Intra-focal lens and camera module

Abstract

The application provides an inner focusing lens and a camera module, wherein the inner focusing lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens; the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens form an upper group lens and a lower group lens; the upper group lens is located at the front end of the lower group lens in the light incident direction; the upper group lens can move along the optical axis direction relative to the lower group lens; when the object distance changes, the gap between the upper group lens and the lower group lens is changed by adjusting the position of the upper group lens, so that the corresponding image space position of the inner focusing lens is unchanged.

Description

Technical Field

[0001] This invention relates to the field of optical imaging technology, and more particularly to an internal focusing lens and a camera module. Background Technology

[0002] Today, we live in a rapidly developing digital age. Mobile phones, as indispensable electronic communication devices, have seen unprecedented performance improvements compared to traditional models. This is especially true in mobile phone photography, where new technologies are constantly emerging, improving, and maturing. The most obvious example is the trend towards thinner and lighter phones – this greatly optimizes the user experience while also placing higher demands on the optical design of mobile phone lenses: it means a shorter overall lens length while maintaining the same image quality performance.

[0003] Current mobile phone lenses focus by shifting the image plane position at different object distances. This method results in more backward image plane compensation at closer object distances, leading to a longer overall optical length at close range. Clearly, this is detrimental to achieving a slimmer and lighter mobile phone design. To address this issue, mobile phone lens optical designs have adopted a series of height-reduction solutions, such as liquid lenses and freeform surfaces, which have been successfully applied in mobile phone lenses.

[0004] While liquid lenses or TLENS can achieve focusing at different object distances while maintaining the image plane position by changing their own optical power, most mobile phone lenses currently use aspherical lenses. Changing the R-value of the spherical lens to change the optical power often introduces excessive field curvature. Furthermore, due to the thickness limitations of liquid lenses or TLENS themselves, it is difficult to compress the initial total optical length to an ideal state. The height reduction solution using freeform surfaces primarily aims to reduce the initial total optical length, but it still uses existing focusing methods. This is not recommended for certain lenses: for example, small lenses that require constant TTL to maintain a fixed head size are difficult to achieve using this method; additionally, for large image planes or telephoto lens designs, ordinary focusing methods result in excessive image plane movement at different object distances, a deficiency that freeform surface height reduction cannot compensate for. Summary of the Invention

[0005] A key advantage of this invention is that it provides an internal focusing lens and a camera module, wherein the internal focusing lens uses internal focusing technology, that is, a motor drives at least one lens of the internal focusing lens while the image plane position of the internal focusing remains unchanged, thereby achieving focusing at different object distances, which is beneficial to shortening the overall length of the lens.

[0006] Another advantage of the present invention is that it provides an internal focusing lens and a camera module, wherein the internal focusing lens can effectively improve field curvature at different object distances while keeping the image plane unchanged.

[0007] Another advantage of the present invention is that it provides an internal focusing lens and a camera module, wherein internal focusing is a scheme to achieve focusing by moving the lens spacing while keeping the image plane position unchanged, which can improve the image quality at close range to a certain extent.

[0008] Another advantage of the present invention is that it provides an internal focusing lens and a camera module, wherein the internal focusing lens maintains the image plane position by moving at least one lens (lens group) to reduce the back focus, thereby helping to reduce the total length of the lens (TTL).

[0009] Another advantage of the present invention is that it provides an internal focusing lens and a camera module, wherein the internal focusing lens can reduce near-field curvature, thereby improving image quality.

[0010] Another advantage of the present invention is that it provides an internal focusing lens and a camera module, wherein the internal focusing lens keeps the image plane position unchanged by internal focusing, realizes focusing at different object distances, and effectively reduces the module height.

[0011] Another advantage of the present invention is that it provides an internal focusing lens and a camera module, wherein the internal focusing lens keeps the image plane position unchanged by internal focusing, and achieves focusing at different object distances, which can effectively improve the close-range performance of the camera module.

[0012] Another advantage of the present invention is that it provides an internal focusing lens and a camera module, wherein the internal focusing lens includes seven non-bonded aspherical lenses with optical power, and at least one lens is configured as a movable lens (group) that can move along the optical axis to provide positive optical power. When the object distance changes, the image space position corresponding to the moving group remains unchanged, thereby keeping the object distance of the group behind the moving group unchanged and fixing the image plane position.

[0013] Another advantage of the present invention is that it provides an internal focusing lens and a camera module, wherein the internal focusing lens achieves a larger range of object distance variation through a smaller stroke, achieves fixed image plane position compared to ordinary lenses, and greatly improves field curvature performance of the lens compared to TLENS lenses.

[0014] Another advantage of the present invention is that it provides an internal focusing lens and a camera module, wherein the first lens of the internal focusing lens is a lens with positive optical power and the second lens is a lens with negative refractive power, which can effectively reduce the distortion of the optical system.

[0015] Another advantage of the present invention is that it provides an internal focusing lens and a camera module, wherein the seventh lens of the internal focusing lens is a negative power lens and an M-type lens, which can effectively improve the field curvature of the optical system.

[0016] Another advantage of the present invention is that it provides an internal focusing lens and a camera module, wherein the internal focusing lens can effectively reduce the chromatic aberration of the image formed by the camera module, thereby improving the image quality.

[0017] According to one aspect of the present invention, an internal focusing lens of the present invention, capable of achieving the aforementioned and other objectives and advantages, comprises: First lens; A second lens; A third lens; A fourth lens; A fifth lens; A sixth lens; and A seventh lens, wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are arranged alternately from the object side to the image side along an optical axis, and the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens form an upper lens group and a lower lens group, wherein the upper lens group is located at the front end of the lower lens group in the light incident direction, and the upper lens group can move relative to the lower lens group along the optical axis. When the object distance changes, the gap between the upper lens group and the lower lens group is changed by adjusting the position of the upper lens group, so that the image space position corresponding to the inner focusing lens remains unchanged.

[0018] According to at least one embodiment of the present invention, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens constitute the upper lens group, and the sixth lens and the seventh lens constitute the lower lens group.

[0019] According to at least one embodiment of the present invention, the first lens, the second lens, and the third lens constitute the upper lens group, the fifth lens, the sixth lens, and the seventh lens constitute the lower lens group, the fourth lens is configured as a middle lens group, and focusing is achieved by adjusting the position of the middle lens group.

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

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

[0022] According to at least one embodiment of the present invention, the focal length of the internal focusing lens is f, the focal length of the movable lens (group) is fM, the focal length of the nth lens is fn, the radius of curvature of the nth lens near the object side is RLnS1, the radius of curvature of the nth lens near the image side is RLnS2, and the maximum stroke of the movable lens (group) is AFD, which satisfies the following conditions: 0.8 < fM / f < 2.9; |∑fn| / f > 1.6; 1.84 < ∑RLnS1 / RLnS2 < 8; 0.09 < AFD < 0.5, and the upper group lens (group) and / or the lower group lens (group) provides positive optical power.

[0023] According to at least one embodiment of the present invention, 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, and the semi-image height of the image plane is ImgeH. Focusing is achieved by moving the movable lens (group), which satisfies the following conditions: 0.05 < CT1 / TTL < 0.15; TTLmax - TTLmin < 0.5; 0.6 < TTL object distance / (2 ImgeH) < 0.8; the gap between any two adjacent lens groups is greater than 0.18.

