provides an optical system. The optical system sequentially includes from the object side to the image side: a first lens having positive refractive power, the object side surface of the first lens is convex at the optical axis, and the image side surface of the first lens is concave at the optical axis and at the circumference; a second lens having refractive power, the object side surface of the second lens is convex at the optical axis, and the image side surface of the second lens is concave at the optical axis and at the circumference; a third lens having refractive power; a fourth lens having refractive power; a fifth lens having refractive power; a sixth lens having refractive power; a seventh lens having negative refractive power, the image side surface of the seventh lens is concave at the optical axis, and at least one inflection point is provided; the optical system satisfies the conditional formula: f / EPD < 1.7; where f is the effective focal length of the optical system, and EPD is the entrance pupil diameter of the optical system. The optical system provided by the present invention, by reasonably configuring the refractive powers and surface types of the first lens to the seventh lens, and simultaneously satisfying that the value of f / EPD is within 1.7, the optical system has a larger light entrance aperture, thereby having a larger light input amount, can improve the shooting effect under dark conditions, and has better imaging effects.

[0007] In one embodiment, the optical system satisfies the conditional formula: TTL / Imgh < 1.7; where TTL is the distance from the object side of the first lens to the imaging plane of the optical system on the optical axis, and Imgh is half of the diagonal length of the effective photosensitive area on the imaging plane of the optical system. By satisfying that the value of TTL / Imgh is within 1.7, the optical system has the characteristic of being ultra-thin, thus realizing the miniaturization of the system.

[0008] In one embodiment, the optical system satisfies the conditional formula: f * tan(HFOV) > 5.15 mm; where HFOV is the half field of view angle of the optical system. By satisfying that the value of f * tan(HFOV) is greater than 5.15 mm, the optical system has the characteristic of a large image plane, thus having the characteristics of high pixels and high definition.

[0009] In one embodiment, the optical system satisfies the conditional formula: 1 < TTL / f < 1.5; where TTL is the distance from the object side of the first lens to the imaging plane of the optical system on the optical axis. By satisfying that the value of TTL / f is between 1 and 1.5, the ratio of the total length of the control system to the focal length is less than 1.5, making the optical system have the characteristic of miniaturization; at the same time, controlling this ratio to be greater than 1 weakens the sensitivity of the optical system, which is beneficial to the processing and production of the product.

[0010] In one embodiment, the optical system satisfies the conditional formula: 0.5 < |R5 / R6| < 1.5; where R5 is the curvature radius of the object side of the third lens on the optical axis, and R6 is the curvature radius of the image side of the third lens on the optical axis. By satisfying that the value of |R5 / R6| is between 0.5 and 0.6, it is beneficial to the processing and forming of the third lens and can effectively reduce the sensitivity of the optical system at the third lens.

[0011] In one embodiment, the optical system satisfies the conditional formula: 0.5 < TTH2 / CT3 < 1.5; where TTH2 is the air interval distance from the second lens to the third lens on the optical axis, and CT3 is the thickness of the third lens on the optical axis. By satisfying that the value of TTH2 / CT3 is between 0.5 and 1.5, the sensitivity of the optical system field area is effectively reduced, which is beneficial to the processing and production of the product.

[0012] In one embodiment, the optical system satisfies the conditional formula: |f1 / f5| < 2; where f1 is the effective focal length of the first lens, and f5 is the effective focal length of the fifth lens. By satisfying that the value of |f1 / f5| is within 2, the distribution of the optical effective focal lengths of the first lens and the fifth lens is reasonably controlled, and the position chromatic aberration of the optical system is effectively corrected.

[0013] In one embodiment, the optical system satisfies the conditional formula: 0.2 < ET2 / CT2 < 1.3; where ET2 is the thickness at the edge of the optical effective area of the second lens, and CT2 is the thickness of the second lens on the optical axis. By satisfying that the value of ET2 / CT2 is between 0.2 and 1.3, controlling the ratio of the edge thickness of the second lens to the middle thickness of the second lens within a suitable range is beneficial to the processing and production of the second lens.

[0014] In one embodiment, the optical system satisfies the conditional formula: TTL / f1 ≤ 1.5; where 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 f1 is the effective focal length of the first lens. By satisfying that the value of TTL / f1 is within 1.5, reasonably controlling the diopter of the first lens, avoiding excessive increase in the refractive power of the first lens, and ensuring a relatively short total length of the optical system.

[0015] In one embodiment, the optical system satisfies the conditional formula: EPD / R1 < 1.5; where R1 is the radius of curvature of the object side surface of the first lens on the optical axis. By satisfying that the value of EPD / R1 is within 1.5, effectively ensuring the rationality of the deflection of the incident light rays of the system on the first lens.

[0016] In one embodiment, the optical system satisfies the conditional formula: sd61 / sd52 ≤ 1.3; where sd61 is the clear aperture of the object side surface of the sixth lens at the maximum field of view angle; sd52 is the clear aperture of the image side surface of the fifth lens at the maximum field of view angle. By satisfying that the value of sd61 / sd52 is within 1.3, effectively reducing the step difference in the structure between the fifth lens and the sixth lens, making the marginal field light rays smoother, and being beneficial to the stability of the processing and production of the product.

[0017] In a second aspect, the present invention further provides a lens module, which includes a lens barrel, a photosensitive element, and the optical system according to any one of the embodiments in the first aspect. The first lens to the seventh lens of the optical system are installed in the lens barrel, and the photosensitive element is arranged on the image side of the optical system. By adding the optical system provided by the present invention to the lens module, the lens module has a larger light entrance aperture, thus having a larger light input amount, which can improve the shooting effect under dark conditions and has a better imaging effect.

