Optical system, imaging device and electronic device

Abstract

The present application discloses an optical system, an imaging device, and an electronic device. The optical system sequentially includes, from the object side to the image side along the optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens; the first lens has a positive refractive power, its object side surface is convex at the optical axis, and its image side surface is concave at the optical axis; the second lens has a positive refractive power, and its object side surface is convex at the optical axis; the third lens has a negative refractive power, its object side surface is convex at the optical axis, and its image side surface is concave at the optical axis; the fifth lens has a positive refractive power, and its image side surface is convex at the optical axis; the seventh lens has a negative refractive power, and its image side surface is concave at the optical axis; the optical system satisfies the following relational expression: TTL / ImgH < 1.3; where TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis, and ImgH is half of the diagonal length of the effective pixel region on the imaging surface of the optical system.

Description

Technical Field

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

[0002] In recent years, with the wide application of electronic products such as mobile phones, tablet computers, drones, and computers in life, people have paid increasing attention to the improvement and innovation of the shooting effects of lenses in these electronic products. Among them, lenses that can capture bright, high-quality, and clear pictures are increasingly favored by users. On the other hand, with the progress of technology, the pixel sizes of photosensitive elements such as charge-coupled device (CCD) and complementary metal-oxide-semiconductor (CMOS) are getting smaller and smaller, and thus the requirements for the imaging quality of the matching optical systems are also getting higher and higher.

[0003] However, traditional miniaturized lenses have weak low-light shooting capabilities while ensuring imaging clarity, and cannot meet the shooting requirements for low-light scenarios such as night scenes, rainy days, and starry skies. Summary of the Invention

[0004] Based on this, in view of the problem that traditional miniaturized lenses are difficult to adapt to low-light scenarios while ensuring imaging quality, it is necessary to provide an improved optical system.

[0005] An optical system sequentially includes, from the object side to the image side along the optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. Among them, the first lens has a positive refractive power, and its object side surface is convex at the optical axis, and its image side surface is concave at the optical axis; the second lens has a positive refractive power, and its object side surface is convex at the optical axis; the third lens has a negative refractive power, and its object side surface is convex at the optical axis, and its image side surface is concave at the optical axis; the fifth lens has a positive refractive power, and its image side surface is convex at the optical axis; the seventh lens has a negative refractive power, and its image side surface is concave at the optical axis; the optical system satisfies the following relational expression: TTL / ImgH < 1.3; where TTL is the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis, and ImgH is half of the diagonal length of the effective pixel region on the imaging surface of the optical system.

[0006] The above optical system rationally distributes the refractive powers, surface types of each lens, and the distances between each lens to ensure that the total length of the optical system is relatively small while having high imaging quality, so as to better meet the application requirements of thin and light electronic devices; at the same time, under the condition that the total length of the control system and the diagonal distance of the effective pixel region satisfy the above relationship, it is also beneficial to realize the miniaturization of the optical system.

[0007] In one embodiment, the optical system satisfies the following relational expression: 1.5 < f / R14 < 2.6; where f is the effective focal length of the optical system, and R14 is the radius of curvature of the image side surface of the seventh lens on the optical axis.

[0008] By controlling the effective focal length of the optical system and the radius of curvature of the image side surface of the seventh lens on the optical axis to satisfy the above relationship, it is beneficial to optimize the value of the radius of curvature of the image side surface of the seventh lens on the optical axis, so as to better match the incident angle of the chief ray of the inner field of view of the photosensitive element on the imaging surface and improve the central brightness of the picture.

[0009] In one embodiment, the optical system satisfies the following relational expression: FNO < 1.9; where FNO is the f-number of the optical system.

[0010] By controlling the f-number of the optical system to satisfy the above relationship, it is possible to make the optical system have a larger effective light transmission aperture while ensuring the miniaturization of the optical system and the invariance of the effective focal length. Compared with traditional miniaturized lenses, it has more incident light, so as to improve the low-light shooting performance of the lens and the imaging clarity, meeting the shooting requirements of low-light scenes such as night scenes and starry skies; in addition, the smaller the FNO, the better the defocusing effect of the optical system, which can bring a better visual experience to users.

[0011] In one embodiment, the optical system satisfies the following relational expression: 1 < f2 / f < 1.7; where f2 is the effective focal length of the second lens, and f is the effective focal length of the optical system.

[0012] By controlling the effective focal length of the second lens and the effective focal length of the optical system to satisfy the above relationship, it is convenient to optimize the effective focal length of the second lens, which is beneficial to reducing the deflection angle of the light rays exiting the optical system and also reducing the sensitivity of the second lens within the optical system.

[0013] In one embodiment, the optical system satisfies the following relational expression: 7 < TTL / T34 < 12; 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 T34 is the distance from the image side surface of the third lens to the object side surface of the fourth lens on the optical axis.

[0014] By controlling that the distance from the object side of the first lens to the imaging surface of the optical system on the optical axis and the distance from the image side of the third lens to the object side of the fourth lens on the optical axis satisfy the above relationship, it is convenient to optimize the gap distance between the third lens and the fourth lens, so as to effectively increase the exit angle of the light rays in the peripheral field of view of the optical system (that is, the cone angle formed by the light rays exiting from the edge of the system and the imaging surface), thereby brightening the periphery of the imaging surface and enhancing the relative brightness of the image.

[0015] In one embodiment, the optical system satisfies the following relational expression: 1 < TTL / f < 1.3; where TTL is the distance from the object side of the first lens to the imaging surface of the optical system on the optical axis, and f is the effective focal length of the optical system.

