Intra-focal lens and camera module

Abstract

The present invention provides an internal focusing lens and a camera module, wherein the internal focusing lens includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, wherein the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are arranged sequentially at intervals from the object side to the image side along an optical axis, and at least one of the lenses is movable along the optical axis and is configured as a movable lens (group), and the movable lens (group) provides positive optical power. When the object distance changes, the image space position corresponding to the internal focusing lens remains unchanged by adjusting the movable lens (group).

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical imaging technology, in particular to an inner focusing lens and a camera module. BACKGROUND

[0002] Nowadays, people's life enters the high-speed development of digital era, and the performance of mobile phones, as an essential electronic communication device in people's life, has also been unprecedentedly developed compared with the past traditional models. Especially in the field of mobile phone shooting, emerging technologies are constantly emerging, constantly improving and maturing. Among them, the most obvious is the thinning of mobile phones, which greatly optimizes the user experience, and also puts forward further requirements on the optical design of mobile phone lenses: it means shorter total length of the lens, while also needs to ensure the same demand for image quality performance.

[0003] The existing mobile phone lens focusing is to move the image plane position to achieve focusing under different object distances. This way, when the object distance is closer, the compensation of the image plane position is more rear, resulting in longer overall optical length for close distance. Obviously, this way is not conducive to the realization of mobile phone thinning. To solve this problem, the optical design of mobile phone lenses has adopted a series of height reduction schemes such as liquid lens and free-form surface, and has been successfully applied to mobile phone lenses.

[0004] Among them, although the use of liquid lens or TLENS can achieve focusing under different object distances while keeping the image plane position unchanged by changing its optical power, but because most of the current mobile phone lenses use aspheric lenses, changing the R value of the spherical surface will often introduce excessive field curvature, and because of the thickness limitation of the liquid lens or TLENS itself, it is difficult to compress the optical total length to a very ideal state in the initial state. For the height reduction scheme of free-form surface, the main purpose is to reduce the optical total length in the initial state, but still uses the existing focusing method, which is not recommended for some lenses: such as small head requirement TTL unchanged, so as to ensure that the head size does not change, it is difficult to achieve this requirement by this way; in addition, for large image surface or long focal length design, the ordinary focusing method causes the image plane to move too much distance under different object distances, and the height reduction of free-form surface cannot make up for this defect. SUMMARY

[0005] One of the main advantages of the present application is to provide an inner focusing lens and a camera module, wherein the inner focusing lens uses inner focusing technology, that is, at least one lens of the inner focusing lens is driven by a motor, and the image plane position of the inner focusing remains unchanged, thereby completing focusing under different object distances, which is beneficial to shorten the total length of the lens.

[0006] Another advantage of the present application is to provide an inner focus lens and camera module, wherein the inner focus lens can effectively improve the field curvature at different object distances while keeping the image plane unchanged.

[0007] Another advantage of the present application is to provide an inner focus lens and camera module, wherein the inner focus lens keeps the image plane position unchanged by inner focus, realizes focusing at different object distances, and effectively reduces the module height.

[0008] Another advantage of the present application is to provide an inner focus lens and camera module, wherein the inner focus lens keeps the image plane position unchanged by inner focus, realizes focusing at different object distances, and effectively improves the near distance performance of the camera module.

[0009] Another advantage of the present application is to provide an inner focus lens and camera module, wherein the inner focus lens includes five lenses with non-adhesive aspheric lenses with optical power, and at least one lens is arranged as a movable group lens, which can move along the optical axis to provide positive optical power, so that the image space position corresponding to the movable group remains unchanged when the object distance changes, thereby keeping the object distance corresponding to the group after the movable group unchanged to fix the image plane position.

[0010] Another advantage of the present application is to provide an inner focus lens and camera module, wherein the inner focus lens realizes a larger object distance change range with a smaller stroke, fixes the image plane position relative to a general lens, and greatly improves the field curvature performance of the lens relative to a TLENS lens.

[0011] Another advantage of the present application is to provide an inner focus lens and camera module, wherein the first lens of the inner focus lens is a positive lens, and the second lens is a negative lens, which can effectively reduce the distortion of the optical system.

[0012] Another advantage of the present application is to provide an inner focus lens and camera module, wherein the fifth lens of the inner focus lens is a negative lens and an M-shaped lens, which can effectively improve the field curvature of the optical system.

[0013] Another advantage of the present application is to provide an inner focus lens and camera module, wherein the inner focus lens can effectively reduce the chromatic aberration of the camera module imaging, thereby improving the imaging quality.

[0014] According to an aspect of the present application, an inner focus lens of the present application capable of achieving the foregoing objects and other objects and advantages includes:

[0015] a first lens;

[0016] a second lens;

[0017] a third lens;

[0018] A fourth lens;

[0019] A fifth lens, wherein the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are arranged sequentially at intervals from the object side to the image side along an optical axis, and at least one of the lenses is movable along the optical axis and configured as a movable lens (group), the focal length of the inner focusing lens is f, and the focal length of the movable lens (group) is f. M Let the focal length of the nth lens be fn, and the radius of curvature of the nth lens near the object side be R. LnS1 The radius of curvature of the nth lens near the image side is R. LnS2 The maximum travel of the movable lens (group) is AFD. max It satisfies the following condition: 0.8 <f M / f<2.9;|∑fn| / f>1.6;1.84<∑R LnS1 / R LnS2 <8; 0.04 <AFD max <0.11, and the movable lens (group) provides positive optical power, so that the image space position corresponding to the inner focusing lens remains unchanged when the object distance changes by adjusting the movable lens (group).

[0020] According to one embodiment of the present invention, the first lens has positive optical power and the second lens has negative optical power.

[0021] According to one embodiment of the present invention, the fifth lens has negative optical power and the fifth lens adopts the shape of an M-type lens.

[0022] According to one embodiment of the present invention, let the thickness of the nth lens on the optical axis be CTn, the total optical length of the optical system of the internal focusing lens be TTL, and the half-image height of the image plane be ImgH. Focusing is achieved by moving the movable lens (group). For the changing gap position, the nth changing gap from the object side to the image side is STn, which satisfies the following condition: 0.05 <CT1 / TTL 主物距 <0.25; TTL 最小物距 -TTL 最大物距 <0.085; 0.6 <TTL 主物距 / (2*ImgH)<0.8;STn≥0.18。

[0023] According to one embodiment of the present application, the object side surface of the first lens is convex, the image side surface of the first lens is concave, the object side surface of the second lens is concave, the image side surface of the second lens is convex, the object side surface of the third lens is concave, the image side surface of the third lens is convex, the object side surface of the fourth lens is convex, the image side surface of the fourth lens is concave, the object side surface of the fifth lens is convex, and the image side surface of the fifth lens is concave.

