Optical System, Lens Module and Terminal Device

Abstract

Embodiments of the present application disclose an optical system, a lens module, and a terminal device. The optical system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged in sequence from the object side to the image side. Among them, the first lens and the fifth lens have negative refractive powers, and the remaining lenses have positive refractive powers. The optical system satisfies the following conditional formula: 40 < (HFOV × f) / Imgh < 60; HFOV is the horizontal field of view angle of the optical system, f is the effective focal length of the optical system, and Imgh is the image height corresponding to the horizontal field of view angle of the optical system. By reasonably configuring the refractive powers of the first lens to the seventh lens in the optical system and limiting (HFOV × f) / Imgh, the optical system of the present application has the characteristics of a long focal length and a high pixel count, can clearly capture objects at a relatively long distance, has better image quality, and the image has more details.

Description

Technical Field

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

[0002] With the continuous development of automotive technology (such as assisted driving technology, autonomous driving and unmanned driving) and the increasing requirements for car driving safety, the application of vehicle-mounted cameras has become more and more popular and favored by more people. The functions of vehicle-mounted lenses vary with their installation locations.

[0003] The front-view camera needs to observe images at a long distance and bring distant objects closer so that the vehicle system can monitor the road conditions ahead in real time to ensure safe driving. Existing front-view cameras need to have a long focal length due to their long-distance shooting characteristics, but the overall pixel is difficult to guarantee.

[0004] How to make the front-view camera have the characteristics of long focal length and high pixel so that it can clearly capture objects at a long distance should be the research and development direction of the industry. Summary of the invention

[0005] The embodiments of the present application provide an optical system, a lens module and a terminal device. The optical system has a long focal length and a high pixel, can observe images beyond a long distance and has good imaging quality.

[0006] In a first aspect, an embodiment of the present application provides an optical system, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence from the object side to the image side, wherein the first lens and the fifth lens have negative refractive power, and the remaining lenses have positive refractive power; the optical system satisfies the following condition: 40<(HFOV×f) / Imgh<60; HFOV is the field of view angle of the optical system in the horizontal direction, f is the effective focal length of the optical system, and Imgh is the image height corresponding to the field of view angle of the optical system in the horizontal direction.

[0007] The present application reasonably configures the refractive power of the first lens to the seventh lens in the optical system, so that the optical system meets the characteristics of long focal length and high pixel, and can clearly capture objects at a longer distance, with better image quality and more details. At the same time, setting the appropriate range of (HFOV×f) / Imgh is conducive to improving the resolution ability of the optical system, improving the imaging quality, and making the system have the characteristics of long focal length, which is conducive to long-distance observation.

[0008] In one embodiment, the image side surface of the first lens is concave, the object side surface of the second lens is convex, the image side surface of the fifth lens is concave, the object side surface of the seventh lens is convex, and the image side surface of the seventh lens is concave. By restricting the surface types of the first lens, the second lens, the fifth lens, and the seventh lens and coordinating with the refractive power, it is beneficial to improve the imaging quality of the optical system.

[0009] In one embodiment, the object side surface and the image side surface of at least one of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are aspherical surfaces, which is beneficial to correcting the aberration of the optical system and improving the imaging quality of the optical system.

[0010] In one embodiment, an infrared filter film is provided on the object side surface or the image side surface of one of the first lens to the seventh lens, or an infrared filter is provided between the seventh lens and the imaging surface of the optical system. The infrared filter film or the infrared filter is used to filter out infrared light. The infrared filter film provided on the lens surface is beneficial to maintaining the color balance of the image plane, and the separate setting of the infrared filter is beneficial to the assembly process of the optical system lens.

[0011] In one embodiment, the optical system satisfies the conditional formula: -5 < f12 / f < -1; f12 is the combined focal length of the first lens and the second lens. The combination of the first lens and the second lens provides a negative refractive power for the system, which is beneficial to suppressing the high-order aberration caused by the light beam around the imaging area. When f12 / f > -5, it can have a negative optical power, which can suppress the reduction of the achromatic effect and make the optical system have high-resolution performance. When f12 / f < -1, it is beneficial to correct the aberration and further reduce the generation ratio of ghost images.

[0012] In one embodiment, the optical system satisfies the conditional formula: 13 < |R1| / CT1 < 25; R1 is the curvature radius at the optical axis of the object side surface of the first lens, and CT1 is the thickness of the first lens on the optical axis. When |R1| / CT1 < 25, it is beneficial to control the curvature radius of the object side surface of the first lens and reduce the generation of ghost images. When |R1| / CT1 > 13, by limiting the thickness of the first lens on the optical axis, the imaging quality of high pixels can be guaranteed, and it is beneficial to the compact structure of the optical system, realizing the characteristics of miniaturization.