[0016] By controlling that the distance from the object side of the first lens to the imaging surface of the optical system on the optical axis and the effective focal length of the optical system satisfy the above relationship, it can be ensured that the total length of the optical system is relatively small, and high-definition imaging performance can be achieved by optimizing the effective focal length of the optical system; at the same time, if the total length of the optical system is determined, the smaller the effective focal length of the optical system, the larger the field of view angle, and the optical system has a wide-angle characteristic; the larger the effective focal length of the optical system, the smaller the field of view angle, and the optical system has a telephoto characteristic. In addition, if the above ratio is less than or equal to 1, the size of the optical system is too small, which increases the sensitivity of the system and is not conducive to the correction of aberrations; if the above ratio is greater than or equal to 1.3, the size of the optical system is too large, which makes the incident angle of the chief ray on the imaging surface too large, and the light rays exiting from the edge of the system cannot be imaged within the effective pixel area, resulting in incomplete imaging information.

[0017] In one embodiment, the optical system satisfies the following relational expression:

[0018] -50 < (R11 + R12) / (R11 - R12) < 100; where R11 is the curvature radius of the object side of the sixth lens at the optical axis, and R12 is the curvature radius of the image side of the sixth lens at the optical axis.

[0019] By controlling that the curvature radius of the object side of the sixth lens at the optical axis and the curvature radius of the image side of the sixth lens at the optical axis satisfy the above relationship, it is convenient to adjust the curvature radii of the object side and the image side of the sixth lens at the optical axis, so as to appropriately increase the light incident area on the imaging surface, meet the image height requirements of the optical system, and at the same time, it can also reduce the sensitivity of the optical system and improve the assembly stability of the optical system.

[0020] In one embodiment, the optical system satisfies the following relationship: 8 < TTL / CT7 < 15; 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 CT7 is the distance of the seventh lens on the optical axis.

[0021] By controlling the distance on the optical axis from the object side surface of the first lens to the imaging surface of the optical system and the distance of the seventh lens on the optical axis to satisfy the above relationship, the processability of the seventh lens can be ensured; at the same time, if the above ratio is too small, the size of the optical system is too small, which is likely to increase the sensitivity of the optical system; if the above ratio is too large, the size of the optical system is too large, which is not conducive to imaging and cannot meet the application requirements of thin and light electronic devices.

[0022] This application also provides an imaging device.

[0023] An imaging device includes the optical system as described above; and an image sensor, which is disposed on the image side of the optical system.

[0024] The above imaging device can capture clear and bright images even under low-light conditions by using the aforementioned optical system. At the same time, the imaging device also has the characteristic of miniaturization, which is convenient for adapting to devices with limited sizes such as thin and light electronic devices.

[0025] This application also provides an electronic device.

[0026] An electronic device includes a housing, and the imaging device as described above, and the imaging device is mounted on the housing.

[0027] The above electronic device has the structural characteristic of being thin and light. By using the imaging device as described above, images with bright, good defocusing effect and high clarity can be captured, which can meet the shooting requirements of users in multiple scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Shows a schematic structural diagram of the optical system according to Embodiment 1 of this application;

[0029] Figures 2A to 2C Are respectively the longitudinal spherical aberration curve graph, astigmatism curve graph and distortion curve graph of the optical system according to Embodiment 1;

[0030] Figure 3 Shows a schematic structural diagram of the optical system according to Embodiment 2 of this application;

[0031] Figures 4A to 4C Are respectively the longitudinal spherical aberration curve graph, astigmatism curve graph and distortion curve graph of the optical system according to Embodiment 2;

[0032] Figure 5 The structural schematic diagram of the optical system according to Embodiment 3 of the present application is shown;

[0033] Figures 6A to 6C They are respectively the longitudinal spherical aberration curve graph, astigmatism curve graph and distortion curve graph of the optical system according to Embodiment 3;

[0034] Figure 7 The structural schematic diagram of the optical system according to Embodiment 4 of the present application is shown;

[0035] Figures 8A to 8C They are respectively the longitudinal spherical aberration curve graph, astigmatism curve graph and distortion curve graph of the optical system according to Embodiment 4;

[0036] Figure 9 The structural schematic diagram of the optical system according to Embodiment 5 of the present application is shown;

[0037] Figures 10A to 10C They are respectively the longitudinal spherical aberration curve graph, astigmatism curve graph and distortion curve graph of the optical system according to Embodiment 5. Detailed implementation manners

[0038] For the convenience of understanding the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to understand the disclosure of the present invention more thoroughly and comprehensively.

[0039] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right", "up", "down", "front", "back", "circumferential" and similar expressions used herein are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0040] It should be noted that in this specification, the expressions such as the first, the second, and the third are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teachings of the present application, the first lens discussed below can also be referred to as the second lens or the third lens.

[0041] It should be noted that the side of each lens in the optical system close to the object side is called the object side surface, and the side close to the image side is called the image side surface. For ease of explanation, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0043] Traditional miniaturized lenses have a small aperture while ensuring image quality, so their low-light shooting capabilities are weak and they cannot adapt to the shooting requirements of low-light environments such as night scenes, rainy days, and starry skies.

[0044] The defects existing in the above schemes are the results obtained by the inventor after practice and careful research. Therefore, the discovery process of the above problems and the solutions proposed in the embodiments of this application below for the above problems should be the contributions made by the inventor to this application during the application process.

[0045] The features, principles and other aspects of the present application will be described in detail below.

[0046] Please also read Figure 1 , Figure 3 , Figure 5 , Figure 7 and Figure 9 The embodiment of the present application provides an optical system that can meet the application requirements of miniaturization and is configured with a large aperture and high imaging quality. The optical system specifically includes seven lenses with refractive power, namely a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an imaging surface located on the image side of the seventh lens. The seven lenses are arranged in sequence from the object side to the image side along the optical axis.

[0047] The first lens has positive refractive power, so it can work with the second lens to converge light, so that the surface changes of the first lens and the second lens are relatively smooth, avoiding excessive aberration. The object side of the first lens is convex at the optical axis, and the image side is concave at the optical axis, which is conducive to converging the light in the sagittal direction and the tangential direction to correct astigmatism.

[0048] The second lens has a positive refractive power, which can improve the light-gathering ability of the optical system, shorten the total length of the optical system, and achieve miniaturization. The object side surface of the second lens is convex at the optical axis, which is beneficial for the second lens to have sufficient light-gathering ability, thereby further shortening the total length of the optical system.