[0024] According to one embodiment of the present application, the object side surface of the first lens is convex, the image side surface of the first lens is concave, the object side surface of the second lens is concave, the image side surface of the second lens is convex, the object side surface of the third lens is concave, the image side surface of the third lens is convex, the object side surface of the fourth lens is convex, the image side surface of the fourth lens is concave, the object side surface of the fifth lens is convex, and the image side surface of the fifth lens is concave.

[0025] According to one embodiment of the present application, the object side surface of the first lens is convex, the image side surface of the first lens is concave, the object side surface of the second lens is concave, the image side surface of the second lens is convex, the object side surface of the third lens is concave, the image side surface of the third lens is convex, the object side surface of the fourth lens is convex, the image side surface of the fourth lens is concave, the object side surface of the fifth lens is convex, and the image side surface of the fifth lens is concave.

[0026] According to one embodiment of the present application, the third lens is the movable lens.

[0027] According to one embodiment of the present application, the first lens, the second lens and the third lens are combined to form the movable lens group.

[0028] According to one embodiment of the present application, the aspheric curve equation of each lens of the inner focusing lens is represented as follows:

[0029]

[0030] wherein X is the relative distance of a point on the aspheric surface with a distance Y from the optical axis to the tangent of the intersection of the aspheric surface and the optical axis; Y is the perpendicular distance of a point on the aspheric curve from the optical axis; R is the radius of curvature; k is the conic coefficient; and Ai is the i-th order aspheric coefficient.

[0031] According to one embodiment of the present application, the gap between the movable lens (group) and the adjacent group is >0.18mm at any effective position.

[0032] According to another aspect of the present application, the present application further provides a camera module, comprising:

[0033] an inner focus lens;

[0034] a photosensitive component, wherein the inner focus lens is disposed in the photosensitive component;

[0035] at least one inner focus motor, wherein the inner focus lens comprises:

[0036] a first lens;

[0037] a second lens;

[0038] a third lens;

[0039] a fourth lens;

[0040] a fifth lens, wherein the first lens, the second lens, the third lens, the fourth lens and the fifth lens are arranged in sequence along an optical axis direction from an object side to an image side with at least one of the lenses being movable along the optical axis direction as a movable lens (group), the movable lens (group) is drivingly connected to the inner focus motor, a focal length of the inner focus lens is f, a focal length of the movable lens (group) is f M , a focal length of the nth lens is fn, a radius of curvature of the nth lens close to the object side is R LnS1 , a radius of curvature of the nth lens close to the image side is R LnS2 , and a maximum stroke of the movable lens (group) is AFD max , which satisfies the following conditions: 0.8 < f M / f < 2.9; |∑fn| / f > 1.6; 1.84 < ∑R LnS1 / R LnS2 < 8; 0.04 < AFD max < 0.11, and the movable lens (group) provides positive refractive power, and the movable lens (group) is driven by the inner focus motor to move along the optical axis direction when the object distance changes so that the corresponding image space position of the inner focus lens remains unchanged.

[0041] Further objects and advantages of the present application can be more fully understood and appreciated by reference to the following description taken in connection with the accompanying drawings.

[0042] These and other objects, features and advantages of the present application will become apparent with reference to the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 is a structural schematic diagram of an inner focus lens according to a first preferred embodiment of the present application.

[0044] Figures 2A to 2Cis a distortion curve corresponding to different object distances of the internal focusing lens according to the first preferred embodiment of the present application.

[0045] Figures 3A to 3C is an astigmatism curve corresponding to different object distances of the internal focusing lens according to the first preferred embodiment of the present application.

[0046] Figures 4A to 4C is an axial chromatic aberration curve corresponding to different object distances of the internal focusing lens according to the first preferred embodiment of the present application.

[0047] Figure 5 is a structural schematic diagram of an internal focusing lens according to the second preferred embodiment of the present application.

[0048] Figures 6A to 6C is a distortion curve corresponding to different object distances of the internal focusing lens according to the second preferred embodiment of the present application.

[0049] Figures 7A to 7C is an astigmatism curve corresponding to different object distances of the internal focusing lens according to the second preferred embodiment of the present application.

[0050] Figures 8A to 8C is an axial chromatic aberration curve corresponding to different object distances of the internal focusing lens according to the second preferred embodiment of the present application.

[0051] Figure 9 is a structural schematic diagram of an internal focusing lens according to the third preferred embodiment of the present application.

[0052] Figures 10A to 10C is a distortion curve corresponding to different object distances of the internal focusing lens according to the third preferred embodiment of the present application.

[0053] Figures 11A to 11C is an astigmatism curve corresponding to different object distances of the internal focusing lens according to the third preferred embodiment of the present application.

[0054] Figures 12A to 12C is an axial chromatic aberration curve corresponding to different object distances of the internal focusing lens according to the third preferred embodiment of the present application.

[0055] Figure 13 is a structural schematic diagram of an internal focusing lens according to the fourth preferred embodiment of the present application.

[0056] Figures 14A to 14C is a distortion curve corresponding to different object distances of the internal focusing lens according to the fourth preferred embodiment of the present application.

[0057] Figures 15A to 15C is an astigmatism curve corresponding to different object distances of the internal focusing lens according to the fourth preferred embodiment of the present application.

[0058] Figures 16A to 16C is the on-axis chromatic aberration curve corresponding to different object distances of the inner focusing lens according to the fourth preferred embodiment of the present application.

[0059] Figure 17 is a schematic diagram of a camera module using the inner focusing lens according to any of the preferred embodiments of the present application. DETAILED DESCRIPTION

[0060] The following description is provided to enable those skilled in the art to realize the present application. The preferred embodiments in the following description are only examples and other obvious modifications can be made by those skilled in the art. The basic principles defined in the following description can be applied to other embodiments, modifications, improvements, equivalents and other technical solutions without departing from the spirit and scope of the present application.

[0061] Those skilled in the art should understand that in the disclosure of the present application, the orientations or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the above terms cannot be understood as a limitation of the present application.

[0062] It can be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of one element can be one, and in another embodiment, the number of the element can be multiple, and the term "one" cannot be understood as a limitation on the number.

