Optical system, camera module and electronic device

Abstract

The present invention relates to an optical system, a camera module and an electronic device. The optical system includes, from the object side to the image side, a first lens unit with positive refractive power; a second lens unit with negative refractive power; a third lens unit and a fourth lens unit with positive refractive power; the positions of the first lens unit and the fourth lens unit are both fixed relative to the imaging surface of the optical system, and the second lens unit and the third lens unit can both move relative to the first lens unit along the optical axis direction of the optical system; when the optical system zooms from the short focal end to the long focal end, the distance between the first lens unit and the second lens unit and the distance between the third lens unit and the fourth lens unit increase. The structure of the above optical system is more compact and has a good zooming effect. In addition, in a long-term high or low temperature environment, the normal operation of the zoom function can still be guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of photography, and in particular to an optical system, a photography module and an electronic device. Background Art

[0002] In recent years, various mobile electronic devices equipped with camera lenses (including digital cameras, smartphones, laptops, tablet computers and other portable information terminals) are rapidly developing and popularizing. Zoom systems have the characteristics of high-quality imaging effects and high zoom ratios. They were originally used in digital cameras or camcorders, but now more and more miniaturized camera units are used in other widely used electronic devices.

[0003] The drive mechanism used to drive the refractive force unit to perform zoom movement in the zoom system generally occupies a large space, and as the number of refractive force units that need to move independently increases, the number of drive mechanisms will also increase accordingly, making it difficult to reduce the size of the system. Therefore, it is often difficult to balance the pursuit of zoom effect and miniaturization design. Therefore, how to further shorten the total length of the optical system and achieve miniaturization while achieving a wide range of zoom has become one of the problems that the industry wants to solve. Summary of the invention

[0004] Based on this, it is necessary to provide an optical system, a camera module and an electronic device to address the problem of how to balance zoom effect and miniaturization design.

[0005] An optical system, comprising, from the object side to the image side, the following:

[0006] A first lens unit having positive refractive power;

[0007] a second lens unit having negative refractive power;

[0008] A third lens unit having positive refractive power;

[0009] a fourth lens unit having positive refractive power;

[0010] The positions of the first lens unit and the fourth lens unit are both kept fixed relative to the imaging plane of the optical system, and the second lens unit and the third lens unit are both movable relative to the first lens unit along the optical axis direction of the optical system; when the optical system zooms from the short focal end to the long focal end, the distance between the first lens unit and the second lens unit increases, and the distance between the third lens unit and the fourth lens unit also increases.

[0011] In the zooming process of the above optical system, the first lens unit closest to the object side and the fourth lens unit closest to the image side are both kept fixed, and the system is switched between the short focal end and the long focal end only by moving the second lens unit and the third lens unit, thereby reducing the number of driving mechanisms and making the structure of the system more compact, thereby promoting the miniaturization design of the system and reducing the production cost. At the same time, since the zooming is achieved by moving two lens units with opposite refractive forces, the optical system can reasonably control the deflection angle of the incident light during the zooming process and correct the aberration well, so as to have a good zooming effect. In addition, in a long-term high or low temperature environment, the components near the first lens unit closest to the object side are most affected by the temperature, and there is no need to set a driving mechanism for the first lens unit in the above optical system, so it can avoid the driving mechanism in the system from being damaged by aging due to being too close to the object side and being affected by the external temperature, thereby ensuring the normal operation of the zoom function. At the same time, the above optical system does not need to set a driving mechanism for the fourth lens unit, which is conducive to the assembly of the optical system and the photosensitive element on the image side, and can avoid the fourth lens unit from colliding with the photosensitive element during zoom movement.

[0012] In one embodiment, the optical system satisfies the following relationship:

[0013] 1.2<fc / fd<3.5;

[0014] Wherein, fc is the focal length of the optical system when it is at the telephoto end, and fd is the focal length of the optical system when it is at the short focal end. When the above relationship is satisfied, the focal lengths of the optical system at the telephoto end and the short focal end can be reasonably configured, making the zoom process more reasonable and appropriate, which is conducive to the optical system having excellent zoom effect and miniaturization characteristics. When fc / fd>3.5, it is not conducive to correcting the spherical aberration of the system at the telephoto end, and will cause the movement distance of the lens unit to be too large when the system switches from telephoto to short focal, thus making it impossible to achieve a miniaturized design; when fc / fd<1.2, the zoom ratio of the system is too low, and no obvious zoom effect can be achieved.

[0015] In one embodiment, the optical system satisfies the following relationship:

[0016] 0.3<(g1+g2+g3+g4) / fd;

[0017] Wherein, g1 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the first lens unit, g2 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the second lens unit, g3 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the third lens unit, g4 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the fourth lens unit, and fd is the focal length of the optical system when it is at the short focal end. When the above relationship is satisfied, it is beneficial for the optical system to have a zoom function while also miniaturizing the entire system. When (g1+g2+g3+g4) / fd<0.3, it will be unfavorable to correct the aberration of the system, and the thickness of each lens will be reduced due to the short total length of the system, thereby increasing the processing cost.

[0018] In one embodiment, the optical system satisfies the following relationship:

[0019] 0.8<f3 / fd<2;

[0020] Wherein, f3 is the focal length of the third lens unit, and fd is the focal length of the optical system when it is at the short focal end. When the above relationship is satisfied, it can ensure that the third lens unit provides appropriate refractive power for the entire optical system, and it is beneficial for the system to obtain a miniature size.

[0021] In one embodiment, the optical system satisfies the following relationship:

[0022] 1.6<f1 / |f2|<2.3;

[0023] Wherein, f1 is the focal length of the first lens unit, and f2 is the focal length of the second lens unit. When the above relationship is satisfied, the refractive power of the first lens unit and the second lens unit can be reasonably configured, so that the distortion generated by the first lens unit can be effectively corrected, and it is also beneficial to achieve miniaturization of the system. When f1 / |f2|>2.3, the refractive power of the first lens unit is too strong, and it is difficult to correct the distortion generated by the first lens unit; when f1 / |f2|<1.6, the refractive power of the first lens unit is too weak, and the incident light cannot be effectively deflected, which leads to an increase in the effective distance of the light, which is not conducive to the miniaturization of the entire optical system.

[0024] In one embodiment, the optical system satisfies the following relationship:

[0025] -0.6<f2 / fc<-0.3;

[0026] Wherein, f2 is the focal length of the second lens unit, and fc is the focal length of the optical system when it is at the telephoto end. When the above relationship is satisfied, the focal length of the second lens unit and the focal length of the system corresponding to the telephoto end can be reasonably configured, thereby ensuring that the system can reasonably achieve zooming, that is, the moving distance of the system during zooming is smaller, the zooming time is shorter, and the system is less affected by the external environment, thereby achieving fast and efficient zooming. At the same time, when the above relationship is satisfied, it is also conducive to correcting the spherical aberration generated by the second lens unit.

[0027] In one embodiment, the optical system satisfies the following relationship:

[0028] 0.1<d2 / d3<0.6;

[0029] Wherein, d2 is the moving distance of the second lens unit when the optical system zooms from the short focal end to the long focal end, and d3 is the moving distance of the third lens unit when the optical system zooms from the short focal end to the long focal end. When the above relationship is satisfied, it will be beneficial to the miniaturization of the optical system and make the zooming process more reasonable, that is, the moving distance of the system during the zooming process is smaller, the zooming time is shorter, and the influence of the external environment is smaller, so that fast and efficient zooming can be achieved.

[0030] In one embodiment, the optical system satisfies the following relationship:

[0031] 1<TTL / fc<1.5;

[0032] Wherein, TTL is the total optical length of the optical system, and fc is the focal length of the optical system when it is at the telephoto end. When the above relationship is satisfied, the total optical length of the system and the focal length of the system corresponding to the telephoto end can be reasonably configured, so that the miniaturization of the optical system can be further achieved on the basis of widening the zoom range.

[0033] In one embodiment, the first lens unit includes a first lens, the second lens unit includes a second lens, a third lens and a fourth lens in order from the object side to the image side, the third lens unit includes a fifth lens, a sixth lens and a seventh lens in order from the object side to the image side, and the fourth lens unit includes an eighth lens. The above design can provide an eight-piece structure for the optical system, so that the system can have good zoom performance with fewer refractive power elements.

[0034] In one embodiment, the optical system satisfies the following relationship:

[0035] 0.3<R16 / f4<0.8;

[0036] Wherein, R16 is the radius of curvature of the object side of the eighth lens at the optical axis, and f4 is the focal length of the fourth lens unit. When the above relationship is satisfied, the radius of curvature of the object side of the eighth lens and the focal length of the fourth lens unit will be reasonably configured, which is conducive to correcting aberrations and improving image quality. When R16 / f4<0.3, the radius of curvature of the object side of the eighth lens is too small, resulting in a complex surface shape of the surface and increasing the difficulty of processing.

[0037] A camera module comprises a photosensitive element and an optical system according to any one of the above embodiments, wherein the photosensitive element is arranged on the image side of the optical system. By adopting the above optical system, the camera module can take into account both zoom effect and miniaturization design, and can also effectively prevent the fourth lens unit and the photosensitive element from colliding during the assembly process, thereby improving the assembly yield. In addition, in a long-term high or low temperature environment, the camera module can still maintain good zoom performance.