[0024] According to at least one embodiment of the present invention, 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 convex, the image side surface of the second lens is concave, the object side surface of the third lens is convex, the image side surface of the third lens is concave, the object side surface of the fourth lens is concave, the image side surface of the fourth lens is convex, the object side surface of the fifth lens is concave, the image side surface of the fifth lens is concave, the object side surface of the sixth lens is convex, the image side surface of the sixth lens is convex, the object side surface of the seventh lens is concave, and the image side surface of the seventh lens is concave.

[0025] According to another aspect of the present invention, the present invention further provides an imaging module, including:

[0026] Where: X is the point on the aspherical surface at a distance Y from the optical axis, and its relative distance from the tangent plane of the intersection point of the aspherical surface and the optical axis; Y is the perpendicular distance from the point on the aspherical curve to the optical axis; R is the radius of curvature; k is the conic coefficient; Ai is the i-th order aspherical coefficient.

[0027] According to another aspect of the present invention, the present invention further provides an imaging module, comprising: One internal focusing lens; A photosensitive assembly, wherein the internal focusing lens is disposed on the photosensitive assembly; and At least one internal focusing motor, wherein the internal focusing lens includes: First lens; A second lens; A third lens; A fourth lens; A fifth lens; A sixth lens; and A seventh lens, wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are arranged alternately from the object side to the image side along an optical axis, and the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens form an upper lens group and a lower lens group, wherein the upper lens group is located at the front end of the lower lens group in the light incident direction, and the upper lens group can move relative to the lower lens group along the optical axis. When the object distance changes, the internal focusing motor changes the gap between the upper lens group and the lower lens group by driving the upper lens group, so that the image space position corresponding to the internal focusing lens remains unchanged.

[0028] According to at least one embodiment of the present invention, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens constitute the upper lens group, and the sixth lens and the seventh lens constitute the lower lens group.

[0029] According to at least one embodiment of the present invention, the first lens, the second lens, and the third lens constitute the upper lens group, the fifth lens, the sixth lens, and the seventh lens constitute the lower lens group, the fourth lens is configured as a middle lens group, and focusing is achieved by adjusting the position of the middle lens group.

[0030] According to at least one embodiment of the present invention, the first lens has positive optical power and the second lens has negative optical power.

[0031] According to at least one embodiment of the present invention, the seventh lens has negative optical power and the seventh lens adopts the shape of an M-type lens.

[0032] According to at least one embodiment of the present invention, the focal length of the internal focusing lens is f, the focal length of the movable lens (group) is fM, the focal length of the nth lens is fn, the radius of curvature of the nth lens near the object side is RLnS1, the radius of curvature of the nth lens near the image side is RLnS2, and the maximum stroke of the movable lens (group) is AFD, which satisfies the following conditions: 0.8 < fM / f < 2.9; |∑fn| / f > 1.6; 1.84 < ∑RLnS1 / RLnS2 < 8; 0.09 < AFD < 0.5, and the upper lens group (group) and / or the lower lens group (group) provides positive optical power.

[0033] According to at least 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 semi-image height of the image plane be ImgeH. Focusing is achieved by moving the movable lens (group), which satisfies the following conditions: 0.05 < CT1 / TTL < 0.15; TTLmax - TTLmin < 0.5; 0.6 < TTL object distance / (2 ImgeH) < 0.8; the gap between any two adjacent lens groups is greater than 0.18.

[0034] According to at least one embodiment of the present invention, 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 convex, the image side surface of the second lens is concave, the object side surface of the third lens is convex, the image side surface of the third lens is concave, the object side surface of the fourth lens is concave, the image side surface of the fourth lens is convex, the object side surface of the fifth lens is concave, the image side surface of the fifth lens is concave, the object side surface of the sixth lens is convex, the image side surface of the sixth lens is convex, the object side surface of the seventh lens is concave, and the image side surface of the seventh lens is concave.

[0035] According to at least one embodiment of the present invention, the aspheric curve equations of each lens of the internal focusing lens are expressed as follows:

[0036] Where: X is the point on the aspheric surface at a distance Y from the optical axis, and its relative distance from the tangent plane at the intersection of the aspheric surface and the optical axis; Y is the perpendicular distance from the point on the aspheric curve to the optical axis; R is the radius of curvature; k is the conic coefficient; Ai is the i-th order aspheric coefficient.

[0037] Through the understanding of the subsequent description and the drawings, the further objects and advantages of the present invention will be fully embodied.

[0038] These and other objects, features and advantages of the present invention are fully embodied through the following detailed description and the drawings. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of an internal focusing lens according to a first preferred embodiment of the present invention.

[0040] Figure 2A and Figure 2B It is the distortion curve corresponding to different object distances of the internal focusing lens according to the first preferred embodiment of the present invention.

[0041] Figure 3A and Figure 3B It is the astigmatism curve corresponding to different object distances of the internal focusing lens according to the first preferred embodiment of the present invention.

[0042] Figure 4A and Figure 4B It is the on-axis chromatic aberration curve corresponding to different object distances of the internal focusing lens according to the first preferred embodiment of the present invention.

[0043] Figure 5 This is a schematic diagram of the structure of an internal focusing lens according to a second preferred embodiment of the present invention.

[0044] Figure 6A and Figure 6B It is the distortion curve corresponding to different object distances of the internal focusing lens according to the second preferred embodiment of the present invention.

[0045] Figure 7A and Figure 7B It is the astigmatism curve corresponding to different object distances of the internal focusing lens according to the second preferred embodiment of the present invention.

[0046] Figure 8A and Figure 8B It is the on-axis chromatic aberration curve corresponding to different object distances of the internal focusing lens according to the second preferred embodiment of the present invention.

[0047] Figure 9A and Figure 9B This is a schematic diagram of the structure of an internal focusing lens according to a third preferred embodiment of the present invention.

[0048] Figure 10A and Figure 10B It is the distortion curve corresponding to different object distances of the internal focusing lens according to the third preferred embodiment of the present invention.

[0049] Figure 11A and Figure 11B It is the astigmatism curve corresponding to different object distances of the internal focusing lens according to the third preferred embodiment of the present invention.

[0050] Figure 12A and Figure 12BIt is the on-axis chromatic aberration curve corresponding to different object distances of the internal focusing lens according to the third preferred embodiment of the present invention.

[0051] Figure 13A and Figure 13B This is a schematic diagram of the structure of an internal focusing lens according to a fourth preferred embodiment of the present invention.

[0052] Figure 14A and Figure 14B It is the distortion curve corresponding to different object distances of the internal focusing lens according to the fourth preferred embodiment of the present invention.

[0053] Figure 15A and Figure 15B It is the astigmatism curve corresponding to different object distances of the internal focusing lens according to the fourth preferred embodiment of the present invention.

[0054] Figure 16A and Figure 16B It is the on-axis chromatic aberration curve corresponding to different object distances of the internal focusing lens according to the fourth preferred embodiment of the present invention.

[0055] Figure 17A and Figure 17B This is a schematic diagram of the structure of an internal focusing lens according to a fifth preferred embodiment of the present invention.

[0056] Figure 18A and Figure 18B It is the distortion curve corresponding to different object distances of the internal focusing lens according to the fifth preferred embodiment of the present invention.

[0057] Figure 19A and Figure 19B It is the astigmatism curve corresponding to different object distances of the internal focusing lens according to the fifth preferred embodiment of the present invention.

[0058] Figure 20A and Figure 20B It is the on-axis chromatic aberration curve corresponding to different object distances of the internal focusing lens according to the fifth preferred embodiment of the present invention.

[0059] Figure 21A and Figure 21B This is a schematic diagram of the structure of an internal focusing lens according to a sixth preferred embodiment of the present invention.