[0063] Referring to the drawings accompanying the present application specification Figures 1 to 17 As shown in the drawings accompanying the present application specification, an inner focusing lens and a camera module according to the present application are illustrated in the following description. The inner focusing lens includes a first lens 10, a second lens 20, a third lens 30, a fourth lens 40 and a fifth lens 50, wherein the first lens 10, the second lens 20, the third lens 30, the fourth lens 40 and the fifth lens 50 are arranged in order from the object side to the image side along the optical axis direction. It is worth mentioning that a diaphragm 100 (not shown in the figure) is located on the light entrance side of the first lens 10, at least one filter 200 is located on the light exit side of the fifth lens 50, the imaging light rays enter the first lens 10 of the inner focusing lens through the diaphragm 100, and the light fibers emitted by the fifth lens 50 are imaged at an image plane position S0 through the filter 200, i.e. a photosensitive chip is located at the image plane position S0.

[0064] It is worth mentioning that in the preferred embodiment of the present application, each lens of the inner focusing lens is a lens with optical power and non-stick aspheric surface, and at least one lens of the inner focusing lens is a movable lens (group). The focal length of the inner focusing lens is f, wherein the focal length of the movable lens (group) is f M , the focal length of the nth lens is fn, the curvature radius of the nth lens close to the object side is R LnS1 , the curvature radius of the nth lens close to the image side is R LnS2 , and the maximum stroke of the inner focusing motor of the optical system of the inner focusing lens is AFD max , which satisfies the following conditions: 0.8 < f M / f < 2.9; |∑fn| / f > 1.6; 1.84 < ∑R LnS1 / R LnS2 < 8; 0.04 < AFD max < 0.11.

[0065] It is worth mentioning that the inner focusing motor drives the movable lens (group) of the inner focusing lens to move along the optical axis direction of the inner focusing lens, so that the movable lens provides positive optical power, and when the object distance changes, the corresponding image space position of the movable lens remains unchanged, thereby fixing the image plane position by adjusting the position of the movable lens (group) when the object distance changes. Those skilled in the art can understand that the inner focusing lens of the present application can achieve a larger object distance change range with a smaller stroke, fix the image plane position relative to the general lens, and greatly improve the field curvature performance of the lens relative to the TLENS lens. More worth mentioning is that the inner focusing lens of the present application can achieve a full field curvature of less than 8um for an object distance of 15cm to 1.2m.

[0066] In the preferred embodiment of the present application, the first lens 10 of the inner focusing lens has positive optical power, and the second lens 20 has negative optical power, which effectively reduces the distortion of the optical system, and since the fifth lens 50 has negative optical power and adopts the shape of M type lens, the field curvature of the optical system can be effectively improved.

[0067] Further, the thickness of the nth lens on the optical axis is CTn, the total optical length of the optical system of the inner focusing lens is TTL, the half image height of the image plane is ImgH, and the focusing is achieved by moving the movable lens (group). For the nth changed gap from the object side to the image side, STn, it satisfies the following conditions: 0.05 < CT1 / TTL 主物距 < 0.25; TTL 最小物距 -TTL最大物距 <0.085; 0.6 <TTL 主 Object distance / (2*ImgH)<0.8; STn≥0.18.

[0068] The internal focusing lens of the present invention can be implemented as a small-head lens, that is, the first lens of the internal focusing lens is thicker in the middle, and the CT1 / TTL principal object distance value is relatively large, about 0.25, and it is necessary to ensure that the total optical length is as small as possible and remains constant under different object distances. In this preferred embodiment of the present invention, the internal focusing lens can satisfy 0.6 while keeping the total optical length of the optical system constant. <TTL 主物距 / (2*ImgH)<0.8, which can effectively solve the problem of small head lenses. The internal focusing lens of the present invention can also be implemented as a movable lens with two groups of upper and lower parts or a movable lens with three groups of upper, middle and lower parts. The internal focusing lens can also be implemented as a small image plane lens or a large image plane lens.

[0069] For large-image-plane optical systems, changes in the object distance of ordinary lenses result in a significant shift in the image plane position, leading to an increase in the overall module height. Furthermore, large image planes typically exhibit poor near-range field curvature. A three-group internal focusing scheme provides minimal change in overall length; by moving the upper and middle lens groups while keeping the image plane constant, the TTL change is less than 0.085. It is worth noting that, in addition to the three-group internal focusing scheme, a two-group internal focusing scheme can also achieve significant improvements in field curvature at different object distances and can be used in most optical systems with multiple object distances.

[0070] It is worth mentioning that, in this invention, the movable lens (group) of the internal focusing lens, when in any effective position, has a gap of >0.18mm with the adjacent group, which provides sufficient space for structural design.

[0071] Referring to the accompanying drawings of this invention Figures 1 to 4CAs shown, an inner focus lens according to the first preferred embodiment of the present application is illustrated in the following description. In the first preferred embodiment of the present application, the first lens 10 has positive refractive power, and the object side surface 11 of the first lens 10 is convex, and the image side surface 12 of the first lens 10 is concave; the second lens 20 has negative refractive power, and the object side surface 21 of the second lens 20 is convex, and the image side surface 22 of the second lens 20 is concave; the third lens 30 has positive refractive power, and the object side surface 31 of the third lens 30 is concave, and the image side surface 32 of the third lens 30 is convex; the fourth lens 40 has negative refractive power, and the object side surface 41 of the fourth lens 40 is convex, and the image side surface 42 of the fourth lens 40 is concave; the fifth lens 50 has negative refractive power, and the object side surface 51 of the fifth lens 50 is convex, and the image side surface 12 of the fifth lens 50 is concave. Each lens of the inner focus lens satisfies the above-mentioned conditional formula, and in this preferred embodiment of the present application, it is preferred that: f M f value is 0.924659; |∑fn| / f value is 7.175023; ∑R LnS1 / R LnS2 value is 7.48364; AFD max value is 0.05; CT1 / TTL 主物距 value is 0.202644; TTL 最小物距 -TTL 最大物距 value is 0; TTL 主物距 / (2*ImgH) value is 0.685558; STn value is 0.28.

[0072] In each embodiment according to the above-mentioned embodiment, the aspherical surface curve equation of each lens of the inner focus lens is represented as follows:

[0073]

[0074] wherein X is the relative distance of a point on the aspherical surface with a distance Y from the optical axis to the tangent plane of the aspherical surface at the intersection point of the optical axis; Y is the vertical distance of a point on the aspherical surface from the optical axis; R is the radius of curvature; k is the conic coefficient; and Ai is the i-th order aspherical coefficient.