[0018] In a third aspect, the present invention further provides an electronic device, which includes a housing and the lens module in the second aspect, and the lens module is arranged in the housing. By adding the lens module provided by the present invention to the electronic device, the optical system has a larger light entrance aperture, thus having a larger light input amount, which can improve the shooting effect of the electronic device under dark conditions and make the electronic device have a better imaging effect. Description of the Drawings

[0019] 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 the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0020] Figure 1a is a schematic structural diagram of the optical system of the first embodiment;

[0021] Figure 1b is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the first embodiment;

[0022] Figure 2a is a schematic structural diagram of the optical system of the second embodiment;

[0023] Figure 2b is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the second embodiment;

[0024] Figure 3a is a schematic structural diagram of the optical system of the third embodiment;

[0025] Figure 3b is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the third embodiment;

[0026] Figure 4a is a schematic structural diagram of the optical system of the fourth embodiment;

[0027] Figure 4b is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the fourth embodiment;

[0028] Figure 5a is a schematic structural diagram of the optical system of the fifth embodiment;

[0029] Figure 5b is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the fifth embodiment;

[0030] Figure 6a is a schematic structural diagram of the optical system of the sixth embodiment;

[0031] Figure 6b is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the sixth embodiment.

[0032] Figure 7a is a schematic structural diagram of the optical system of the seventh embodiment;

[0033] Figure 7b is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the seventh embodiment;

[0034] Figure 8a is a schematic structural diagram of the optical system of the eighth embodiment;

[0035] Figure 8b are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the eighth embodiment;

[0036] Figure 9a is a schematic structural diagram of the optical system of the ninth embodiment;

[0037] Figure 9b are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the ninth embodiment;

[0038] Figure 10a is a schematic structural diagram of the optical system of the tenth embodiment;

[0039] Figure 10b are the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the tenth embodiment. Detailed implementation manners

[0040] 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0041] The embodiments of the present invention provide an electronic device. The electronic device includes a housing and the lens module provided by the embodiments of the present invention. The lens module is disposed 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 adding the lens module provided by the present invention to the electronic device, the optical system has a larger light entrance aperture, so that there is a larger amount of incident light, which can improve the shooting effect of the electronic device under dark conditions and enable the electronic device to have a better imaging effect.

[0042] An embodiment of the present invention further provides a lens module. The lens module includes a lens barrel, a photosensitive element, and the optical system provided by the embodiment of the present invention. The first lens to the seventh lens of the optical system are installed in the lens barrel, and the photosensitive element is arranged on the image side of the optical system, and is used to convert the light of the object incident on the photosensitive element through the first lens to the seventh lens into an electrical signal of an image. The photosensitive element may be a Complementary Metal Oxide Semiconductor (CMOS) or a Charge-coupled Device (CCD). The lens module may be an independent lens of a digital camera or an imaging module integrated on an electronic device such as a smart phone. By adding the optical system provided by the present invention to the lens module, the lens module has a larger light entrance aperture, so that there is a larger amount of incident light, the shooting effect under dark conditions can be improved, and a better imaging effect is obtained.

[0043] An embodiment of the present invention provides an optical system. The optical system sequentially includes, from the object side to the image side: a first lens with positive refractive power, the object side surface of the first lens is convex at the optical axis, and the image side surface of the first lens is concave at the optical axis and at the circumference; a second lens with refractive power, the object side surface of the second lens is convex at the optical axis, and the image side surface near the second lens is concave at the optical axis and at the circumference; a third lens with refractive power; a fourth lens with refractive power; a fifth lens with refractive power; a sixth lens with refractive power; a seventh lens with negative refractive power, the image side surface of the seventh lens is concave at the optical axis and is provided with at least one inflection point; the optical system satisfies the conditional formula: f / EPD < 1.7; where f is the effective focal length of the optical system, and EPD is the entrance pupil diameter of the optical system. For the optical system provided by the present invention, by reasonably configuring the refractive powers and surface shapes of the first lens to the seventh lens, and at the same time satisfying that the value of f / EPD is within 1.7, the optical system has a larger light entrance aperture, so that there is a larger amount of incident light, the shooting effect under dark conditions can be improved, and a better imaging effect is obtained. Specifically, the value of f / EPD may be 1.7, 1.4, 1.1, 0.7, 0.5, 0.1, etc.

[0044] In an 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 photosensitive area on the imaging surface of the optical system. By satisfying that the value of TTL / Imgh is within 1.7, the optical system has the characteristic of being ultra-thin, thereby realizing miniaturization of the system. Specifically, the value of TTL / Imgh may be 1.7, 1.5, 1.2, 1.0, 0.5, 0.3, 0.1, etc.

[0045] In one embodiment, the optical system satisfies the conditional formula: f * tan(HFOV) > 5.15 mm; where HFOV is the half field of view angle of the optical system. By satisfying that the value of f * tan(HFOV) is greater than 5.15 mm, the optical system has the characteristic of a large image plane, and thus has the characteristics of high pixels and high definition. The value of f * tan(HFOV) can be 5.15 mm, 5.18 mm, 5.2 mm, 5.5 mm, 6 mm, 8 mm, 10 mm, etc.

[0046] In one embodiment, the optical system satisfies the conditional formula: 1 < TTL / f < 1.5; 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. By satisfying that the value of TTL / f is between 1 and 1.5, the ratio of the total length of the control system to the focal length is less than 1.5, making the optical system have the characteristic of miniaturization; at the same time, controlling this ratio to be greater than 1 weakens the sensitivity of the optical system and is beneficial to the processing and production of the product. Specifically, the value of TTL / f can be 1, 1.1, 1.2, 1.3, 1.4, 1.5, etc.