[0060] Figure 22A and Figure 22B It is the distortion curve corresponding to different object distances of the internal focusing lens according to the sixth preferred embodiment of the present invention.

[0061] Figure 23A and Figure 23B It is the astigmatism curve corresponding to different object distances of the internal focusing lens according to the sixth preferred embodiment of the present invention.

[0062] Figure 24A and Figure 24B It is the on-axis chromatic aberration curve corresponding to different object distances of the internal focusing lens according to the sixth preferred embodiment of the present invention.

[0063] Figure 25 This is a schematic diagram of a camera module using the internal focusing lens described in any of the preferred embodiments of the present invention. Detailed Implementation

[0064] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0065] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting the invention.

[0066] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0067] Refer to the accompanying drawings in this specification to... Figures 1 to 4BAs shown, an internal focusing lens and camera module according to the present invention will be described in the following description. The internal focusing lens includes a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, and a seventh lens 70, wherein the first lens 10, the second lens 20, the third lens 30, the fourth lens 40, the fifth lens 50, the sixth lens 60, and the seventh lens 70 are arranged sequentially from the object side to the image side along the optical axis. Notably, an aperture stop 100 (not shown in the figure) is located on the light-incident side of the first lens 10, and at least one filter 200 is located on the light-outcident side of the seventh lens 70. The imaging light rays are incident on the first lens 10 of the internal focusing lens through the aperture stop 100, and the optical fiber emitted from the seventh lens 70 is imaged at an image plane position S0 by the filter 200, i.e., a photosensitive chip is located at the image plane position S0.

[0068] It is worth mentioning that, in this preferred embodiment of the present invention, each lens of the internal focusing lens is a lens with optical power and a non-bonded aspherical surface, and at least one lens of the internal focusing lens is a movable lens (group).

[0069] In detail, in this preferred embodiment of the present invention, at least one lens of the inner focusing lens forms an upper lens group, and at least one lens forms a lower lens group. The upper lens group is movable relative to the lower lens group along the optical axis. The image plane position S0 is adjusted by adjusting the gap between the upper and lower lens groups, so that the image plane position S0 is maintained at the position of the photosensitive chip. In other optional embodiments of the present invention, at least one lens of the inner focusing lens forms a middle lens group. The middle lens group is located between the upper and lower lens groups, and its position is movable relative to the upper and / or lower lens groups to achieve focusing of the camera module. In short, when the lenses of the internal focusing lens are divided into three groups, focusing is achieved by adjusting the position of the middle lens group. The upper lens group and the middle lens group are movable lenses. When the lenses of the internal focusing lens are divided into two groups, the upper lens group is a movable lens group, and the lower lens group is a fixed lens group. By moving the position of the movable lens group, the image plane position S0 is always kept at the position of the photosensitive chip.

[0070] The focal length of the internal focusing lens is f, and the focal length of the movable lens (group) is f. M The focal length of the upper lens group is f. 上The focal length of the lower lens group is f. 下 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 stroke of the internal focusing motor of the optical system of the internal focusing lens is AFD. max It satisfies the following condition: 0.8 <f M / f<2.9;|∑fn| / f>1.6;0.8<∑R LnS1 / R LnS2 <3.2; 0.09 <AFD max <0.5.

[0071] It is worth mentioning that the internal focusing motor drives the movable lens (group) of the internal focusing lens to move along the optical axis of the internal focusing lens, so that the movable lens provides positive optical power. When the object distance changes, the image space position corresponding to the movable lens remains unchanged. Therefore, when the object distance changes, the image plane position is fixed by adjusting the position of the movable lens (group). Those skilled in the art will understand that the internal focusing lens of the present invention achieves a larger range of object distance variation with a smaller stroke, achieving image plane position fixation compared to ordinary lenses, and significantly improving field curvature performance compared to TLENS lenses. More importantly, the internal focusing lens of the present invention can achieve a field curvature of less than 8µm across the entire field of view for object distances of 15cm to 1.2m.

[0072] In this preferred embodiment of the present invention, the first lens 10 of the internal focusing lens has a positive optical power and the second lens 20 has a negative optical power, which effectively reduces the distortion of the optical system. Furthermore, since the seventh lens 70 has a negative optical power and adopts the shape of an M-type lens, the field curvature of the optical system can be effectively improved.

[0073] Furthermore, let the focal length of the upper lens group be f. 上 The focal length of the lower lens group is f. 下 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 back focal length of the inner focusing lens is BFL, and the half-image height in the D direction of the chip is ImgeH. Focusing is achieved by moving the movable lens (group). For changing gap positions, the gap between any two lens groups is SP, which satisfies the following condition: 0.05 <CT1 / TTL<0.15;TTL max -TTL min <0.5; 0.6 <TTL / (2 ImgeH) < 0.8; SP ≥ 0.18; |f 上 / f 下 | < 1; 0.06 < BFL / TTL < 0.15; 0.015 < AFDmax / ImageH < 0.08. It is worth mentioning that if the internal focusing lens is divided into an upper group of lenses (group) and the lower group of lenses (group), then SP is the air gap between the upper group of lens groups and the lower group of lens groups; if the internal focusing lens is divided into an upper group of lenses (group), the middle group of lenses (group) and the lower group of lenses (group), then SP is the air gap between the upper group of lens groups and the middle group of lens groups, or the air gap between the middle group of lens groups and the lower group of lens groups.

[0074] Preferably, in this preferred embodiment of the present invention, the internal focusing lens satisfies the following conditional formula: 0.06 < BFL / TTL < 0.1.

[0075] The internal focusing lens of the present invention can be implemented as a small head lens, that is, the middle part of the first lens of the internal focusing lens is thicker, and the CT1 / TTL main object distance value is larger, about 0.25, and it is necessary to ensure that the overall optical length is as small as possible and remains unchanged at different object distances. In this preferred embodiment of the present invention, the internal focusing lens can satisfy 0.6 < TTL / (2 ImgH) < 0.8 on the basis of keeping the overall optical length of the optical system unchanged, which can effectively solve the small head lens. The internal focusing lens of the present invention can also be implemented as a movable lens with two upper and lower groups or a movable lens with upper, middle and lower groups, and the internal focusing lens can also be implemented as a small image plane lens or a large image plane lens.

[0076] For a large image plane optical system, the change of the object distance of an ordinary lens will cause a large movement of the image plane position, which will lead to an increase in the overall module height. At the same time, the near field curvature performance of a large image plane is usually poor. The three-group internal focusing scheme can provide the smallest change in the overall length. By moving the upper group of lenses and the middle group of lenses, while keeping the image plane unchanged, the TTL change < 0.085. It is worth mentioning that in addition to the three-group internal focusing scheme, the two-group internal focusing scheme can also greatly improve the field curvature at different object distances and can be used in optical systems with multiple object distances in most application scenarios.

[0077] It is worth mentioning that in the present invention, when the movable lens (group) of the internal focusing lens is in any effective position, the gap between it and the relative adjacent group is > 0.18 mm, reserving enough space for the structural design.

[0078] Summary of the Invention: In this invention, the lens is divided into several groups. The object corresponding to the first group (the upper lens group) forms an intermediate image, which becomes the object of the second group (the middle lens group or the lower lens group), and so on, thus forming the final image on the final image plane. It can be seen that the position and image quality of the intermediate image of the penultimate group directly determine the final image plane presentation. When the object distance changes, the ordinary focusing method moves the image plane to achieve focusing at the new object distance, without changing the spacing between the lenses. Since the intermediate image of the penultimate group, as the object of the last group, is almost impossible to provide the optimal object state for the final image, when the object distance changes (generally at close range), at the central field of view focus position, other outer fields of view often have significant field curvature. For typical mobile phone lenses, it is desirable to achieve focusing from inf (infinity) to 10cm. This focusing method severely affects the image quality at close range.