[0075] In this preferred embodiment of the present application, the focal length of the optical projection lens is f, the f-number of the optical projection lens is Fno, and the maximum view angle of the optical projection lens is FOV, and the values are as follows: f=3.33mm; Fno=2.45; and FOV=87.55 degrees.

[0076] Table 1 shows the structure parameters of each lens of the inner focus lens according to the first preferred embodiment of the present application.

[0077] Table 1

[0078]

[0079] Table 1 shows detailed structural data of each lens of the inner focusing lens of the first preferred embodiment of the present application, wherein the units of curvature radius, thickness and focal length are mm. Table 2 shows aspherical surface data of each lens of the inner focusing lens of the first preferred embodiment of the present application, wherein K represents the conic coefficient in the aspherical curve equation, and A4-A20 represent the 4th-20th order aspherical coefficients of each surface. In addition, the following tables are corresponding to the schematic diagrams and aberration curve diagrams of each embodiment, and the definitions of the data in the tables are the same as those of Table 1 and Table 2 of the embodiments, which are not described herein.

[0080] Table 2

[0081]

[0082]

[0083] In detail, in the preferred embodiment of the present application, the third lens 30 of the inner focusing lens is implemented as the movable lens, i.e. the third lens 30 can be driven to move along the optical axis direction by the inner focusing motor. When the object distance changes, the third lens 30 is driven to move by the inner focusing motor to keep the image plane position formed by the inner focusing lens unchanged. The first lens 10 and the second lens 20 of the inner focusing lens constitute an upper group lens, the fourth lens 40 and the fifth lens 50 constitute a lower group lens, and the third lens 30 is movably arranged between the upper group lens and the lower group lens.

[0084] Table 3 shows the basic parameters of the inner focusing lens of the first preferred embodiment of the present application.

[0085] Table 3

[0086]

[0087] In the preferred embodiment of the present application, the image height ImgH value of the image surface formed by the inner focusing lens is 3.282, and the variable distance of the object distance is 15cm-1.2m as an example, wherein the total optical length TTL value of the optical system of the inner focusing lens is 4.5mm. When the object distance is 1.2m, the maximum view angle FOV value of the optical projection lens of the inner focusing lens is 86.8599183018296; when the object distance is 35cm, the maximum view angle FOV value of the optical projection lens of the inner focusing lens is 87.5516700199324; and when the object distance is 15cm, the maximum view angle FOV value of the optical projection lens of the inner focusing lens is 88.5879237756514. In the preferred embodiment of the present application, the stroke distance of the third lens 30 (movable lens) driven by the inner focusing motor along the optical axis direction is 50um. When the object distance is 1.2m, the gap between the third lens 30 and the upper group lens is 0.328804332119603mm; when the object distance is 35cm, the gap between the third lens 30 and the upper group lens is 0.308634056700254mm; and when the object distance is 15cm, the gap between the third lens 30 and the upper group lens is 0.28mm. When the object distance is 1.2m, the gap between the third lens 30 and the lower group lens is 0.310000163764306mm; when the object distance is 35cm, the gap between the third lens 30 and the lower group lens is 0.327266253674679mm; and when the object distance is 15cm, the gap between the third lens 30 and the upper group lens is 0.35880448125395.

[0088] Figures 2A to 2C The inner focusing lens of the first preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2m, 35cm and 15cm, and it can be seen that the inner focusing lens of the first preferred embodiment of the present application effectively improves the distortion of the lens. In particular, when the object distance is 35cm, the distortion of the inner focusing lens is <2.5%. Figures 3A to 3C The inner focusing lens of the first preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2m, 35cm and 15cm, and it can be seen that the inner focusing lens of the first preferred embodiment of the present application effectively improves the distortion of the lens. In particular, when the object distance is 35cm, the distortion of the inner focusing lens is <2.5%. Figures 4A to 4C The inner focusing lens of the first preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2m, 35cm and 15cm, and it can be seen that the inner focusing lens of the first preferred embodiment of the present application effectively improves the distortion of the lens. In particular, when the object distance is 35cm, the distortion of the inner focusing lens is <2.5%.

[0089] The inner focusing lens of the first preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2m, 35cm and 15cm, and it can be seen that the inner focusing lens of the first preferred embodiment of the present application effectively improves the distortion of the lens. In particular, when the object distance is 35cm, the distortion of the inner focusing lens is <2.5%. Figures 5 to 8CAs shown, an inner focusing lens according to the second preferred embodiment of the present application is illustrated in the following description. In this preferred embodiment of the present application, the first lens 10 has positive refractive power, and the object side surface 11 of the first lens 10 is convex, and the image side surface 12 of the first lens 10 is concave; the second lens 20 has negative refractive power, and the object side surface 21 of the second lens 20 is concave, and the image side surface 22 of the second lens 20 is convex; the third lens 30 has positive refractive power, and the object side surface 31 of the third lens 30 is concave, and the image side surface 32 of the third lens 30 is convex; the fourth lens 40 has negative refractive power, and the object side surface 41 of the fourth lens 40 is convex, and the image side surface 42 of the fourth lens 40 is concave; the fifth lens 50 has negative refractive power, and the object side surface 51 of the fifth lens 50 is convex, and the image side surface 12 of the fifth lens 50 is concave. The lenses of the inner focusing lens satisfy the above-mentioned conditional expressions, and in this preferred embodiment of the present application, the conditional expressions are preferably: 0.935968011; |∑fn| / f value is 6.187687042; ∑R LnS1 / R LnS2 value is 7.3765; AFD max value is 0.05; CT1 / TTL main object distance value is 0.188974; TTL minimum object distance-TTL maximum object distance value is 0; TTL main object distance / (2*ImgH) value is 0.735567; STn value is 0.3.

[0090] In each of the embodiments according to the above-mentioned embodiments, the aspherical surface curve equation of each of the lenses of the inner focusing lens is represented as follows:

[0091]

[0092] wherein X is the relative distance of a point on the aspherical surface with a distance Y from the optical axis to the tangent plane of the aspherical surface at the intersection point of the optical axis; Y is the perpendicular distance of a point on the aspherical surface curve from the optical axis; R is the radius of curvature; k is the conic coefficient; and Ai is the i-th order aspherical coefficient.