[0047] In one embodiment, the optical system satisfies the conditional formula: 0.5 < |R5 / R6| < 1.5; where R5 is the curvature radius of the object side surface of the third lens on the optical axis, and R6 is the curvature radius of the image side surface of the third lens on the optical axis. By satisfying that the value of |R5 / R6| is between 0.5 and 0.6, it is beneficial to the processing and forming of the third lens and can effectively reduce the sensitivity of the optical system at the third lens. Specifically, the value of |R5 / R6| can be 0.5, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, etc.

[0048] In one embodiment, the optical system satisfies the conditional formula: 0.5 < TTH2 / CT3 < 1.5; where TTH2 is the air separation distance between the second lens and the third lens on the optical axis, and CT3 is the thickness of the third lens on the optical axis. By satisfying that the value of TTH2 / CT3 is between 0.5 and 1.5, the sensitivity of the optical system field area is effectively reduced, which is beneficial to the processing and production of the product. Specifically, the value of TTH2 / CT3 can be 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, etc.

[0049] In one embodiment, the optical system satisfies the conditional formula: |f1 / f5| < 2; where f1 is the effective focal length of the first lens and f5 is the effective focal length of the fifth lens. By satisfying that the value of |f1 / f5| is within 2, the distribution of the optical effective focal lengths of the first lens and the fifth lens is reasonably controlled, and the axial chromatic aberration of the optical system is effectively corrected. Specifically, the value of |f1 / f5| can be 0.1, 0.4, 0.7, 1, 1.4, 1.8, 2, etc.

[0050] In one embodiment, the optical system satisfies the conditional formula: 0.2 < ET2 / CT2 < 1.3. Where ET2 is the thickness of the edge of the optical effective area of the second lens, and CT2 is the thickness of the second lens on the optical axis. By satisfying that the value of ET2 / CT2 is between 0.2 and 1.3, the ratio of the edge thickness to the middle thickness of the second lens is controlled within a suitable range, which is beneficial to the processing and production of the second lens. Specifically, the value of ET2 / CT2 can be 0.2, 0.5, 0.7, 1, 1.1, 1.3, etc.

[0051] In one embodiment, the optical system satisfies the conditional formula: TTL / f1 ≤ 1.5; where 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 f1 is the effective focal length of the first lens. By satisfying that the value of TTL / f1 is within 1.5, the diopter of the first lens is reasonably controlled, the excessive increase of the refractive power of the first lens is avoided, and a relatively short total optical system length is ensured. Specifically, the value of TTL / f1 can be 1.5, 1.2, 1, 0.8, 0.5, 0.3, 0.1, etc.

[0052] In one embodiment, the optical system satisfies the conditional formula: EPD / R1 < 1.5; where R1 is the radius of curvature of the object side surface of the first lens on the optical axis. By satisfying that the value of EPD / R1 is within 1.5, the rationality of the deflection of the incident light of the system on the first lens is effectively ensured. Specifically, the value of EPD / R1 can be 1.5, 1.2, 1, 0.8, 0.5, 0.3, 0.1, etc.

[0053] In one embodiment, the optical system satisfies the conditional formula: sd61 / sd52 ≤ 1.3. Where sd61 is the clear aperture of the object side surface of the sixth lens at the maximum field of view; sd52 is the clear aperture of the image side surface of the fifth lens at the maximum field of view. By satisfying that the value of sd61 / sd52 is within 1.3, the step difference in the structure between the fifth lens and the sixth lens is effectively reduced, the edge field light is made smoother, and the stability of the processing and production of the product is facilitated. Specifically, the value of sd61 / sd52 can be 1.2, 1, 0.8, 0.5, 0.3, 0.1, etc.

[0054] First Embodiment

[0055] Please refer to Figure 1a and Figure 1b , the optical system of this embodiment sequentially includes, from the object side to the image side along the optical axis direction:

[0056] The first lens L1 has a positive refractive power. The object side surface S1 of the first lens L1 is convex both at the optical axis and at the circumference; the image side surface S2 of the first lens L1 is concave both at the optical axis and at the circumference;

[0057] The second lens L2 has a negative refractive power. The object side surface S3 of the second lens L2 is convex both at the optical axis and at the circumference; the image side surface S4 of the second lens L2 is concave both at the optical axis and at the circumference;

[0058] The third lens L3 has a positive refractive power. The object side surface S5 of the third lens L3 is convex at the optical axis and concave at the circumference; the image side surface S6 of the third lens L3 is convex both at the optical axis and at the circumference;

[0059] The fourth lens L4 has a negative refractive power. The object side surface S7 of the fourth lens L4 is concave both at the optical axis and at the circumference; the image side surface S8 of the fourth lens L4 is concave at the optical axis and convex at the circumference;

[0060] The fifth lens L5 has a positive refractive power. The object side surface S9 of the fifth lens L5 is concave both at the optical axis and at the circumference; the image side surface S10 of the fifth lens L5 is convex both at the optical axis and at the circumference.

[0061] The sixth lens L6 has a positive refractive power. The object side surface S11 of the sixth lens L6 is convex at the optical axis and concave at the circumference; the image side surface S12 of the sixth lens L6 is concave at the optical axis and convex at the circumference.

[0062] The seventh lens L7 has a negative refractive power. The object side surface S13 of the seventh lens L7 is convex at the optical axis and concave at the circumference; the image side surface S14 of the seventh lens L7 is concave at the optical axis and convex at the circumference.