[0079] Lens-based focusing achieves focus by moving the distance between lens elements. When the object distance changes, the lens is divided into several groups, and the spacing between these groups is altered—for example, changing the spacing between the first and second groups—thus changing the position and quality of the intermediate image. For instance, a change in the object distance alters the position of the intermediate image in the first group, causing a change in the object distance in the second group. Optimizing the system by making the spacing at different object distances a variable helps us find the optimal relative positions between groups. This ensures that the position and image quality of the penultimate group's intermediate image contribute more significantly to the final image quality, resulting in improved field curvature compared to traditional focusing methods.

[0080] While a large number of focus groups can effectively improve image quality, the complex structure poses a significant challenge to the stability and reliability of the system. Here, we use a two- or three-group focusing method to significantly improve the MTF image quality at close range.

[0081] Referring to the accompanying drawings of this invention Figures 1 to 4BAs shown, an internal focusing lens according to a first preferred embodiment of the present invention will be described in the following description. In this preferred embodiment of the invention, the first lens 10 has positive optical power, and the object-side surface 11 of the first lens is convex, and the image-side surface 12 of the first lens 10 is concave; the second lens 20 has negative optical power, and the object-side surface 21 of the second lens is convex, and the image-side surface 22 of the second lens 20 is concave; the third lens 30 has positive optical power, and the object-side surface 31 of the third lens is convex, and the image-side surface 32 of the third lens 30 is concave; the fourth lens 40 has positive optical power, and the fourth lens... The object-side surface 41 of the fourth lens 40 is concave, and the image-side surface 42 of the fifth lens 40 is convex; the fifth lens 50 has negative optical power, and both its object-side surface 51 and image-side surface 52 are concave; the sixth lens 60 has positive optical power, wherein both its object-side surface 61 and image-side surface 62 are convex; the seventh lens 70 has negative optical power, wherein both its object-side surface 71 and image-side surface 72 are concave. Each lens of the internal focusing lens conforms to the above-described conditional expression, and in this preferred embodiment of the invention, it is preferably: f M / f value is 2.278877499; |∑fn| / f value is 1.68400519; ∑R LnS1 / R LnS2 The value is 1.61168; AFD max The value is 0.107; the CT1 / TTL value is 0.0979138; the TTL... max -TTL min The value is 0.0711; TTL / (2 The ImgH value was 0.658489; the SP value was 0.18; the BFL / TTL value was 0.112707574548256; the f-up / f-down value was -0.92312612; and the ImageH value was 6.27.

[0082] In each embodiment conforming to the above implementation method, the aspherical curve equation of each lens of the internal focusing lens is expressed as follows:

[0083] Where: X is the point on the aspherical surface at a distance Y from the optical axis, and its relative distance to the tangent plane at the intersection point on the optical axis of the aspherical surface; Y is the perpendicular distance between the point on the aspherical curve and the optical axis; R is the radius of curvature; k is the conic coefficient; Ai is the i-th order aspherical coefficient.

[0084] In this preferred embodiment of the present invention, 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 angle of view of the optical projection lens is FOV, with the following values: f = 6.58 mm; Fno = 1.8; and FOV = 85 degrees.

[0085] Table 1 shows the structural parameters of each lens of the internal focusing lens according to the first preferred embodiment of the present invention.

[0086] Table 1

[0087] Table 1 shows detailed structural data for each lens of the internal focusing lens according to the first preferred embodiment of the present invention, where the units for radius of curvature, thickness, and focal length are mm. Table 2 shows the aspherical data for each lens of the internal focusing lens according to the first preferred embodiment of the present invention, where K represents the cone coefficient in the aspherical curve equation, and A4-A20 represent the 4th-20th order aspherical coefficients of each surface. Furthermore, the tables for the following embodiments are corresponding schematic diagrams and aberration curves for each embodiment. The definitions of the data in the tables are the same as those in Tables 1 and 2 of the embodiments, and will not be repeated here.

[0088] Table 2

[0089] In detail, in this preferred embodiment of the present invention, the first lens 10, the second lens 20, and the third lens 30 of the internal focusing lens form the upper lens group L1, and the fifth lens 50, the sixth lens 60, and the seventh lens 70 form the lower lens group L2. The fourth lens 40 is drivably disposed between the upper lens group and the lower lens group. The fourth lens 40 of the internal focusing lens is implemented as a movable lens, and the upper lens group is implemented as a movable lens group, that is, the fourth lens 40 can be driven by the internal focusing motor to move along the optical axis, and the upper lens group can also be driven along the optical axis. It can be understood that the fourth lens 40 can also be referred to as the middle lens L3 of the internal focusing motor. When the object distance changes, the fourth lens 30 (movable lens) is driven by the internal focusing motor to move, so as to keep the position of the image plane formed by the internal focusing lens unchanged.

[0090] In short, in this preferred embodiment of the present invention, the upper lens group consisting of the first lens 10, the second lens 20, and the third lens 30 can be moved as a whole along the optical axis by the internal focusing motor; the fourth lens 40, as a movable lens, can also be moved along the optical axis by the internal focusing motor, thereby fixing the imaging position of the internal focusing lens. It is worth mentioning that in this preferred embodiment of the present invention, focusing is achieved by adjusting the position of the fourth lens 40 (middle lens group).

[0091] Table 3 shows the basic parameters of the internal focusing lens according to the first preferred embodiment of the present invention.

[0092] Table 3

[0093] In this preferred embodiment of the invention, the half-image height (ImgH) of the image plane formed by the internal focusing lens is 6.27. As an example, the variable object distance is from 30 cm to infinity. When the object distance is infinity, the total optical length (TTL) of the optical system of the internal focusing lens is 8.1 mm; when the object distance is 30 cm, the total optical length (TTL) of the internal focusing lens is 8.1711. When the object distance is infinity, the maximum field of view (FOV) of the optical projection lens of the internal focusing lens is 85.0000064280624; when the object distance is 30 cm, the maximum field of view (FOV) of the optical projection lens of the internal focusing lens is 84.8091870819496. In this preferred embodiment of the present invention, the travel distance between the upper lens group and the fourth lens 40 (movable lens) along the optical axis is 35.7 μm; the travel distance between the lower lens group and the fourth lens 40 (movable lens) along the optical axis is 107 μm. When the object distance is infinitely far, the gap between the fourth lens 40 and the upper lens group is 0.634398185366369 mm, and the gap between the fourth lens 40 and the lower lens group is 0.180000554563717 mm; when the object distance is 30 cm, the gap between the fourth lens 40 and the upper lens group is 0.59871273237129 mm, and the gap between the fourth lens 40 and the lower lens group is 0.287407938865411 mm.

[0094] Figure 2A and 2BThe diagram shows the distortion curves of the internal focusing lens of the first preferred embodiment of the present invention at object distances of infinity and 30cm. It can be seen that the internal focusing lens of the first preferred embodiment of the present invention effectively improves lens distortion. Specifically, when the object distance is infinity, the distortion of the internal focusing lens is <2.30%. Figure 3A and Figure 3B The astigmatism curves of the internal focusing lens according to the first preferred embodiment of the present invention are shown at an object distance of infinity and 30cm. Figure 4A and Figure 4B The diagram shows the chromatic aberration curves on each axis of the internal focusing lens according to the first preferred embodiment of the present invention at an object distance of infinity (30 cm). It can be seen that the internal focusing lens of the first preferred embodiment of the present invention effectively improves the astigmatism and chromatic aberration performance of the lens, which is beneficial to improving the imaging quality of the camera module.