[0093] In this preferred embodiment of the present application, the focal length of the optical projection lens is f, the aperture value (f-number) of the optical projection lens is Fno, and the maximum view angle of the optical projection lens is FOV, and the values are as follows: f=3.56mm; Fno=2.64; and FOV=84.1 degrees.

[0094] Table 4 shows the structure parameters of each of the lenses of the inner focusing lens according to the second preferred embodiment of the present application.

[0095] Table 4

[0096]

[0097]

[0098] Table 4 shows detailed structural data of each lens of the inner focusing lens of the second preferred embodiment of the present application, wherein the units of curvature radius, thickness and focal length are mm. Table 5 shows aspherical surface data of each lens of the inner focusing lens of the second preferred embodiment of the present application, wherein K represents the conic coefficient in the aspherical surface equation, and A4-A20 represent the 4th-20th order aspherical surface coefficients of each surface. In addition, the following tables of each embodiment correspond to the schematic diagram and the aberration curve diagram of each embodiment, and the definitions of the data in the tables are the same as those of Table 4 and Table 5 of the embodiment, which are not described herein.

[0099] Table 4

[0100]

[0101]

[0102] In detail, in the preferred embodiment of the present application, the third lens 30 of the inner focusing lens is implemented as the movable lens, i.e. the third lens 30 can be driven to move along the optical axis direction by the inner focusing motor. When the object distance changes, the third lens 30 is driven to move by the inner focusing motor to keep the image plane position formed by the inner focusing lens unchanged. The first lens 10 and the second lens 20 of the inner focusing lens constitute an upper group lens set, the fourth lens 40 and the fifth lens 50 constitute a lower group lens set, and the third lens 30 is movably arranged between the upper group lens set and the lower group lens set.

[0103] Table 6 shows the basic parameters of the inner focusing lens of the second preferred embodiment of the present application.

[0104] Table 6

[0105]

[0106]

[0107] In the preferred embodiment of the present application, the image height ImgH value of the image surface formed by the inner focusing lens is 3.25, and the variable distance of the object distance is 15 cm-1.2 m as an example, wherein the total optical length TTL value of the optical system of the inner focusing lens is 4.78 mm. When the object distance is 1.2 m, the maximum view angle FOV value of the optical projection lens of the inner focusing lens is 82.471146180203; when the object distance is 35 cm, the maximum view angle FOV value of the optical projection lens of the inner focusing lens is 83.2019227914764; and when the object distance is 15 cm, the maximum view angle FOV value of the optical projection lens of the inner focusing lens is 84.1023591751656. In the preferred embodiment of the present application, the stroke distance of the third lens 30 (movable lens) driven by the inner focusing motor along the optical axis direction is 58 um. When the object distance is 1.2 m, the gap between the third lens 30 and the upper group lens is 0.359495998414212 mm; when the object distance is 35 cm, the gap between the third lens 30 and the upper group lens is 0.333260890430891 mm; and when the object distance is 15 cm, the gap between the third lens 30 and the upper group lens is 0.301860100375606 mm. When the object distance is 1.2 m, the gap between the third lens 30 and the lower group lens is 0.31018501287963 mm; when the object distance is 35 cm, the gap between the third lens 30 and the lower group lens is 0.331626142901814 mm; and when the object distance is 15 cm, the gap between the third lens 30 and the upper group lens is 0.367820910918237.

[0108] Figures 6A to 6C The inner focusing lens of the second preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2 m, 35 cm and 15 cm. It can be seen that the inner focusing lens of the second preferred embodiment of the present application effectively improves the distortion of the lens. In particular, when the object distance is 35 cm, the distortion of the inner focusing lens is <2.40%. Figures 7A to 7C The inner focusing lens of the second preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2 m, 35 cm and 15 cm. It can be seen that the inner focusing lens of the second preferred embodiment of the present application effectively improves the distortion of the lens. In particular, when the object distance is 35 cm, the distortion of the inner focusing lens is <2.40%. Figures 8A to 8C The inner focusing lens of the second preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2 m, 35 cm and 15 cm. It can be seen that the inner focusing lens of the second preferred embodiment of the present application effectively improves the distortion of the lens. In particular, when the object distance is 35 cm, the distortion of the inner focusing lens is <2.40%.

[0109] The inner focusing lens of the second preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2 m, 35 cm and 15 cm. It can be seen that the inner focusing lens of the second preferred embodiment of the present application effectively improves the distortion of the lens. In particular, when the object distance is 35 cm, the distortion of the inner focusing lens is <2.40%.Figures 9 to 12C As shown, an inner focus lens according to the third preferred embodiment of the present application is illustrated in the following description. In this preferred embodiment of the present application, the first lens 10 has positive refractive power, and the object side surface 11 of the first lens 10 is convex, and the image side surface 12 of the first lens 10 is concave; the second lens 20 has negative refractive power, and the object side surface 21 of the second lens 20 is convex, and the image side surface 22 of the second lens 20 is concave; the third lens 30 has positive refractive power, and the object side surface 31 of the third lens 30 is concave, and the image side surface 32 of the third lens 30 is convex; the fourth lens 40 has negative refractive power, and the object side surface 41 of the fourth lens 40 is convex, and the image side surface 42 of the fourth lens 40 is concave; the fifth lens 50 has negative refractive power, and the object side surface 51 of the fifth lens 50 is convex, and the image side surface 52 of the fifth lens 50 is concave. Each lens of the inner focus lens satisfies the above conditions, and in this preferred embodiment of the present application, it is preferred that: f M f-number is 0.847638108; |∑fn| / f value is 10.3273011; ∑R LnS1 / R LnS2 value is 2.00474; AFD max value is 0.048; CT1 / TTL 主物距 value is 0.206213; TTL 最小物距 -TTL 最大物距 value is 0.048; TTL 主物距 / (2*ImgH) value is 0.658438; STn value is 0.33.

[0110] In each embodiment of the above embodiment, the aspherical surface equation of each lens of the inner focus lens is represented as follows:

[0111]

[0112] wherein X is the relative distance of a point on the aspherical surface with a vertical distance Y from the optical axis to the tangent plane of the aspherical surface at the intersection point; Y is the vertical distance of a point on the aspherical surface from the optical axis; R is the radius of curvature; k is the conic coefficient; and Ai is the aspherical coefficient of the i-th order.

[0113] In this preferred embodiment of the present application, the focal length of the optical projection lens is f, the f-number of the optical projection lens is Fno, and the maximum field of view of the optical projection lens is FOV, and the values are as follows: f=3.3mm; Fno=2.45; and FOV=87.65 degrees.

