Optical system, lens module and electronic equipment

Abstract

An optical system comprises five lens elements with refractive power, and the five lens elements are sequentially arranged from an object side to an image side along an optical axis direction as follows: a first lens element with negative refractive power, an object side surface being convex in a paraxial region, and an image side surface being concave in a paraxial region; a second lens element with positive refractive power having an object-side surface being convex in a paraxial region and an image-side surface being concave in a paraxial region; a third lens element with refractive power having an object-side surface being concave in a paraxial region and an image-side surface being convex in a paraxial region; a fourth lens element with positive and negative refractive power having an object-side surface being convex in a paraxial region and an image-side surface being concave in a paraxial region; a fifth lens element with refractive power having an object-side surface being convex in a paraxial region and an image-side surface being concave in a paraxial region; wherein the first to fourth lenses are movable lens groups, the fifth lens is a fixed lens group, the fixed lens group is fixed relative to the imaging surface of the optical system, and the movable lens groups move along the optical axis direction.

Description

Technical Field

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

[0002] With the development of technology, especially the rapid development of optical systems, optical systems are widely used in smart devices such as mobile phones and tablet computers, and people's requirements for the miniaturized design of lenses are also getting higher and higher. The traditional focusing method generally realizes focusing by moving the entire lens through a focusing motor so that the imaging surface coincides with the photosensitive surface of the photosensitive chip. Therefore, a relatively large space (mechanical back focus) needs to be reserved between the lens and the photosensitive chip, which is not conducive to the miniaturized design of the lens module. In addition, moving the entire lens requires a relatively high driving force for the focusing motor, resulting in a relatively large size of the focusing motor, which is not conducive to the miniaturized design of the lens module and will also cause a significant decrease in the focusing speed. Therefore, it is urgent to design an optical system to solve the above problems. Summary of the Invention

[0003] The purpose of the present invention is to provide an optical system, a lens module, and an electronic device, and this optical system can meet the characteristics of having a moving focusing function and miniaturization.

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

[0005] In a first aspect, an optical system includes a total of five lenses with refractive power. Along the optical axis direction from the object side to the image side, they are in sequence: a first lens with negative refractive power, the object side surface is convex near the optical axis, and the image side surface is concave near the optical axis; a second lens with positive refractive power, the object side surface is convex near the optical axis, and the image side surface is concave near the optical axis; a third lens with refractive power, the object side surface is concave near the optical axis, and the image side surface is convex near the optical axis; a fourth lens with positive and negative refractive power, the object side surface is convex near the optical axis, and the image side surface is concave near the optical axis; a fifth lens with refractive power, the object side surface is convex near the optical axis, and the image side surface is concave near the optical axis; wherein, the first lens to the fourth lens form a moving lens group, the fifth lens is a fixed lens group, the fixed lens group is fixed relative to the imaging surface of the optical system, and the moving lens group moves along the optical axis direction between the near focus end and the far focus end to achieve focusing; the optical system satisfies the relational expressions: 20° < FOV < 40°; and / or, 1.4 < FNO < 3.2; and / or, 2.5 < TDmax / ImgH < 4.5; where FOV is the maximum field of view angle of the optical system, FNO is the aperture number of the optical system, TDmax is the maximum distance on the optical axis from the object side surface of the first lens to the image side surface of the fifth lens, and ImgH is the image height corresponding to half of the maximum field of view angle of the optical system.

[0006] The present application uses a mobile lens group to move between a fixed lens group and an imaging surface, so that the optical system can have a mobile focusing function, which can further meet the design requirements of miniaturization of the optical system; at the same time, only by moving the mobile lens group, the burden of the optical system on the motor can be further reduced, and the effect of fast focusing of the optical system can be achieved when using a motor with lower power; using five lenses with refractive power, the pressure of light refraction can be evenly distributed to each lens, so as to reduce the task of a single lens to refract light, and avoid the lens from being too bent and increasing the tolerance sensitivity. In addition, the number of lenses in the mobile lens group is set to four, so that the optical system can reduce the burden of the lens on the motor while ensuring clear imaging, and the momentum required by the motor during the focusing process is lower, so that the corresponding effect of fast focusing can be achieved; the reasonable configuration of the distribution of refractive power is helpful to balance the aberration and improve the imaging quality of the optical system, and with the reasonable surface setting, the lenses can be more compatible, which can not only reasonably utilize the space, but also smoothly undertake the propagation of light, effectively reduce the introduction of aberration, and improve the imaging quality.

[0007] The above relationship is satisfied, the overall parameters of the optical system are reasonably configured, and both the axial and radial dimensions conform to the miniaturized setting, which reduces the space occupied by the lens body and leaves enough moving space for the back-end module to focus.

[0008] In a second aspect, the present invention further provides a lens module, the lens module comprising the optical system and a photosensitive chip as described in any one of the embodiments of the first aspect, wherein the photosensitive chip is arranged on the image side of the optical system. By adding the optical system provided by the present invention to the lens module, by reasonably designing the surface shape and refractive power of each lens in the optical system and fixing the total optical length, the lens module can have the characteristics of mobile focusing function and miniaturization.

[0009] In a third aspect, the present invention further provides an electronic device, the electronic device comprising a housing and the lens module according to the second aspect, wherein the lens module is arranged in the housing. By adding the lens module provided by the present invention to the electronic device, the electronic device can have a mobile focus function, thereby obtaining a faster focus response speed; the miniaturized lens module design can also save more space for installing other devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0011] Figure 1a Schematic diagram of the optical system when the moving lens group of the first embodiment is at the telephoto end;

[0012] Figure 1b Aberration diagram of the optical system when the moving lens group of the first embodiment is at the telephoto end;

[0013] Figure 1c Schematic diagram of the optical system when the moving lens group of the first embodiment is at the close - focus end;

[0014] Figure 1d Aberration diagram of the optical system when the moving lens group of the first embodiment is at the close - focus end;

[0015] Figure 2a Schematic diagram of the optical system when the moving lens group of the second embodiment is at the telephoto end;

[0016] Figure 2b Aberration diagram of the optical system when the moving lens group of the second embodiment is at the telephoto end;

[0017] Figure 3a Schematic diagram of the optical system when the moving lens group of the third embodiment is at the telephoto end;

[0018] Figure 3b Aberration diagram of the optical system when the moving lens group of the third embodiment is at the telephoto end;

[0019] Figure 4a Schematic diagram of the optical system when the moving lens group of the fourth embodiment is at the telephoto end;