[0013] In one embodiment, the optical system satisfies the condition: <d2<2;0<d3<1;d2为所述第二透镜和所述第三透镜于光轴上的空气间隔,d3为所述第三透镜和所述第四透镜于光轴上的空气间隔。通过对第二透镜和第三透镜及第三透镜和第四透镜间的空气间隔的合理设置,使光学系统的结构更加紧凑,并降低鬼影产生风险,提高成像质量。

[0014] In one embodiment, the optical system satisfies the condition: <f34 / f5<0;f34为所述第三透镜和所述第四透镜的组合焦距,f5为所述第五透镜的焦距。第三透镜和第四透镜的组合焦距为系统提供正屈折力,第五透镜为系统提供负屈折力,f34 / f5<0时,对光线起到发散作用,使尽可能多的光线通过光阑到达第五透镜,f34 / f5>-2时,有利于提升系统解像力,降低鬼影产生风险。

[0015] In one embodiment, the optical system satisfies the condition: f6 / f<10; f6 is the focal length of the sixth lens. By limiting f6 / f, it is beneficial to correct system aberrations and distortions, and make the optical system miniaturized.

[0016] In one embodiment, 0 <CT6 / d17<1;CT6为所述第六透镜于光轴上的厚度,d17为所述第一透镜至所述第七透镜中任意两个相邻透镜之间于光轴上的空气间隔之和。通过对第六透镜于光轴上的厚度的限定,可以控制光学系统总长度、保证系统小型化特点,并有利于校正系统像差,提升系统解像力。

[0017] In one embodiment, the optical system satisfies the condition: <f7 / f<5;f7为所述第七透镜的焦距。通过对f7 / f的限定,有利于强化光学系统的成像能力,f7 / f<5时,有利于校正系统像差,降低温度敏感度,f7绝对值越大,由温度引起的后焦变化量则越小,有利于避免因温度差异而造成的离焦现象,提升成像质量,使画面更清晰。

[0018] In one embodiment, the optical system satisfies the condition: <TTL / f<2;TTL为所述光学系统的总长。TTL / f<2时,可以避免光学系统总长太长或焦距过长,利于系统小型化,TTL / f>0时,有利于光学系统具有长焦距的特性。

[0019] In one embodiment, the optical system satisfies the conditional formula: FNO ≤ 1.6; FNO is the aperture number of the optical system. By controlling the light flux of the system, it helps to improve the imaging quality, endow the system with the characteristic of large depth of field, facilitate bringing distant objects closer, and enable the vehicle-mounted system to anticipate and analyze road conditions in advance.

[0020] In a second aspect, the present application provides a lens module, including a photosensitive element and the optical system according to any one of the foregoing embodiments, wherein the photosensitive element is located on the image side of the optical system.

[0021] In a third aspect, the present application provides a terminal device, including the lens module described above.

[0022] Through the reasonable configuration of the refractive powers of the first lens to the seventh lens in the optical system, the present application enables the optical system to have the characteristics of long focal length and high pixel count, allowing for clear shooting of objects at relatively long distances, with better image quality and more details in the picture. At the same time, setting the appropriate range of (HFOV × f) / Imgh is beneficial to improving the resolution of the optical system, enhancing pixel quality, and endowing the system with the characteristic of long focal length, which is conducive to long-distance observation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the background art, the following will describe the drawings required to be used in the embodiments of the present invention or the background art.

[0024] Figure 1 is a schematic diagram of the optical system provided by the present application applied in a terminal device;

[0025] Figure 2 is a schematic structural diagram of the optical system provided by the first embodiment of the present application;

[0026] Figure 3 is the spherical aberration curve of the optical system of the first embodiment;

[0027] Figure 4 is the astigmatism curve of the optical system of the first embodiment;

[0028] Figure 5 is the distortion curve of the optical system of the first embodiment;

[0029] Figure 6 is a schematic structural diagram of the optical system provided by the second embodiment of the present application;

[0030] Figure 7 is the spherical aberration curve of the optical system of the second embodiment;

[0031] Figure 8 is the astigmatism curve of the optical system of the second embodiment;

[0032] Figure 9 is the distortion curve of the optical system of the second embodiment;

[0033] Figure 10 is a schematic structural diagram of the optical system provided in the third embodiment of the present application;

[0034] Figure 11 is the spherical aberration curve of the optical system of the third embodiment;

[0035] Figure 12 is the astigmatism curve of the optical system of the third embodiment;

[0036] Figure 13 is the distortion curve of the optical system of the third embodiment;

[0037] Figure 14 is a schematic structural diagram of the optical system provided in the fourth embodiment of the present application;

[0038] Figure 15 is the spherical aberration curve of the optical system of the fourth embodiment;

[0039] Figure 16 is the astigmatism curve of the optical system of the fourth embodiment;

[0040] Figure 17 is the distortion curve of the optical system of the fourth embodiment;

[0041] Figure 18 is a schematic structural diagram of the optical system provided in the fifth embodiment of the present application;

[0042] Figure 19 is the spherical aberration curve of the optical system of the fifth embodiment;

[0043] Figure 20 is the astigmatism curve of the optical system of the fifth embodiment;

[0044] Figure 21 is the distortion curve of the optical system of the fifth embodiment. Detailed implementation manners

[0045] The embodiments of the present invention will be described below with reference to the accompanying drawings in the embodiments of the present invention.

[0046] Refer to Figure 1 , the optical system 10 involved in the present application is applied to the lens module 20 in the terminal device 30. The terminal device 30 can be a mobile phone, a monitor, a vehicle-mounted device, etc. The photosensitive element 210 of the lens module 20 is located on the image side of the optical system 10, and the lens module 20 is assembled inside the terminal device 30.