[0114] Table 7 shows the structure parameters of each lens of the inner focus lens according to the third preferred embodiment of the present application.

[0115] Table 7

[0116]

[0117]

[0118] Table 7 The detailed structure data of each lens of the inner focusing lens of the third preferred embodiment of the present application, wherein the units of curvature radius, thickness and focal length are mm. Table 8 is the aspheric surface data of each lens of the inner focusing lens of the third preferred embodiment of the present application, wherein K represents the conic coefficient in the aspheric surface equation, and A4-A20 represent the 4th-20th order aspheric surface coefficients of each surface. In addition, the following tables of each embodiment are corresponding to the schematic diagram and aberration curve diagram of each embodiment, and the definitions of the data in the tables are the same as those of Table 7 and Table 8 of the embodiments, which are not described here.

[0119] Table 8

[0120]

[0121]

[0122] Unlike the above preferred embodiments, in this preferred embodiment of the present application, the first lens 10, the second lens 20 and the third lens 30 of the inner focusing lens are implemented as the movable lens group (or upper group lens group), that is, the first lens 10, the second lens 20 and the third lens 30 are driven by the inner focusing motor to move along the optical axis direction as a movable upper group lens assembly. Correspondingly, the fourth lens 40 and the fifth lens 50 of the inner focusing lens are as a fixed position lower group lens assembly. When the object distance changes, the movable lens group (i.e. the first lens 10, the second lens 20 and the third lens 30) is driven by the inner focusing motor to move to keep the image plane position formed by the inner focusing lens unchanged. The fourth lens 40 and the fifth lens 50 constitute a lower group lens group, which is fixed in position.

[0123] Table 9 shows the basic parameters of the inner focusing lens of the third preferred embodiment of the present application.

[0124] Table 9

[0125]

[0126]

[0127] In the preferred embodiment of the present application, the half image height ImgH value of the image surface formed by the inner focusing lens is 3.282, and the variable distance of the object distance is 15cm-1.2m as an example, wherein the optical total length TTL value of the optical system of the inner focusing lens is 4.322mm when the object distance is 1.2m; the optical total length TTL value of the optical system of the inner focusing lens is 4.3388mm when the object distance is 35cm; and the optical total length TTL value of the optical system of the inner focusing lens is 4.37mm when the object distance is 15cm. The maximum view angle FOV value of the optical projection lens of the inner focusing lens is 87.6000000000108 when the object distance is 1.2m; the maximum view angle FOV value of the optical projection lens of the inner focusing lens is 87.653719005222 when the object distance is 35cm; and the maximum view angle FOV value of the optical projection lens of the inner focusing lens is 87.7730122510316 when the object distance is 15cm. In the preferred embodiment of the present application, the stroke distance of the inner focusing motor driving the movable lens group (i.e. the movable lens group composed of the first lens, the second lens and the third lens) along the optical axis direction is 48um. The gap between the movable lens group and the lower group lens group is 0.330966763348643mm when the object distance is 1.2m; the gap between the movable lens group and the lower group lens group is 0.347815565605643mm when the object distance is 35cm; and the gap between the movable lens group and the lower group lens group is 0.378978479607452mm when the object distance is 15cm.

[0128] Figures 10A to 10C The inner focusing lens of the third preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2m, 35cm and 15cm, and it can be known that the inner focusing lens of the third preferred embodiment of the present application effectively improves the distortion of the lens. In particular, the distortion of the inner focusing lens is <2.80% when the object distance is 35cm. Figures 11A to 11C The inner focusing lens of the third preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2m, 35cm and 15cm, and it can be known that the inner focusing lens of the third preferred embodiment of the present application effectively improves the distortion of the lens. In particular, the distortion of the inner focusing lens is <2.80% when the object distance is 35cm. Figures 12A to 12C The inner focusing lens of the third preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2m, 35cm and 15cm, and it can be known that the inner focusing lens of the third preferred embodiment of the present application effectively improves the distortion of the lens. In particular, the distortion of the inner focusing lens is <2.80% when the object distance is 35cm.

[0129] The inner focusing lens of the third preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2m, 35cm and 15cm, and it can be known that the inner focusing lens of the third preferred embodiment of the present application effectively improves the distortion of the lens. In particular, the distortion of the inner focusing lens is <2.80% when the object distance is 35cm. Figures 13 to 16CAs shown, an inner focus lens according to the fourth preferred embodiment of the present application is illustrated in the following description. It is worth mentioning that in this preferred embodiment of the present application, the first lens 10 has positive refractive power, and the object side surface 11 of the first lens 10 is convex, and the image side surface 12 of the first lens 10 is concave; the second lens 20 has negative refractive power, and the object side surface 21 of the second lens 20 is convex, and the image side surface 22 of the second lens 20 is concave; the third lens 30 has positive refractive power, and the object side surface 31 of the third lens 30 is concave, and the image side surface 32 of the third lens 30 is convex; the fourth lens 40 has negative refractive power, and the object side surface 41 of the fourth lens 40 is concave, and the image side surface 42 of the fourth lens 40 is concave; the fifth lens 50 has negative refractive power, and the object side surface 51 of the fifth lens 50 is convex, and the image side surface 12 of the fifth lens 50 is concave. The lenses of the inner focus lens satisfy the above-mentioned conditional expressions, and in this preferred embodiment of the present application, the following conditions are preferably satisfied: f M The f value is 0.859528476; the |∑fn| / f value is 7.604312034; the ∑R LnS1 The f value is 0.859528476; the |∑fn| / f value is 7.604312034; the ∑R LnS2 The f value is 0.859528476; the |∑fn| / f value is 7.604312034; the ∑R max The f value is 0.859528476; the |∑fn| / f value is 7.604312034; the ∑R 主物距 The f value is 0.859528476; the |∑fn| / f value is 7.604312034; the ∑R 最小物距 The f value is 0.859528476; the |∑fn| / f value is 7.604312034; the ∑R 最大物距 The f value is 0.859528476; the |∑fn| / f value is 7.604312034; the ∑R 主物距 The f value is 0.859528476; the |∑fn| / f value is 7.604312034; the ∑R

[0130] In each of the above-mentioned embodiments, the aspherical surface equation of each lens of the inner focus lens is represented as follows:

[0131]

[0132] Wherein: X is the relative distance of a point on the aspherical surface with a distance Y from the optical axis to the tangent plane of the aspherical surface at the intersection point of the optical axis; Y is the perpendicular distance of a point on the aspherical surface from the optical axis; R is the radius of curvature; k is the conic coefficient; Ai is the i-th order aspherical coefficient.