[0020] Figure 4b Aberration diagram of the optical system when the moving lens group of the fourth embodiment is at the telephoto end;

[0021] Figure 5a Schematic diagram of the optical system when the moving lens group of the fifth embodiment is at the telephoto end;

[0022] Figure 5b Aberration diagram of the optical system when the moving lens group of the fifth embodiment is at the telephoto end;

[0023] Figure 6 Schematic diagram of the lens module provided by an embodiment of the present invention;

[0024] Figure 7 Schematic diagram of the structure of the electronic device provided by an embodiment of the present invention. Detailed implementation manners

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] In a first aspect, the present invention provides an optical system, which has a total of five lenses with refractive power. Along the optical axis direction from the object side to the image side, they are in turn

[0027] The first lens has a negative refractive power. The object side surface is convex near the optical axis, and the image side surface is concave near the optical axis, which helps wide-angle light enter the optical system, avoids the light converging too quickly, and reduces the incident angle of the light on the lens.

[0028] The second lens has a positive refractive power. The object side surface is convex near the optical axis, and the image side surface is concave near the optical axis, which matches the surface shape of the first lens and helps balance the aberration generated by the first lens.

[0029] The third lens has a refractive power. The object side surface is concave near the optical axis, and the image side surface is convex near the optical axis, which helps adjust the deflection angle of the light, makes the light propagation between the third lens and the fourth lens smoother, and is conducive to realizing moving focusing.

[0030] The fourth lens has a positive refractive power. The object side surface is concave near the optical axis, and can adjust the Petzval number to reduce the generation of astigmatism and field curvature.

[0031] The fifth lens has a refractive power, which is beneficial to correcting aberration and correcting the off-axis light deflection angle to improve the overall imaging quality.

[0032] Among them, the first lens to the fourth lens are a moving lens group, and the fifth lens is a fixed lens group. The fixed lens group is fixed relative to the imaging surface of the optical system, and the moving lens group moves along the optical axis direction.

[0033] The present application enables the optical system to have a continuous mobile focus function by utilizing the movement of the mobile lens group on the optical axis, which can further meet the design requirements of miniaturization of the optical system; at the same time, only by using the mobile lens group to move, the burden of the optical system on the motor can be further reduced, and the effect of fast focusing of the optical system can be achieved when using a motor with lower power; using five lenses with refractive power, the pressure of light refraction can be evenly distributed to each lens, so as to reduce the task of a single lens to refract light, and avoid the lens from being too bent and increasing the tolerance sensitivity. In addition, the number of lenses in the mobile lens group is set to four, so that the optical system can reduce the burden of the lens on the motor while ensuring clear imaging, and the momentum required by the motor during the focusing process is lower, so that the corresponding effect of fast focusing can be achieved; the reasonable configuration of the distribution of refractive power is helpful to balance the aberration and improve the imaging quality of the optical system. With the reasonable surface setting, the lenses can be more compatible, which can not only reasonably utilize the space, but also smoothly undertake the propagation of light, effectively reduce the introduction of aberration, and improve the imaging quality.

[0034] In some embodiments, the optical system satisfies the relationship: 15° <FOV<45°,FOV为所述光学系统的最大视场角。满足上述关系式,光学系统具备合理的取像范围,有助于远距离取像的设计。进一步的,满足15°<FOV<40°,光学系统成像质量更佳。

[0035] In some embodiments, the optical system satisfies the relationship: 1.4 <FNO<3.2,FNO为光学系统的光圈数,满足上述关系式,光圈大小合适,有助于径向小型化设计,有助于提高进光量。进一步的,满足1.6<FNO<3,光学系统成像质量更佳。

[0036] In some embodiments, the optical system satisfies the relationship: 2.5 <TDmax / ImgH<4.5,TDmax为所述第一透镜物侧面至所述第五透镜像侧面于光轴上的最大距离,ImgH为所述光学系统的最大视场角的一半所对应的像高。满足上述关系式,光学系统在轴向尺寸可以满足小型化设计。进一步的,满足3<TDmax / ImgH<4,光学系统成像质量更佳。

[0037] In some embodiments, the optical system has a prism disposed on the object side of the first lens and fixedly opposed to the imaging surface of the optical system. The prism has an incident surface and an exit surface. Light enters the prism from the incident surface and is transmitted to the first lens from the exit surface. With the above technical features satisfied, the moving lens group moves between the prism and the fixed lens group, and the total length of the optical system remains unchanged. That is, the optical system can achieve the characteristic of internal focusing, can reduce the redundant space for focusing, and helps to shorten the total length of the optical system.

[0038] In some embodiments, the optical system satisfies the relation: 5 < TTL / ImgH < 9, where TTL is the distance on the optical axis from the incident surface to the imaging surface. With the above relation satisfied, the optical system can meet the miniaturization design. Further, when 6 < TTL / ImgH < 8, the miniaturization design effect is better.

[0039] In some embodiments, the optical system satisfies the relation: 0.7 < f_z1 / f_z2 < 1.4, where f_z1 is the focal length of the optical system when the moving lens group is at the telephoto end, and f_z2 is the focal length of the optical system when the moving lens group is at the wide-angle end. With the above relation satisfied, the change in focal length during the moving focusing process will not be too large, avoiding introducing excessive aberrations that affect the imaging quality. Further, when 0.9 < f_z1 / f_z2 < 1.2, the imaging quality of the optical system is better.

[0040] In some embodiments, the optical system satisfies the relation: 1.05 < FOV_z1 / FOV_z2 < 1.4, where FOV_z1 is the maximum field of view angle of the optical system when the moving lens group is at the telephoto end, and FOV_z2 is the maximum field of view angle of the optical system when the moving lens group is at the wide-angle end. With the above relation satisfied, the change in the field of view angle during the moving focusing process will not be too large, and the imaging quality of the edge field of view can be ensured to remain stable. Further, when 1.05 < FOV_z1 / FOV_z2 < 1.2, the imaging quality of the optical system is better.

[0041] In some embodiments, the optical system satisfies the relation: 1 < FNO_z1 / FNO_z2 < 1.4, where FNO_z1 is the f-number of the optical system when the moving lens group is at the telephoto end, and FNO_z2 is the f-number of the optical system when the moving lens group is at the wide-angle end. With the above relation satisfied, the change in the aperture will not be too drastic, avoiding significant blurring phenomena, helping to improve the imaging quality and the stability of imaging. Further, when 1.05 < FNO_z1 / FNO_z2 < 1.2, the imaging quality of the optical system is better.