[0047] The present application provides a lens module, including a photosensitive element and an optical system provided by the embodiments of the present application. The photosensitive element is located on the image side of the optical system and is used to convert the light passing through the first lens to the seventh lens and incident on the electronic photosensitive element into an electrical signal of an image. The electronic photosensitive element can be a Complementary Metal Oxide Semiconductor (CMOS) or a Charge-coupled Device (CCD). By installing the optical system in the lens module, the lens module meets the characteristics of long focal length and high pixel, can clearly capture objects at a relatively long distance, has better image quality, and the picture has more details.

[0048] The present application also provides a terminal device, which includes the lens module provided by the embodiments of the present application. The terminal device can be a mobile phone, a monitor, a vehicle-mounted device, etc. By installing the lens module in the terminal device, the terminal device meets the characteristics of long focal length and high pixel, can clearly capture objects at a relatively long distance, has better image quality, and the picture has more details.

[0049] An optical system provided by the present application includes seven lenses. The seven lenses are sequentially distributed from the object side to the image side as the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens.

[0050] Specifically, the refractive powers of the seven lenses are as follows:

[0051] The first lens has a negative refractive power; the second lens has a positive refractive power; the third lens has a positive refractive power; the fourth lens has a positive refractive power; the fifth lens has a negative refractive power; the sixth lens has a positive refractive power; the seventh lens has a positive refractive power.

[0052] The optical system satisfies the following conditional formula: 40 < (HFOV × f) / Imgh < 60; HFOV is the horizontal field of view angle of the optical system, f is the effective focal length of the optical system, and Imgh is the image height corresponding to the horizontal field of view angle of the optical system.

[0053] Through the reasonable configuration of the refractive powers of the first lens to the seventh lens in the optical system, the present application enables the optical system to meet the characteristics of long focal length and high pixel, can clearly capture objects at a relatively long distance, has better image quality, and the picture has more details. At the same time, setting the appropriate range of (HFOV × f) / Imgh is beneficial to improving the resolution ability of the optical system, enhancing the pixel quality, and enabling the system to have the characteristic of long focal length, which is beneficial to long-distance observation.

[0054] In one embodiment, the image side surface of the first lens is concave, the object side surface of the second lens is convex, the image side surface of the fifth lens is concave, the object side surface of the seventh lens is convex, and the image side surface of the seventh lens is concave. By restricting the surface types of the first lens, the second lens, the fifth lens, and the seventh lens and coordinating with the refractive power, it is beneficial to improve the imaging quality of the optical system.

[0055] In one embodiment, the object side surface and the image side surface of at least one of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are aspherical surfaces to correct the aberration of the optical system and improve the imaging quality of the optical system. In one embodiment, an infrared filter film is provided on the object side surface or the image side surface of any one of the first lens to the seventh lens, or an infrared filter is provided between the seventh lens and the image side of the optical system. The infrared filter film or the infrared filter is used to filter out infrared light. The infrared filter film is arranged on the lens surface to help maintain color balance of the image plane, and separately arranging the infrared filter is beneficial to the assembly process of the lenses of the optical system.

[0056] In one embodiment, the optical system satisfies the conditional formula: -5 < f12 / f < -1; f12 is the combined focal length of the first lens and the second lens. The combination of the first lens and the second lens provides negative refractive power for the system, which is beneficial to suppressing high-order aberrations caused by the light beams around the imaging area. When f12 / f > -5, it can have a negative optical power, which can suppress the reduction of the achromatic aberration effect and enable the optical system to have high-resolution performance. When f12 / f < -1, it is beneficial to correct aberrations and further reduce the generation ratio of ghost images.

[0057] In one embodiment, the optical system satisfies the conditional formula: 13 < |R1| / CT1 < 25; R1 is the radius of curvature of the object side surface of the first lens, and CT1 is the thickness of the first lens on the optical axis. When |R1| / CT1 < 25, it is beneficial to control the radius of curvature of the object side surface of the first lens and reduce the generation of ghost images. When |R1| / CT1 > 13, by limiting the thickness of the first lens on the optical axis, it is possible to ensure high-pixel imaging quality and is beneficial to the compact structure of the optical system, realizing the characteristics of miniaturization.

[0058] In one embodiment, the optical system satisfies the conditional formulas: 0 < d2 < 2; 0 < d3 < 1; d2 is the air gap between the second lens and the third lens on the optical axis, and d3 is the air gap between the third lens and the fourth lens on the optical axis. By reasonably setting the air gaps between the second lens and the third lens and between the third lens and the fourth lens, the structure of the optical system is made more compact, the risk of ghost image generation is reduced, and the imaging quality is improved.

[0059] In one embodiment, the optical system satisfies the condition: <f34 / f5<0;f34为所述第三透镜和所述第四透镜的组合焦距,f5为所述第五透镜的焦距。第三透镜和第四透镜的组合焦距为系统提供正屈折力,第五透镜为系统提供负屈折力,f34 / f5<0时,对光线起到发散作用,使尽可能多的光线通过光阑到达第五透镜,f34 / f5>-2时,有利于提升系统解像力,降低鬼影产生风险。

[0060] In one embodiment, the optical system satisfies the condition: f6 / f<10; f6 is the focal length of the sixth lens. By limiting f6 / f, it is beneficial to correct system aberrations and distortions, and make the optical system miniaturized.