[0049] The third lens has a negative refractive power, which can effectively correct chromatic aberration and avoid image overlap caused by the offset of the imaging positions of different color lights. The object side surface of the third lens is convex at the optical axis, and the image side surface is concave at the optical axis, which is beneficial for compensating the aberration generated by the second lens and improving the imaging quality.

[0050] The fifth lens has a positive refractive power, and its image side surface is convex at the optical axis, which is beneficial for further correcting the aberration of the optical system.

[0051] The seventh lens has a negative refractive power, which can ensure the back focal length of the optical system and is beneficial for adapting the optical system to thin and light electronic devices. The image side surface of the sixth lens is concave at the optical axis to further configure the back focal length of the optical system to ensure the miniaturization of the optical system.

[0052] Specifically, the optical system satisfies the following relationship: TTL / ImgH < 1.3; 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 (i.e., the total length of the optical system), and ImgH is half of the diagonal length of the effective pixel area on the imaging surface of the optical system. TTL / ImgH can be 1.20, 1.22, 1.24, 1.26, or 1.28. By controlling the total length of the optical system and the diagonal distance of the effective pixel area of the imaging surface of the optical system to satisfy the above relationship, it can not only ensure that the total length of the optical system is small and meet the application requirements of miniaturization, but also adjust the diagonal distance of the effective pixel area when the total length of the system is determined, so that the optical system has wide-angle characteristics or telephoto characteristics. Among them, the larger the diagonal distance of the effective pixel area, the more wide-angle characteristics the optical system has; the smaller the diagonal distance of the effective pixel area, the more telephoto characteristics the optical system has.

[0053] When the above optical system is used for imaging, the light emitted or reflected by the object to be photographed enters the optical system from the object side direction and sequentially passes through the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens, and finally converges on the imaging surface.

[0054] The above optical system reasonably distributes the optical power, surface shape of each lens, and the spacing between each lens to ensure that the total length of the optical system is small, so as to better meet the application requirements of thin and light electronic devices; at the same time, it can also reduce the aberration of the optical system and ensure the imaging quality of the optical system.

[0055] In an exemplary embodiment, the effective focal length of the optical system is f, the radius of curvature of the image side surface of the seventh lens at the optical axis is R14, and the optical system satisfies the following relational expression: 1.5 < f / R14 < 2.6. f / R14 can be 1.65, 1.75, 1.85, 1.95, 2.05, 2.15, 2.25, 2.35, 2.45, or 2.55. Under the condition of satisfying the above relationship, it is beneficial to optimize the value of the radius of curvature of the image side surface of the seventh lens at the optical axis, so that the incident angle of the chief ray of the inner field of view of the photosensitive element on the imaging surface can be better matched, and the central brightness of the image can be improved.

[0056] In an exemplary embodiment, the f-number (i.e., F-number) of the optical system is FNO, and the optical system satisfies the following relational expression: FNO < 1.9. FNO can be 1.78, 1.80, 1.82, 1.84, 1.86, or 1.88. Under the condition of satisfying the above relationship, the optical system can have a larger effective aperture while ensuring the miniaturization of the optical system and the invariance of the effective focal length. Compared with traditional miniaturized lenses, it has more light input, so that the low-light shooting performance of the lens can be improved, and the imaging clarity can be increased to meet the shooting requirements of low-light scenes such as night scenes and starry skies; in addition, the smaller the FNO, the better the defocusing effect of the optical system, which can bring a better visual experience to users.

[0057] In an exemplary embodiment, the effective focal length of the second lens is f2, the effective focal length of the optical system is f, and the optical system satisfies the following relational expression: 1 < f2 / f < 1.7. f2 / f can be 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, 1.55, 1.60, or 1.65. Under the condition of satisfying the above relationship, it is convenient to optimize the effective focal length of the second lens, which is beneficial to reducing the deflection angle of the light rays exiting the optical system and also reducing the sensitivity of the second lens within the optical system.

[0058] In an exemplary embodiment, the distance on the optical axis from the object side surface of the first lens to the imaging surface of the optical system is TTL, and the distance on the optical axis from the image side surface of the third lens to the object side surface of the fourth lens is T34. The optical system satisfies the following relational expression: 7 < TTL / T34 < 12. TTL / T34 can be 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, or 11.5. Under the condition of satisfying the above relationship, it is convenient to optimize the gap distance between the third lens and the fourth lens to effectively increase the exit angle of the light rays in the marginal field of view of the optical system (i.e., the cone angle formed by the light rays exiting from the edge of the system and the imaging surface), so that the periphery of the imaging surface becomes brighter and the relative brightness of the image is improved.

[0059] In an exemplary embodiment, the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis is TTL, the effective focal length of the optical system is f, and the optical system satisfies the following relationship: 1 < TTL / f < 1.3. TTL / f can be 1.05, 1.08, 1.11, 1.14, 1.17, 1.20, or 1.23. Under the condition of satisfying the above relationship, it can be ensured that the total length of the optical system is relatively small, and high-definition imaging performance can be achieved by optimizing the effective focal length of the optical system; at the same time, if the total length of the optical system is determined, the smaller the effective focal length of the optical system, the larger the field of view angle, and the optical system has a wide-angle characteristic; the larger the effective focal length of the optical system, the smaller the field of view angle, and the optical system has a telephoto characteristic. In addition, if the above ratio is less than or equal to 1, the size of the optical system is too small, which will increase the sensitivity of the system and is not conducive to the correction of aberrations; if the above ratio is greater than or equal to 1.3, the size of the optical system is too large, which will cause the incident angle of the chief ray on the imaging surface to be too large, so that the light rays emerging from the edge of the system cannot be imaged within the effective pixel area, resulting in incomplete imaging information.