[0063] The materials of the above-mentioned first lens L1 to seventh lens L7 are all plastics.

[0064] In addition, the optical system further includes a stop STO, an infrared cut-off filter L8, and an imaging surface S17. The stop STO is disposed on the object side surface S1 of the first lens L1 for controlling 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 cut-off 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 cut-off filter L8 is used to filter out infrared light so that the light incident on the imaging surface S17 is visible light, and the wavelength of the visible light is 380 nm - 780 nm. The material of the infrared cut-off filter L8 is glass, and a film may be coated on the glass. The imaging surface S17 is the effective pixel region of the photosensitive element.

[0065] Table 1a shows a table of the characteristics of the optical system of this embodiment, where the data is obtained using light with a wavelength of 555 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0066] Table 1a

[0067]

[0068] Among them, f is the effective focal length of the optical system, FNO is the f-number of the optical system, FOV is the maximum field of view angle in the diagonal direction 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.

[0069] 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:

[0070]

[0071] Among them, x is the maximum sagitta distance from the vertex of the aspherical surface when the aspherical surface is at a position with a height of 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 of the aspherical mirror surfaces S1 - S14 in the first embodiment.

[0072] Table 1b

[0073]

[0074] Figure 1bThe longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the first embodiment are shown. The ray reference wavelength of the astigmatism curve and the distortion curve is 555 nm. 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.

[0075] Second Embodiment

[0076] 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:

[0077] The first lens L1 has a positive refractive power. The object side surface S1 of the first lens L1 is convex both at the optical axis and at the circumference; the image side surface S2 of the first lens L1 is concave both at the optical axis and at the circumference;

[0078] The second lens L2 has a negative refractive power. The object side surface S3 of the second lens L2 is convex both at the optical axis and at the circumference; the image side surface S4 of the second lens L2 is concave both at the optical axis and at the circumference;

[0079] The third lens L3 has a positive refractive power. The object side surface S5 of the third lens L3 is convex at the optical axis and concave at the circumference; the image side surface S6 of the third lens L3 is convex both at the optical axis and at the circumference;

[0080] The fourth lens L4 has a negative refractive power. The object side surface S7 of the fourth lens L4 is concave both at the optical axis and at the circumference; the image side surface S8 of the fourth lens L4 is concave at the optical axis and convex at the circumference;

[0081] The fifth lens L5 has a positive refractive power. The object side surface S9 of the fifth lens L5 is concave both at the optical axis and at the circumference; the image side surface S10 of the fifth lens L5 is convex both at the optical axis and at the circumference.

[0082] The sixth lens L6 has a negative refractive power. The object side surface S11 of the sixth lens L6 is convex at the optical axis and concave at the circumference; the image side surface S12 of the sixth lens L6 is concave at the optical axis and convex at the circumference.

[0083] The seventh lens L7 has a negative refractive power. The object side surface S13 of the seventh lens L7 is convex at the optical axis and concave at the circumference; the image side surface S14 of the seventh lens L7 is concave at the optical axis and convex at the circumference.

[0084] The other structures of the second embodiment are the same as those of the first embodiment, and can be referred to.

[0085] 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 555 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0086] Table 2a

[0087]

[0088] Among them, f is the effective focal length of the optical system, FNO is the f-number of the optical system, FOV is the maximum field of view angle in the diagonal direction 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.

[0089] Table 2b gives the higher-order term coefficients of each aspherical mirror surface that can be used in the second embodiment. Among them, each aspherical surface type can be defined by the formula given in the first embodiment.

[0090] Table 2b

[0091]

[0092] Figure 2b Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the second embodiment. The reference wavelength of the light for the astigmatism curve and distortion curve is 555 nm. According to Figure 2b It can be seen that the optical system given in the second embodiment can achieve good imaging quality.

[0093] The third embodiment

[0094] Please refer to Figure 3a and Figure 3b , the optical system of this embodiment sequentially includes, from the object side to the image side along the optical axis direction:

[0095] The first lens L1, which has a positive refractive power. The object side surface S1 of the first lens L1 is convex both at the optical axis and at the circumference; the image side surface S2 of the first lens L1 is concave both at the optical axis and at the circumference;

[0096] The second lens L2, which has a negative refractive power. The object side surface S3 of the second lens L2 is convex both at the optical axis and at the circumference; the image side surface S4 of the second lens L2 is concave both at the optical axis and at the circumference;

[0097] The third lens L3, which has a positive refractive power. The object side surface S5 of the third lens L3 is convex at the optical axis and concave at the circumference; the image side surface S6 of the third lens L3 is convex both at the optical axis and at the circumference;

[0098] The fourth lens L4 has a negative refractive power. The object side surface S7 of the fourth lens L4 is concave both on the optical axis and at the circumference; the image side surface S8 of the fourth lens L4 is concave on the optical axis and convex at the circumference.

[0099] The fifth lens L5 has a positive refractive power. The object side surface S9 of the fifth lens L5 is concave both on the optical axis and at the circumference; the image side surface S10 of the fifth lens L5 is convex both on the optical axis and at the circumference.

[0100] The sixth lens L6 has a positive refractive power. The object side surface S11 of the sixth lens L6 is convex on the optical axis and concave at the circumference; the image side surface S12 of the sixth lens L6 is concave on the optical axis and convex at the circumference.

[0101] The seventh lens L7 has a negative refractive power. The object side surface S13 of the seventh lens L7 is convex on the optical axis and concave at the circumference; the image side surface S14 of the seventh lens L7 is concave on the optical axis and convex at the circumference.