[0061] In one embodiment, 0 <CT6 / d17<1;CT6为所述第六透镜于光轴上的厚度,d17为所述第一透镜至所述第七透镜中任意两个相邻透镜之间于光轴上的空气间隔之和。通过对第六透镜于光轴上的厚度的限定,可以控制光学系统总长度、保证系统小型化特点,并有利于校正系统像差,提升系统解像力。

[0062] In one embodiment, the optical system satisfies the condition: <f7 / f<5;f7为所述第七透镜的焦距。通过对f7 / f的限定,有利于强化光学系统的成像能力,f7 / f<5时,有利于校正系统像差,降低温度敏感度,f7绝对值越大,由温度引起的后焦变化量则越小,有利于避免因温度差异而造成的离焦现象,提升成像质量,使画面更清晰。

[0063] In one embodiment, the optical system satisfies the condition: <TTL / f<2;TTL为所述光学系统的总长。TTL / f<2时,可以避免光学系统总长太长或焦距过长,利于系统小型化,TTL / f>0时,有利于光学系统具有长焦距的特性。

[0064] In one embodiment, the optical system satisfies the condition: FNO≤1.6; FNO is the aperture number of the optical system. By controlling the light flux of the system, it helps to improve the imaging quality, so that the system has the characteristics of a large depth of field, which is conducive to bringing distant objects closer, and enables the vehicle-mounted system to predict and analyze the road conditions in advance.

[0065] By defining the above various parameters, the optical system has good imaging quality. For example, preferably: the value of f12 / f can be -4.15 or -2.98 or -3.53, etc.; the value of |R1| / CT1 can be 19.734 or 21.288 or 15.648, etc.; the value of d2 can be 1.626 or 0.12 or 0.1, etc.; the value of d3 can be 0.12 or 0.177 or 0.611, etc.; the value of f34 / f5 can be -1.10 or -0.94 or -0.97, etc.; the value of f6 / f can be 2.324 or 6.276 or 9.042, etc.

[0066] Among all the lenses of the optical system, the object side and the image side of at least one of the lenses are aspherical surfaces, which is beneficial to correcting the system aberration and improving the system imaging quality. The aspherical curve equation includes but is not limited to the following aspherical formula:

[0067]

[0068] Where Z is the distance from the corresponding point on the aspherical surface to the plane tangent to the surface vertex, r is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the aspherical vertex, k is the conic constant, and Ai is the coefficient corresponding to the i-th high-order term in the aspherical surface formula.

[0069] The following details the present application through five specific embodiments. The reference wavelength of the optical systems in the following five embodiments is 546.074 nm.

[0070] Embodiment 1

[0071] As Figure 2 shown, the middle straight line represents the optical axis. The left side of the optical system is the object side, and the right side is the image side. In the optical system provided in this embodiment, from the object side to the image side, there are successively the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the aperture stop STO, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the protective glass CG.

[0072] The first lens L1 has negative refractive power and is made of glass. Its object side surface S1 is convex, and its image side surface S2 is concave, and both are spherical surfaces.

[0073] The second lens L2 has positive refractive power and is made of glass. Its object side surface S3 is convex, and its image side surface S4 is concave, and both are spherical surfaces.

[0074] The third lens L3 has positive refractive power and is made of glass. Its object side surface S5 is convex, and its image side surface S6 is flat, and both are spherical surfaces.

[0075] The fourth lens L4 has a positive refractive power and is made of glass. Its object-side surface S7 is convex, and its image-side surface S8 is flat, and both are spherical surfaces.

[0076] The fifth lens L5 has a negative refractive power and is made of glass. Its object-side surface S9 is concave, and its image-side surface S10 is concave, and both are spherical surfaces.

[0077] The sixth lens L6 has a positive refractive power and is made of glass. Its object-side surface S11 is convex, and its image-side surface S12 is convex, and both are aspherical surfaces.

[0078] The seventh lens L7 has a positive refractive power and is made of glass. Its object-side surface S13 is convex, and its image-side surface S14 is concave, and both are aspherical surfaces.

[0079] The aperture stop STO can be located between the object side of the optical system and the seventh lens. In this embodiment, the aperture stop STO is located behind the fourth lens L4 and tends to be in the middle position of the optical system, which is beneficial to balancing the aberration of the optical system.

[0080] In this embodiment, an infrared filter film IRCF ( Figure 2 not shown) is provided on one side of the image-side surface S6 of the third lens. The infrared filter film IRCF includes an object side surface and an image side surface. The infrared filter film IRCF is used to filter out infrared light so that the light incident on the imaging surface is visible light. The wavelength of the visible light is 380nm - 780nm, and the material of the infrared filter film IRCF is glass.

[0081] The protective glass CG is located behind the seventh lens L7 and includes an object-side surface S15 and an image-side surface S16. The protective glass CG is used to protect the photosensitive element, prevent the photosensitive element from being exposed outside, and protect the photosensitive element from the influence of dust, etc., to ensure the imaging quality. The imaging surface S17 is the effective pixel area of the electronic photosensitive element.

[0082] Table 1a shows the characteristic table of the optical system of this embodiment.

[0083] Table 1a

[0084]

[0085]

[0086] Among them, f is the effective focal length of the optical system, FNO is the f-number of the optical system, and FOV is the field of view angle in the diagonal direction of the optical system.