[0060] In an exemplary embodiment, the radius of curvature of the object side surface of the sixth lens on the optical axis is R11, the radius of curvature of the image side surface of the sixth lens on the optical axis is R12, and the optical system satisfies the following relationship: -50 < (R11 + R12) / (R11 - R12) < 100. (R11 + R12) / (R11 - R12) can be -45, -10, 5, 6, 7, 8, 10, 20, 30, 40, 50, 60, 70, or 80. Under the condition of satisfying the above relationship, it is convenient to adjust the radius of curvature of the object side surface and the image side surface of the sixth lens on the optical axis to appropriately increase the light incident area on the imaging surface, meet the image height requirements of the optical system, and at the same time, it can also reduce the sensitivity of the optical system and improve the assembly stability of the optical system.

[0061] In an exemplary embodiment, the distance from the object side surface of the first lens to the imaging surface of the optical system on the optical axis is TTL, the distance of the seventh lens on the optical axis is CT7, and the optical system satisfies the following relationship: 8 < TTL / CT7 < 15. TTL / CT7 can be 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, or 13.0. Under the condition of satisfying the above relationship, the processability of the seventh lens can be ensured; at the same time, if the above ratio is too small, the size of the optical system is too small, which is likely to increase the sensitivity of the optical system; if the above ratio is too large, the size of the optical system is too large, which is not conducive to imaging and cannot meet the application requirements of thin and light electronic devices.

[0062] In an exemplary embodiment, the optical system further includes an aperture stop, which can be disposed between the object side of the optical system and the first lens, or between the first lens and the seventh lens. In some other embodiments, the aperture stop can also be located on the surface of any one of the first lens to the seventh lens (such as the object side surface and the image side surface), forming an interaction relationship with the lens. For example, an opaque coating is applied on the surface of the lens to form an aperture stop on this surface; or a clamping member is used to fixedly clamp the surface of the lens, and the clamping member structure located on this surface can limit the width of the imaging beam of the on-axis object point, thereby forming an aperture stop on this surface. Preferably, the aperture stop is located between the object side of the optical system and the first lens to effectively suppress the excessive increase of the chief ray incident angle, so that the chief ray can better match the photosensitive chip of the traditional specification.

[0063] In an exemplary embodiment, among the first lens to the seventh lens, the lens surfaces of each lens are all aspherical surfaces, which can improve the flexibility of lens design, effectively correct aberration, and enhance the imaging resolution of the optical system. In some other embodiments, the object side surfaces and the image side surfaces of each lens of the optical system can also be spherical surfaces. It should be noted that the above embodiments are only examples of some embodiments of the present application. In some embodiments, the surfaces of each lens in the optical system can be any combination of aspherical surfaces or spherical surfaces.

[0064] In an exemplary embodiment, the materials of each lens in the optical system can all be glass or all be plastic. The plastic lens can reduce the weight of the optical system and lower the production cost, while the glass lens can endow the optical system with excellent optical performance and high temperature resistance characteristics. It should be noted that the materials of each lens in the optical system can also be any combination of glass and plastic, and do not necessarily have to be all glass or all plastic.

[0065] In an exemplary embodiment, the optical system further includes a filter for filtering infrared light and / or a protective glass for protecting the photosensitive element, wherein the photosensitive element is located on the imaging surface. Further, the imaging surface can be the photosensitive surface of the photosensitive element.

[0066] The optical system of the above embodiment of the present application can adopt multiple lenses, such as the seven lenses described above. By reasonably allocating the focal length, refractive power, surface type, thickness of each lens, and the on-axis spacing between each lens, etc., it can be ensured that the total length of the above optical system is relatively small and has a large aperture (FNO can be 1.78), and at the same time has high imaging quality to better meet the adaptation requirements of thin and light electronic devices such as mobile phones and tablets and the low-light shooting requirements. It can be understood that although seven lenses are taken as an example for description in the embodiment, the optical system is not limited to including seven lenses. If necessary, the optical system can also include other numbers of lenses.

[0067] The following further describes specific embodiments of the optical system applicable to the above embodiments with reference to the accompanying drawings.

[0068] Embodiment 1

[0069] The following refers to Figures 1 to 2C to describe the optical system of Embodiment 1 of the present application.

[0070] Figure 1 The structural schematic diagram of the optical system of Embodiment 1 is shown. As Figure 1 shown, the optical system sequentially includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an imaging surface S17 along the optical axis from the object side to the image side.

[0071] The first lens L1 has a positive refractive power. Its object surface S1 is convex at the optical axis and convex at the circumference, and its image surface S2 is concave at the optical axis and concave at the circumference.

[0072] The second lens L2 has a positive refractive power. Its object surface S3 is convex at the optical axis and convex at the circumference, and its image surface S4 is convex at the optical axis and convex at the circumference.

[0073] The third lens L3 has a negative refractive power. Its object surface S5 is convex at the optical axis and concave at the circumference, and its image surface S6 is concave at the optical axis and concave at the circumference.

[0074] The fourth lens L4 has a positive refractive power. Its object surface S7 is convex at the optical axis and concave at the circumference, and its image surface S8 is concave at the optical axis and convex at the circumference.

[0075] The fifth lens L5 has a positive refractive power. Its object surface S9 is concave at the optical axis and concave at the circumference, and its image surface S10 is convex at the optical axis and convex at the circumference.

[0076] The sixth lens L6 has a negative refractive power. Its object surface S11 is convex at the optical axis and concave at the circumference, and its image surface S12 is concave at the optical axis and convex at the circumference.

[0077] The seventh lens L7 has a negative refractive power. Its object surface S13 is convex at the optical axis and convex at the circumference, and its image surface S14 is concave at the optical axis and convex at the circumference.

[0078] The object surfaces and image surfaces of each of the first lens L1 to the sixth lens L7 are aspherical surfaces. The design of the aspherical surfaces can solve the problem of field distortion and can also enable the lens to achieve excellent optical imaging effects in a smaller, thinner, and flatter state, thereby enabling the optical system to have the characteristics of miniaturization.

[0079] The materials of the first lens L1 to the seventh lens L7 are all plastics. Lenses made of plastic materials can reduce the weight of the optical system and at the same time reduce the production cost.