[0095] Referring to the accompanying drawings of this invention Figures 5 to 8B As shown, an internal focusing lens according to a second preferred embodiment of the present invention will be described in the following description. In this preferred embodiment of the invention, the first lens 10 has positive optical power, and the object-side surface 11 of the first lens is convex, and the image-side surface 12 of the first lens 10 is concave; the second lens 20 has negative optical power, and the object-side surface 21 of the second lens is convex, and the image-side surface 22 of the second lens 20 is concave; the third lens 30 has positive optical power, and the object-side surface 31 of the third lens is convex, and the image-side surface 32 of the third lens 30 is concave; the fourth lens 40 has positive optical power, and the fourth lens... The object-side surface 41 of the fourth lens 40 is concave, and the image-side surface 42 of the fifth lens 40 is convex; the fifth lens 50 has negative optical power, and both its object-side surface 51 and image-side surface 52 are concave; the sixth lens 60 has positive optical power, wherein both its object-side surface 61 and image-side surface 62 are convex; the seventh lens 70 has negative optical power, wherein both its object-side surface 71 and image-side surface 72 are concave. Each lens of the internal focusing lens conforms to the above-described conditional expression, and in this preferred embodiment of the invention, it is preferably: f M / f = 2.856874385; |∑fn| / f = 2.131044602; ∑R LnS1 / R LnS2 The value is 1.48868; AFD max The value is 0.093; the CT1 / TTL value is 0.0872464; the TTL value is... max -TTL min The value is 0.0644; TTL / (2 The values ​​for ImgH were 0.661929; SP was 0.19; BFL / TTL was 0.113696896591513; f_up / f_down was -0.89123344; and ImageH was 5.42.

[0096] In each embodiment conforming to the above implementation method, the aspherical curve equation of each lens of the internal focusing lens is expressed as follows:

[0097] Where: X is the point on the aspherical surface at a distance Y from the optical axis, and its relative distance to the tangent plane at the intersection point on the optical axis of the aspherical surface; Y is the perpendicular distance between the point on the aspherical curve and the optical axis; R is the radius of curvature; k is the conic coefficient; Ai is the i-th order aspherical coefficient.

[0098] In this preferred embodiment of the invention, 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 viewing angle of the optical projection lens is FOV, with the following values: f = 5.8 mm; Fno = 2; and FOV = 85 degrees.

[0099] Table 4 shows the structural parameters of each lens of the internal focusing lens according to the second preferred embodiment of the present invention.

[0100] Table 4

[0101] Table 4 shows detailed structural data for each lens of the internal focusing lens according to the second preferred embodiment of the present invention, where the units for radius of curvature, thickness, and focal length are mm. Table 5 shows the aspherical data for each lens of the internal focusing lens according to the second preferred embodiment of the present invention, where K represents the cone coefficient in the aspherical curve equation, and A4-A20 represent the 4th-20th order aspherical coefficients of each surface. Furthermore, the tables for the following embodiments are corresponding schematic diagrams and aberration curves for each embodiment. The definitions of the data in the tables are the same as those in Tables 4 and 5 of the embodiments, and will not be repeated here.

[0102] Table 5

[0103] In detail, in this preferred embodiment of the present invention, the first lens 10, the second lens 20, and the third lens 30 of the internal focusing lens form the upper lens group L1, and the fifth lens 50, the sixth lens 60, and the seventh lens 70 form the lower lens group L2. The fourth lens 40 is drivably disposed between the upper lens group and the lower lens group. The fourth lens 40 of the internal focusing lens is implemented as a movable lens, and the upper lens group is implemented as a movable lens group, that is, the fourth lens 40 can be driven by the internal focusing motor to move along the optical axis, and the upper lens group can also be driven along the optical axis. It can be understood that the fourth lens 40 can also be referred to as the middle lens L3 of the internal focusing motor. When the object distance changes, the fourth lens 30 (movable lens) is driven by the internal focusing motor to move, so as to keep the position of the image plane formed by the internal focusing lens unchanged.

[0104] In short, in this preferred embodiment of the present invention, the upper lens group consisting of the first lens 10, the second lens 20, and the third lens 30 can be moved as a whole along the optical axis by the internal focusing motor; the fourth lens 40, as a movable lens, can also be moved along the optical axis by the internal focusing motor, thereby fixing the imaging position of the internal focusing lens.

[0105] Table 6 shows the basic parameters of the internal focusing lens according to the second preferred embodiment of the present invention.

[0106] Table 6

[0107] In this preferred embodiment of the invention, the half-image height (ImgH) of the image plane formed by the internal focusing lens is 5.42. As an example, the variable object distance is 30cm-inf (infinity). When the object distance is infinity, the total optical length (TTL) of the internal focusing lens's optical system is 7.1767mm; when the object distance is 30cm, the TTL is 7.2411. When the object distance is infinity, the maximum field of view (FOV) of the internal focusing lens's optical projection lens is 85.0000064280624; when the object distance is 30cm, the maximum field of view (FOV) is 84.6. In this preferred embodiment of the invention, the travel distance between the upper lens group and the fourth lens 40 (movable lens) along the optical axis is 29µm; the travel distance between the lower lens group and the fourth lens 40 (movable lens) along the optical axis is 93µm. When the object distance is infinite, the gap between the fourth lens 40 and the upper lens group is 0.576058651839191 mm, and the gap between the fourth lens 40 and the lower lens group is 0.19 mm; when the object distance is 30 cm, the gap between the fourth lens 40 and the upper lens group is 0.547380334656721 mm, and the gap between the fourth lens 40 and the lower lens group is 0.283144532700109 mm.

[0108] Figure 6A and 6B The diagram shows the distortion curves of the internal focusing lens according to the second preferred embodiment of the present invention at object distances of inf and 30cm. It can be seen that the internal focusing lens of the second preferred embodiment of the present invention effectively improves lens distortion. Specifically, when the object distance is infinity, the distortion of the internal focusing lens is <2.40%. Figure 7A and Figure 7B The following are the astigmatism curves of the internal focusing lens according to the second preferred embodiment of the present invention at an object distance of infinity and 30cm. Figure 8A and Figure 8B The diagram shows the chromatic aberration curves on each axis of the internal focusing lens according to the second preferred embodiment of the present invention at an object distance of infinity (30 cm). It can be seen that the internal focusing lens of the second preferred embodiment of the present invention effectively improves the astigmatism and chromatic aberration performance of the lens, which is beneficial to improving the imaging quality of the camera module.