[0102] The other structures of the third embodiment are the same as those of the first embodiment, and can be referred to.

[0103] Table 3a 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 555 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0104] Table 3a

[0105]

[0106] Among them, f is the effective focal length of the optical system, FNO is the f-number of the optical system, FOV is the maximum field of view angle in the diagonal direction 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.

[0107] Table 3b gives the higher-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.

[0108] Table 3b

[0109]

[0110] Figure 3b Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the third embodiment. The light ray reference wavelengths of the astigmatism curve and the distortion curve are 555 nm. According to Figure 3b It can be seen that the optical system given in the third embodiment can achieve good imaging quality.

[0111] Fourth Embodiment

[0112] 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:

[0113] The first lens L1, having a positive refractive power, the object side surface S1 of the first lens L1 is convex both at the optical axis and at the circumference; the image side surface S2 of the first lens L1 is concave both at the optical axis and at the circumference;

[0114] The second lens L2, having a negative refractive power, the object side surface S3 of the second lens L2 is convex both at the optical axis and at the circumference; the image side surface S4 of the second lens L2 is concave both at the optical axis and at the circumference;

[0115] The third lens L3, having a positive refractive power, the object side surface S5 of the third lens L3 is convex at the optical axis and concave at the circumference; the image side surface S6 of the third lens L3 is convex both at the optical axis and at the circumference;

[0116] The fourth lens L4, having a positive refractive power, the object side surface S7 of the fourth lens L4 is concave both at the optical axis and at the circumference; the image side surface S8 of the fourth lens L4 is convex both at the optical axis and at the circumference;

[0117] The fifth lens L5, having a positive refractive power, the object side surface S9 of the fifth lens L5 is concave both at the optical axis and at the circumference; the image side surface S10 of the fifth lens L5 is convex both at the optical axis and at the circumference.

[0118] The sixth lens L6, having a positive refractive power, the object side surface S11 of the sixth lens L6 is convex at the optical axis and concave at the circumference; the image side surface S12 of the sixth lens L6 is concave at the optical axis and convex at the circumference.

[0119] The seventh lens L7, having a negative refractive power, the object side surface S13 of the seventh lens L7 is convex at the optical axis and concave at the circumference; the image side surface S14 of the seventh lens L7 is concave at the optical axis and convex at the circumference.

[0120] The other structures of the fourth embodiment are the same as those of the first embodiment, and reference can be made accordingly.

[0121] Table 4a 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 555 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0122] Table 4a

[0123]

[0124] Wherein, f is the effective focal length of the optical system, FNO is the f-number of the optical system, FOV is the maximum field of view angle in the diagonal direction 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.

[0125] Table 4b gives the higher-order term coefficients of the aspherical mirror surfaces that can be used in the fourth embodiment. Among them, the aspherical surface profiles can be defined by the formulas given in the first embodiment.

[0126] Table 4b

[0127]

[0128] Figure 4b shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the fourth embodiment. The light reference wavelengths of the astigmatism curve and the distortion curve are 555 nm. According to Figure 4b it can be seen that the optical system given in the fourth embodiment can achieve good imaging quality.

[0129] Fifth Embodiment

[0130] Please refer to Figure 5a and Figure 5b , the optical system of this embodiment includes, in order from the object side to the image side along the optical axis:

[0131] The first lens L1, having a positive refractive power, the object side surface S1 of the first lens L1 is convex both at the optical axis and at the circumference; the image side surface S2 of the first lens L1 is concave both at the optical axis and at the circumference;

[0132] The second lens L2, having a negative refractive power, the object side surface S3 of the second lens L2 is convex both at the optical axis and at the circumference; the image side surface S4 of the second lens L2 is concave both at the optical axis and at the circumference;

[0133] The third lens L3, having a positive refractive power, the object side surface S5 of the third lens L3 is convex at the optical axis and concave at the circumference; the image side surface S6 of the third lens L3 is convex both at the optical axis and at the circumference;

[0134] The fourth lens L4, having a negative refractive power, the object side surface S7 of the fourth lens L4 is concave both at the optical axis and at the circumference; the image side surface S8 of the fourth lens L4 is convex both at the optical axis and at the circumference;

[0135] The fifth lens L5, having a negative refractive power, the object side surface S9 of the fifth lens L5 is concave both at the optical axis and at the circumference; the image side surface S10 of the fifth lens L5 is convex at the optical axis and concave at the circumference.

[0136] The sixth lens L6 has a positive refractive power. The object side surface S11 of the sixth lens L6 is convex at the optical axis and concave at the circumference; the image side surface S12 of the sixth lens L6 is concave at the optical axis and convex at the circumference.

[0137] The seventh lens L7 has a negative refractive power. The object side surface S13 of the seventh lens L7 is convex at the optical axis and concave at the circumference; the image side surface S14 of the seventh lens L7 is concave at the optical axis and convex at the circumference.

[0138] The other structures of the fifth embodiment are the same as those of the first embodiment, and can be referred to accordingly.

[0139] Table 5a 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 555 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0140] Table 5a

[0141]

[0142] Among them, f is the effective focal length of the optical system, FNO is the f-number of the optical system, FOV is the maximum field of view angle in the diagonal direction 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.

[0143] Table 5b gives the high-order term coefficients that can be used 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.

[0144] Table 5b

[0145]

[0146] Figure 5b Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the fifth embodiment. The light reference wavelength of the astigmatism curve and the distortion curve is 555 nm. According to Figure 5b It can be seen that the optical system given in the fifth embodiment can achieve good imaging quality.