[0038] An electronic device comprises a fixing part and the camera module, wherein the camera module is arranged on the fixing part. By adopting the camera module, the electronic device will have excellent shooting performance and can be assembled in a small space. In addition, in a long-term high or low temperature environment, the electronic device can still maintain good zoom shooting performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic diagram of the optical system of the first embodiment of the present application at a short focal length;

[0040] Figure 2 It is a schematic diagram of the optical system of the first embodiment of the present application at a mid-focus end;

[0041] Figure 3 A schematic diagram of the optical system of the first embodiment of the present application at a telephoto end;

[0042] Figure 4 The optical system in the first embodiment is Figure 1 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the short focal end;

[0043] Figure 5 The optical system in the first embodiment is Figure 2 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the mid-focus end;

[0044] Figure 6 The optical system in the first embodiment is Figure 3 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the telephoto end;

[0045] Figure 7 A schematic diagram of the optical system of the second embodiment of the present application at a short focal length;

[0046] Figure 8 A schematic diagram of the optical system of the second embodiment of the present application at a mid-focus end;

[0047] Fig. 9 A schematic diagram of the optical system of the second embodiment of the present application at a telephoto end;

[0048] Fig.10 The optical system in the second embodiment is Figure 7 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the short focal end;

[0049] Fig.11 The optical system in the second embodiment is Figure 8 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the mid-focus end;

[0050] Fig.12 The optical system in the second embodiment is Fig. 9 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the telephoto end;

[0051] Fig.13 A schematic diagram of the optical system of the third embodiment of the present application at a short focal length;

[0052] Fig.14 A schematic diagram of the optical system of the third embodiment of the present application at a mid-focus end;

[0053] Fig.15 A schematic diagram of the optical system of the third embodiment of the present application at a telephoto end;

[0054] Fig.16 The optical system in the third embodiment is Fig.13 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the short focal end;

[0055] Fig.17 The optical system in the third embodiment is Fig.14 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the mid-focus end;

[0056] Fig.18 The optical system in the third embodiment is Fig.15 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the telephoto end;

[0057] Fig.19A schematic diagram of the optical system of the fourth embodiment of the present application at a short focal length;

[0058] Fig. 20 A schematic diagram of the optical system of the fourth embodiment of the present application at a mid-focus end;

[0059] Fig.21 A schematic diagram of the optical system of the fourth embodiment of the present application at a telephoto end;

[0060] Fig. 22 The optical system in the fourth embodiment is Fig.19 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the short focal end;

[0061] Fig.23 The optical system in the fourth embodiment is Fig. 20 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the mid-focus end;

[0062] Fig.24 The optical system in the fourth embodiment is Fig.21 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the telephoto end;

[0063] Fig.25 is a schematic diagram of the optical system of the fifth embodiment of the present application at a short focal end;

[0064] Fig.26 is a schematic diagram of the optical system of the fifth embodiment of the present application at a mid-focus end;

[0065] Fig. 27 is a schematic diagram of the optical system of the fifth embodiment of the present application at a telephoto end;

[0066] Fig.28 The optical system in the fifth embodiment is Fig.25 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the short focal end;

[0067] Fig.29 The optical system in the fifth embodiment is Fig.26 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the mid-focus end;

[0068] Fig.30 The optical system in the fifth embodiment is Fig. 27 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the telephoto end;

[0069] Fig.31 A schematic diagram of a camera module provided in one embodiment of the present application;

[0070] Fig.32 A schematic diagram of an electronic device provided in accordance with an embodiment of the present application. DETAILED DESCRIPTION

[0071] In order to facilitate understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are shown 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, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0072] It should be noted that when an element is referred to as being "fixed to" another original, it may be directly on another element or may also have a centered element. When an element is considered to be "connected" to another original, it may be directly connected to another element or may simultaneously have a centered element. On the contrary, when an element is referred to as being "directly on" another original, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for illustrative purposes.

[0073] 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 in this specification 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.

[0074] refer to Figure 1In some embodiments of the present application, the optical system 10 includes, from the object side to the image side, a first lens unit 110 having positive refractive power and fixedly arranged, a second lens unit 120 having negative refractive power and movable arranged, a third lens unit 130 having positive refractive power and movable arranged, and a fourth lens unit 140 having positive refractive power and fixedly arranged. Among them, the first lens unit 110 includes a first lens L1, the second lens unit 120 includes, from the object side to the image side, a second lens L2, a third lens L3, and a fourth lens L4, the third lens unit 130 includes, from the object side to the image side, a fifth lens L5, a sixth lens L6, a seventh lens L7, and a stop STO, and the fourth lens unit 140 includes an eighth lens L8, and each of the first lens L1 to the eighth lens L8 contains only one lens. In addition, the first lens L1 has positive refractive power, the second lens L2 has negative refractive power, the third lens L3 has negative refractive power, the fourth lens L4 has positive refractive power, the fifth lens L5 has positive refractive power, the sixth lens L6 has positive refractive power, the seventh lens L7 has negative refractive power, and the eighth lens L8 has positive refractive power. Each lens in the optical system 10 is coaxially arranged with the aperture STO, that is, the optical axis of each lens and the center of the aperture STO are all located on the same straight line, and the straight line can be called the optical axis of the optical system 10.

[0075] The first lens L1 includes an object side surface S1 and an image side surface S2, the second lens L2 includes an object side surface S3 and an image side surface S4, the third lens L3 includes an object side surface S5 and an image side surface S6, the fourth lens L4 includes an object side surface S7 and an image side surface S8, the fifth lens L5 includes an object side surface S9 and an image side surface S10, the sixth lens L6 includes an object side surface S11 and an image side surface S12, the seventh lens L7 includes an object side surface S13 and an image side surface S14, and the eighth lens L8 includes an object side surface S15 and an image side surface S16. In addition, the optical system 10 also has a virtual imaging surface S17, and the imaging surface S17 is located on the image side of the fourth lens unit 140. Generally, the imaging surface S17 of the optical system 10 coincides with the photosensitive surface of the photosensitive element. For ease of understanding, when the optical system 10 and the photosensitive element are assembled into a camera module, the photosensitive surface of the photosensitive element can be regarded as the imaging surface S17, and the effective photosensitive area of ​​the photosensitive surface is the effective imaging area of ​​the imaging surface S17.

[0076] In the above embodiment, the first lens unit 110 and the fourth lens unit 140 are both fixed relative to the imaging surface S17 of the system, while the second lens unit 120 and the third lens unit 130 can move relative to the first lens unit 110 along the optical axis direction of the optical system 10, so that the optical system 10 can achieve optical zoom. That is, the first lens L1 and the eighth lens L8 are always fixed in the system, while the second lens L2, the third lens L3 and the fourth lens L4 can be fixed together by the clamp and move synchronously as a whole along the optical axis direction of the optical system 10, and the fifth lens L5, the sixth lens L6, the seventh lens L7 and the aperture STO can be fixed together by the clamp and move synchronously as another whole along the optical axis direction of the optical system 10. The zoom design enables the optical system 10 to switch between the short focal end and the long focal end. When the optical system 10 is at the short focal end, the system will have a large viewing angle characteristic; and when the optical system 10 is at the long focal end, the system will have a telephoto characteristic. Specifically, when the optical system 10 switches from the short focal end to the long focal end, the second lens unit 120 will move away from the first lens unit 110, and the third lens unit 130 will also move away from the fourth lens unit 140, that is, when the system switches from the short focal end to the long focal end, the second lens unit 120 and the third lens unit 130 will gradually approach each other.

[0077] In the zooming process of the optical system 10, the first lens unit 110 closest to the object side and the fourth lens unit 140 closest to the image side are both kept fixed, and the system is switched between the short focal end and the long focal end only by moving the second lens unit 120 and the third lens unit 130, thereby reducing the number of driving mechanisms, making the structure of the system more compact, thereby promoting the miniaturization design of the system and reducing the production cost. At the same time, since the zooming is achieved by moving two lens units with opposite refractive forces, the optical system 10 can reasonably control the deflection angle of the incident light during the zooming process and well correct the aberration, so as to have a good zooming effect. In addition, in a long-term high or low temperature environment, the components near the first lens unit 110 closest to the object side are most affected by the temperature, and the optical system 10 does not need to set a driving mechanism for the first lens unit 110, so it can avoid the driving mechanism in the system from being damaged by the external temperature due to being too close to the object side, thereby ensuring the normal operation of the zoom function. At the same time, the above-mentioned optical system 10 does not need to set a driving mechanism for the fourth lens unit 140, which is conducive to the assembly of the optical system 10 and the photosensitive element on the image side, and can avoid the fourth lens unit 140 from colliding with the photosensitive element during the zoom movement process.

[0078] In addition, in the above embodiments, the object side and image side of the first lens L1, the second lens L2, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all spherical, while the object side and image side of the third lens L3, the fourth lens L4 and the eighth lens L8 are all aspherical. The manufacturing process of spherical lenses is simple and the manufacturing cost is low. Aspherical lenses can further help the optical system 10 eliminate aberrations and solve the problem of visual distortion. At the same time, they can have excellent optical performance in a small and thin case, which is conducive to the miniaturization design of the optical system 10. Through the reasonable combination of spherical lenses and aspherical lenses, the system will be able to take into account miniaturization, high image quality and low cost. Of course, in some embodiments, the object side of any lens in the optical system 10 can be a spherical surface or an aspherical surface, and the image side of any lens can be a spherical surface or an aspherical surface. It should be noted that the specific shapes of the spherical and aspherical surfaces in the embodiments are not limited to the shapes of the spherical and aspherical surfaces shown in the drawings. The drawings are mainly for example reference and are not strictly drawn to scale. In particular, when the lens closest to the image side in the system is reasonably designed as an aspherical lens, the lens can effectively correct the aberrations generated by the lenses on the object side, thereby helping the system to maintain high image quality.