[0087] Table 1b gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for the aspherical surfaces S11, S12, S13, and S14 in the first embodiment.

[0088] Table 1b

[0089] Surface number S11 S12 S13 S14 K 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A4 2.76E-05 -1.55E-03 -3.60E-03 -2.94E-03 A6 9.45E-06 1.59E-04 1.95E-04 8.71E-05 A8 -3.48E-07 -5.32E-06 -4.95E-06 -1.10E-06 A10 -1.05E-08 6.28E-08 4.98E-08 0.00E+00 A12 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A14 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A16 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A18 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A20 0.00E+00 0.00E+00 0.00E+00 0.00E+00

[0090] Figure 3 Shows the spherical aberration curve of the optical system of the first embodiment, which represents the deviation of the convergence points of light rays of different wavelengths after passing through each lens of the optical system;

[0091] Figure 4 Shows the astigmatism curve of the optical system of the first embodiment, which represents the curvature of the meridional image plane and the curvature of the sagittal image plane;

[0092] Figure 5 Shows the distortion curve of the optical system of the first embodiment, which represents the distortion magnitude values corresponding to different field angles;

[0093] According to Figure 3 , Figure 4 and Figure 5 it can be known that the optical system given in the first embodiment can achieve good imaging quality.

[0094] Embodiment Two

[0095] As Figure 6 shown, the middle straight line represents the optical axis. The left side of the optical system is the object side, and the right side is the image side. In the optical system provided in this embodiment, from the object side to the image side are successively the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the aperture STO, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the protective glass CG.

[0096] The first lens L1 has a negative refractive power and is made of glass. Its object-side surface S1 is concave, and its image-side surface S2 is concave, and both are spherical surfaces.

[0097] The second lens L2 has a positive refractive power and is made of glass. Its object-side surface S3 is convex, and its image-side surface S4 is convex, and both are spherical surfaces.

[0098] The third lens L3 has a positive refractive power and is made of glass. Its object-side surface S5 is convex, and its image-side surface S6 is concave, and both are spherical surfaces.

[0099] The fourth lens L4 has a positive refractive power and is made of glass. Its object-side surface S7 is convex, and its image-side surface S8 is flat, and both are spherical surfaces.

[0100] The fifth lens L5 has a negative refractive power and is made of glass. Its object-side surface S9 is concave, and its image-side surface S10 is concave, and both are spherical surfaces.

[0101] The sixth lens L6 has a positive refractive power and is made of glass. Its object-side surface S11 is convex, and its image-side surface S12 is concave, and both are aspherical surfaces.

[0102] The seventh lens L7 has a positive refractive power and is made of glass. Its object-side surface S13 is convex, and its image-side surface S14 is concave, and both are aspherical surfaces.

[0103] The stop STO can be located between the object side of the optical system and the seventh lens. In this embodiment, the stop STO is located behind the fourth lens L4 and tends to be in the middle position of the optical system, which is beneficial to balancing the aberration of the optical system.

[0104] In this embodiment, an infrared filter film IRCF ( Figure 6 not shown) is provided on one side of the image side surface S8 of the fourth lens. The infrared filter film IRCF includes an object side surface and an image side surface. The infrared filter film IRCF is used to filter out infrared light so that the light incident on the imaging surface is visible light. The wavelength of the visible light is 380nm - 780nm, and the material of the infrared filter film IRCF is glass.

[0105] The protective glass CG is located behind the seventh lens L7 and includes an object side surface S15 and an image side surface S16. The protective glass CG is used to protect the photosensitive element, prevent the photosensitive element from being exposed, protect the photosensitive element from dust, etc., and ensure the imaging quality. The imaging surface S17 is the effective pixel area of the electronic photosensitive element.

[0106] Table 2a shows the characteristic table of the optical system of this embodiment.

[0107] Table 2a

[0108]

[0109] Among them, f is the effective focal length of the optical system, FNO is the aperture number of the optical system, and FOV is the field of view angle in the diagonal direction of the optical system.

[0110] Table 2b gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for the aspherical mirror surfaces S11, S12, S13, and S14 in the second embodiment.

[0111] Table 2b

[0112] Surface number S11 S12 S13 S14 K 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A4 -1.58E-04 -1.34E-03 -3.73E-03 -2.98E-03 A6 1.26E-06 1.16E-04 1.09E-04 5.64E-05 A8 -2.86E-07 -3.77E-06 -6.72E-07 -3.75E-07 A10 -4.20E-09 5.35E-08 -8.22E-09 0.00E+00 A12 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A14 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A16 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A18 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A20 0.00E+00 0.00E+00 0.00E+00 0.00E+00

[0113] Figure 7 shows the spherical aberration curve of the optical system of the second embodiment, which represents the deviation of the convergence points of light rays of different wavelengths after passing through the respective lenses of the optical system;

[0114] Figure 8The astigmatism curve of the optical system of the second embodiment is shown, which represents the curvature of the meridional image plane and the curvature of the sagittal image plane;

[0115] Figure 9 The distortion curve of the optical system of the second embodiment is shown, which represents the distortion magnitude values corresponding to different field angles;

[0116] According to Figure 7 、 Figure 8 and Figure 9 it can be known that the optical system given in the second embodiment can achieve good imaging quality.