[0147] Sixth Embodiment

[0148] 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:

[0149] The first lens L1 has a positive refractive power. The object side surface S1 of the first lens L1 is convex both at the optical axis and at the circumference; the image side surface S2 of the first lens L1 is concave both at the optical axis and at the circumference;

[0150] The second lens L2 has a negative refractive power. The object side surface S3 of the second lens L2 is convex both at the optical axis and at the circumference. The image side surface S4 of the second lens L2 is concave both at the optical axis and at the circumference.

[0151] The third lens L3 has a negative refractive power. The object side surface S5 of the third lens L3 is concave both at the optical axis and at the circumference. The image side surface S6 of the third lens L3 is convex both at the optical axis and at the circumference.

[0152] The fourth lens L4 has a negative refractive power. The object side surface S7 of the fourth lens L4 is concave both at the optical axis and at the circumference. The image side surface S8 of the fourth lens L4 is concave at the optical axis and convex at the circumference.

[0153] The fifth lens L5 has a positive refractive power. The object side surface S9 of the fifth lens L5 is convex at the optical axis and concave at the circumference. The image side surface S10 of the fifth lens L5 is convex both at the optical axis and at the circumference.

[0154] The sixth lens L6 has a positive refractive power. The object side surface S11 of the sixth lens L6 is convex at the optical axis and concave at the circumference. The image side surface S12 of the sixth lens L6 is concave at the optical axis and convex at the circumference.

[0155] The seventh lens L7 has a negative refractive power. The object side surface S13 of the seventh lens L7 is convex at the optical axis and concave at the circumference. The image side surface S14 of the seventh lens L7 is concave at the optical axis and convex at the circumference.

[0156] The other structures of the sixth embodiment are the same as those of the first embodiment, and can be referred to.

[0157] 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 555 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0158] Table 6a

[0159]

[0160] Among them, f is the effective focal length of the optical system, FNO is the f-number of the optical system, FOV is the maximum field of view angle in the diagonal direction 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.

[0161] Table 6b gives the higher-order term coefficients of the aspherical mirror surfaces 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.

[0162] Table 6b

[0163]

[0164] Figure 6b Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the sixth embodiment. The ray reference wavelength of the astigmatism curve and the distortion curve is 555 nm. According to Figure 6b It can be seen that the optical system given in the sixth embodiment can achieve good imaging quality.

[0165] The Seventh Embodiment

[0166] 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:

[0167] The first lens L1, having a positive refractive power, the object side surface S1 of the first lens L1 is convex both at the optical axis and at the circumference; the image side surface S2 of the first lens L1 is concave both at the optical axis and at the circumference;

[0168] The second lens L2, having a positive refractive power, the object side surface S3 of the second lens L2 is convex both at the optical axis and at the circumference; the image side surface S4 of the second lens L2 is concave both at the optical axis and at the circumference;

[0169] The third lens L3, having a positive refractive power, the object side surface S5 of the third lens L3 is convex at the optical axis and concave at the circumference; the image side surface S6 of the third lens L3 is convex both at the optical axis and at the circumference;

[0170] The fourth lens L4, having a negative refractive power, the object side surface S7 of the fourth lens L4 is concave both at the optical axis and at the circumference; the image side surface S8 of the fourth lens L4 is concave at the optical axis and convex at the circumference;

[0171] The fifth lens L5, having a positive refractive power, the object side surface S9 of the fifth lens L5 is convex at the optical axis and concave at the circumference; the image side surface S10 of the fifth lens L5 is convex both at the optical axis and at the circumference.

[0172] The sixth lens L6, having a positive refractive power, the object side surface S11 of the sixth lens L6 is convex at the optical axis and concave at the circumference; the image side surface S12 of the sixth lens L6 is concave at the optical axis and convex at the circumference.

[0173] The seventh lens L7, having a negative refractive power, the object side surface S13 of the seventh lens L7 is convex at the optical axis and concave at the circumference; the image side surface S14 of the seventh lens L7 is concave at the optical axis and convex at the circumference.

[0174] The other structures of the seventh embodiment are the same as those of the first embodiment, and can be referred to.

[0175] Table 7a shows a table of the characteristics of the optical system of this embodiment, where the data is obtained using light with a wavelength of 555 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0176] Table 7a

[0177]

[0178] Among them, f is the effective focal length of the optical system, FNO is the f-number of the optical system, FOV is the maximum field of view angle in the diagonal direction 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.

[0179] Table 7b gives the higher-order term coefficients of the aspherical mirror surfaces that can be used in the seventh embodiment. Among them, each aspherical surface type can be defined by the formula given in the first embodiment.

[0180] Table 7b

[0181]

[0182]

[0183] Figure 7b shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the seventh embodiment. The light reference wavelength of the astigmatism curve and the distortion curve is 555 nm. According to Figure 7b it can be seen that the optical system given in the seventh embodiment can achieve good imaging quality.

[0184] Eighth Embodiment

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

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

[0187] The second lens L2 has a positive refractive power. The object side surface S3 of the second lens L2 is convex both at the optical axis and at the circumference; the image side surface S4 of the second lens L2 is concave both at the optical axis and at the circumference;

[0188] The third lens L3 has a positive refractive power. The object side surface S5 of the third lens L3 is convex at the optical axis and concave at the circumference; the image side surface S6 of the third lens L3 is convex both at the optical axis and at the circumference;

[0189] The fourth lens L4 has a negative refractive power. The object side surface S7 of the fourth lens L4 is concave both at the optical axis and at the circumference. The image side surface S8 of the fourth lens L4 is concave at the optical axis and convex at the circumference.