[0079] The calculation of the aspheric surface can refer to the aspheric surface formula:

[0080]

[0081] Among them, 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 cone coefficient, and Ai is the coefficient corresponding to the i-th high-order term in the aspherical surface shape formula.

[0082] It should be noted that, in some embodiments, when the object side or image side of a lens is an aspheric surface, the surface may be a structure that is convex as a whole or concave as a whole; or the surface may also be designed to have a structure with an inflection point, in which case the surface shape of the surface from the center to the edge will change, for example, the surface is convex at the center and concave at the edge. It should be noted that when the embodiments of the present application describe a side surface of a lens as convex at the paraxial position (the central area of ​​the side surface), it can be understood that the area of ​​the side surface of the lens near the optical axis is convex; when describing a side surface of a lens as concave at the circumference, it can be understood that the area of ​​the side surface near the maximum effective semi-aperture is concave. For example, when the side surface is convex at the paraxial position and is also convex at the circumference, the shape of the side surface from the center (optical axis) to the edge direction may be a pure convex surface; or it may first transition from a convex shape at the center to a concave shape, and then become convex when it is close to the maximum effective semi-aperture. The examples here are only used to illustrate the relationship between the proximal axis and the circumference. The various shape structures (concave-convex relationship) of the side are not fully reflected, but other situations can be deduced based on the above examples and should also be regarded as the contents recorded in this application.

[0083] In some embodiments, the spherical lenses (lenses with both the object side and the image side being spherical) in the optical system 10 are made of glass, while the aspherical lenses (at least one of the object side and the image side being aspherical) are made of plastic. In some embodiments, the materials of all lenses in the optical system 10 are glass. In other embodiments, the materials of all lenses in the optical system 10 are plastic. Lenses made of glass can withstand higher temperatures and have excellent optical effects, while lenses made of plastic can reduce the weight of the optical system 10 and reduce the manufacturing cost. In other embodiments, the material of the first lens L1 is glass, and the materials of the other lenses in the optical system 10 are plastic. At this time, since the material of the lenses close to the object side in the optical system 10 is glass, these glass lenses close to the object side have a good tolerance effect on extreme environments and are not easily affected by the object side environment and aging, etc., so that when the optical system 10 is in an extreme environment such as exposure to high temperature, this structure can better balance the optical performance and production cost of the system. Of course, the material configuration relationship of the lenses in the optical system 10 is not limited to the above embodiments, and the material of any lens in the system can be plastic or glass.

[0084] In some embodiments, the optical system 10 further includes an infrared cut-off filter L9, which is disposed on the image side of the fourth lens unit 140 and is fixedly disposed relative to the first lens unit 110 and the fourth lens unit 140. The infrared cut-off filter L9 is used to filter out infrared light to prevent infrared light from reaching the imaging surface S17 of the system, thereby preventing infrared light from interfering with normal imaging. The infrared cut-off filter L9 can be assembled together with each lens as a part of the optical system 10. In other embodiments, the infrared cut-off filter L9 does not belong to the components of the optical system 10. In this case, the infrared cut-off filter L9 can be installed between the optical system 10 and the photosensitive element when the optical system 10 and the photosensitive element are assembled into a camera module. In some embodiments, the infrared cut-off filter L9 can also be disposed on the object side of the first lens L1. In addition, in some embodiments, the infrared cut-off filter L9 may not be disposed, but an infrared filter film may be disposed on any lens from the first lens L1 to the fifth lens L5 to achieve the effect of filtering out infrared light. By setting an infrared cut-off filter L9 or setting an infrared filter film on the lens surface, the phenomenon of false color or ripples in imaging due to interference of infrared light can be avoided, and the effective resolution and color reproduction can be improved.

[0085] In some embodiments, the first lens unit 110 and the fourth lens unit 140 include but are not limited to a case of one lens, and the second lens unit 120 and the third lens unit 130 include but are not limited to a case of three lenses.

[0086] In some embodiments, the optical system 10 also satisfies the following relationships:

[0087] 1.2<fc / fd<3.5; wherein fc is the focal length of the optical system 10 at the telephoto end, and fd is the focal length of the optical system 10 at the short focal end. In some embodiments, fc / fd is 1.50, 1.60, 1.80, 2.00, 2.20, 2.50, 2.80 or 3.00. When the above relationship is satisfied, the focal length of the optical system 10 at the telephoto end and the short focal end can be reasonably configured, so that the zooming process is more reasonable and appropriate, which is conducive to the optical system 10 having excellent zooming effect and miniaturization characteristics. When fc / fd>3.5, it is not conducive to correcting the spherical aberration of the system at the telephoto end, and it will cause the moving distance of the lens unit to be too large when the system switches from telephoto to short focal, so that the miniaturization design cannot be achieved; when fc / fd<1.2, the zoom ratio of the system is too low, and a significant zooming effect cannot be achieved.

[0088] 0.3<(g1+g2+g3+g4) / fd; wherein g1 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the first lens unit 110, g2 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the second lens unit 120, g3 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the third lens unit 130, g4 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the fourth lens unit 140, and fd is the focal length of the optical system 10 when it is at the short focal end. In some embodiments, (g1+g2+g3+g4) / fd is 0.45, 0.50, 0.60, 0.70, 0.80 or 0.85. When the above relationship is satisfied, it is beneficial for the optical system 10 to have a zoom function while also miniaturizing the entire system. When (g1+g2+g3+g4) / fd<0.3, it will be disadvantageous to correct the aberration of the system, and the total length of the system will be too short, resulting in a reduction in the thickness of each lens and an increase in processing costs.

[0089] 0.8<f3 / fd<2; wherein f3 is the focal length of the third lens unit 130, and fd is the focal length of the optical system 10 when it is at the short focal end. In some embodiments, f3 / fd is 1.00, 1.10, 1.20, 1.40, 1.50, 1.60, 1.70 or 1.80. When the above relationship is satisfied, it can ensure that the third lens unit 130 provides a suitable refractive power for the entire optical system 10, and it is beneficial for the system to obtain a miniature size.

[0090] 1.6<f1 / |f2|<2.3; wherein f1 is the focal length of the first lens unit 110, and f2 is the focal length of the second lens unit 120. In some embodiments, f1 / |f2| is 1.80, 1.90, 2.00, 2.10 or 2.15. When the above relationship is satisfied, the refractive power of the first lens unit 110 and the second lens unit 120 can be reasonably configured, so that the distortion generated by the first lens unit 110 can be effectively corrected, and it is also beneficial to achieve a miniaturized design of the system. When f1 / |f2|>2.3, the refractive power of the first lens unit 110 is too strong, and it is difficult to correct the distortion generated by the first lens unit 110; when f1 / |f2|<1.6, the refractive power of the first lens unit 110 is too weak, and the incident light cannot be effectively deflected, thereby increasing the effective distance of the light, which is not conducive to the miniaturization of the entire optical system 10.

[0091] -0.6<f2 / fc<-0.3; wherein f2 is the focal length of the second lens unit 120, and fc is the focal length of the optical system 10 when it is at the telephoto end. In some embodiments, f2 / fc is -0.50, -0.49, -0.47, -0.45 or -0.43. When the above relationship is satisfied, the focal length of the second lens unit 120 and the focal length corresponding to the system at the telephoto end can be reasonably configured, thereby ensuring that the system can reasonably achieve zooming, that is, the moving distance of the system during the zooming process is smaller, the zooming time is shorter, and it is less affected by the external environment, thereby achieving fast and efficient zooming. At the same time, when the above relationship is satisfied, it is also beneficial to correct the spherical aberration generated by the second lens unit 120.

[0092] 0.1<d2 / d3<0.6; wherein d2 is the moving distance of the second lens unit 120 when the optical system 10 is zoomed from the short focal end to the long focal end, and d3 is the moving distance of the third lens unit 130 when the optical system 10 is zoomed from the short focal end to the long focal end. In some embodiments, d2 / d3 is 0.25, 0.30, 0.35, 0.40, 0.45 or 0.50. When the above relationship is satisfied, it will be beneficial to the miniaturization of the optical system 10 and make the zooming process more reasonable, that is, the moving distance of the system during the zooming process is smaller, the zooming time is shorter, and it is less affected by the external environment, so that fast and efficient zooming can be achieved.

[0093] 1<TTL / fc<1.5; wherein TTL is the total optical length of the optical system 10, and fc is the focal length of the optical system 10 when it is at the telephoto end. In some embodiments, TTL / fc is 1.15, 1.20, 1.25, 1.30, 1.35 or 1.40. When the above relationship is satisfied, the total optical length of the system and the focal length of the system at the telephoto end can be reasonably configured, so that the miniaturization of the optical system 10 can be further achieved on the basis of widening the zoom range.