[0117] Embodiment Three

[0118] As Figure 10 shown, the middle straight line represents the optical axis. The left side of the optical system is the object side, and the right side is the image side. In the optical system provided in this embodiment, from the object side to the image side are successively the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the aperture stop STO, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the protective glass CG.

[0119] The first lens L1 has a negative refractive power and is made of glass. Its object-side surface S1 is concave, and its image-side surface S2 is concave, and both are spherical surfaces.

[0120] The second lens L2 has a positive refractive power and is made of glass. Its object-side surface S3 is convex, and its image-side surface S4 is convex, and both are spherical surfaces.

[0121] The third lens L3 has a positive refractive power and is made of glass. Its object-side surface S5 is convex, and its image-side surface S6 is concave, and both are spherical surfaces.

[0122] The fourth lens L4 has a positive refractive power and is made of glass. Its object-side surface S7 is convex, and its image-side surface S8 is flat, and both are spherical surfaces.

[0123] The fifth lens L5 has a negative refractive power and is made of glass. Its object-side surface S9 is concave, and its image-side surface S10 is concave, and both are spherical surfaces.

[0124] The sixth lens L6 has a positive refractive power and is made of glass. Its object-side surface S11 is convex, and its image-side surface S12 is concave, and both are aspherical surfaces.

[0125] The seventh lens L7 has a positive refractive power and is made of glass. Its object-side surface S13 is convex, and its image-side surface S14 is concave, and both are aspherical surfaces.

[0126] The aperture STO can be located between the object side of the optical system and the seventh lens. In this embodiment, the aperture STO is located behind the fourth lens L4 and tends to be in the middle position of the optical system, which is beneficial to balancing the aberration of the optical system.

[0127] In this embodiment, an infrared filter film IRCF ( Figure 10 not shown) is provided on one side of the object surface S9 of the fifth lens. The infrared filter film IRCF includes an object side and an image side. The infrared filter film IRCF is used to filter out infrared light so that the light incident on the imaging surface is visible light. The wavelength of the visible light is 380nm - 780nm, and the material of the infrared filter film IRCF is glass.

[0128] The protective glass CG is located behind the seventh lens L7 and includes an object side S15 and an image side S16. The protective glass CG is used to protect the photosensitive element, prevent the photosensitive element from being exposed outside, and make the photosensitive element not affected by dust, etc., to ensure the imaging quality. The imaging surface S17 is the effective pixel area of the electronic photosensitive element.

[0129] Table 3a shows the characteristic table of the optical system of this embodiment.

[0130] Table 3a

[0131]

[0132] Among them, f is the effective focal length of the optical system, FNO is the f-number of the optical system, and FOV is the field angle in the diagonal direction of the optical system.

[0133] Table 3b gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for the aspherical mirror surfaces S11, S12, S13, and S14 in the third embodiment.

[0134] Table 3b

[0135]

[0136]

[0137] Figure 11 shows the spherical aberration curve of the optical system of the third embodiment, which represents the deviation of the convergence points of light rays with different wavelengths after passing through the lenses of the optical system;

[0138] Figure 12 shows the astigmatism curve of the optical system of the third embodiment, which represents the meridional image plane curvature and the sagittal image plane curvature;

[0139] Figure 13 shows the distortion curve of the optical system of the third embodiment, which represents the distortion magnitude values corresponding to different field angles;

[0140] According to Figure 11 、 Figure 12 and Figure 13 it can be seen that the optical system given in the third embodiment can achieve good imaging quality.

[0141] Embodiment Four

[0142] As Figure 14 shown, the middle straight line represents the optical axis. The left side of the optical system is the object side, and the right side is the image side. In the optical system provided in this embodiment, from the object side to the image side are successively the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the aperture stop STO, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the protective glass CG.

[0143] The first lens L1 has a negative refractive power and is made of glass. Its object-side surface S1 is concave, and its image-side surface S2 is concave, and both are spherical surfaces.

[0144] The second lens L2 has a positive refractive power and is made of glass. Its object-side surface S3 is convex, and its image-side surface S4 is convex, and both are spherical surfaces.

[0145] The third lens L3 has a positive refractive power and is made of glass. Its object-side surface S5 is convex, and its image-side surface S6 is concave, and both are spherical surfaces.

[0146] The fourth lens L4 has a positive refractive power and is made of glass. Its object-side surface S7 is convex, and its image-side surface S8 is flat, and both are spherical surfaces.

[0147] The fifth lens L5 has a negative refractive power and is made of glass. Its object-side surface S9 is concave, and its image-side surface S10 is concave, and both are spherical surfaces.

[0148] The sixth lens L6 has a positive refractive power and is made of glass. Its object-side surface S11 is convex, and its image-side surface S12 is concave, and both are aspherical surfaces.

[0149] The seventh lens L7 has a positive refractive power and is made of glass. Its object-side surface S13 is convex, and its image-side surface S14 is concave, and both are aspherical surfaces.

[0150] The aperture stop STO can be located between the object side of the optical system and the seventh lens. In this embodiment, the aperture stop STO is located behind the fourth lens L4 and tends to the middle position of the optical system, which is beneficial to balancing the aberration of the optical system.