[0042] In some embodiments, the optical system satisfies the relation: 0.5 < f1234 / f_z1 < 1.4, where f1234 is the combined focal length of the first lens, the second lens, the third lens, and the fourth lens. By satisfying the above relation, the refractive power of the moving lens group is moderate, the resolution pressure of the fixed lens group is moderate, and the image quality is stable during the moving focusing process. Further, when 0.7 < f1234 / f_z1 < 1.2, the imaging quality of the optical system is better.

[0043] In some embodiments, the optical system satisfies the relation: 1 < |f5| / f1234, where f5 is the focal length of the fifth lens. By satisfying the above relation, the refractive powers of the moving lens group and the fixed lens group are adapted to each other, which can effectively balance aberrations and improve the imaging quality. Further, when 1.7 < |f5| / f1234, the imaging quality of the optical system is better.

[0044] In some embodiments, the optical system satisfies the relation: 2 < TDmin / ImgH < 4, where TDmin is the minimum distance on the optical axis from the object side surface of the first lens to the image side surface of the fifth lens. By satisfying the above relation, the length of the optical system is smaller, which can meet the concept of miniaturized design. Further, when 2.5 < TDmin / ImgH < 3.5, the miniaturization effect of the optical system is better.

[0045] In some embodiments, the optical system satisfies the relation: 0.7 < SD10 / SD1 < 1.4, where SD1 is the effective semi-aperture of the object side surface of the first lens, and SD10 is the effective semi-aperture of the image side surface of the fifth lens. By satisfying the above relation, the radial dimensions of the lenses of the optical system are adapted to each other, which is helpful for the periscope design and is beneficial to improving the overall space utilization rate. Further, when 0.8 < SD10 / SD1 < 1.3, the miniaturized design effect of the optical system is better.

[0046] In some embodiments, the optical system satisfies the relation: 0.75 < SDmax / ImgH < 1.2, where SDmax is the maximum value of the effective semi-apertures of the object side surfaces or image side surfaces from the first lens to the fifth lens. By satisfying the above relation, the radial dimension of the optical system matches the image plane, meeting the radial miniaturized design effect. Further, when 0.85 < SDmax / ImgH < 1.1, the miniaturized design effect of the optical system is better.

[0047] In some embodiments, the optical system satisfies the relation: 1 < TDmax / TDmin < 1.5, where TDmin is the minimum distance from the object side of the first lens to the image side of the fifth lens on the optical axis. Satisfying the above relation provides sufficient movement space for the movable lens group and can improve the focusing ability of the optical system. Further, when 1.1 < TDmax / TDmin < 1.3, the imaging quality of the optical system is better.

[0048] In some embodiments, the optical system satisfies the relation: 0.6 < TD_z1 / f_z1 < 1.05, where TD_z1 is the distance from the object side of the first lens to the image side of the fifth lens on the optical axis when the movable lens group is at the telephoto end, and TD_z2 is the distance from the object side of the first lens to the image side of the fifth lens on the optical axis when the movable lens group is at the wide-angle end. Satisfying the above relation, the optical system satisfies the telephoto characteristic, which is helpful for taking images at a long distance. Further, when 0.65 < TD_z1 / f_z1 < 1, the telephoto characteristic of the optical system is better.

[0049] In some embodiments, the optical system satisfies the relation: 0.75 < TD_z2 / f_z2 < 1.2; satisfying the above relation, the optical system satisfies the telephoto characteristic, which is helpful for taking images at a long distance. Further, when 0.8 < TD_z2 / f_z2 < 1.15, the imaging quality of the optical system is better.

[0050] In some embodiments, the optical system satisfies the relation: 1.7 < AT23 / AT12 < 3.5, where AT12 is the distance between the first lens and the second lens on the optical axis, and AT23 is the distance between the second lens and the third lens on the optical axis. Satisfying the above relation, the lenses of the movable lens group are reasonably arranged, which is beneficial to improving the space utilization rate, balancing aberration, and improving the imaging quality. Further, when 2 < AT23 / AT12 < 3, the imaging quality of the optical system is better.

[0051] In some embodiments, the optical system satisfies the relation: 1 < Cz2 / Cz1 < 5, where Cz1 is the distance between the fourth lens and the fifth lens on the optical axis when the movable lens group is at the telephoto end, and Cz2 is the distance between the fourth lens and the fifth lens on the optical axis when the movable lens group is at the wide-angle end. Satisfying the above relation provides sufficient movement space for the movable lens group and can improve the focusing ability of the optical system. Further, when 1.2 < Cz2 / Cz1 < 4, the imaging quality of the optical system is better.

[0052] In some embodiments, the optical system satisfies the relationships: 4 < GL / CT5 < 8, 0.5 < CT1 / CT2 < 1.5, 0.5 < CT3 / CT4 < 1.4, 0.5 < CT5 / CT4 < 1.3, 0.7 < CT2 / CT3 < 2.3, where CT1 is the thickness of the first lens on the optical axis, CT2 is the thickness of the second lens on the optical axis, CT3 is the thickness of the third lens on the optical axis, CT4 is the thickness of the fourth lens on the optical axis, CT5 is the thickness of the fifth lens on the optical axis, and GL is the distance on the optical axis from the object side surface of the first lens to the image side surface of the fourth lens. Satisfying the above relationships can reasonably allocate the lens sizes, help improve the space utilization rate of the optical system, contribute to the collaborative work between the lenses, be beneficial to balancing aberrations, and improve the imaging quality. Further, when 5 < GL2CT5 < 7, 0.65 < CT1 / CT2 < 1.3, 0.65 < CT3 / CT4 < 1.2, 0.65 < CT5 / CT4 < 1, 0.8 < CT2 / CT3 < 1.9, the imaging quality of the optical system is better.

[0053] In some embodiments, the optical system satisfies the relationships: -2.5 < F1 / f_z1 < -0.8, 0.4 < f2 / f_z1 < 1.1, 2 < |f3| / f_z1, 0.7 < f4 / f_z1 < 2.2, 1 < |F5| / f_z1, where f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, and f5 is the focal length of the fifth lens. Satisfying the above relationships can reasonably configure the refractive power distribution of each lens in the optical system and improve the imaging quality of the optical system. Further, when -2.2 < f1 / f_z1 < -0.9, 0.45 < f2 / f_z1 < 1, 2.5 < |f3| / f_z1, 0.9 < f4 / f_z1 < 1.95, 1.2 < |F5| / f_z1, the imaging quality of the optical system is better.