[0109] Referring to the accompanying drawings of this invention Figures 9A to 12BAs shown, an internal focusing lens according to a third preferred embodiment of the present invention will be described in the following description. In this preferred embodiment of the invention, the first lens 10 has positive optical power, and the object-side surface 11 of the first lens is convex, and the image-side surface 12 of the first lens 10 is concave; the second lens 20 has negative optical power, and the object-side surface 21 of the second lens is convex, and the image-side surface 22 of the second lens 20 is concave; the third lens 30 has positive optical power, and the object-side surface 31 of the third lens is convex, and the image-side surface 32 of the third lens 30 is concave; the fourth lens 40 has negative optical power, and the fourth lens... The object-side surface 41 of the fourth lens 40 is concave, and the image-side surface 42 of the fifth lens 40 is convex; the fifth lens 50 has positive optical power, and both its object-side surface 51 and image-side surface 52 are convex; the sixth lens 60 has positive optical power, wherein its object-side surface 61 is concave and its image-side surface 62 is convex; the seventh lens 70 has negative optical power, wherein both its object-side surface 71 and image-side surface 72 are concave. Each lens of the internal focusing lens conforms to the above-described conditional expression, and in this preferred embodiment of the invention, it is preferably: f M / f = 0.890931007847845; |∑fn| / f = 3.2738202318575; ∑R LnS1 / R LnS2 The value is 2.39693; AFD max The value is 0.307432; the CT1 / TTL value is 0.121166; the TTL value is... max -TTL min The value is 0.307432; TTL / (2 The value of ImgH was 0.657226; the value of SP was 0.18; the value of BFL / TTL was 0.0792877; the value of f_up / f_down was -0.969469009643951; and the value of ImageH was 5.12.

[0110] In each embodiment conforming to the above implementation method, the aspherical curve equation of each lens of the internal focusing lens is expressed as follows:

[0111] Where: X is the point on the aspherical surface at a distance Y from the optical axis, and its relative distance to the tangent plane at the intersection point on the optical axis of the aspherical surface; Y is the perpendicular distance between the point on the aspherical curve and the optical axis; R is the radius of curvature; k is the conic coefficient; Ai is the i-th order aspherical coefficient.

[0112] In this preferred embodiment of the invention, 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 viewing angle of the optical projection lens is FOV, with the following values: f = 5.8 mm; Fno = 2; and FOV = 85 degrees.

[0113] Table 7 shows the structural parameters of each lens of the internal focusing lens according to the third preferred embodiment of the present invention.

[0114] Table 7

[0115] Table 7 shows detailed structural data for each lens of the internal focusing lens according to the third preferred embodiment of the present invention, where the units for radius of curvature, thickness, and focal length are mm. Table 8 shows the aspherical data for each lens of the internal focusing lens according to the third preferred embodiment of the present invention, where K represents the cone coefficient in the aspherical curve equation, and A4-A20 represent the 4th-20th order aspherical coefficients of each surface. Furthermore, the tables for the following embodiments are corresponding schematic diagrams and aberration curves for each embodiment. The definitions of the data in the tables are the same as those in Tables 7 and 8 of the embodiments, and will not be repeated here.

[0116] Table 8

[0117] In detail, in this preferred embodiment of the present invention, the internal focusing lens consists of an upper lens group L1 and a lower lens group L2. The upper lens group L1 is composed of a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, and a fifth lens 50. The lower lens group L2 is composed of a sixth lens 60 and a seventh lens 70. The positions of the lenses in the lower lens group L2 are fixed. The upper lens group L1 can move as a whole relative to the lower lens group L2; that is, the upper lens group L1 can be driven to move along the optical axis by the internal focusing motor. It is understood that when the object distance changes, the upper lens group L1 (the movable lens) is moved by the internal focusing motor to maintain the image plane position formed by the internal focusing lens unchanged.

[0118] In short, in this preferred embodiment of the present invention, the upper lens group consisting of the first lens 10, the second lens 20, the third lens 30, the fourth lens 40 and the fifth lens 50 can be driven by the internal focusing motor to move as a whole along the optical axis, thereby fixing the imaging position of the internal focusing lens.

[0119] Table 9 shows the basic parameters of the internal focusing lens according to the third preferred embodiment of the present invention.

[0120] Table 9

[0121] In this preferred embodiment of the invention, the half-image height (ImgH) of the image plane formed by the internal focusing lens is 5.12. As an example, the variable object distance is 10cm-inf (infinity). When the object distance is infinity, the total optical length (TTL) of the internal focusing lens's optical system is 6.73mm; when the object distance is 10cm, the TTL is 7.0374. When the object distance is infinity (inf), the maximum field of view (FOV) of the internal focusing lens's optical projection lens is 80°; when the object distance is 10cm, the maximum field of view (FOV) is 78°. In this preferred embodiment of the invention, the travel distance of the upper lens group L1 along the optical axis is 0.307431937mm. When the object distance is infinite, the gap between the lower lens group L2 and the upper lens group L1 is 0.18 mm; when the object distance is 10 cm, the gap between the lower lens group L2 and the upper lens group L1 is 0.487431937 mm.

[0122] Figure 10A and 10B The distortion curves of the internal focusing lens of the third preferred embodiment of the present invention are shown at object distances of inf and 10cm. It can be seen that the internal focusing lens of the third preferred embodiment of the present invention effectively improves the lens distortion. Figure 11A and Figure 11B The astigmatism curves of the internal focusing lens according to the third preferred embodiment of the present invention are shown at an object distance of infinity and 10 cm. Figure 12A and Figure 12B The diagram shows the chromatic aberration curves on each axis of the internal focusing lens according to the third preferred embodiment of the present invention at an object distance of infinity (30 cm). It can be seen that the internal focusing lens of the third preferred embodiment of the present invention effectively improves the astigmatism and chromatic aberration performance of the lens, which is beneficial to improving the imaging quality of the camera module.

[0123] Referring to the accompanying drawings of this invention Figures 13A to 16BAs shown, an internal focusing lens according to a fourth preferred embodiment of the present invention will be described in the following description. In this preferred embodiment of the invention, the first lens 10 has positive optical power, and the object-side surface 11 of the first lens is convex, and the image-side surface 12 of the first lens 10 is concave; the second lens 20 has negative optical power, and the object-side surface 21 of the second lens is convex, and the image-side surface 22 of the second lens 20 is concave; the third lens 30 has positive optical power, and the object-side surface 31 of the third lens is convex, and the image-side surface 32 of the third lens 30 is concave; the fourth lens 40 has negative optical power, and the fourth lens... The object-side surface 41 of the fourth lens 40 is concave, and the image-side surface 42 of the fifth lens 40 is convex; the fifth lens 50 has positive optical power, and both its object-side surface 51 and image-side surface 52 are convex; the sixth lens 60 has positive optical power, wherein its object-side surface 61 is concave and its image-side surface 62 is convex; the seventh lens 70 has negative optical power, wherein both its object-side surface 71 and image-side surface 72 are concave. Each lens of the internal focusing lens conforms to the above-described conditional expression, and in this preferred embodiment of the invention, it is preferably: f M / f = 0.885866176; |∑fn| / f = 7.895225; ∑R LnS1 / R LnS2 The value is 2.72652; AFD max The value is 0.396615; the CT1 / TTL value is 0.11645; the TTL... max -TTL min The value is 0.396615; TTL / (2 The values ​​for ImgH were 0.652826; SP was 0.191748; BFL / TTL was 0.0848515; f_up / f_down was -0.970083708286766; and ImageH was 5.82.

[0124] In each embodiment conforming to the above implementation method, the aspherical curve equation of each lens of the internal focusing lens is expressed as follows:

[0125] Where: X is the point on the aspherical surface at a distance Y from the optical axis, and its relative distance to the tangent plane at the intersection point on the optical axis of the aspherical surface; Y is the perpendicular distance between the point on the aspherical curve and the optical axis; R is the radius of curvature; k is the conic coefficient; Ai is the i-th order aspherical coefficient.