[0151] In this embodiment, an infrared filter film IRCF is provided on the side of the image surface S8 of the fourth lens ( Figure 14(not shown), the infrared filter film IRCF includes an object side and an image side. The infrared filter film IRCF is used to filter out infrared light so that the light incident on the imaging surface is visible light with a wavelength of 380nm - 780nm. The material of the infrared filter film IRCF is glass.

[0152] The protective glass CG is located behind the seventh lens L7 and includes an object side S15 and an image side S16. The protective glass CG is used to protect the photosensitive element, prevent the photosensitive element from being exposed, protect the photosensitive element from dust, etc., and ensure the imaging quality. The imaging surface S17 is the effective pixel area of the electronic photosensitive element.

[0153] Table 4a shows the characteristic table of the optical system of this embodiment.

[0154] Table 4a

[0155]

[0156] Among them, f is the effective focal length of the optical system, FNO is the aperture number of the optical system, and FOV is the field of view angle in the diagonal direction of the optical system.

[0157] Table 4b gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for each aspherical mirror surface S11, S12, S13, S14 in the fourth embodiment.

[0158] Table 4b

[0159] Surface number S11 S12 S13 S14 K 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A4 -2.46E-04 -1.50E-03 -2.73E-03 -2.59E-03 A6 -5.74E-06 9.25E-05 8.31E-05 5.57E-05 A8 1.25E-07 -4.96E-06 -1.21E-06 -9.69E-07 A10 -1.64E-08 6.90E-08 -5.16E-08 0.00E+00 A12 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A14 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A16 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A18 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A20 0.00E+00 0.00E+00 0.00E+00 0.00E+00

[0160] Figure 15 shows the spherical aberration curve of the optical system of the fourth embodiment, which represents the deviation of the focusing points of light rays with different wavelengths after passing through each lens of the optical system;

[0161] Figure 16 shows the astigmatism curve of the optical system of the fourth embodiment, which represents the curvature of the meridional image plane and the curvature of the sagittal image plane;

[0162] Figure 17 shows the distortion curve of the optical system of the fourth embodiment, which represents the distortion magnitude values corresponding to different field of view angles;

[0163] According to Figure 15 , Figure 16 and Figure 17 it can be seen that the optical system given in the fourth embodiment can achieve good imaging quality.

[0164] Embodiment Five

[0165] As Figure 18As shown, the middle straight line represents the optical axis. The left side of the optical system is the object side, and the right side is the image side. In the optical system provided in this embodiment, from the object side to the image side, there are successively the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the aperture STO, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the protective glass CG.

[0166] The first lens L1 has a negative refractive power and is made of glass. Its object-side surface S1 is concave, and its image-side surface S2 is concave, and both are spherical surfaces.

[0167] The second lens L2 has a positive refractive power and is made of glass. Its object-side surface S3 is convex, and its image-side surface S4 is convex, and both are spherical surfaces.

[0168] The third lens L3 has a positive refractive power and is made of glass. Its object-side surface S5 is convex, and its image-side surface S6 is concave, and both are spherical surfaces.

[0169] The fourth lens L4 has a positive refractive power and is made of glass. Its object-side surface S7 is convex, and its image-side surface S8 is flat, and both are spherical surfaces.

[0170] The fifth lens L5 has a negative refractive power and is made of glass. Its object-side surface S9 is concave, and its image-side surface S10 is concave, and both are spherical surfaces.

[0171] The sixth lens L6 has a positive refractive power and is made of glass. Its object-side surface S11 is convex, and its image-side surface S12 is concave, and both are aspherical surfaces.

[0172] The seventh lens L7 has a positive refractive power and is made of glass. Its object-side surface S13 is convex, and its image-side surface S14 is concave, and both are aspherical surfaces.

[0173] The aperture STO can be located between the object side of the optical system and the seventh lens. In this embodiment, the aperture STO is located behind the fourth lens L4 and tends to the middle position of the optical system, which is beneficial to balancing the aberration of the optical system.

[0174] In this embodiment, an infrared filter film IRCF ( Figure 18 not shown) is provided on one side of the object-side surface S3 of the second lens. The infrared filter film IRCF includes an object-side surface and an image-side surface. The infrared filter film IRCF is used to filter out infrared light so that the light incident on the imaging surface is visible light. The wavelength of the visible light is 380nm - 780nm, and the material of the infrared filter film IRCF is glass.

[0175] The protective glass CG is located behind the seventh lens L7, and includes an object side surface S15 and an image side surface S16. The protective glass CG is used to protect the photosensitive element, prevent the photosensitive element from being exposed outside, protect the photosensitive element from dust, etc., and ensure the imaging quality. The imaging surface S17 is the effective pixel area of the electronic photosensitive element.

[0176] Table 5a shows the characteristic table of the optical system of this embodiment.

[0177] Table 5a

[0178]

[0179]

[0180] Among them, f is the effective focal length of the optical system, FNO is the aperture number of the optical system, and FOV is the field of view angle in the diagonal direction of the optical system.

[0181] Table 5b gives the high-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for each aspherical mirror surface S11, S12, S13, S14 in the fifth embodiment.