[0094] 0.3<R16 / f4<0.8; wherein R16 is the radius of curvature of the object side surface S15 of the eighth lens L8 at the optical axis, and f4 is the focal length of the fourth lens unit 140. In some embodiments, R16 / f4 is 0.40, 0.43, 0.45, 0.50, 0.55, 0.58, 0.60 or 0.62. When the above relationship is satisfied, the radius of curvature of the object side surface S15 of the eighth lens L8 and the focal length of the fourth lens unit 140 will be reasonably configured, which is conducive to correcting aberrations and improving image quality. When R16 / f4<0.3, the radius of curvature of the object side surface S15 of the eighth lens L8 is too small, which makes the surface shape of the surface complex and increases the difficulty of processing.

[0095] In some embodiments, the optical system 10 has only one telephoto end position and one short focal end position, that is, the system can only switch between these two positions. In some embodiments, the optical system 10 also has a mid-focal end position, and the system can switch between the three positions of the telephoto end, the mid-focal end, and the short focal end. The focal length of the optical system 10 at the telephoto end is greater than the focal length at the mid-focal end, and the focal length of the optical system 10 at the mid-focal end is greater than the focal length at the short focal end. The switching of the optical system 10 between the above-mentioned different focal lengths is achieved by the zoom movement of the second lens unit 120 and the third lens unit 130. However, it should be noted that in some embodiments, the optical system 10 is not only able to switch between the above-mentioned two or three focal lengths. In these embodiments, the second lens unit 120 and the third lens unit 130 can remain stationary at any reasonable position within the range of movement, so that the optical system 10 has the ability of continuous zooming, and thus has more focal length options.

[0096] In some embodiments, the second lens unit 120 and the third lens unit 130 may be provided with voice coil motors and magnets and other driving mechanisms respectively so that the two can move independently, thereby achieving a zoom effect. Specifically, in some embodiments, each lens in the second lens unit 120 is assembled in a lens barrel, and a coil electrically connected to a driving chip is provided on the lens barrel, and a magnet corresponding to the coil is also provided in the optical system 10, and the lens barrel is driven to move by the magnetic force between the coil and the magnet after power is supplied. Similarly, each lens and aperture STO in the third lens unit 130 are assembled in another lens barrel, and a coil electrically connected to a driving chip is provided on the lens barrel, and a magnet corresponding to the coil is also provided in the optical system 10, and the lens barrel is driven to move by the magnetic force between the coil and the magnet after power is supplied.

[0097] Next, the optical system 10 of the present application is described with more specific and detailed embodiments:

[0098] First embodiment

[0099] refer to Figure 1 , Figure 2 and Figure 3In the first embodiment, the optical system 10 includes, from the object side to the image side, a first lens unit 110 having positive refractive power and fixedly arranged, a second lens unit 120 having negative refractive power and movable arranged, a third lens unit 130 having positive refractive power and movable arranged, and a fourth lens unit 140 having positive refractive power and fixedly arranged. Among them, the first lens unit 110 includes a first lens L1, the second lens unit 120 includes, from the object side to the image side, a second lens L2, a third lens L3, and a fourth lens L4, the third lens unit 130 includes, from the object side to the image side, a fifth lens L5, a sixth lens L6, a seventh lens L7, and a stop STO, and the fourth lens unit 140 includes an eighth lens L8, and the first lens L1 to the eighth lens L8 each include only one lens. The first lens L1 has positive refractive power, the second lens L2 has negative refractive power, the third lens L3 has negative refractive power, the fourth lens L4 has positive refractive power, the fifth lens L5 has positive refractive power, the sixth lens L6 has positive refractive power, the seventh lens L7 has negative refractive power, and the eighth lens L8 has positive refractive power. The first lens unit 110 and the fourth lens unit 140 are both fixedly arranged relative to the imaging surface of the optical system 10, and the optical system 10 realizes optical zoom by moving the second lens unit 120 and the third lens unit 130.

[0100] During zooming, the first lens L1 and the eighth lens L8 are always kept fixed in the system, while the second lens L2, the third lens L3 and the fourth lens L4 can be fixed together by a clamp and move synchronously as a whole along the optical axis of the optical system 10, and the fifth lens L5, the sixth lens L6, the seventh lens L7 and the aperture STO can be fixed together by a clamp and move synchronously as another whole along the optical axis of the optical system 10. When the optical system 10 gradually switches from the short focal end to the long focal end, the second lens unit 120 will be away from the first lens unit 110, and the third lens unit 130 and the fourth lens unit 140 will also be away from each other.

[0101] In the zooming process of the optical system 10, the first lens unit 110 closest to the object side and the fourth lens unit 140 closest to the image side are both kept fixed, and the system is switched between the short focal end and the long focal end only by moving the second lens unit 120 and the third lens unit 130, thereby reducing the number of driving mechanisms, making the structure of the system more compact, thereby promoting the miniaturization design of the system and reducing the production cost. At the same time, since the zooming is achieved by moving two lens units with opposite refractive forces, the optical system 10 can reasonably control the deflection angle of the incident light during the zooming process and well correct the aberration, so as to have a good zooming effect. In addition, in a long-term high or low temperature environment, the components near the first lens unit 110 closest to the object side are most affected by the temperature, and the optical system 10 does not need to set a driving mechanism for the first lens unit 110, so it can avoid the driving mechanism in the system from being damaged by the external temperature due to being too close to the object side, thereby ensuring the normal operation of the zoom function. At the same time, the above-mentioned optical system 10 does not need to set a driving mechanism for the fourth lens unit 140, which is conducive to the assembly of the optical system 10 and the photosensitive element on the image side, and can avoid the fourth lens unit 140 from colliding with the photosensitive element during the zoom movement process.

[0102] Figure 1 is a schematic diagram of the optical system 10 of the first embodiment at a short focal end; Figure 2 is a schematic diagram of the optical system 10 of the first embodiment at a mid-focus end; Figure 3 FIG. 1 is a schematic diagram of the optical system 10 of the first embodiment at a telephoto end. Figure 4 The optical system 10 is Figure 1 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the short focal end; Figure 5 The optical system 10 is Figure 2 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the mid-focus end; Figure 6 The optical system 10 is Figure 3 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the telephoto end. The ordinate of each astigmatism diagram and distortion diagram is half of the diagonal length of the imaging surface S17 of the optical system 10 in the effective imaging area, and the unit is mm. In addition, the astigmatism diagram and distortion diagram in the following embodiments are curve diagrams at a wavelength of 555nm.

[0103] above Figure 1 , Figure 2 and Figure 3The positional relationship of each lens when the optical system 10 is at a short focal end, a medium focal end and a long focal end is respectively shown, and the optical system 10 includes but is not limited to switching between the above three focal length states. The focal length of the optical system 10 at the long focal end is greater than the focal length at the medium focal end, and the focal length of the optical system 10 at the medium focal end is greater than the focal length at the short focal end.

[0104] The object-side surface S1 of the first lens L1 is convex at the paraxial position, and the image-side surface S2 is convex at the paraxial position; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is convex at the circumference.

[0105] The object-side surface S3 of the second lens L2 is concave at the paraxial position, and the image-side surface S4 is concave at the paraxial position; the object-side surface S3 is concave at the circumference, and the image-side surface S4 is concave at the circumference.

[0106] The object-side surface S5 of the third lens L3 is convex at the paraxial position, and the image-side surface S6 is concave at the paraxial position; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is concave at the circumference.

[0107] The object-side surface S7 of the fourth lens L4 is convex at the paraxial position, and the image-side surface S8 is concave at the paraxial position; the object-side surface S7 is convex at the circumference, and the image-side surface S8 is convex at the circumference.

[0108] The object-side surface S9 of the fifth lens L5 is convex at the paraxial position, and the image-side surface S10 is convex at the paraxial position; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is convex at the circumference.

[0109] The object-side surface S11 of the sixth lens L6 is convex at the paraxial position, and the image-side surface S12 is concave at the paraxial position; the object-side surface S11 is convex at the circumference, and the image-side surface S12 is concave at the circumference.

[0110] The object-side surface S13 of the seventh lens L7 is concave at the paraxial position, and the image-side surface S14 is concave at the paraxial position; the object-side surface S13 is concave at the circumference, and the image-side surface S14 is concave at the circumference.

[0111] The object-side surface S15 of the eighth lens L8 is convex at the paraxial position, and the image-side surface S16 is concave at the paraxial position; the object-side surface S15 is convex at the circumference, and the image-side surface S16 is convex at the circumference.

[0112] The object side and image side of the first lens L1, the second lens L2, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all spherical. The object side and image side of the third lens L3, the fourth lens L4 and the eighth lens L8 are all aspherical. The material of the first lens L1, the second lens L2, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all glass. Lenses made of glass can withstand extreme temperatures and have excellent and stable optical effects. The material of the third lens L3, the fourth lens L4 and the eighth lens L8 are all plastic.