[0126] In this preferred embodiment of the invention, 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 viewing angle of the optical projection lens is FOV, with the following values: f = 5.8 mm; Fno = 2; and FOV = 85 degrees.

[0127] Table 10 shows the structural parameters of each lens of the internal focusing lens according to the fourth preferred embodiment of the present invention.

[0128] Table 10

[0129] Table 10 shows detailed structural data for each lens of the internal focusing lens according to the fourth preferred embodiment of the present invention, where the units for radius of curvature, thickness, and focal length are mm. Table 11 shows the aspherical data for each lens of the internal focusing lens according to the fourth preferred embodiment of the present invention, where K represents the cone coefficient in the aspherical curve equation, and A4-A20 represent the 4th-20th order aspherical coefficients of each surface. Furthermore, the tables in the following embodiments are corresponding schematic diagrams and aberration curves for each embodiment. The definitions of the data in the tables are the same as those in Tables 10 and 11 of the embodiments, and will not be repeated here.

[0130] Table 11

[0131] In detail, in this preferred embodiment of the present invention, the internal focusing lens consists of an upper lens group L1 and a lower lens group L2. The upper lens group L1 is composed of a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, and a fifth lens 50. The lower lens group L2 is composed of a sixth lens 60 and a seventh lens 70. The positions of the lenses in the lower lens group L2 are fixed. The upper lens group L1 can move as a whole relative to the lower lens group L2; that is, the upper lens group L1 can be driven to move along the optical axis by the internal focusing motor. It is understood that when the object distance changes, the upper lens group L1 (the movable lens) is moved by the internal focusing motor to maintain the image plane position formed by the internal focusing lens unchanged.

[0132] In short, in this preferred embodiment of the present invention, the upper lens group consisting of the first lens 10, the second lens 20, the third lens 30, the fourth lens 40 and the fifth lens 50 can be driven by the internal focusing motor to move as a whole along the optical axis, thereby fixing the imaging position of the internal focusing lens.

[0133] Table 12 shows the basic parameters of the internal focusing lens according to the fourth preferred embodiment of the present invention.

[0134] Table 12

[0135] In this preferred embodiment of the invention, the half-image height (ImgH) of the image plane formed by the internal focusing lens is 5.82084578200054. As an example, the variable object distance is 10cm-inf (infinity), where the total optical length (TTL) of the optical system of the internal focusing lens is 7.52mm when the object distance is infinity. The maximum field of view (FOV) of the optical projection lens of the internal focusing lens is 80° when the object distance is infinity. In this preferred embodiment of the invention, the travel distance of the upper lens group L1 along the optical axis is 0.397183mm. When the object distance is infinity, the gap between the lower lens group L2 and the upper lens group L1 is 0.232654329754316mm; when the object distance is 10cm, the gap between the lower lens group L2 and the upper lens group L1 is 0.629837556671249mm.

[0136] Figure 14A and 14B The distortion curves of the internal focusing lens according to the fourth preferred embodiment of the present invention are shown at object distances of inf and 10cm. It can be seen that the internal focusing lens of the fourth preferred embodiment of the present invention effectively improves the lens distortion. Figure 15A and Figure 15B The following are the astigmatism curves of the internal focusing lens according to the fourth preferred embodiment of the present invention at an object distance of infinity and 10cm. Figure 16A and Figure 16B The diagram shows the chromatic aberration curves on each axis of the internal focusing lens according to the fourth preferred embodiment of the present invention at an object distance of infinity (10 cm). It can be seen that the internal focusing lens of the fourth preferred embodiment of the present invention effectively improves the astigmatism and chromatic aberration performance of the lens, which is beneficial to improving the imaging quality of the camera module.

[0137] Referring to the accompanying drawings of this invention Figures 17A to 20BAs shown, an internal focusing lens according to a fifth preferred embodiment of the present invention will be described in the following description. In this preferred embodiment of the invention, the first lens 10 has positive optical power, and the object-side surface 11 of the first lens is convex, and the image-side surface 12 of the first lens 10 is concave; the second lens 20 has negative optical power, and the object-side surface 21 of the second lens is convex, and the image-side surface 22 of the second lens 20 is concave; the third lens 30 has positive optical power, and the object-side surface 31 of the third lens is convex, and the image-side surface 32 of the third lens 30 is concave; the fourth lens 40 has negative optical power, and the fourth lens... The object-side surface 41 of the fourth lens 40 is concave, and the image-side surface 42 of the fifth lens 40 is convex; the fifth lens 50 has positive optical power, and its object-side surface 51 is convex, while its image-side surface 52 is concave; the sixth lens 60 has positive optical power, wherein its object-side surface 61 is concave, and its image-side surface 62 is convex; the seventh lens 70 has negative optical power, wherein its object-side surface 71 is concave, and its image-side surface 72 is concave. Each lens of the internal focusing lens conforms to the above-described conditional expression, and in this preferred embodiment of the present invention, it is preferably: f M / f = 0.889264706; |∑fn| / f = 8.50639852941176; ∑R LnS1 / R LnS2 The value is 3.00093; AFD max The value is 0.397183; the CT1 / TTL value is 0.0968783; the TTL value is... max -TTL min The value is 0.397183; TTL / (2 The values ​​for ImgH were 0.645954; SP was 0.232654; BFL / TTL was 0.0914541; f_up / f_down was -0.973466713459179; and ImageH was 5.82.

[0138] In each embodiment conforming to the above implementation method, the aspherical curve equation of each lens of the internal focusing lens is expressed as follows:

[0139] Where: X is the point on the aspherical surface at a distance Y from the optical axis, and its relative distance to the tangent plane at the intersection point on the optical axis of the aspherical surface; Y is the perpendicular distance between the point on the aspherical curve and the optical axis; R is the radius of curvature; k is the conic coefficient; Ai is the i-th order aspherical coefficient.

[0140] In this preferred embodiment of the invention, 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 viewing angle of the optical projection lens is FOV, with the following values: f = 5.8 mm; Fno = 2; and FOV = 85 degrees.

[0141] Table 13 shows the structural parameters of each lens of the internal focusing lens according to the fifth preferred embodiment of the present invention.

[0142] Table 13

[0143] Table 13 shows detailed structural data for each lens of the internal focusing lens according to the fifth preferred embodiment of the present invention, where the units for radius of curvature, thickness, and focal length are mm. Table 14 shows the aspherical data for each lens of the internal focusing lens according to the fifth preferred embodiment of the present invention, where K represents the cone coefficient in the aspherical curve equation, and A4-A20 represent the 4th-20th order aspherical coefficients of each surface. Furthermore, the tables in the following embodiments are corresponding schematic diagrams and aberration curves for each embodiment. The definitions of the data in the tables are the same as those in Tables 13 and 14 of the embodiments, and will not be repeated here.

[0144] Table 14

[0145] In detail, in this preferred embodiment of the present invention, the internal focusing lens consists of an upper lens group L1 and a lower lens group L2. The upper lens group L1 is composed of a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, and a fifth lens 50. The lower lens group L2 is composed of a sixth lens 60 and a seventh lens 70. The positions of the lenses in the lower lens group L2 are fixed. The upper lens group L1 can move as a whole relative to the lower lens group L2; that is, the upper lens group L1 can be driven to move along the optical axis by the internal focusing motor. It is understood that when the object distance changes, the upper lens group L1 (the movable lens) is moved by the internal focusing motor to maintain the image plane position formed by the internal focusing lens unchanged.