[0133] In this preferred embodiment of the present application, the focal length of the optical projection lens is f, the f-number of the optical projection lens is Fno, and the maximum field of view of the optical projection lens is FOV, and the values are as follows: f = 3.57 mm; Fno = 2.6543; and FOV = 76.55 degrees.

[0134] Table 10 shows the structure parameters of each lens of the inner focus lens according to the fourth preferred embodiment of the present application.

[0135] Table 10

[0136]

[0137] Table 10 shows the detailed structure data of each lens of the inner focusing lens of the fourth preferred embodiment of the present application, wherein the units of curvature radius, thickness and focal length are mm. Table 11 shows the aspheric surface data of each lens of the inner focusing lens of the fourth preferred embodiment of the present application, wherein K represents the conic coefficient in the aspheric surface equation, and A4-A20 represent the 4th-20th order aspheric surface coefficients of each surface. In addition, the following tables of each embodiment are corresponding to the schematic diagram and aberration curve diagram of each embodiment, and the definitions of the data in the tables are the same as those of Table 10 and Table 11 of the embodiments, which are not described here.

[0138] Table 11

[0139]

[0140] In the preferred embodiment of the present application, the first lens 10, the second lens 20 and the third lens 30 of the inner focusing lens are implemented as the movable lens group (or upper group lens group), i.e. the first lens 10, the second lens 20 and the third lens 30 are driven by the inner focusing motor to move along the optical axis direction as a movable upper group lens assembly. Correspondingly, the fourth lens 40 and the fifth lens 50 of the inner focusing lens are as a fixed lower group lens assembly. When the object distance changes, the movable lens group (i.e. the first lens 10, the second lens 20 and the third lens 30) is driven by the inner focusing motor to move to keep the image plane position formed by the inner focusing lens unchanged. The fourth lens 40 and the fifth lens 50 constitute a lower group lens group, which is fixed in position.

[0141] Table 12 shows the basic parameters of the inner focusing lens of the fourth preferred embodiment of the present application.

[0142] Table 9

[0143]

[0144] In the preferred embodiment of the present application, the half image height ImgH value of the image surface formed by the inner focusing lens is 2.93, and the variable distance of the object distance is 15 cm-1.2 m as an example, wherein the total optical length TTL value of the optical system of the inner focusing lens is 4.6306 mm when the object distance is 1.2 m; the total optical length TTL value of the optical system of the inner focusing lens is 4.65 mm when the object distance is 35 cm; and the total optical length TTL value of the optical system of the inner focusing lens is 4.6881 mm when the object distance is 15 cm. The maximum view angle FOV value of the optical projection lens of the inner focusing lens is 76.6328445038738 when the object distance is 1.2 m; the maximum view angle FOV value of the optical projection lens of the inner focusing lens is 76.5573485010474 when the object distance is 35 cm; and the maximum view angle FOV value of the optical projection lens of the inner focusing lens is 76.4194474576408 when the object distance is 15 cm. In the preferred embodiment of the present application, the stroke distance of the inner focusing motor driving the movable lens group (i.e. the movable lens group composed of the first lens, the second lens and the third lens) along the optical axis direction is 57 um. The gap between the movable lens group and the lower group lens group is 0.364058759974018 mm when the object distance is 1.2 m; the gap between the movable lens group and the lower group lens group is 0.383360772875968 mm when the object distance is 35 cm; and the gap between the movable lens group and the lower group lens group is 0.42154646927177 mm when the object distance is 15 cm.

[0145] Figures 14A to 14C The inner focusing lens of the fourth preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2 m, 35 cm and 15 cm, and it can be known that the inner focusing lens of the fourth preferred embodiment of the present application effectively improves the distortion of the lens. In particular, the distortion of the inner focusing lens is <2.62% when the object distance is 35 cm. Figures 15A to 15C The inner focusing lens of the fourth preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2 m, 35 cm and 15 cm, and it can be known that the inner focusing lens of the fourth preferred embodiment of the present application effectively improves the distortion of the lens. In particular, the distortion of the inner focusing lens is <2.62% when the object distance is 35 cm. Figures 16A to 16C The inner focusing lens of the fourth preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2 m, 35 cm and 15 cm, and it can be known that the inner focusing lens of the fourth preferred embodiment of the present application effectively improves the distortion of the lens. In particular, the distortion of the inner focusing lens is <2.62% when the object distance is 35 cm.

[0146] The inner focusing lens of the fourth preferred embodiment of the present application is shown in the corresponding distortion curves at the object distances of 1.2 m, 35 cm and 15 cm, and it can be known that the inner focusing lens of the fourth preferred embodiment of the present application effectively improves the distortion of the lens. In particular, the distortion of the inner focusing lens is <2.62% when the object distance is 35 cm. Figure 17As shown, a camera module according to another aspect of the present application is illustrated in the following description. The camera module comprises an inner focus lens 300 as any of the above, a photosensitive assembly 400, and at least one inner focus motor 500, wherein the inner focus lens 300 is disposed along a photosensitive path of the photosensitive assembly 400, the inner focus motor 500 is connected with at least one movable lens of the inner focus lens 300, and the inner focus motor 500 drives the movable lens so that the imaging position of the inner focus lens 300 is fixed when the object distance of the camera module changes. It is worth mentioning that, in this preferred embodiment of the present application, the inner focus motor 500 is the inner focus motor in the above preferred embodiment.

[0147] It should be understood by those skilled in the art that the embodiments of the present application described above and shown in the drawings are only examples and do not limit the present application. The purpose of the present application has been fully and effectively achieved. The function and structural principle of the present application has been demonstrated and explained in the embodiments, and the embodiments of the present application can be any modification or change without departing from the principle.