[0113] In the zooming process of the optical system 10, the first lens unit 110 closest to the object side and the fourth lens unit 140 closest to the image side are both kept fixed, and the system is switched between the short focal end and the long focal end only by moving the second lens unit 120 and the third lens unit 130, thereby reducing the number of driving mechanisms, making the structure of the system more compact, thereby promoting the miniaturization design of the system and reducing the production cost. At the same time, since the zooming is achieved by moving two lens units with opposite refractive forces, the optical system 10 can reasonably control the deflection angle of the incident light during the zooming process and well correct the aberration, so as to have a good zooming effect. In addition, in a long-term high or low temperature environment, the components near the first lens unit 110 closest to the object side are most affected by the temperature, and the optical system 10 does not need to set a driving mechanism for the first lens unit 110, so it can avoid the driving mechanism in the system from being damaged by the external temperature due to being too close to the object side, thereby ensuring the normal operation of the zoom function. At the same time, the optical system 10 does not need to set a driving mechanism for the fourth lens unit 140, which is conducive to the assembly of the optical system 10 and the photosensitive element on the image side, and can avoid the fourth lens unit 140 from colliding with the photosensitive element during the zoom movement. In addition, in the first embodiment, the optical system 10 also satisfies the following relationships:

[0114] fc / fd=2.32; wherein fc is the focal length of the optical system 10 at the telephoto end, and fd is the focal length of the optical system 10 at the short focal end. When the above relationship is satisfied, the focal lengths of the optical system 10 at the telephoto end and the short focal end can be reasonably configured, making the zooming process more reasonable and appropriate, thereby facilitating the optical system 10 to have an excellent zooming effect and miniaturization characteristics.

[0115] (g1+g2+g3+g4) / fd=0.81; wherein g1 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the first lens unit 110, g2 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the second lens unit 120, g3 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the third lens unit 130, g4 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the fourth lens unit 140, and fd is the focal length of the optical system 10 at the short focal end. When the above relationship is satisfied, it is beneficial for the optical system 10 to have a zoom function while also enabling the entire system to be miniaturized.

[0116] f3 / fd=1.51; wherein f3 is the focal length of the third lens unit 130, and fd is the focal length of the optical system 10 at the short focal end. When the above relationship is satisfied, it can ensure that the third lens unit 130 provides a suitable refractive power for the entire optical system 10, and it is beneficial for the system to obtain a miniature size.

[0117] f1 / |f2|=2.17; wherein f1 is the focal length of the first lens unit 110, and f2 is the focal length of the second lens unit 120. When the above relationship is satisfied, the refractive power of the first lens unit 110 and the second lens unit 120 can be reasonably configured, so that the distortion generated by the first lens unit 110 can be effectively corrected, and it is also beneficial to realize a miniaturized design of the system.

[0118] f2 / fc=-0.46; wherein f2 is the focal length of the second lens unit 120, and fc is the focal length of the optical system 10 when it is at the telephoto end. When the above relationship is satisfied, the focal length of the second lens unit 120 and the focal length of the system corresponding to the telephoto end can be reasonably configured, thereby ensuring that the system can reasonably achieve zooming, that is, the moving distance of the system during zooming is smaller, the zooming time is shorter, and the system is less affected by the external environment, thereby achieving fast and efficient zooming, and at the same time, it is also beneficial to correct the spherical aberration generated by the second lens unit 120.

[0119] d2 / d3=0.51; wherein d2 is the moving distance of the second lens unit 120 when the optical system 10 is zooming from the short focal end to the long focal end, and d3 is the moving distance of the third lens unit 130 when the optical system 10 is zooming from the short focal end to the long focal end. When the above relationship is satisfied, it will be beneficial to the miniaturization of the optical system 10 and make the zooming process more reasonable, that is, the moving distance of the system during the zooming process is smaller, the zooming time is shorter, and the system is less affected by the external environment, so that fast and efficient zooming can be achieved.

[0120] TTL / fc=1.37; wherein TTL is the total optical length of the optical system 10, and fc is the focal length of the optical system 10 at the telephoto end. When the above relationship is satisfied, the total optical length of the system and the focal length of the system at the telephoto end can be reasonably configured, thereby further miniaturizing the optical system 10 on the basis of widening the zoom range.

[0121] R16 / f4=0.50; wherein R16 is the radius of curvature of the object-side surface S15 of the eighth lens L8 at the optical axis, and f4 is the focal length of the fourth lens unit 140. When the above relationship is satisfied, the radius of curvature of the object-side surface S15 of the eighth lens L8 and the focal length of the fourth lens unit 140 are reasonably configured, which is beneficial to correct aberrations and improve image quality.

[0122] The short focal end and the long focal end involved in the above-mentioned relationships of the first embodiment correspond to Figure 1 and Figure 3 The system status shown does not mean that each lens unit can only be adjusted to the short focal end and the long focal end position.

[0123] In addition, the lens parameters of the optical system 10 are given in Table 1, Table 2 and Table 3. The elements from the object side to the image side are arranged in the order of the elements from top to bottom in Table 1, wherein the object located on the object plane can form a clear image on the image plane (imaging plane S17) of the optical system 10, and the imaging plane S17 can also be understood as the photosensitive surface of the photosensitive element during later assembly. The surface numbers 1 and 2 respectively represent the object side surface S1 and the image side surface S2 of the first lens L1, that is, in the same lens, the surface with a smaller surface number is the object side surface, and the surface with a larger surface number is the image side surface. The Y radius in Table 1 is the radius of curvature of the object side surface or the image side surface of the corresponding surface number on the optical axis. The first value of the lens in the "Thickness" parameter column is the thickness of the lens on the optical axis, and the second value is the distance from the image side surface of the lens to the object side surface of the next optical element (lens or aperture STO) on the optical axis. The value of the aperture STO in the "Thickness" parameter column is the distance from the aperture STO to the object side surface of the next lens on the optical axis. The centers of the optical axis-level apertures STO of each lens are all on the same straight line, and the straight line serves as the optical axis of the optical system 10. D1 in the table is the distance between the first lens unit 110 and the second lens unit 120 on the optical axis, that is, the distance from the image side surface S2 of the first lens L1 to the object side surface S3 of the second lens L2 on the optical axis; D2 is the distance between the second lens unit 120 and the third lens unit 130 on the optical axis, that is, the distance from the image side surface S8 of the fourth lens L4 to the object side surface S9 of the fifth lens L5 on the optical axis; D3 is the distance between the third lens unit 130 and the fourth lens unit 140 on the optical axis, that is, the distance from the image side surface S14 of the seventh lens L7 to the object side surface S15 of the eighth lens L8 on the optical axis.

[0124] Figures 1 to 3 The lens position states at three different system focal lengths in the first embodiment are shown respectively. Figure 1 A short focal position is shown. Figure 2 A mid-focus position is shown. Figure 3 The optical system 10 has a telephoto end position. The focal length fd of the optical system 10 at the short focal end is 12.9 mm, the aperture number FNOd is 3.85, and the maximum diagonal field angle FOVd is 11.69°; the focal length fz of the optical system 10 at the mid-focal end is 23.30 mm, the aperture number FNOz is 4.63, and the maximum diagonal field angle FOVz is 6.42°; the focal length fc of the optical system 10 at the telephoto end is 29.90 mm, the aperture number FNOc is 5.02, and the maximum diagonal field angle FOVc is 5.01°. For the corresponding tables of the following embodiments, the three values ​​of the focal length f, the aperture number FNO, and the maximum diagonal field angle FOV of the system are respectively given, from left to right, the values ​​of the system at the short focal end, the mid-focal end, and the telephoto end. The total optical length TTL of the optical system 10 is 41 mm, and the total optical length is the distance from the object side surface S1 of the first lens L1 to the imaging surface S17 of the system on the optical axis. In some embodiments, the infrared cut-off filter L9 in Table 1 does not belong to the components of the optical system 10. In this case, the total optical length TTL of the optical system 10 is still 41 mm, and the distance from the image side surface S16 of the eighth lens L8 to the imaging surface S17 is still 12.60 mm. Table 2 gives the values ​​of D1, D2 and D3 of the optical system 10 at the above-mentioned short focal end, medium focal end and long focal end, and the unit of the value is mm. K in Table 3 is the cone coefficient, and Ai is the coefficient corresponding to the i-th high-order term in the aspheric surface shape formula.

[0125] In addition, in the following embodiments (the first embodiment to the fifth embodiment), the refractive index, Abbe number and focal length of each lens are all values ​​at a wavelength of 587.56 nm. In addition, the relationship calculation and lens structure of each embodiment are based on the lens parameters (parameter data in Table 1, Table 2, and Table 3 corresponding to the first embodiment).