[0182] Table 5b

[0183] Surface number S11 S12 S13 S14 K 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A4 -2.45E-04 -1.47E-03 -3.01E-03 -3.55E-03 A6 -6.70E-06 9.13E-05 9.41E-05 3.62E-05 A8 1.23E-07 -5.03E-06 -8.66E-07 1.76E-06 A10 -1.58E-08 7.51E-08 -4.64E-08 0.00E+00 A12 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A14 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A16 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A18 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A20 0.00E+00 0.00E+00 0.00E+00 0.00E+00

[0184] Figure 19 Shows the spherical aberration curve of the optical system of the fifth embodiment, which represents the deviation of the focusing points of light rays with different wavelengths after passing through each lens of the optical system;

[0185] Figure 20 Shows the astigmatism curve of the optical system of the fifth embodiment, which represents the curvature of the meridional image plane and the curvature of the sagittal image plane;

[0186] Figure 21 Shows the distortion curve of the optical system of the fifth embodiment, which represents the distortion magnitude values corresponding to different field of view angles;

[0187] According to Figure 19 、 Figure 20 and Figure 21 it can be known that the optical system given in the fifth embodiment can achieve good imaging quality.

[0188] Table 6 shows the values of f12 / f, |R1| / CT1, d2, d3, f34 / f5, (HFOV×f) / Imgh, CT6 / d17, f6 / f, f7 / f, TTL / f, and FNO of the optical systems of the first to fifth embodiments.

[0189] Table 6

[0190]

[0191]

[0192] As can be seen from Table 6, each embodiment can meet the following conditions: -5 < f12 / f < -1, 13 < |R1| / CT1 < 25, 0 < d2 < 2, 0 < d3 < 1, -2 < f34 / f5 < 0, 40 < (HFOV×f) / Imgh < 60, 0 < CT6 / d17 < 1, 0 < f6 / f < 10, 0 < f7 / f < 5, 0 < TTL / f < 2, FNO ≤ 1.6.

[0193] The above is the preferred embodiment of the present application. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present application, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present application.

Claims

1. An optical system, characterized in that, There are a total of seven lenses with refractive power, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged in sequence from the object side to the image side. Among them, the first lens and the fifth lens have negative refractive power, and the remaining lenses have positive refractive power. The object side surface of the third lens is convex; The optical system satisfies the following conditional expressions: 40° < (HFOV × f) / Imgh < 60°; HFOV is the horizontal field of view angle of the optical system, f is the effective focal length of the optical system, and Imgh is the image height corresponding to the horizontal field of view angle of the optical system.

2. The optical system according to claim 1, characterized in that, The image side surface of the first lens is concave, the object side surface of the second lens is convex, the object side surface of the fourth lens is convex, the image side surface of the fourth lens is flat, the object side surface of the fifth lens is concave, the image side surface of the fifth lens is concave, the object side surface of the sixth lens is convex, the object side surface of the seventh lens is convex, and the image side surface of the seventh lens is concave.

3. The optical system according to claim 1, characterized in that, At least one of the object side surface and the image side surface of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens is an aspherical surface.

4. The optical system according to claim 1, characterized in that, An infrared filter film is provided on the object side surface or the image side surface of one of the first lens to the seventh lens, or an infrared filter is provided between the seventh lens and the imaging surface of the optical system.

5. The optical system according to any one of claims 1 to 4, characterized in that The optical system satisfies the conditional expression: -5 < f12 / f < -1; f12 is the combined focal length of the first lens and the second lens.

6. The optical system according to any one of claims 1 to 4, characterized in that, The optical system satisfies the conditional expression: 13 < |R1| / CT1 < 25; R1 is the radius of curvature at the optical axis of the object side surface of the first lens, and CT1 is the thickness of the first lens on the optical axis.

7. The optical system according to any one of claims 1 to 4, characterized in that The optical system satisfies the conditional expression: 0mm < d2 < 2mm; 0mm < d3 < 1mm; d2 is the air gap on the optical axis between the second lens and the third lens, and d3 is the air gap on the optical axis between the third lens and the fourth lens.

8. The optical system according to any one of claims 1 to 4, characterized in that, The optical system satisfies the conditional expression: -2 < f34 / f5 < 0; f34 is the combined focal length of the third lens and the fourth lens, and f5 is the focal length of the fifth lens.

9. The optical system according to any one of claims 1 to 4, characterized in that, The optical system satisfies the conditional expression: 0 < f6 / f < 10; f6 is the focal length of the sixth lens.

10. The optical system according to any one of claims 1 to 4, characterized in that, The optical system satisfies the conditional expression: 0 < CT6 / d17 < 1; CT6 is the thickness of the sixth lens on the optical axis, and d17 is the sum of the air gaps on the optical axis between any two adjacent lenses among the first lens to the seventh lens.

11. The optical system according to any one of claims 1 to 4, characterized in that, The optical system satisfies the conditional expression: 0 < f7 / f < 5; f7 is the focal length of the seventh lens.

12. The optical system according to any one of claims 1 to 4, characterized in that, The optical system satisfies the conditional expression: 0 < TTL / f < 2; TTL is the total length of the optical system.

13. The optical system according to any one of claims 1 to 4, characterized in that, The optical system satisfies the conditional expression: FNO ≤ 1.6; FNO is the f-number of the optical system.

14. A lens module, characterized in that, It includes a photosensitive element and the optical system according to any one of claims 1 to 13, and the photosensitive element is located on the image side of the optical system.

15. A terminal device, characterized in that, Including the lens module as described in claim 14.

Images