[0080] An aperture stop STO is also provided between the object OBJ and the first lens L1 to further improve the imaging quality of the optical system.

[0081] The optical system also includes a filter L8 having an object side S15 and an image side S16. The light from the object OBJ sequentially passes through the surfaces S1 to S16 and finally forms an image on the imaging surface S17. Further, the filter L8 is an infrared filter for filtering out the infrared light in the external light incident on the optical system to avoid imaging distortion. Specifically, the material of the infrared filter L8 is glass. The infrared filter L8 can be part of the optical system and be assembled together with the lenses, or can also be installed when the optical system is assembled with the photosensitive element.

[0082] Table 1 shows the surface type, radius of curvature, thickness, material, refractive index, Abbe number (i.e., dispersion coefficient) of each lens of the optical system in Embodiment 1, and the effective focal length of each lens. Among them, the units of the radius of curvature, thickness, and the effective focal length of each lens are all millimeters (mm). The reference wavelength is 555 nm.

[0083] Table 1

[0084]

[0085]

[0086] The aspherical surface types of each lens are defined by the following formula:

[0087]

[0088] Among them, x is the 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 (i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1); k is the conic coefficient; Ai is the i-th order coefficient of the aspherical surface. Table 2 below gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for the aspherical surfaces S1 - S10 of the lenses in Embodiment 1.

[0089] Table 2

[0090]

[0091]

[0092] In this embodiment, half of the diagonal length of the effective pixel region on the imaging surface S17 of the optical system, ImgH, is 6.34 mm. Therefore, based on the data in Table 1 and Table 2, it can be known that the optical system in Embodiment 1 satisfies:

[0093] TTL / ImgH = 1.24, where TTL is the distance from the object side surface S1 of the first lens L1 to the imaging surface S17 of the optical system on the optical axis, and ImgH is half of the diagonal length of the effective pixel region on the imaging surface S17 of the optical system;

[0094] f / R14 = 2.41, where f is the effective focal length of the optical system, and R14 is the curvature radius of the image side surface S14 of the seventh lens L7 at the optical axis;

[0095] FNO = 1.88, where FNO is the f-number of the optical system;

[0096] f2 / f = 1.62, where f2 is the effective focal length of the second lens L2, and f is the effective focal length of the optical system;

[0097] TTL / T34 = 8.02, where TTL is the distance from the object side surface S1 of the first lens L1 to the imaging surface S17 of the optical system on the optical axis, and T34 is the distance from the image side surface S6 of the third lens L3 to the object side surface S7 of the fourth lens L4 on the optical axis;

[0098] TTL / f = 1.15, where TTL is the distance from the object side surface S1 of the first lens L1 to the imaging surface S17 of the optical system on the optical axis, and f is the effective focal length of the optical system;

[0099] (R11 + R12) / (R11 - R12) = 5.48, where R11 is the curvature radius of the object side surface S11 of the sixth lens L6 at the optical axis, and R12 is the curvature radius of the image side surface S12 of the sixth lens L6 at the optical axis;

[0100] TTL / CT7 = 12.57, where TTL is the distance from the object side surface S1 of the first lens L1 to the imaging surface S17 of the optical system on the optical axis, and CT7 is the distance of the seventh lens L7 on the optical axis.

[0101] Figure 2A The longitudinal spherical aberration curve of the optical system of Embodiment 1 is shown, which respectively represents the deviation of the convergence points of the light rays with wavelengths of 470 nm, 510 nm, 555 nm, 610 nm, and 650 nm after passing through the optical system; Figure 2B The astigmatism curve of the optical system of Embodiment 1 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature; Figure 2C The distortion curve of the optical system of Embodiment 1 is shown, which represents the distortion rate under different image heights. According to Figures 2A to 2CIt can be seen that the optical system given in Embodiment 1 can achieve good imaging quality.

[0102] Embodiment 2

[0103] The following refers to Figures 3 to 4C Describe the optical system of Embodiment 2 of the present application. In this embodiment, for the sake of simplicity, some descriptions similar to those in Embodiment 1 will be omitted. Figure 3 The structural schematic diagram of the optical system of Embodiment 2 of the present application is shown.

[0104] As Figure 3 shown, the optical system sequentially includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an imaging surface S17 along the optical axis from the object side to the image side.

[0105] The first lens L1 has a positive refractive power. Its object surface S1 is convex at the optical axis and convex at the circumference, and its image surface S2 is concave at the optical axis and concave at the circumference.

[0106] The second lens L2 has a positive refractive power. Its object surface S3 is convex at the optical axis and convex at the circumference, and its image surface S4 is convex at the optical axis and convex at the circumference.

[0107] The third lens L3 has a negative refractive power. Its object surface S5 is convex at the optical axis and convex at the circumference, and its image surface S6 is concave at the optical axis and concave at the circumference.

[0108] The fourth lens L4 has a positive refractive power. Its object surface S7 is convex at the optical axis and concave at the circumference, and its image surface S8 is convex at the optical axis and convex at the circumference.

[0109] The fifth lens L5 has a positive refractive power. Its object surface S9 is concave at the optical axis and concave at the circumference, and its image surface S10 is convex at the optical axis and convex at the circumference.

[0110] The sixth lens L6 has a negative refractive power. Its object surface S11 is convex at the optical axis and concave at the circumference, and its image surface S12 is concave at the optical axis and convex at the circumference.

[0111] The seventh lens L7 has a negative refractive power. Its object surface S13 is concave at the optical axis and convex at the circumference, and its image surface S14 is concave at the optical axis and convex at the circumference.

[0112] The object surfaces and image surfaces of each of the first lens L1 to the sixth lens L7 are aspherical surfaces. The design of the aspherical surfaces can solve the problem of field distortion, and can also enable the lens to achieve excellent optical imaging effects under the conditions of being smaller, thinner, and flatter, thereby enabling the optical system to have the characteristics of miniaturization.

[0113] The materials of the first lens L1 to the seventh lens L7 are all plastics. Lenses made of plastic materials can reduce the weight of the optical system and at the same time reduce the production cost.