[0054] In some embodiments, the optical system satisfies the relationships: 0.2 < R1 / f_z1 < 0.7, 0.1 < R2 / f_z1 < 0.4, 0.15 < R3 / f_z1 < 0.5, 0.7 < R4 / f_z1 < 2.2, -0.5 < R5 / f_z1 < -0.1, -0.5 < R6 / f_z1 < -0.1, 0.1 < R7 / f_z1 < 0.5, 0.15 < R8 / f_z1 < 0.6, 0.5 < R9 / f_z1 < 2.5, 0.4 < R10 / f_z1 < 1.4, where R1 is the radius of curvature of the object side surface of the first lens on the optical axis, R2 is the radius of curvature of the image side surface of the first lens on the optical axis, R3 is the radius of curvature of the object side surface of the second lens on the optical axis, R4 is the radius of curvature of the image side surface of the second lens on the optical axis, R5 is the radius of curvature of the object side surface of the third lens on the optical axis, R6 is the radius of curvature of the image side surface of the third lens on the optical axis, R7 is the radius of curvature of the object side surface of the fourth lens on the optical axis, R8 is the radius of curvature of the image side surface of the fourth lens on the optical axis, R9 is the radius of curvature of the object side surface of the fifth lens on the optical axis, and R10 is the radius of curvature of the image side surface of the fifth lens on the optical axis. By satisfying the above relationships, the surface profiles of the respective lenses are reasonably set and cooperate with each other, which helps to balance aberrations and improve the imaging quality. Further, when 0.25 < R1 / f_z1 < 0.5, 0.15 < R2 / f_z1 < 0.3, 0.2 < R3 / f_z1 < 0.4, 0.85 < R4 / f_z1 < 1.9, -0.35 < R5 / f_z1 < -0.15, -0.35 < R6 / f_z1 < -0.2, 0.15 < R7 / f_z1 < 0.35, 0.2 < R8 / f_z1 < 0.45, 0.6 < R9 / f_z1 < 2, 0.45 < R10 / f_z1 < 1.2, the imaging quality of the optical system is even better.

[0055] All the technical features in the optical system provided by the present invention can be combined and configured to achieve the corresponding effects.

[0056] In one embodiment, the material of the lens can be glass or plastic. If the material of the lens is glass, the degree of freedom in configuring the refractive power of the lens in the optical system can be increased, and the glass lens can be made by techniques such as grinding or molding. If the material of the lens is plastic, the production cost can be effectively reduced. In addition, a spherical surface or an aspherical surface (ASP) can be provided on the lens surface. Among them, the spherical lens can reduce the manufacturing difficulty. If an aspherical surface is provided on the lens surface, more control variables can be obtained thereby to reduce aberrations, reduce the number of lenses, and effectively reduce the total length of the optical system disclosed herein. The aspherical surface can be made by methods such as plastic injection molding or molding of glass lenses.

[0057] In one embodiment, additives can be selectively added to any (or more) of the lens materials to produce light absorption or light interference effects, so as to change the transmittance of the lens to light in a specific wavelength band, thereby reducing stray light and color deviation. Optionally, if the lens surface is aspherical, it means that the entire or a part of the optically effective area of the lens surface is aspherical.

[0058] In one embodiment, if the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface can be convex near the optical axis; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface can be concave near the optical axis. In the optical system provided by the present disclosure, if the lens has positive refractive power or negative refractive power, or the focal length of the lens, it can refer to the refractive power or focal length of the lens near the optical axis. Optionally, the critical point is the tangent point on the lens surface that is tangent to a tangent plane perpendicular to the optical axis except for the intersection point with the optical axis; the inflection point is the intersection point of the positive and negative changes of the lens surface curvature.

[0059] In one embodiment, in the optical system, the prism can also be an element with the function of turning the optical path between the object to be photographed and the imaging surface on the optical path, such as a right-angled triangular prism, etc., to provide a more flexible spatial configuration for the optical system, so that the thinning of the electronic device is not restricted by the total optical length of the optical system. Optionally, the optical system can also be selectively configured with two or more optical path turning elements, and the types, quantities, and positions of the optical path turning elements are limited.

[0060] In one embodiment, the optical system can be widely applied to electronic devices such as three-dimensional (3D) image capture, digital cameras, mobile products, digital tablets, smart TVs, network monitoring devices, motion-sensing game consoles, driving recorders, reverse imaging devices, wearable products, and aerial drones.

[0061] In a second aspect, the present invention also provides a lens module, which includes the optical system according to any one of the embodiments in the first aspect and an image sensor chip, and the image sensor chip is disposed on the image side of the optical system. By adding the optical system provided by the present invention to the lens module, through reasonable design of the surface shape and refractive power of each lens in the optical system, the lens module can have the functions of moving focus and miniaturization. Optionally, the lens module can further include a lens barrel, a supporting device, or a combination thereof.

[0062] In a third aspect, the present invention also provides an electronic device, which includes a housing and the lens module in the second aspect, and the lens module is disposed in the housing. By adding the lens module provided by the present invention to the electronic device, the electronic device can have the function of moving focus, thereby obtaining a faster focus response speed; the design of the miniaturized lens module can also save more space for installing other components. Optionally, the electronic device can further include a control unit, a display unit, a storage unit, a temporary storage unit, or a combination thereof.

[0063] The first embodiment

[0064] Please refer to Figures 1a to 1d , the optical system 10 of this embodiment includes, in order from the object side to the image side:

[0065] The first lens L1 has a negative refractive power. At the near optical axis, the object side surface S1 is convex and the image side surface S2 is concave.

[0066] The second lens L2 has a positive refractive power. At the near optical axis, the object side surface S3 is convex and the image side surface S4 is concave.

[0067] The third lens L3 has a negative refractive power. At the near optical axis, the object side surface S5 is concave and the image side surface S6 is convex.

[0068] The fourth lens L4 has a positive refractive power. At the near optical axis, the object side surface S7 is convex and the image side surface S8 is concave.

[0069] The fifth lens L5 has a positive refractive power. At the near optical axis, the object side surface S9 is convex and the image side surface S10 is concave.