[0126] Table 1

[0127]

[0128]

[0129] Table 2

[0130] Variable distance Short focus position Mid-focus position Telephoto position D1 2.3370 5.9054 7.1494 D2 14.7505 4.7507 0.4000 D3 0.5000 6.7813 9.9381

[0131] Table 3

[0132] Surface number 5 6 7 8 16 17 K 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A4 -2.23E-03 -3.07E-03 -1.10E-04 -2.00E-04 -2.50E-04 -1.60E-04 A6 2.00E-05 1.00E-05 2.00E-05 2.00E-05 -1.00E-05 -2.00E-05 A8 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A10 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A12 0.00E+00 0.00E+00 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 0.00E+00 0.00E+00 A16 0.00E+00 0.00E+00 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 0.00E+00 0.00E+00 A20 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00

[0133] Second embodiment

[0134] refer to Figure 7 , Figure 8 and Fig. 9 In the second embodiment, the optical system 10 includes, from the object side to the image side, a first lens unit 110 having positive refractive power and fixedly arranged, a second lens unit 120 having negative refractive power and movable arranged, a third lens unit 130 having positive refractive power and movable arranged, and a fourth lens unit 140 having positive refractive power and fixedly arranged. Among them, the first lens unit 110 includes a first lens L1, the second lens unit 120 includes, from the object side to the image side, a second lens L2, a third lens L3, and a fourth lens L4, the third lens unit 130 includes, from the object side to the image side, a fifth lens L5, a sixth lens L6, a seventh lens L7, and a stop STO, and the fourth lens unit 140 includes an eighth lens L8, and the first lens L1 to the eighth lens L8 each include only one lens. The first lens L1 has positive refractive power, the second lens L2 has negative refractive power, the third lens L3 has negative refractive power, the fourth lens L4 has positive refractive power, the fifth lens L5 has positive refractive power, the sixth lens L6 has positive refractive power, the seventh lens L7 has negative refractive power, and the eighth lens L8 has positive refractive power. The first lens unit 110 and the fourth lens unit 140 are both fixedly arranged relative to the imaging surface of the optical system 10, and the optical system 10 realizes optical zoom by moving the second lens unit 120 and the third lens unit 130.

[0135] During zooming, the first lens L1 and the eighth lens L8 are always kept fixed in the system, while the second lens L2, the third lens L3 and the fourth lens L4 can be fixed together by a clamp and move synchronously as a whole along the optical axis of the optical system 10, and the fifth lens L5, the sixth lens L6, the seventh lens L7 and the aperture STO can be fixed together by a clamp and move synchronously as another whole along the optical axis of the optical system 10. When the optical system 10 gradually switches from the short focal end to the long focal end, the second lens unit 120 will be away from the first lens unit 110, and the third lens unit 130 and the fourth lens unit 140 will also be away from each other.

[0136] Figure 7 is a schematic diagram of the optical system 10 of the second embodiment at a short focal end; Figure 8 is a schematic diagram of the optical system 10 of the second embodiment at a mid-focus end; Fig. 9 FIG. 1 is a schematic diagram of the optical system 10 of the second embodiment at a telephoto end. Fig.10 The optical system 10 is Figure 7 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the short focal end; Fig.11 The optical system 10 is Figure 8 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the mid-focus end; Fig.12 The optical system 10 is Fig. 9 Corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the telephoto end.

[0137] The object-side surface S1 of the first lens L1 is convex at the paraxial position, and the image-side surface S2 is convex at the paraxial position; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is convex at the circumference.

[0138] The object-side surface S3 of the second lens L2 is concave at the paraxial position, and the image-side surface S4 is concave at the paraxial position; the object-side surface S3 is concave at the circumference, and the image-side surface S4 is concave at the circumference.

[0139] The object-side surface S5 of the third lens L3 is convex at the paraxial position, and the image-side surface S6 is concave at the paraxial position; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is concave at the circumference.

[0140] The object-side surface S7 of the fourth lens L4 is convex at the paraxial position, and the image-side surface S8 is concave at the paraxial position; the object-side surface S7 is convex at the circumference, and the image-side surface S8 is convex at the circumference.

[0141] The object-side surface S9 of the fifth lens L5 is convex at the paraxial position, and the image-side surface S10 is convex at the paraxial position; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is convex at the circumference.

[0142] The object-side surface S11 of the sixth lens L6 is convex at the paraxial position, and the image-side surface S12 is concave at the paraxial position; the object-side surface S11 is convex at the circumference, and the image-side surface S12 is concave at the circumference.

[0143] The object-side surface S13 of the seventh lens L7 is convex at the paraxial position, and the image-side surface S14 is concave at the paraxial position; the object-side surface S13 is convex at the circumference, and the image-side surface S14 is concave at the circumference.

[0144] The object-side surface S15 of the eighth lens L8 is convex at the paraxial position, and the image-side surface S16 is concave at the paraxial position; the object-side surface S15 is concave at the circumference, and the image-side surface S16 is convex at the circumference.

[0145] In addition, the lens parameters of the optical system 10 in the second embodiment are given in Table 4, Table 5 and Table 6, wherein the definitions of the structures and parameters can be obtained from the first embodiment and are not elaborated here.

[0146] Table 4

[0147]

[0148]

[0149] Table 5

[0150] Variable distance Short focus position Mid-focus position Telephoto position D1 0.0300 5.5694 6.6095 D2 19.3615 4.2010 0.4000 D3 0.5000 10.1110 12.8770

[0151] Table 6

[0152] Surface number 5 6 7 8 16 17 K 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A4 -2.30E-03 -2.73E-03 -7.00E-04 -7.70E-04 -2.60E-04 -1.90E-04 A6 9.00E-05 8.00E-05 3.00E-05 4.00E-05 -1.00E-05 -1.00E-05 A8 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A10 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A12 0.00E+00 0.00E+00 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 0.00E+00 0.00E+00 A16 0.00E+00 0.00E+00 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 0.00E+00 0.00E+00 A20 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00

[0153] The optical system 10 in this embodiment satisfies the following relationship:

[0154] fc / fd 3.04 f2 / fc -0.42 (g1+g2+g3+g4) / fd 0.89 d2 / d3 0.53 f3 / fd 1.87 TTL / fc 1.32 f1 / |f2| 2.15 R16 / f4 0.52

[0155] Third embodiment

[0156] refer to Fig.13 , Fig.14 and Fig.15 In the third embodiment, the optical system 10 includes, from the object side to the image side, a first lens unit 110 having positive refractive power and fixedly arranged, a second lens unit 120 having negative refractive power and movable arranged, a third lens unit 130 having positive refractive power and movable arranged, and a fourth lens unit 140 having positive refractive power and fixedly arranged. Among them, the first lens unit 110 includes a first lens L1, the second lens unit 120 includes, from the object side to the image side, a second lens L2, a third lens L3, and a fourth lens L4, the third lens unit 130 includes, from the object side to the image side, a fifth lens L5, a sixth lens L6, a seventh lens L7, and a stop STO, and the fourth lens unit 140 includes an eighth lens L8, and each of the first lens L1 to the eighth lens L8 includes only one lens. The first lens L1 has positive refractive power, the second lens L2 has negative refractive power, the third lens L3 has negative refractive power, the fourth lens L4 has positive refractive power, the fifth lens L5 has positive refractive power, the sixth lens L6 has positive refractive power, the seventh lens L7 has negative refractive power, and the eighth lens L8 has positive refractive power. The first lens unit 110 and the fourth lens unit 140 are both fixedly arranged relative to the imaging surface of the optical system 10, and the optical system 10 realizes optical zoom by moving the second lens unit 120 and the third lens unit 130.

[0157] During zooming, the first lens L1 and the eighth lens L8 are always kept fixed in the system, while the second lens L2, the third lens L3 and the fourth lens L4 can be fixed together by a clamp and move synchronously as a whole along the optical axis of the optical system 10, and the fifth lens L5, the sixth lens L6, the seventh lens L7 and the aperture STO can be fixed together by a clamp and move synchronously as another whole along the optical axis of the optical system 10. When the optical system 10 gradually switches from the short focal end to the long focal end, the second lens unit 120 will be away from the first lens unit 110, and the third lens unit 130 and the fourth lens unit 140 will also be away from each other.

[0158] Fig.13 is a schematic diagram of the optical system 10 of the third embodiment at a short focal end; Fig.14 is a schematic diagram of the optical system 10 of the third embodiment at a mid-focus end; Fig.15 FIG. 1 is a schematic diagram of the optical system 10 of the third embodiment at a telephoto end. Fig.16 The optical system 10 is Fig.13 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the short focal end; Fig.17 The optical system 10 is Fig.14 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the mid-focus end; Fig.18 The optical system 10 is Fig.15 Corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the telephoto end.

[0159] The object-side surface S1 of the first lens L1 is convex at the paraxial position, and the image-side surface S2 is convex at the paraxial position; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is convex at the circumference.

[0160] The object-side surface S3 of the second lens L2 is concave at the paraxial position, and the image-side surface S4 is concave at the paraxial position; the object-side surface S3 is concave at the circumference, and the image-side surface S4 is concave at the circumference.

[0161] The object-side surface S5 of the third lens L3 is convex at the paraxial position, and the image-side surface S6 is concave at the paraxial position; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is concave at the circumference.

[0162] The object-side surface S7 of the fourth lens L4 is convex at the paraxial position, and the image-side surface S8 is concave at the paraxial position; the object-side surface S7 is convex at the circumference, and the image-side surface S8 is concave at the circumference.

[0163] The object-side surface S9 of the fifth lens L5 is convex at the paraxial position, and the image-side surface S10 is convex at the paraxial position; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is convex at the circumference.

[0164] The object-side surface S11 of the sixth lens L6 is convex at the paraxial position, and the image-side surface S12 is concave at the paraxial position; the object-side surface S11 is convex at the circumference, and the image-side surface S12 is concave at the circumference.

[0165] The object-side surface S13 of the seventh lens L7 is convex at the paraxial position, and the image-side surface S14 is concave at the paraxial position; the object-side surface S13 is convex at the circumference, and the image-side surface S14 is concave at the circumference.

[0166] The object-side surface S15 of the eighth lens L8 is convex at the paraxial position, and the image-side surface S16 is concave at the paraxial position; the object-side surface S15 is convex at the circumference, and the image-side surface S16 is concave at the circumference.