[0190] The fifth lens L5 has a positive refractive power. The object side surface S9 of the fifth lens L5 is convex at the optical axis and concave at the circumference. The image side surface S10 of the fifth lens L5 is convex both at the optical axis and at the circumference.

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

[0192] The seventh lens L7 has a negative refractive power. The object side surface S13 of the seventh lens L7 is convex at the optical axis and concave at the circumference. The image side surface S14 of the seventh lens L7 is concave at the optical axis and convex at the circumference.

[0193] The other structures of the eighth embodiment are the same as those of the first embodiment, and can be referred to accordingly.

[0194] Table 8a 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 555 nm. The units of the Y radius, thickness, and focal length are all millimeters (mm).

[0195] Table 8a

[0196]

[0197] Among them, f is the effective focal length of the optical system, FNO is the f-number of the optical system, FOV is the maximum field of view angle in the diagonal direction 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.

[0198] Table 8b gives the higher-order term coefficients that can be used for each aspherical mirror surface in the eighth embodiment. Among them, each aspherical surface type can be defined by the formula given in the first embodiment.

[0199] Table 8b

[0200]

[0201]

[0202] Figure 8b Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the eighth embodiment. The light ray reference wavelengths of the astigmatism curve and the distortion curve are 555 nm. According to Figure 8b It can be seen that the optical system given in the eighth embodiment can achieve good imaging quality.

[0203] Ninth Embodiment

[0204] Please refer to Figure 9a and Figure 9b , the optical system of this embodiment includes, in order from the object side to the image side along the optical axis direction:

[0205] The first lens L1, having a positive refractive power, the object side surface S1 of the first lens L1 is convex both at the optical axis and at the circumference; the image side surface S2 of the first lens L1 is concave both at the optical axis and at the circumference;

[0206] The second lens L2, having a negative refractive power, the object side surface S3 of the second lens L2 is convex both at the optical axis and at the circumference; the image side surface S4 of the second lens L2 is concave both at the optical axis and at the circumference;

[0207] The third lens L3, having a positive refractive power, the object side surface S5 of the third lens L3 is convex at the optical axis and concave at the circumference; the image side surface S6 of the third lens L3 is convex both at the optical axis and at the circumference;

[0208] The fourth lens L4, having a negative refractive power, the object side surface S7 of the fourth lens L4 is concave both at the optical axis and at the circumference; the image side surface S8 of the fourth lens L4 is concave at the optical axis and convex at the circumference;

[0209] The fifth lens L5, having a positive refractive power, the object side surface S9 of the fifth lens L5 is convex at the optical axis and concave at the circumference; the image side surface S10 of the fifth lens L5 is convex both at the optical axis and at the circumference.

[0210] The sixth lens L6, having a positive refractive power, the object side surface S11 of the sixth lens L6 is convex at the optical axis and concave at the circumference; the image side surface S12 of the sixth lens L6 is concave at the optical axis and convex at the circumference.

[0211] The seventh lens L7, having a negative refractive power, the object side surface S13 of the seventh lens L7 is convex at the optical axis and concave at the circumference; the image side surface S14 of the seventh lens L7 is concave at the optical axis and convex at the circumference.

[0212] The other structures of the ninth embodiment are the same as those of the first embodiment, and reference can be made thereto.

[0213] Table 9a 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 555 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0214] Table 9a

[0215]

[0216] Wherein, f is the effective focal length of the optical system, FNO is the f-number of the optical system, FOV is the maximum field of view angle in the diagonal direction 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.

[0217] Table 9b gives the coefficients of the higher-order terms for each aspherical mirror surface that can be used in the ninth embodiment. Among them, each aspherical surface type can be defined by the formula given in the first embodiment.

[0218] Table 9b

[0219]

[0220]

[0221] Figure 9b shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the ninth embodiment. The light reference wavelength for the astigmatism curve and the distortion curve is 555 nm. According to Figure 9b it can be known that the optical system given in the ninth embodiment can achieve good imaging quality.

[0222] Tenth embodiment

[0223] Please refer to Figure 10a and Figure 10b , the optical system of this embodiment includes, in sequence from the object side to the image side along the optical axis direction:

[0224] The first lens L1, which has a positive refractive power. The object side surface S1 of the first lens L1 is convex both at the optical axis and at the circumference; the image side surface S2 of the first lens L1 is concave both at the optical axis and at the circumference;

[0225] The second lens L2, which has a negative refractive power. The object side surface S3 of the second lens L2 is convex both at the optical axis and at the circumference; the image side surface S4 of the second lens L2 is concave both at the optical axis and at the circumference;

[0226] The third lens L3, which has a positive refractive power. The object side surface S5 of the third lens L3 is convex at the optical axis and concave at the circumference; the image side surface S6 of the third lens L3 is convex both at the optical axis and at the circumference;

[0227] The fourth lens L4, which has a negative refractive power. The object side surface S7 of the fourth lens L4 is concave both at the optical axis and at the circumference; the image side surface S8 of the fourth lens L4 is concave at the optical axis and convex at the circumference;

[0228] The fifth lens L5, which has a positive refractive power. The object side surface S9 of the fifth lens L5 is concave both at the optical axis and at the circumference; the image side surface S10 of the fifth lens L5 is convex both at the optical axis and at the circumference.

[0229] The sixth lens L6 has a negative refractive power. The object side surface S11 of the sixth lens L6 is concave both at the optical axis and at the circumference; the image side surface S12 of the sixth lens L6 is concave at the optical axis and convex at the circumference.