[0070] In addition, the optical system 10 further includes an aperture STO, a filter IR, and an imaging surface IMG. In this embodiment, the aperture STO is disposed between the first lens L1 and the second lens. In other embodiments, the aperture STO can also be disposed between other two lenses, for example, between the second lens L2 and the third lens L3, and the aperture STO can also be on the object side of the first lens L1. The filter IR can be an infrared cut-off filter or a dual-channel filter, and is disposed between the fifth lens L5 and the imaging surface IMG, and includes an object side surface S11 and an image side surface S12. The material of the filter IR is glass (GLASS), and a film can be coated on the lens. The materials of the first lens L1 to the fifth lens L5 are plastics. In other embodiments, they can also all be glass lenses, or a combination of glass lenses and plastic lenses. The effective pixel region of the photosensitive chip is located on the imaging surface.

[0071] Among them, the first lens L1 to the fourth lens L4 are fixedly combined to form a movable lens group, and the fifth lens L5 forms a fixed lens group. The fixed lens group is relatively fixed to the image surface IMG, and the movable lens group can move along the extension direction of the optical axis 101, so as to achieve continuous moving focusing.

[0072] In this embodiment, the optical system 10 is further provided with a prism P1. The prism P1 is located on the object side of the first lens L1 and has an incident surface PS1 and an exit surface PS2. Light enters the optical system through the incident surface PS1 and propagates through the exit surface PS2 to the movable lens group and subsequent lenses for imaging. The prism P1 is relatively fixed with respect to the imaging surface IMG, that is, the total length of the optical system 10 is fixed. The movable lens group moves along the optical axis direction between the prism P1 and the fixed lens group, thereby realizing internal focusing of the optical system 10. During the shooting process, when the object distance gradually decreases, the movable lens group moves away from the fixed lens group along the optical axis direction; when the object distance gradually increases, the movable lens group moves towards the fixed lens group along the optical axis direction. Of course, in other embodiments, it can also be that when the object distance gradually decreases, the movable lens group moves towards the fixed lens group along the optical axis direction; when the object distance gradually increases, the movable lens group moves away from the fixed lens group along the optical axis direction. It should be noted that on the premise of equivalent optical path, the prism P1 can be a refracting element, such as a right-angled triangular prism, etc., for changing the propagation direction of the incident light. In other embodiments, the two surfaces of the prism P1 can also be curved surfaces, so that the prism P1 has refractive power and thus participates in imaging; or the prism P1 can be not provided, and at this time the optical system 10 can be regarded as having a telescopic characteristic.

[0073] Table 1a shows the data table of the optical system 10 of this embodiment. Among them, the reference wavelength of the focal length of the lens is 555 nm, the reference wavelength of the refractive index and Abbe number of the lens is 587.5618 nm, and the Y radius in Table 1a is the curvature radius of the surface with the corresponding surface number at the optical axis 101. The surface number S1 and the surface number S2 are respectively 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 the smaller surface number is the object side surface, and the surface with the larger surface number is the image side surface, and so on. The values in the "Thickness" parameter column are the distances from the current surface to the next surface on the optical axis 101. For example, the surface with the surface number S1 is the object side surface of the first lens L1, and the corresponding "thickness" is the distance from the object side surface S1 of the first lens L1 to the image side surface S2 of the first lens L1, that is, the thickness of the first lens L1, while the surface with the surface number S2 is the image side surface of the first lens L1, and the corresponding "thickness" 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, that is, the distance between the first lens L1 and the second lens L2 on the optical axis, and so on. The units of the Y radius, thickness, and focal length are all millimeters (mm). Table 1b is the supplementary parameter of Table 1a, specifically the end values corresponding to the parameters of the movable lens group moving along the optical axis.

[0074] Table 1a

[0075]

[0076]

[0077] Table 1b

[0078] A (mm) B (mm) C (mm) FNO TTL (mm) FOV (°) ImgH (mm) f (mm) Telephoto end (z1) Infinity 3.506 1.163 1.800 30.300 32.100 4.100 14.200 Macro end (z2) 100.000 0.700 3.969 2.100 30.300 28.000 4.100 14.450

[0079] Among them, as shown in Table 1a and Table 1b, A is the object distance of the optical system 10 (the distance between the prism P1 and the object on the optical axis), B is the distance between the first lens L1 and the prism P1 on the optical axis, C is the distance between the fourth lens L4 and the fifth lens L5 on the optical axis, FNO is the f-number of the optical system 10, f is the focal length of the optical system 10, FOV is the maximum field of view angle of the optical system, ImgH is the image height corresponding to half of the maximum field of view angle of the optical system, and TTL is the distance from the object side surface of the first lens to the imaging surface IMG of the optical system on the optical axis 101.

[0080] In this embodiment, the object side surfaces and image side surfaces of the first lens L1 to the fifth lens L5 are all aspherical surfaces. In other embodiments, the object side surfaces and image side surfaces of the first lens L1 to the fifth lens L5 can also be all spherical surfaces, or a combination of spherical and aspherical surfaces. For example, the object side surface S1 of the first lens is spherical and the image side surface S2 is aspherical. The surface profile x of the aspherical surface can be defined by, but not limited to, the following aspherical formula:

[0081]

[0082] Among them, x is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex on the axis, h is the distance from the corresponding point on the aspherical surface to the optical axis 101, c is the curvature of the aspherical vertex, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th high-order term in the aspherical surface profile formula. Table 1c gives the high-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, A30 of the aspherical mirror surfaces S1 to S14 that can be used in the first embodiment.

[0083] Table 1c

[0084]

[0085] Figure 1b In (a) shows the longitudinal spherical aberration curve graph of the optical system when the moving lens group of the first embodiment is located at the far focus end. Figure 1d In (a) shows the longitudinal spherical aberration curve graph of the optical system when the moving lens group of the first embodiment is located at the near focus end. Its reference wavelengths are 650nm, 610nm, 555nm, 510nm, and 470nm. Among them, the abscissa along the X-axis direction represents the focus shift, the ordinate along the Y-axis direction represents the normalized field of view, and the longitudinal spherical aberration curve represents the deviation of the convergence points of the light rays of different wavelengths after passing through each lens of the optical system. From Figure 1bAs can be seen from Fig. (a), the spherical aberration value of the optical system in the first embodiment is relatively good, indicating that the imaging quality of the optical system in this embodiment is better.