[0167] In addition, the lens parameters of the optical system 10 in the third embodiment are given in Table 7, Table 8 and Table 9, wherein the definitions of the structures and parameters can be obtained from the first embodiment and will not be elaborated here.

[0168] Table 7

[0169]

[0170]

[0171] Table 8

[0172] Variable distance Short focus position Mid-focus position Telephoto position D1 0.1537 0.6436 1.9016 D2 6.3794 4.8442 0.4000 D3 0.5000 1.6403 4.7265

[0173] Table 9

[0174] Surface number 5 6 7 8 16 17 K 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A4 -2.54E-03 -2.71E-03 -1.00E-05 -3.60E-04 9.00E-05 1.60E-04 A6 7.00E-05 4.00E-05 0.00E+00 3.00E-05 -2.00E-05 -2.00E-05 A8 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A10 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A12 0.00E+00 0.00E+00 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 0.00E+00 0.00E+00 A16 0.00E+00 0.00E+00 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 0.00E+00 0.00E+00 A20 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00

[0175] The optical system 10 in this embodiment satisfies the following relationship:

[0176] fc / fd 1.43 f2 / fc -0.45 (g1+g2+g3+g4) / fd 0.42 d2 / d3 0.41 f3 / fd 0.96 TTL / fc 1.14 f1 / |f2| 1.82 R16 / f4 0.40

[0177] Fourth embodiment

[0178] refer to Fig.19 , Fig. 20 and Fig.21In the fourth embodiment, the optical system 10 includes, from the object side to the image side, a first lens unit 110 having positive refractive power and fixedly arranged, a second lens unit 120 having negative refractive power and movable arranged, a third lens unit 130 having positive refractive power and movable arranged, and a fourth lens unit 140 having positive refractive power and fixedly arranged. Among them, the first lens unit 110 includes a first lens L1, the second lens unit 120 includes, from the object side to the image side, a second lens L2, a third lens L3, and a fourth lens L4, the third lens unit 130 includes, from the object side to the image side, a fifth lens L5, a sixth lens L6, a seventh lens L7, and a stop STO, and the fourth lens unit 140 includes an eighth lens L8, and each of the first lens L1 to the eighth lens L8 includes only one lens. The first lens L1 has positive refractive power, the second lens L2 has negative refractive power, the third lens L3 has negative refractive power, the fourth lens L4 has positive refractive power, the fifth lens L5 has positive refractive power, the sixth lens L6 has positive refractive power, the seventh lens L7 has negative refractive power, and the eighth lens L8 has positive refractive power. The first lens unit 110 and the fourth lens unit 140 are both fixedly arranged relative to the imaging surface of the optical system 10, and the optical system 10 realizes optical zoom by moving the second lens unit 120 and the third lens unit 130.

[0179] During zooming, the first lens L1 and the eighth lens L8 are always kept fixed in the system, while the second lens L2, the third lens L3 and the fourth lens L4 can be fixed together by a clamp and move synchronously as a whole along the optical axis of the optical system 10, and the fifth lens L5, the sixth lens L6, the seventh lens L7 and the aperture STO can be fixed together by a clamp and move synchronously as another whole along the optical axis of the optical system 10. When the optical system 10 gradually switches from the short focal end to the long focal end, the second lens unit 120 will be away from the first lens unit 110, and the third lens unit 130 and the fourth lens unit 140 will also be away from each other.

[0180] Fig.19 is a schematic diagram of the optical system 10 of the fourth embodiment at a short focal end; Fig. 20 is a schematic diagram of the optical system 10 of the fourth embodiment at a mid-focus end; Fig.21 FIG. 1 is a schematic diagram of the optical system 10 of the fourth embodiment at a telephoto end. Fig. 22 The optical system 10 is Fig.19 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the short focal end; Fig.23 The optical system 10 is Fig. 20 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the mid-focus end; Fig.24 The optical system 10 is Fig.21Corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the telephoto end.

[0181] The object-side surface S1 of the first lens L1 is convex at the paraxial position, and the image-side surface S2 is convex at the paraxial position; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is convex at the circumference.

[0182] The object-side surface S3 of the second lens L2 is concave at the paraxial position, and the image-side surface S4 is concave at the paraxial position; the object-side surface S3 is concave at the circumference, and the image-side surface S4 is concave at the circumference.

[0183] The object-side surface S5 of the third lens L3 is convex at the paraxial position, and the image-side surface S6 is concave at the paraxial position; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is concave at the circumference.

[0184] The object-side surface S7 of the fourth lens L4 is convex at the paraxial position, and the image-side surface S8 is convex at the paraxial position; the object-side surface S7 is convex at the circumference, and the image-side surface S8 is concave at the circumference.

[0185] The object-side surface S9 of the fifth lens L5 is convex at the paraxial position, and the image-side surface S10 is convex at the paraxial position; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is convex at the circumference.

[0186] The object-side surface S11 of the sixth lens L6 is convex at the paraxial position, and the image-side surface S12 is concave at the paraxial position; the object-side surface S11 is convex at the circumference, and the image-side surface S12 is concave at the circumference.

[0187] The object-side surface S13 of the seventh lens L7 is convex at the paraxial position, and the image-side surface S14 is concave at the paraxial position; the object-side surface S13 is convex at the circumference, and the image-side surface S14 is concave at the circumference.

[0188] The object-side surface S15 of the eighth lens L8 is convex at the paraxial position, and the image-side surface S16 is convex at the paraxial position; the object-side surface S15 is convex at the circumference, and the image-side surface S16 is convex at the circumference.

[0189] In addition, the lens parameters of the optical system 10 in the fourth embodiment are given in Table 10, Table 11 and Table 12, wherein the definitions of the structures and parameters can be obtained from the first embodiment and will not be elaborated here.

[0190] Table 10

[0191]

[0192] Table 11

[0193] Variable distance Short focus position Mid-focus position Telephoto position D1 4.0000 7.2785 8.2312 D2 13.1467 3.8640 0.4421 D3 0.5000 6.4943 8.9684

[0194] Table 12

[0195] Surface number 5 6 7 8 16 17 K 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A4 -2.41E-03 -2.99E-03 -7.00E-05 -9.00E-05 -4.30E-04 -3.60E-04 A6 1.00E-05 2.00E-05 3.00E-05 3.00E-05 -2.00E-05 -2.00E-05 A8 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A10 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A12 0.00E+00 0.00E+00 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 0.00E+00 0.00E+00 A16 0.00E+00 0.00E+00 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 0.00E+00 0.00E+00 A20 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00

[0196] The optical system 10 in this embodiment satisfies the following relationship:

[0197] fc / fd 2.07 f2 / fc -0.48 (g1+g2+g3+g4) / fd 0.72 d2 / d3 0.50 f3 / fd 1.44 TTL / fc 1.41 f1 / |f2| 2.19 R16 / f4 0.56

[0198] Fifth embodiment

[0199] refer to Fig.25 , Fig.26 and Fig. 27 In the fifth embodiment, the optical system 10 includes, from the object side to the image side, a first lens unit 110 having positive refractive power and fixedly arranged, a second lens unit 120 having negative refractive power and movable arranged, a third lens unit 130 having positive refractive power and movable arranged, and a fourth lens unit 140 having positive refractive power and fixedly arranged. Among them, the first lens unit 110 includes a first lens L1, the second lens unit 120 includes, from the object side to the image side, a second lens L2, a third lens L3, and a fourth lens L4, the third lens unit 130 includes, from the object side to the image side, a fifth lens L5, a sixth lens L6, a seventh lens L7, and a stop STO, and the fourth lens unit 140 includes an eighth lens L8, and the first lens L1 to the eighth lens L8 each include only one lens. The first lens L1 has positive refractive power, the second lens L2 has negative refractive power, the third lens L3 has negative refractive power, the fourth lens L4 has positive refractive power, the fifth lens L5 has positive refractive power, the sixth lens L6 has positive refractive power, the seventh lens L7 has negative refractive power, and the eighth lens L8 has positive refractive power. The first lens unit 110 and the fourth lens unit 140 are both fixedly arranged relative to the imaging surface of the optical system 10, and the optical system 10 realizes optical zoom by moving the second lens unit 120 and the third lens unit 130.

[0200] During zooming, the first lens L1 and the eighth lens L8 are always kept fixed in the system, while the second lens L2, the third lens L3 and the fourth lens L4 can be fixed together by a clamp and move synchronously as a whole along the optical axis of the optical system 10, and the fifth lens L5, the sixth lens L6, the seventh lens L7 and the aperture STO can be fixed together by a clamp and move synchronously as another whole along the optical axis of the optical system 10. When the optical system 10 gradually switches from the short focal end to the long focal end, the second lens unit 120 will be away from the first lens unit 110, and the third lens unit 130 and the fourth lens unit 140 will also be away from each other.

[0201] Fig.25 is a schematic diagram of the optical system 10 of the fifth embodiment at a short focal end; Fig.26 is a schematic diagram of the optical system 10 of the fifth embodiment at a mid-focus end; Fig. 27 FIG. 1 is a schematic diagram of the optical system 10 of the fifth embodiment at a telephoto end. Fig.28 The optical system 10 is Fig.25 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the short focal end; Fig.29 The optical system 10 is Fig.26 The corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the mid-focus end; Fig.30 The optical system 10 is Fig. 27 Corresponding longitudinal spherical aberration diagram (mm), astigmatism diagram (mm) and distortion diagram (%) at the telephoto end.