[0114] An aperture STO is also provided between the object OBJ and the first lens L1 to further improve the imaging quality of the optical system. The optical system also includes a filter L8 having an object side S15 and an image side S16. The light from the object OBJ sequentially passes through the surfaces S1 to S16 and finally forms an image on the imaging surface S17. Further, the filter L8 is an infrared filter for filtering out the infrared light in the external light incident on the optical system to avoid imaging distortion.

[0115] Table 3 shows the surface types, radii of curvature, thicknesses, materials, refractive indices, Abbe numbers of the lenses of the optical system in Example 2, and the effective focal lengths of the lenses. Among them, the units of the radius of curvature, thickness, and the effective focal length of each lens are all millimeters (mm); Table 4 shows the higher-order term coefficients of the aspherical surfaces S1 - S14 of the lenses that can be used in Example 2, where the aspherical surface type can be defined by the formula (1) given in Example 1; Table 5 shows the numerical values of the relevant parameters of the optical system given in Example 2. The reference wavelength is 555 nm.

[0116] Table 3

[0117]

[0118] Table 4

[0119]

[0120]

[0121] Table 5

[0122] f (mm) 6.83 f / R14 1.74 FNO 1.88 f2 / f 1.55 FOV (degrees) 84.9 TTL / T34 11.19 ImgH (mm) 6.34 TTL / f 1.15 TTL (mm) 7.83 (R11 + R12) / (R11 - R12) 7.88 TTL / ImgH 1.24 TTL / CT7 11.93

[0123] Figure 4A shows the longitudinal spherical aberration curve of the optical system in Example 2, which respectively represents the deviation of the convergence points of light rays of different wavelengths after passing through the optical system; Figure 4B shows the astigmatism curve of the optical system in Example 2, which represents the meridional image plane curvature and the sagittal image plane curvature; Figure 4C shows the distortion curve of the optical system in Example 2, which represents the distortion rate under different image heights. According to Figures 4A to 4C it can be known that the optical system given in Example 2 can achieve good imaging quality.

[0124] Example 3

[0125] The following refers to Figures 5 to 6CDescribe the optical system of Embodiment 3 of the present application. In this embodiment, for the sake of brevity, some descriptions similar to those in Embodiment 1 will be omitted. Figure 5 The structural schematic diagram of the optical system of Embodiment 3 of the present application is shown.

[0126] As Figure 5 shown, the optical system sequentially includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an imaging surface S17 along the optical axis from the object side to the image side.

[0127] The first lens L1 has a positive refractive power. Its object surface S1 is convex at the optical axis and convex at the circumference, and its image surface S2 is concave at the optical axis and concave at the circumference.

[0128] The second lens L2 has a positive refractive power. Its object surface S3 is convex at the optical axis and convex at the circumference, and its image surface S4 is concave at the optical axis and convex at the circumference.

[0129] The third lens L3 has a negative refractive power. Its object surface S5 is convex at the optical axis and convex at the circumference, and its image surface S6 is concave at the optical axis and concave at the circumference.

[0130] The fourth lens L4 has a negative refractive power. Its object surface S7 is convex at the optical axis and concave at the circumference, and its image surface S8 is concave at the optical axis and convex at the circumference.

[0131] The fifth lens L5 has a positive refractive power. Its object surface S9 is concave at the optical axis and concave at the circumference, and its image surface S10 is convex at the optical axis and convex at the circumference.

[0132] The sixth lens L6 has a negative refractive power. Its object surface S11 is convex at the optical axis and concave at the circumference, and its image surface S12 is concave at the optical axis and convex at the circumference.

[0133] The seventh lens L7 has a negative refractive power. Its object surface S13 is convex at the optical axis and convex at the circumference, and its image surface S14 is concave at the optical axis and convex at the circumference.

[0134] The object surfaces and image surfaces of each of the first lens L1 to the sixth lens L7 are aspherical surfaces. The design of the aspherical surfaces can solve the problem of visual field distortion, and can also enable the lens to achieve excellent optical imaging effects under the conditions of being smaller, thinner, and flatter, thereby enabling the optical system to have the characteristics of miniaturization.

[0135] The materials of the first lens L1 to the seventh lens L7 are all plastics. The lenses made of plastic materials can reduce the weight of the optical system and at the same time reduce the production cost.

[0136] An aperture STO is also disposed between the object OBJ and the first lens L1 to further improve the imaging quality of the optical system. The optical system further includes a filter L8 having an object side S15 and an image side S16. The light from the object OBJ sequentially passes through the surfaces S1 to S16 and finally forms an image on the imaging surface S17. Further, the filter L8 is an infrared filter for filtering out the infrared light in the external light incident on the optical system to avoid imaging distortion.

[0137] Table 6 shows the surface types, radii of curvature, thicknesses, materials, refractive indices, Abbe numbers, and effective focal lengths of the lenses of the optical system of Embodiment 3. Among them, the units of the radius of curvature, thickness, and effective focal length of each lens are all millimeters (mm); Table 7 shows the high-order term coefficients of the aspherical surfaces S1-S14 of the lenses that can be used in Embodiment 3, where the aspherical surface type can be defined by the formula (1) given in Embodiment 1; Table 8 shows the numerical values of the relevant parameters of the optical system given in Embodiment 3. The reference wavelength is 555 nm.

[0138] Table 6

[0139]

[0140]

[0141] Table 7

[0142]

[0143] Table 8

[0144] f (mm) 6.79 f / R14 2.42 FNO 1.88 f2 / f 1.18 FOV (degrees) 84.8 TTL / T34 8.35 ImgH (mm) 6.34 TTL / f 1.19 TTL (mm) 8.1 (R11 + R12) / (R11 - R12) 6.88 TTL / ImgH 1.28 TTL / CT7 9.43

[0145] Figure 6A shows the longitudinal spherical aberration curve of the optical system of Embodiment 3, which respectively represents the deviation of the converging points of the light rays of different wavelengths after passing through the optical system; Figure 6B shows the astigmatism curve of the optical system of Embodiment 3, which represents the meridional image plane curvature and the sagittal image plane curvature; Figure 6C shows the distortion curve of the optical system of Embodiment 3, which represents the distortion rate under different image heights. According to Figures 6A to 6C it can be seen that the optical system given in Embodiment 3 can achieve good imaging quality.