[0086] Figure 1b Fig. (b) also shows the astigmatism curve graph of the optical system when the moving lens group in the first embodiment is located at the far focal end. Figure 1d Fig. (b) also shows the astigmatism curve graph of the optical system when the moving lens group in the first embodiment is located at the near focal end. Among them, the abscissa along the X-axis direction represents the focus offset, and the ordinate along the Y-axis direction represents the image height, with the unit being mm. In the astigmatism curve graph, T represents the curvature of the imaging surface IMG in the meridional direction, and S represents the curvature of the imaging surface IMG in the sagittal direction. From Figure 1b As can be seen from Fig. (b), the astigmatism of the optical system is well compensated.

[0087] Figure 1b Fig. (c) also shows the distortion curve graph of the optical system when the moving lens group in the first embodiment is located at the far focal end. Figure 1d Fig. (c) also shows the distortion curve graph of the optical system when the moving lens group in the first embodiment is located at the far focal end. Among them, the abscissa along the X-axis direction represents the focus offset, and the ordinate along the Y-axis direction represents the image height. The distortion curve represents the distortion magnitude values corresponding to different field angles. From Figure 1b As can be seen from Fig. (c), at the provided wavelength, the distortion of the optical system is well corrected.

[0088] From Figure 1b Figs. (a), (b), (c) and Figure 1d As can be seen from Figs. (a), (b), (c), the optical system in this embodiment has small aberrations and good imaging quality, and has good imaging performance.

[0089] To avoid repetition, subsequent embodiments only show the structural schematic diagram and aberration diagram of the optical system when the moving lens group is located at the far focal end.

[0090] Second Embodiment

[0091] Please refer to Figures 2a to 2b , the difference between the structure of the second embodiment and that of the first embodiment is that the refractive power of the fifth lens L5 is negative, and the rest can be referred to.

[0092] Table 2a

[0093]

[0094] Table 2b

[0095]

[0096]

[0097] Table 2c gives the high-order term coefficients available for each aspherical mirror surface in the second embodiment. Among them, each aspherical surface type can be defined by the formula given in the first embodiment.

[0098] Table 2c

[0099]

[0100] Figure 2b The aberration diagram of the optical system when the moving lens group of the second embodiment is located at the far focus end is shown. Among them, the longitudinal spherical aberration curve represents the deviation of the convergence points of light rays of different wavelengths after passing through each lens of the optical system; in the astigmatism diagram, T represents the curvature of the imaging surface IMG in the meridional direction, and S represents the curvature of the imaging surface IMG in the sagittal direction; the distortion curve represents the distortion magnitude values corresponding to different field angles. From Figure 2b the aberration diagram in, it can be seen that the longitudinal spherical aberration, field curvature, and distortion of the optical system are all well controlled, so the optical system of this embodiment has good imaging quality.

[0101] Third Embodiment

[0102] Please refer to Figures 3a to 3b , the difference between the structure of the third embodiment and the first embodiment is that the refractive power of the third lens L3 is positive, the refractive power of the fifth lens L5 is negative, and the rest can be referred to.

[0103] Table 3a

[0104]

[0105]

[0106] Table 3b

[0107] A (mm) B (mm) C (mm) FNO TTL (mm) FOV (°) ImgH (mm) f (mm) Telephoto end (z1) Infinity 3.105 1.566 1.900 31.200 31.900 4.100 14.500 Macro end (z2) 100.000 0.700 3.969 2.100 31.200 28.700 4.100 14.200

[0108] Table 3c gives the high-order term coefficients available for each aspherical mirror surface in the third embodiment. Among them, each aspherical surface type can be defined by the formula given in the first embodiment.

[0109] Table 3c

[0110]

[0111] Figure 3b The aberration diagram of the optical system when the moving lens group of the third embodiment is located at the far focus end is shown. Among them, the longitudinal spherical aberration curve represents the deviation of the convergence points of light rays of different wavelengths after passing through each lens of the optical system; in the astigmatism diagram, T represents the curvature of the imaging surface IMG in the meridional direction, and S represents the curvature of the imaging surface IMG in the sagittal direction; the distortion curve represents the distortion magnitude values corresponding to different field angles. From Figure 3bFrom the aberration diagram, it can be seen that the longitudinal spherical aberration, field curvature, and distortion of the optical system are all well controlled, so the optical system of this embodiment has good imaging quality.

[0112] Fourth Embodiment

[0113] Please refer to Figures 4a to 4b , the difference between the structure of the fourth embodiment and the first embodiment is that the refractive power of the third lens L3 is positive and the refractive power of the fifth lens L5 is negative. Just refer to it.

[0114] Table 4a

[0115]

[0116]

[0117] Table 4b

[0118] A (mm) B (mm) C (mm) FNO TTL (mm) FOV (°) ImgH (mm) f (mm) Telephoto end (z1) Infinity 2.335 2.331 1.900 27.100 37.300 4.100 12.200 Macro end (z2) 100.000 0.700 3.969 2.100 27.100 33.900 4.100 12.200

[0119] Table 4c gives the higher-order term coefficients that can be used for each aspherical mirror surface in the fourth embodiment. Among them, each aspherical surface type can be defined by the formula given in the first embodiment.

[0120] Table 4c

[0121]

[0122] Figure 4b shows the aberration diagram of the optical system when the moving lens group of the fourth embodiment is at the far-focus end. Among them, the longitudinal spherical aberration curve represents the deviation of the convergence points of light rays of different wavelengths after passing through each lens of the optical system; in the astigmatism diagram, T represents the curvature of the imaging surface IMG in the meridional direction, and S represents the curvature of the imaging surface IMG in the sagittal direction; the distortion curve represents the distortion magnitude values corresponding to different field angles. From Figure 4b the aberration diagram, it can be seen that the longitudinal spherical aberration, field curvature, and distortion of the optical system are all well controlled, so the optical system of this embodiment has good imaging quality.

[0123] Fifth Embodiment

[0124] Please refer to Figures 5a to 5b , the difference between the structure of the fifth embodiment and the first embodiment is that the refractive power of the third lens L3 is positive, and the others can be referred to accordingly.

[0125] Table 5a

[0126]

[0127] Table 5b

[0128] A (mm) B (mm) C (mm) FNO TTL (mm) FOV (°) ImgH (mm) f (mm) Telephoto end (z1) Infinity 2.692 1.975 2.400 28.300 36.000 4.100 12.600 Macro end (z2) 100.000 0.700 3.969 2.800 28.300 32.300 4.100 12.700

[0129] Table 5c gives the coefficients of the higher-order terms for each aspherical mirror surface that can be used in the fifth embodiment. Among them, each aspherical surface profile can be defined by the formula given in the first embodiment.