[0202] The object-side surface S1 of the first lens L1 is convex at the paraxial position, and the image-side surface S2 is convex at the paraxial position; the object-side surface S1 is convex at the circumference, and the image-side surface S2 is convex at the circumference.

[0203] The object-side surface S3 of the second lens L2 is concave at the paraxial position, and the image-side surface S4 is concave at the paraxial position; the object-side surface S3 is concave at the circumference, and the image-side surface S4 is concave at the circumference.

[0204] The object-side surface S5 of the third lens L3 is convex at the paraxial position, and the image-side surface S6 is concave at the paraxial position; the object-side surface S5 is concave at the circumference, and the image-side surface S6 is convex at the circumference.

[0205] The object-side surface S7 of the fourth lens L4 is convex at the paraxial position, and the image-side surface S8 is concave at the paraxial position; the object-side surface S7 is convex at the circumference, and the image-side surface S8 is concave at the circumference.

[0206] The object-side surface S9 of the fifth lens L5 is convex at the paraxial position, and the image-side surface S10 is concave at the paraxial position; the object-side surface S9 is convex at the circumference, and the image-side surface S10 is concave at the circumference.

[0207] The object-side surface S11 of the sixth lens L6 is convex at the paraxial position, and the image-side surface S12 is concave at the paraxial position; the object-side surface S11 is convex at the circumference, and the image-side surface S12 is concave at the circumference.

[0208] The object-side surface S13 of the seventh lens L7 is convex at the paraxial position, and the image-side surface S14 is concave at the paraxial position; the object-side surface S13 is convex at the circumference, and the image-side surface S14 is concave at the circumference.

[0209] The object-side surface S15 of the eighth lens L8 is convex at the paraxial position, and the image-side surface S16 is convex at the paraxial position; the object-side surface S15 is convex at the circumference, and the image-side surface S16 is convex at the circumference.

[0210] In addition, the lens parameters of the optical system 10 in the fifth embodiment are given in Table 13, Table 14 and Table 15, wherein the definitions of the structures and parameters can be obtained from the first embodiment and will not be elaborated here.

[0211] Table 13

[0212]

[0213] Table 14

[0214]

[0215]

[0216] Table 15

[0217] Surface number 5 6 7 8 16 17 K 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A4 -2.55E-03 -2.89E-03 -2.70E-04 -1.30E-04 -2.40E-04 -1.90E-04 A6 0.00E+00 2.00E-05 3.00E-05 2.00E-05 0.00E+00 0.00E+00 A8 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A10 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 A12 0.00E+00 0.00E+00 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 0.00E+00 0.00E+00 A16 0.00E+00 0.00E+00 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 0.00E+00 0.00E+00 A20 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00

[0218] The optical system 10 in this embodiment satisfies the following relationship:

[0219] fc / fd 2.25 f2 / fc -0.51 (g1+g2+g3+g4) / fd 0.79 d2 / d3 0.21 f3 / fd 1.76 TTL / fc 1.41 f1 / |f2| 1.74 R16 / f4 0.64

[0220] refer to Fig.31 In one embodiment provided in the present application, the optical system 10 is assembled with a photosensitive element 210 to form a camera module 20, and the photosensitive element 210 is arranged on the image side of the fourth lens unit 140. Generally, the photosensitive surface of the photosensitive element 210 overlaps with the imaging surface S17 of the optical system 10. The photosensitive element 210 can be a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). By adopting the above-mentioned optical system 10, the camera module 20 will have good zoom performance, and can take into account both zoom effect and miniaturized design, while also being able to effectively prevent the fourth lens unit 140 and the photosensitive element 210 from colliding during the assembly process, thereby improving the assembly yield. In addition, in a long-term high or low temperature environment, the camera module 20 can still maintain good zoom performance.

[0221] In some embodiments, a protective glass and an infrared cut-off filter L9 are further provided between the fourth lens unit 140 and the imaging surface S17 of the system. The infrared cut-off filter L9 is used to filter out infrared light, and the protective glass is used to protect the photosensitive element 210. The protective glass and the infrared cut-off filter L9 may be part of the optical system 10, or may be installed between the optical system 10 and the photosensitive element 210 when the optical system 10 and the photosensitive element 210 are assembled, so as to serve as part of the module.

[0222] refer to Fig.32Some embodiments of the present application also provide an electronic device 30, in which the camera module 20 is applied to the electronic device 30 so that the electronic device 30 has a zoom camera function. Specifically, the electronic device 30 includes a fixing member 310, and the camera module 20 is installed on the fixing member 310. The fixing member 310 in some embodiments is a circuit board, a middle frame or a housing and other components. The electronic device 30 can be, but is not limited to, a smart phone, a smart watch, an e-book reader, a vehicle-mounted camera device (such as a driving recorder), a monitoring device, a medical device, a laptop, a tablet computer, a biometric device (such as a fingerprint recognition device or a pupil recognition device, etc.), a PDA (Personal Digital Assistant), a drone, etc. Specifically, in some embodiments, the electronic device 30 is a smart phone, and the smart phone includes a middle frame and a circuit board, the circuit board is arranged in the middle frame, the camera module 20 is installed in the middle frame of the smart phone, and the photosensitive element 210 therein is electrically connected to the circuit board. The camera module 20 can be used as a front camera module or a rear camera module of a smart phone. By adopting the camera module 20 provided in the embodiment of the present application, the electronic device 30 will have excellent shooting performance and can be assembled in a smaller space. In addition, in a long-term high or low temperature environment, the electronic device 30 can still maintain good zoom shooting performance.

[0223] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0224] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An optical system, characterized in that: There are eight lenses with refractive power, including: A first lens unit with positive refractive power includes a first lens; A second lens unit with negative refractive power includes, from the object side to the image side, a second lens, a third lens, and a fourth lens; A third lens unit with positive refractive power, including a fifth lens, a sixth lens, and a seventh lens in order from the object side to the image side; a fourth lens unit having positive refractive power, including an eighth lens; The positions of the first lens unit and the fourth lens unit are both kept fixed relative to the imaging plane of the optical system, and the second lens unit and the third lens unit are both movable relative to the first lens unit along the optical axis direction of the optical system; when the optical system zooms from the short focal end to the long focal end, the distance between the first lens unit and the second lens unit increases, and the distance between the third lens unit and the fourth lens unit also increases; The optical system satisfies the following relationship: 1.2<fc / fd<3.5; 1.14≤TTL / fc<1.5; Wherein, fc is the focal length of the optical system when it is at the telephoto end, fd is the focal length of the optical system when it is at the short focal end, and TTL is the total optical length of the optical system.

2. The optical system according to claim 1, characterized in that The following relations are satisfied: 0.3<(g1+g2+g3+g4) / fd; Among them, g1 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the first lens unit, g2 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the second lens unit, g3 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the third lens unit, and g4 is the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the fourth lens unit.

3. The optical system according to claim 1, characterized in that The following relations are satisfied: 0.8<f3 / fd<2; Wherein, f3 is the focal length of the third lens unit.

4. The optical system according to claim 1, characterized in that The following relations are satisfied: 1.6<f1 / |f2|<2.3; Wherein, f1 is the focal length of the first lens unit, and f2 is the focal length of the second lens unit.

5. The optical system according to claim 1, characterized in that The following relations are satisfied: -0.6<f2 / fc<-0.3; Wherein, f2 is the focal length of the second lens unit.

6. The optical system according to claim 1, characterized in that The following relations are satisfied: 0.1<d2 / d3<0.6; Wherein, d2 is the moving distance of the second lens unit when the optical system zooms from the short focal end to the long focal end, and d3 is the moving distance of the third lens unit when the optical system zooms from the short focal end to the long focal end.

7. The optical system according to claim 1, characterized in that The following relations are satisfied: 0.3<R16 / f4<0.8; Wherein, R16 is the radius of curvature of the object side of the eighth lens at the optical axis, and f4 is the focal length of the fourth lens unit.

8. The optical system according to claim 1, characterized in that The first lens has positive refractive power; The second lens has negative refractive power; The third lens has negative refractive power; The fourth lens has positive refractive power; The fifth lens has positive refractive power; The sixth lens has positive refractive power; The seventh lens has negative refractive power; The eighth lens has positive refractive power.

9. The optical system according to claim 8, characterized in that The image side surface of the first lens is convex at the near optical axis; The object side surface of the second lens is concave at the near optical axis, and the image side surface is concave at the near optical axis; The object side surface of the third lens is convex at the near optical axis, and the image side surface is concave at the near optical axis; The object side surface of the fourth lens is convex at the near optical axis; The object side surface of the fifth lens is convex at the near optical axis; The object side surface of the sixth lens is convex at the near optical axis, and the image side surface is concave at the near optical axis; The object side surface of the seventh lens is convex near the optical axis; The object side surface of the eighth lens is convex near the optical axis.

10. A camera module, characterized in that: The optical system comprises a photosensitive element and any one of claims 1 to 9, wherein the photosensitive element is arranged on the image side of the optical system.

11. An electronic device, characterized in that: It comprises a fixing part and the camera module as claimed in claim 10, wherein the camera module is arranged on the fixing part.

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