[0146] Embodiment 4

[0147] The following refers to Figures 7 to 8C to describe the optical system of Embodiment 4 of the present application. In this embodiment, for the sake of simplicity, some descriptions similar to those in Embodiment 1 will be omitted. Figure 7 shows a schematic structural diagram of the optical system of Embodiment 4 of the present application.

[0148] AsFigure 7 As shown, the optical system sequentially includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an imaging surface S17 along the optical axis from the object side to the image side.

[0149] The first lens L1 has a positive refractive power. Its object surface S1 is convex at the optical axis and convex at the circumference, and its image surface S2 is concave at the optical axis and concave at the circumference.

[0150] The second lens L2 has a positive refractive power. Its object surface S3 is convex at the optical axis and convex at the circumference, and its image surface S4 is convex at the optical axis and convex at the circumference.

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

[0152] The fourth lens L4 has a positive refractive power. Its object surface S7 is concave at the optical axis and concave at the circumference, and its image surface S8 is convex at the optical axis and convex at the circumference.

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

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

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

[0156] The object surfaces and image surfaces of each of the first lens L1 to the sixth lens L7 are aspherical surfaces. The design of the aspherical surfaces can solve the problem of visual field distortion, and can also enable the lens to achieve excellent optical imaging effects in a smaller, thinner, and flatter state, thereby making the optical system have the characteristics of miniaturization.

[0157] The materials of the first lens L1 to the seventh lens L7 are all plastics. The plastic lenses can reduce the weight of the optical system and at the same time reduce the production cost.

[0158] An aperture STOP is also provided between the object OBJ and the first lens L1 to further improve the imaging quality of the optical system. The optical system further includes a filter L8 having an object side S15 and an image side S16. The light from the object OBJ sequentially passes through the surfaces S1 to S16 and finally forms an image on the imaging surface S17. Further, the filter L8 is an infrared filter for filtering infrared light in the external light incident on the optical system to avoid imaging distortion.

[0159] Table 9 shows the surface types, radii of curvature, thicknesses, materials, refractive indices, Abbe numbers, and effective focal lengths of the lenses of the optical system of Example 4. Among them, the units of the radius of curvature, thickness, and effective focal length of each lens are all millimeters (mm); Table 10 shows the higher-order term coefficients of the aspherical surfaces S1-S14 of the lenses that can be used in Example 4, and the aspherical surface type can be defined by the formula (1) given in Example 1; Table 11 shows the numerical values of the relevant parameters of the optical system given in Example 4. The reference wavelength is 555 nm.

[0160] Table 9

[0161]

[0162] Table 10

[0163]

[0164]

[0165] Table 11

[0166] f (mm) 6.78 f / R14 2.39 FNO 1.88 f2 / f 1.15 FOV (degrees) 84.9 TTL / T34 9.73 ImgH (mm) 6.34 TTL / f 1.19 TTL (mm) 8.1 (R11 + R12) / (R11 - R12) 80.72 TTL / ImgH 1.28 TTL / CT7 10.24

[0167] Figure 8A shows the longitudinal spherical aberration curve of the optical system of Example 4, which respectively represents the deviation of the convergence points of light rays of different wavelengths after passing through the optical system; Figure 8B shows the astigmatism curve of the optical system of Example 4, which represents the meridional image plane curvature and the sagittal image plane curvature; Figure 8C shows the distortion curve of the optical system of Example 4, which represents the distortion rate under different image heights. According to Figures 8A to 8C it can be seen that the optical system given in Example 4 can achieve good imaging quality.

[0168] Example 5

[0169] The following refers to Figures 9 to 10C to describe the optical system of Embodiment 5 of the present application. In this embodiment, for the sake of simplicity, some descriptions similar to those in Embodiment 1 will be omitted. Figure 9 shows a schematic structural diagram of the optical system of Embodiment 5 of the present application.

[0170] AsFigure 9 As shown, the optical system sequentially includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an imaging surface S17 along the optical axis from the object side to the image side.

[0171] The first lens L1 has a positive refractive power. Its object surface S1 is convex at the optical axis and convex at the circumference, and its image surface S2 is concave at the optical axis and concave at the circumference.

[0172] The second lens L2 has a positive refractive power. Its object surface S3 is convex at the optical axis and convex at the circumference, and its image surface S4 is convex at the optical axis and convex at the circumference.

[0173] The third lens L3 has a negative refractive power. Its object surface S5 is convex at the optical axis and convex at the circumference, and its image surface S6 is concave at the optical axis and concave at the circumference.

[0174] The fourth lens L4 has a negative refractive power. Its object surface S7 is concave at the optical axis and concave at the circumference, and its image surface S8 is concave at the optical axis and convex at the circumference.

[0175] The fifth lens L5 has a positive refractive power. Its object surface S9 is convex at the optical axis and concave at the circumference, and its image surface S10 is convex at the optical axis and convex at the circumference.

[0176] The sixth lens L6 has a positive refractive power. Its object surface S11 is convex at the optical axis and concave at the circumference, and its image surface S12 is concave at the optical axis and convex at the circumference.

[0177] The seventh lens L7 has a negative refractive power. Its object surface S13 is convex at the optical axis and convex at the circumference, and its image surface S14 is concave at the optical axis and convex at the circumference.

[0178] The object surfaces and image surfaces of each of the first lens L1 to the sixth lens L7 are aspherical surfaces. The design of the aspherical surfaces can solve the problem of visual field distortion, and can also enable the lens to achieve excellent optical imaging effects in a smaller, thinner, and flatter state, thereby enabling the optical system to have the characteristic of miniaturization.

[0179] The materials of the first lens L1 to the seventh lens L7 are all plastics. The lenses made of plastic materials can reduce the weight of the optical system and at the same time reduce the production cost.