[0130] Table 5c

[0131]

[0132]

[0133] Figure 5b Fig. shows the aberration diagram of the optical system when the moving lens group of the fifth embodiment is at the telephoto end. Among them, the longitudinal spherical aberration curve represents the deviation of the convergence points of light rays of different wavelengths after passing through each lens of the optical system; in the astigmatism curve diagram, T represents the curvature of the imaging surface in the meridional direction, and S represents the curvature of the imaging surface in the sagittal direction; the distortion curve represents the distortion magnitude values corresponding to different field angles. From Figure 5b the aberration diagram in, it can be seen that the longitudinal spherical aberration, field curvature, and distortion of the optical system are all well controlled, so that the optical system of this embodiment has good imaging quality.

[0134] Table 6 shows the relationship values between some parameters of the optical system 10 in the first embodiment to the fifth embodiment.

[0135] Table 6

[0136] Formula Example 1 Example 2 Example 3 Example 4 Example 5 f1 / f_z1 -1.273 -0.994 -1.221 -2.057 -1.320 f2 / f_z1 0.668 0.499 0.683 0.933 0.753 f3 / f_z1 -3.698 -2.677 407.920 109.256 18.282 f4 / f_z1 1.490 0.952 1.605 1.652 1.887 f5 / f_z1 10.361 -1.283 -9.301 -3353.800 43.778 R1 / f_z1 0.370 0.278 0.373 0.360 0.421 R2 / f_z1 0.227 0.171 0.226 0.244 0.253 R3 / f_z1 0.307 0.243 0.292 0.344 0.295 R4 / f_z1 1.673 1.831 1.150 0.951 0.915 R5 / f_z1 -0.234 -0.173 -0.238 -0.292 -0.271 R6 / f_z1 -0.303 -0.224 -0.283 -0.332 -0.301 R7 / f_z1 0.263 0.195 0.267 0.311 0.318 R8 / f_z1 0.330 0.258 0.328 0.392 0.382 R9 / f_z1 0.666 1.986 0.847 0.781 1.087 R10 / f_z1 0.713 0.504 0.692 0.744 1.100 f_z1 / f_z2 0.983 1.116 1.021 1.000 0.992 f1234 / f_z1 1.123 0.744 0.987 1.053 1.051 f5 / f1234 9.224 -1.723 -9.424 -3186.108 41.670 FOV_z1 / FOV_z2 1.146 1.102 1.111 1.100 1.115 FNO_z1 / FNO_z2 1.167 1.167 1.105 1.105 1.167 TTL / ImgH 7.390 7.951 7.610 6.610 6.902 SD10 / SD1 0.972 0.859 1.047 1.176 1.279 SDmax / ImgH 0.982 0.937 1.030 0.980 0.891 GL / CT5 5.312 6.597 5.952 6.577 6.027 TDmax / ImgH 3.389 3.671 3.604 3.314 3.299 TDmin / ImgH 2.704 3.156 3.018 2.914 2.813 TDmax / TDmin 1.253 1.163 1.194 1.137 1.173 TD_z1 / f_z1 0.781 0.676 0.853 0.979 0.915 TD_z2 / f_z2 0.961 0.878 1.041 1.114 1.065 AT23 / AT12 2.977 2.161 2.717 2.410 2.373 Cz2 / Cz1 3.413 2.140 2.534 1.702 2.010 CT1 / CT2 1.000 0.698 0.896 1.273 1.198 CT3 / CT4 0.849 0.734 1.168 0.765 0.704 CT5 / CT4 0.983 0.793 0.976 0.676 0.709 CT2 / CT3 1.177 1.803 0.983 0.870 0.952

[0137] The optical systems provided in the above embodiments can meet the characteristics of having a continuous internal focusing function and miniaturization.

[0138] Referring to Figure 6 , the embodiment of the present invention also provides a lens module 20. The lens module 20 includes the optical system and the photosensitive chip in any of the foregoing embodiments. The photosensitive chip is disposed on the image side of the optical system, and the two can be fixed by a bracket. The photosensitive chip can be a CCD sensor (Charge Coupled Device) or a CMOS sensor (Complementary Metal Oxide Semiconductor). Generally, during assembly, the imaging surface IMG of the optical system overlaps with the photosensitive surface of the photosensitive chip. By adopting the above optical system, the lens module 20 can have the characteristics of continuous internal focusing function and miniaturization.

[0139] Referring to Figure 7, an embodiment of the present invention further provides an electronic device 30. The electronic device 30 includes a housing 310 and the lens module 20 in the foregoing embodiment. The lens module 20 is installed in the housing 310, and the housing 310 may be components such as a display screen, a circuit board, a middle frame, and a rear cover. The electronic device 30 may be, but is not limited to, a smart phone, a smart watch, smart glasses, an e-book reader, a tablet computer, a biometric device (such as a fingerprint recognition device or a pupil recognition device, etc.), a PDA (Personal Digital Assistant), etc. Since the above lens module 20 can have the characteristics of miniaturization while having a continuous internal focusing function, when the above lens module 20 is adopted, the electronic device 30 can assemble the above lens module 20 with a smaller space, so that the thickness of the device can be compressed, and at the same time, the corresponding speed of photographing and focusing becomes faster.

[0140] The foregoing disclosures are only some preferred embodiments of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. An optical system, characterized in that, There are a total of five lenses with refractive power, which are arranged along the optical axis direction from the object side to the image side in sequence as follows: The first lens has negative refractive power. The object side surface is convex near the optical axis, and the image side surface is concave near the optical axis. The second lens has positive refractive power. The object side surface is convex near the optical axis, and the image side surface is concave near the optical axis. The third lens has refractive power. The object side surface is concave near the optical axis, and the image side surface is convex near the optical axis. The fourth lens has positive and negative refractive power. The object side surface is convex near the optical axis, and the image side surface is concave near the optical axis. The fifth lens has refractive power. The object side surface is convex near the optical axis, and the image side surface is concave near the optical axis. Among them, the first lens to the fourth lens are a movable lens group, and the fifth lens is a fixed lens group. The fixed lens group is fixed relative to the imaging surface of the optical system, and the movable lens group moves between the near focus end and the far focus end along the optical axis direction to achieve focusing. The optical system satisfies the relational expressions: 15° < FOV < 45°; and / or, 1.4 < FNO < 3.2; and / or, 2.5 < TDmax / ImgH < 4.5; Wherein, FOV is the maximum field of view angle of the optical system, FNO is the f-number of the optical system, TDmax is the maximum distance on the optical axis from the object side surface of the first lens to the image side surface of the fifth lens, and ImgH is the image height corresponding to half of the maximum field of view angle of the optical system.