[0230] The seventh lens L7 has a negative refractive power. The object side surface S13 of the seventh lens L7 is convex at the optical axis and concave at the circumference; the image side surface S14 of the seventh lens L7 is concave at the optical axis and convex at the circumference.

[0231] The other structures of the tenth embodiment are the same as those of the first embodiment, and can be referred to.

[0232] Table 10a 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 555 nm, and the units of the Y radius, thickness, and focal length are all millimeters (mm).

[0233] Table 10a

[0234]

[0235] Among them, f is the effective focal length of the optical system, FNO is the f-number of the optical system, FOV is the maximum field of view angle in the diagonal direction 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.

[0236] Table 10b gives the higher-order term coefficients of the aspherical mirror surfaces that can be used in the tenth embodiment. Among them, each aspherical surface type can be defined by the formula given in the first embodiment.

[0237] Table 10b

[0238]

[0239]

[0240] Figure 10b Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the tenth embodiment. The light reference wavelength of the astigmatism curve and the distortion curve is 555 nm. According to Figure 10b It can be seen that the optical system given in the tenth embodiment can achieve good imaging quality.

[0241] Table 11 shows the values of f / EPD, f*tan(HFOV), TTL / Imgh, TTL / f, |R5 / R6|, TTH2 / CT3, |f1 / f5|, ET2 / CT2, TTL / f1, EPD / R1, and sd61 / sd52 of the optical systems of the first to tenth embodiments. Among them, the unit of f*tan(HFOV) is millimeters (mm).

[0242] Table 11

[0243]

[0244]

[0245] As can be seen from Table 11, the optical systems provided in the embodiments of the present invention all satisfy the following conditional expressions: f / EPD < 1.7, f * tan(HFOV) > 5.15 mm, TTL / Imgh < 1.7, 1 < TTL / f < 1.5, 0.5 < |R5 / R6| < 1.5, 0.5 < TTH2 / CT3 < 1.5, |f1 / f5| < 2, 0.2 < ET2 / CT2 < 1.3, TTL / f1 ≤ 1.5, EPD / R1 < 1.5, sd61 / sd52 ≤ 1.3.

[0246] The above-disclosed is only a preferred embodiment of the present invention. Of course, the scope of rights of the present invention cannot be limited thereby. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the invention.

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: A first lens with positive refractive power, the object side surface of the first lens is convex at the optical axis, and the image side surface of the first lens is concave both at the optical axis and at the circumference; A second lens with refractive power, the object side surface of the second lens is convex at the optical axis, and the image side surface of the second lens is concave both at the optical axis and at the circumference; A third lens with refractive power, the image side surface of the third lens is convex at the optical axis; A fourth lens with refractive power, the object side surface of the fourth lens is concave at the optical axis; A fifth lens with refractive power, the image side surface of the fifth lens is convex at the optical axis; A sixth lens with refractive power, the image side surface of the sixth lens is concave at the optical axis; A seventh lens with negative refractive power, the object side surface of the seventh lens is convex at the optical axis, the image side surface of the seventh lens is concave at the optical axis, and there is at least one inflection point; The optical system satisfies the conditional formula: f / EPD < 1.7; f * tan(HFOV) > 5.15 mm; 0.5 < |R5 / R6| < 1.5; Wherein, f is the effective focal length of the optical system, EPD is the entrance pupil diameter of the optical system, HFOV is the half field of view angle of the optical system, R5 is the curvature radius of the object side surface of the third lens at the optical axis, and R6 is the curvature radius of the image side surface of the third lens at the optical axis.

2. The optical system according to claim 1, characterized in that, The optical system satisfies the conditional formula: 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 photosensitive area on the imaging surface of the optical system.

3. The optical system according to claim 1, wherein The optical system satisfies the conditional formula: 1 < TTL / f < 1.5; 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.

4. The optical system according to claim 1, wherein The optical system satisfies the conditional formula: 0.5 < TTH2 / CT3 < 1.5; Wherein, TTH2 is the air interval distance on the optical axis from the second lens to the third lens, and CT3 is the thickness of the third lens on the optical axis.

5. The optical system according to claim 1, characterized in that, The optical system satisfies the conditional formula: |f1 / f5| < 2; Wherein, f1 is the effective focal length of the first lens, and f5 is the effective focal length of the fifth lens.

6. The optical system according to claim 1, characterized in that, The optical system satisfies the conditional formula: 0.2 < ET2 / CT2 < 1.3; Wherein, ET2 is the thickness at the edge of the optical effective area of the second lens, and CT2 is the thickness of the second lens on the optical axis.

7. The optical system according to claim 1, characterized in that, The optical system satisfies the conditional formula: 1.30 ≤ TTL / f1 ≤ 1.5; 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 f1 is the effective focal length of the first lens.

8. The optical system according to claim 1, wherein The optical system satisfies the conditional formula: 1.15 ≤ EPD / R1 < 1.5; Wherein, R1 is the curvature radius of the object side surface of the first lens at the optical axis.

9. The optical system according to claim 1, characterized in that, The optical system satisfies the conditional formula: 1.08 ≤ sd61 / sd52 ≤ 1.3; Wherein, sd61 is the light-passing aperture of the object side of the sixth lens at the maximum field of view angle; sd52 is the light-passing aperture of the image side of the fifth lens at the maximum field of view angle.

10. A lens module, characterized in that, It includes a lens barrel, a photosensitive element, and the optical system according to any one of claims 1 to 9. The first lens to the seventh lens of the optical system are installed in the lens barrel, and the photosensitive element is arranged on the image side of the optical system.

11. An electronic device, characterized in that, It includes a housing and the lens module according to claim 10. The lens module is arranged in the housing.

Images