Claims

1. An inner focus lens consisting of five lens groups, characterized by, comprising: a first lens having positive refractive power, wherein an object side surface of the first lens is convex and an image side surface of the first lens is concave; a second lens having negative refractive power; a third lens having positive refractive power, wherein an object side surface of the third lens is concave and the image side surface of the third lens is convex; a fourth lens having negative refractive power, wherein the image side surface of the fourth lens is concave; and a fifth lens having negative refractive power, wherein an object side surface of the fifth lens is convex, and an image side surface of the fifth lens is concave; wherein the first lens, the second lens, the third lens, the fourth lens and the fifth lens are sequentially and spaced apart from each other along an optical axis direction from an object side to an image side, and at least one of the lenses is movable along the optical axis direction and is arranged as a movable lens group, a focal length of the inner focus lens is f, and a focal length of the movable lens group is f M , a focal length of the nth lens is fn, a curvature radius of the nth lens close to the object side is R LnS1 , a curvature radius of the nth lens close to the image side is R LnS2 , wherein 1≤n≤5; a maximum stroke of the movable lens group is AFD max , which satisfies the following conditions: 0.8 M / f<2.9; |∑fn| / f>1.6; 1.84<∑R LnS1 / R LnS2 <8; 0.04mm<AFD max <0.11mm, and the movable lens group provides positive refractive power, and when an object distance changes, the movable lens group is adjusted so that a corresponding image space position of the inner focus lens is unchanged.

2. The inner focus lens of claim 1, wherein the fifth lens adopts a shape of an M-type lens.

3. The internal focusing lens according to claim 1, wherein the thickness of the nth lens on the optical axis is CTn, the total optical length of the optical system of the internal focusing lens is TTL, the half-image height of the image plane is ImgH, focusing is achieved by moving the movable lens group, and for the changing gap position, the nth changing gap from the object side to the image side is STn, which satisfies the following condition: 0.05 <CT1 / TTL 主物距 <0.25; TTL 最小物距 -TTL 最大物距 <0.085mm; 0.6 <TTL 主物距 / (2*ImgH)<0.8;STn≥0.18mm.

4. The inner focus lens of claim 3, wherein an object side surface of the second lens is convex, an image side surface of the second lens is concave, and an object side surface of the fourth lens is convex.

5. The inner focus lens of claim 3, wherein an object side surface of the second lens is concave, an image side surface of the second lens is convex, and an object side surface of the fourth lens is convex.

6. The inner focus lens of claim 3, wherein an object side surface of the second lens is convex, an image side surface of the second lens is concave, and an object side surface of the fourth lens is concave.

7. The inner focus lens of claim 4 or 5, wherein the third lens is the movable lens.

8. The inner focus lens of claim 4 or 6, wherein the first lens, the second lens, and the third lens are grouped as the movable lens group.

9. The inner focus lens of any one of claims 4 to 6, wherein an aspherical curve equation of each lens of the inner focus lens is represented as follows: X = Y2 / R + kY4 / AiYi where X is a relative distance of a point on the aspherical surface at a distance Y from the optical axis to a tangent plane at the intersection of the optical axis; Y is a perpendicular distance of a point on the aspherical curve from the optical axis; R is a radius of curvature; k is a conic coefficient; and Ai is an aspherical coefficient of the i-th order. wherein:

10. The inner focus lens of claim 9, wherein a gap between the movable lens group and each of the adjacent groups is > 0.18 mm at any effective position. comprising:

11. A camera module, characterized by an inner focus lens; a photosensitive assembly, wherein the inner focus lens is disposed in the photosensitive assembly; and at least one inner focus motor, wherein the inner focus lens comprises: a first lens having positive refractive power, wherein an object side surface of the first lens is convex and an image side surface of the first lens is concave; a second lens having negative refractive power; a third lens having positive refractive power, wherein an object side surface of the third lens is concave and the image side surface of the third lens is convex; a fourth lens having negative refractive power, wherein the image side surface of the fourth lens is concave; and 12. The camera module of claim 11, wherein the fifth lens adopts a shape of an M-type lens.

14. The camera module of claim 13, wherein an object side surface of the second lens is convex, an image side surface of the second lens is concave, and an object side surface of the fourth lens is convex. a fifth lens having negative refractive power, wherein an object side surface of the fifth lens is convex and an image side surface of the fifth lens is concave, wherein the first lens, the second lens, the third lens, the fourth lens and the fifth lens are arranged in sequence and spaced apart from each other along an optical axis direction from the object side to the image side, and at least one of the lenses is arranged as a movable lens group which is movable along the optical axis direction, the movable lens group is drivingly connected to the inner focus motor, a focal length of the inner focus lens is f, a focal length of the movable lens group is f M , a focal length of the nth lens is fn, a curvature radius of the nth lens close to the object side is R LnS1 , a curvature radius of the nth lens close to the image side is R LnS2 , wherein 1≤n≤5; a maximum stroke of the movable lens group is AFD max , which satisfies the following conditions: 0.8 M / f<2.9; |∑fn| / f>1.6; 1.84<∑R LnS1 / R LnS2 <8; 0.04mm<AFD max <0.11mm, and the movable lens group provides positive refractive power, and the movable lens group is driven to move along the optical axis direction by the inner focus motor when the object distance changes, so that the corresponding image space position of the inner focus lens is unchanged.

15. The camera module of claim 13, wherein an object side surface of the second lens is concave, an image side surface of the second lens is convex, and an object side surface of the fourth lens is convex.

13. The camera module according to claim 11, wherein the thickness of the nth lens on the optical axis is CTn, the total optical length of the optical system of the inner focusing lens is TTL, the half-image height of the image plane is ImgH, focusing is achieved by moving the movable lens group, and for the changing gap position, the nth changing gap from the object side to the image side is STn, which satisfies the following condition: 0.05 <CT1 / TTL 主物距 <0.25; TTL 最小物距 -TTL 最大物距 <0.085mm; 0.6 <TTL 主物距 / (2*ImgH)<0.8;STn≥0.18mm. ​ ​ 16.The camera module of claim 13, wherein the object side surface of the second lens is convex, the image side surface of the second lens is concave, and the object side surface of the fourth lens is concave. 17.The camera module of claim 14 or 15, wherein the third lens is the movable lens. 18.The inner focus lens of claim 14 or 16, wherein the first lens, the second lens, and the third lens are combined to form the movable lens group. 19.The camera module of any one of claims 14-16, wherein the aspherical curve equation of each lens of the inner focus lens is represented as follows: wherein X is the relative distance of a point on the aspherical surface with a distance Y from the optical axis, at the intersection of the tangent to the aspherical surface and the optical axis; Y is the perpendicular distance of a point on the aspherical curve from the optical axis; R is the radius of curvature; k is the conic coefficient; and Ai is the i-th order aspherical coefficient. wherein: 20.The camera module of claim 19, wherein the movable lens group has a gap > 0.18mm with the opposite adjacent group at any effective position. ​

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