2. The optical system according to claim 1, characterized in that, The optical system has a prism. The prism is arranged on the object side of the first lens and is relatively fixed with respect to the imaging surface of the optical system. The prism has an incident surface and an exit surface. Light enters the prism from the incident surface and is transmitted to the first lens from the exit surface, satisfying the relational expression: 5 < TTL / ImgH < 9; Wherein, TTL is the distance on the optical axis from the incident surface to the imaging surface.

3. The optical system according to claim 1, wherein The optical system satisfies the relational expressions: 0.7 < f_z1 / f_z2 < 1.4; and / or, 1.05 < FOV_z1 / FOV_z2 < 1.4; and / or, 1 < FNO_z1 / FNO_z2 < 1.4; and / or, 0.5 < f1234 / f_z1 < 1.4; and / or, 1 < |f5| / f1234; Wherein, f_z1 is the focal length of the optical system when the movable lens group is at the far focus end, f_z2 is the focal length of the optical system when the movable lens group is at the near focus end, FOV_z1 is the maximum field of view angle of the optical system when the movable lens group is at the far focus end, FOV_z2 is the maximum field of view angle of the optical system when the movable lens group is at the near focus end, FNO_z1 is the f-number of the optical system when the movable lens group is at the far focus end, FNO_z2 is the f-number of the optical system when the movable lens group is at the near focus end, f1234 is the combined focal length of the first lens, the second lens, the third lens and the fourth lens, and f5 is the focal length of the fifth lens.

4. The optical system according to claim 1, characterized in that, The optical system satisfies the relational expressions: 2 < TDmin / ImgH < 4; and / or, 0.7 < SD10 / SD1 < 1.4; and / or, 0.75 < SDmax / ImgH < 1.2; Wherein, TDmin is the minimum distance on the optical axis from the object side surface of the first lens to the image side surface of the fifth lens, SD1 is the effective semi-aperture of the object side surface of the first lens, SD10 is the effective semi-aperture of the image side surface of the fifth lens, and SDmax is the maximum value of the effective semi-apertures of the object side surfaces or image side surfaces from the first lens to the fifth lens.

5. The optical system according to claim 1, characterized in that, The optical system satisfies the relational expressions: 1 < TDmax / TDmin < 1.5; and / or, 0.6 < TD_z1 / f_z1 < 1.05; and / or, 0.75 < TD_z2 / f_z2 < 1.2; and / or, 1.7 < AT23 / AT12 < 3.5; and / or, 1 < Cz2 / Cz1 < 5; Wherein, TDmin is the minimum distance on the optical axis from the object side surface of the first lens to the image side surface of the fifth lens, TD_z1 is the distance on the optical axis from the object side surface of the first lens to the image side surface of the fifth lens when the moving lens group is at the far focus end, TD_z2 is the distance on the optical axis from the object side surface of the first lens to the image side surface of the fifth lens when the moving lens group is at the near focus end, f_z1 is the focal length of the optical system when the moving lens group is at the far focus end, f_z2 is the focal length of the optical system when the moving lens group is at the near focus end, AT12 is the distance on the optical axis between the first lens and the second lens, AT23 is the distance on the optical axis between the second lens and the third lens, Cz1 is the distance on the optical axis between the fourth lens and the fifth lens when the moving lens group is at the far focus end, and Cz2 is the distance on the optical axis between the fourth lens and the fifth lens when the moving lens group is at the near focus end.

6. The optical system according to claim 1, characterized in that The optical system satisfies the relational expressions: 4 < GL / CT5 < 8; and / or, 0.5 < CT1 / CT2 < 1.5; and / or, 0.5 < CT3 / CT4 < 1.4; and / or, 0.5 < CT5 / CT4 < 1.3; and / or, 0.7 < CT2 / CT3 < 2.3; Wherein, CT1 is the thickness of the first lens on the optical axis, CT2 is the thickness of the second lens on the optical axis, CT3 is the thickness of the third lens on the optical axis, CT4 is the thickness of the fourth lens on the optical axis, CT5 is the thickness of the fifth lens on the optical axis, and GL is the distance on the optical axis from the object side surface of the first lens to the image side surface of the fourth lens.

7. The optical system according to claim 1, characterized in that, The optical system satisfies the relational expressions: -2.5 < F1 / f_z1 < -0.8; and / or, 0.4 < f2 / f_z1 < 1.1; and / or, 2 < |f3| / f_z1; and / or, 0.7 < f4 / f_z1 < 2.2; and / or, 1 < |F5| / f_z1; Wherein, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, and f_z1 is the focal length of the optical system when the moving lens group is at the far focus end.

8. The optical system according to claim 1, characterized in that, The optical system satisfies the relational expressions: 0.2 < R1 / f_z1 < 0.7; and / or, 0.1 < R2 / f_z1 < 0.4; and / or, 0.15 < R3 / f_z1 < 0.5; and / or, 0.7 < R4 / f_z1 < 2.2; and / or, -0.5 < R5 / f_z1 < -0.1; and / or, -0.5 < R6 / f_z1 < -0.1; and / or, 0.1 < R7 / f_z1 < 0.5; and / or, 0.15 < R8 / f_z1 < 0.6; and / or, 0.5 < R9 / f_z1 < 2.5; and / or, 0.4 < R10 / f_z1 < 1.4; Wherein, R1 is the curvature radius of the object side surface of the first lens at the optical axis, R2 is the curvature radius of the image side surface of the first lens at the optical axis, R3 is the curvature radius of the object side surface of the second lens at the optical axis, R4 is the curvature radius of the image side surface of the second lens at the optical axis, R5 is the curvature radius of the object side surface of the third lens at the optical axis, R6 is the curvature radius of the image side surface of the third lens at the optical axis, R7 is the curvature radius of the object side surface of the fourth lens at the optical axis, R8 is the curvature radius of the image side surface of the fourth lens at the optical axis, R9 is the curvature radius of the object side surface of the fifth lens at the optical axis, R10 is the curvature radius of the image side surface of the fifth lens at the optical axis, and f_z1 is the focal length of the optical system when the moving lens group is located at the far focus end.

9. A lens module, characterized in that, Comprising the optical system according to any one of claims 1 to 8 and a photosensitive chip, the photosensitive chip is disposed on the image side of the optical system.

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

Images