[0180] A stop STO is also provided between the object OBJ and the first lens L1 to further improve the imaging quality of the optical system. The optical system further includes a filter L8 having an object side S15 and an image side S16. The light from the object OBJ sequentially passes through the surfaces S1 to S16 and finally forms an image on the imaging surface S17. Further, the filter L8 is an infrared filter for filtering infrared light in the external light incident on the optical system to avoid imaging distortion.

[0181] Table 12 shows the surface type, radius of curvature, thickness, material, refractive index, Abbe number of each lens of the optical system of Example 5, and the effective focal length of each lens. Among them, the units of the radius of curvature, thickness, and the effective focal length of each lens are all millimeters (mm); Table 13 shows the high-order term coefficients of the aspherical surfaces S1-S14 that can be used in the lenses of Example 5, and the aspherical surface type can be defined by the formula (1) given in Example 1; Table 14 shows the numerical values of the relevant parameters of the optical system given in Example 5. The reference wavelength is 555 nm.

[0182] Table 12

[0183]

[0184]

[0185] Table 13

[0186]

[0187] Table 14

[0188] f (mm) 6.78 f / R14 2.56 FNO 1.78 f2 / f 1.15 FOV (degrees) 84.9 TTL / T34 10.86 ImgH (mm) 6.34 TTL / f 1.19 TTL (mm) 8.1 (R11 + R12) / (R11 - R12) -43.45 TTL / ImgH 1.28 TTL / CT7 11.65

[0189] Figure 10A shows the longitudinal spherical aberration curve of the optical system of Example 5, which respectively represents the deviation of the convergence points of light rays of different wavelengths after passing through the optical system; Figure 10B shows the astigmatism curve of the optical system of Example 5, which represents the meridional image plane curvature and the sagittal image plane curvature; Figure 10C shows the distortion curve of the optical system of Example 5, which represents the distortion rate under different image heights. According to Figures 10A to 10C it can be seen that the optical system given in Example 5 can achieve good imaging quality.

[0190] The present application also provides an imaging device, which includes the optical system as described above; and an image sensor, which is disposed on the image side of the optical system to receive the light carrying image information formed by the optical system. Specifically, the image sensor may adopt a complementary metal oxide semiconductor (CMOS) image sensor or a charge-coupled device (CCD) image sensor.

[0191] For the above imaging device, by using the aforementioned optical system, a clear and bright image can be captured even under low-light conditions. Meanwhile, the imaging device also has the feature of miniaturization, which is convenient to be adapted to devices with limited sizes such as thin and light electronic devices.

[0192] The present application also provides an electronic device, which includes a housing and the imaging device as described above. The imaging device is installed on the housing to acquire images.

[0193] Specifically, the imaging device is disposed inside the housing and exposed from the housing to acquire images. The housing can provide protection such as dust-proof, waterproof and anti-drop for the imaging device. A hole corresponding to the imaging device is opened on the housing to allow light to penetrate into or out of the housing through the hole.

[0194] The above electronic device has the structural feature of being thin and light. By using the imaging device as described above, bright images with good defocusing effect and high clarity can be captured, meeting the multi-scene shooting requirements of devices such as mobile phones and tablets.

[0195] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0196] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. An optical system, comprising a total of seven refractive lenses, which are sequentially arranged from the object side to the image side along the optical axis and include: The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens, characterized in that the first lens has a positive refractive power, its object side is convex at the optical axis, and its image side is concave at the optical axis; the second lens has a positive refractive power, and its object side is convex at the optical axis; the third lens has a negative refractive power, its object side is convex at the optical axis, and its image side is concave at the optical axis; the fifth lens has a positive refractive power, and its image side is convex at the optical axis; the seventh lens has a negative refractive power, and its image side is concave at the optical axis; the optical system satisfies the following relationships: TTL / ImgH < 1.3; FNO < 1.9; 1 < TTL / f < 1.3; wherein, TTL is the distance on the optical axis from the object side of the first lens to the imaging surface of the optical system, ImgH is half of the diagonal length of the effective pixel region on the imaging surface of the optical system, FNO is the aperture number of the optical system, and f is the effective focal length of the optical system.

2. The optical system according to claim 1, wherein the optical system satisfies the following relationships: 1.5 < f / R14 < 2.6; wherein, R14 is the radius of curvature of the image side of the seventh lens at the optical axis.

3. The optical system according to claim 1, wherein the optical system satisfies the following relationships: 1.78 ≤ FNO < 1.

9.

4. The optical system according to claim 1, wherein the optical system satisfies the following relationships: 1.15 ≤ f2 / f < 1.7; wherein, f2 is the effective focal length of the second lens.

5. The optical system according to claim 1, wherein the optical system satisfies the following relationships: 7 < TTL / T34 ≤ 10.86; wherein, T34 is the distance on the optical axis from the image side of the third lens to the object side of the fourth lens.

6. The optical system according to claim 1, wherein the optical system satisfies the following relationships: 1.15 ≤ TTL / f < 1.

3.

7. The optical system according to claim 1, wherein the optical system satisfies the following relationships: -50 < (R11 + R12) / (R11 - R12) < 100; wherein, R11 is the radius of curvature of the object side of the sixth lens at the optical axis, and R12 is the radius of curvature of the image side of the sixth lens at the optical axis.

8. The optical system according to claim 1, wherein the optical system satisfies the following relationships: 8 < TTL / CT7 ≤ 12.57; wherein, CT7 is the distance of the seventh lens on the optical axis.

9. The optical system according to claim 1, wherein the optical system satisfies the following relationships: 1.2 ≤ TTL / ImgH ≤ 1.

28.

10. An imaging device, characterized in that, Comprising: the optical system according to any one of claims 1-9; and, a photosensitive element, the photosensitive element being disposed on the image side of the optical system.

11. An electronic device, characterized in that, Comprising: a housing; and, the imaging device according to claim 10, the imaging device being mounted on the housing.

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