[0146] In short, in this preferred embodiment of the present invention, the upper lens group consisting of the first lens 10, the second lens 20, the third lens 30, the fourth lens 40 and the fifth lens 50 can be driven by the internal focusing motor to move as a whole along the optical axis, thereby fixing the imaging position of the internal focusing lens.

[0147] Table 15 shows the basic parameters of the internal focusing lens according to the fifth preferred embodiment of the present invention.

[0148] Table 15

[0149] In this preferred embodiment of the invention, the half-image height (ImgH) of the image plane formed by the internal focusing lens is 5.82084578200054. As an example, the variable object distance is 10cm-inf (infinity), where the total optical length (TTL) of the optical system of the internal focusing lens is 7.52mm when the object distance is infinity. The maximum field of view (FOV) of the optical projection lens of the internal focusing lens is 80° when the object distance is infinity. In this preferred embodiment of the invention, the travel distance of the upper lens group L1 along the optical axis is 0.397183mm. When the object distance is infinity, the gap between the lower lens group L2 and the upper lens group L1 is 0.232654329754316mm; when the object distance is 10cm, the gap between the lower lens group L2 and the upper lens group L1 is 0.629837556671249mm.

[0150] Figure 18A and 18B The distortion curves of the internal focusing lens of the fifth preferred embodiment of the present invention are shown at object distances of inf and 10cm. It can be seen that the internal focusing lens of the fifth preferred embodiment of the present invention effectively improves the lens distortion. Figure 19A and Figure 19B The following are the astigmatism curves of the internal focusing lens according to the fifth preferred embodiment of the present invention at an object distance of infinity and 10cm. Figure 20A and Figure 20B The diagram shows the chromatic aberration curves on each axis of the internal focusing lens according to the fifth preferred embodiment of the present invention at an object distance of infinity (10 cm). It can be seen that the internal focusing lens of the fifth preferred embodiment of the present invention effectively improves the astigmatism and chromatic aberration performance of the lens, which is beneficial to improving the imaging quality of the camera module.

[0151] Referring to the accompanying drawings of this invention Figures 21A to 24BAs shown, an internal focusing lens according to a sixth preferred embodiment of the present invention will be described in the following description. In this preferred embodiment of the invention, the first lens 10 has positive optical power, and the object-side surface 11 of the first lens is convex, and the image-side surface 12 of the first lens 10 is concave; the second lens 20 has negative optical power, and the object-side surface 21 of the second lens is convex, and the image-side surface 22 of the second lens 20 is concave; the third lens 30 has positive optical power, and the object-side surface 31 of the third lens is convex, and the image-side surface 32 of the third lens 30 is concave; the fourth lens 40 has negative optical power, and the fourth lens... The object-side surface 41 of the fourth lens 40 is concave, and the image-side surface 42 of the fifth lens 40 is convex; the fifth lens 50 has positive optical power, and its object-side surface 51 is convex, while its image-side surface 52 is concave; the sixth lens 60 has positive optical power, wherein its object-side surface 61 is concave, and its image-side surface 62 is convex; the seventh lens 70 has negative optical power, wherein its object-side surface 71 is concave, and its image-side surface 72 is concave. Each lens of the internal focusing lens conforms to the above-described conditional expression, and in this preferred embodiment of the present invention, it is preferably: f M / f = 0.945422222; |∑fn| / f = 2.75903333333333; ∑R LnS1 / R LnS2 The value is 3.14458; AFD max The value is 0.185924; the CT1 / TTL value is 0.114148; the TTL value is... max -TTL min The value is 0.185924; TTL / (2 The value of ImgH is 0.662084; the value of SP is 0.34777; the value of BFL / TTL is 0.0646081; the value of f_up / f_down is -0.850344283101646; and the value of ImageH is 4.2.

[0152] In each embodiment conforming to the above implementation method, the aspherical curve equation of each lens of the internal focusing lens is expressed as follows:

[0153] Where: X is the point on the aspherical surface at a distance Y from the optical axis, and its relative distance to the tangent plane at the intersection point on the optical axis of the aspherical surface; Y is the perpendicular distance between the point on the aspherical curve and the optical axis; R is the radius of curvature; k is the conic coefficient; Ai is the i-th order aspherical coefficient.

[0154] In this preferred embodiment of the invention, 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 viewing angle of the optical projection lens is FOV, with the following values: f = 5.8 mm; Fno = 2; and FOV = 85 degrees.

[0155] Table 16 shows the structural parameters of each lens of the internal focusing lens according to the sixth preferred embodiment of the present invention.

[0156] Table 16

[0157] Table 16 shows detailed structural data for each lens of the internal focusing lens according to the sixth preferred embodiment of the present invention, where the units for radius of curvature, thickness, and focal length are mm. Table 17 shows the aspherical data for each lens of the internal focusing lens according to the sixth preferred embodiment of the present invention, where K represents the cone coefficient in the aspherical curve equation, and A4-A20 represent the 4th-20th order aspherical coefficients of each surface. Furthermore, the tables in the following embodiments are corresponding schematic diagrams and aberration curves for each embodiment. The definitions of the data in the tables are the same as those in Tables 16 and 17 of the embodiments, and will not be repeated here.

[0158] Table 17

[0159] In detail, in this preferred embodiment of the present invention, the internal focusing lens consists of an upper lens group L1 and a lower lens group L2. The upper lens group L1 is composed of a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, and a fifth lens 50. The lower lens group L2 is composed of a sixth lens 60 and a seventh lens 70. The positions of the lenses in the lower lens group L2 are fixed. The upper lens group L1 can move as a whole relative to the lower lens group L2; that is, the upper lens group L1 can be driven to move along the optical axis by the internal focusing motor. It is understood that when the object distance changes, the upper lens group L1 (the movable lens) is moved by the internal focusing motor to maintain the image plane position formed by the internal focusing lens unchanged.

[0160] In short, in this preferred embodiment of the present invention, the upper lens group consisting of the first lens 10, the second lens 20, the third lens 30, the fourth lens 40 and the fifth lens 50 can be driven by the internal focusing motor to move as a whole along the optical axis, thereby fixing the imaging position of the internal focusing lens.

[0161] Table 18 shows the basic parameters of the internal focusing lens according to the sixth preferred embodiment of the present invention.

[0162] Table 18

[0163] In this preferred embodiment of the invention, the half-image height (ImgH) of the image plane formed by the internal focusing lens is 4.20591839714915. As an example, the variable object distance is 10cm-inf (infinity), where the total optical length (TTL) of the optical system of the internal focusing lens is 5.3232mm when the object distance is infinity. The maximum field of view (FOV) of the optical projection lens of the internal focusing lens is 85° when the object distance is infinity. In this preferred embodiment of the invention, the travel distance of the upper lens group L1 along the optical axis is 0.185924327mm. When the object distance is infinity, the gap between the lower lens group L2 and the upper lens group L1 is 0.34777018569938mm; when the object distance is 10cm, the gap between the lower lens group L2 and the upper lens group L1 is 0.533694512735mm.

[0164] Figure 22A and 22B The distortion curves of the internal focusing lens of the sixth preferred embodiment of the present invention are shown at object distances of inf and 10cm. It can be seen that the internal focusing lens of the sixth preferred embodiment of the present invention effectively improves the lens distortion. Figure 23A and Figure 23B The following are the astigmatism curves of the internal focusing lens according to the sixth preferred embodiment of the present invention at an object distance of infinity and 10cm. Figure 24A and Figure 24B The diagram shows the chromatic aberration curves on each axis of the internal focusing lens according to the sixth preferred embodiment of the present invention at an object distance of infinity (10 cm). It can be seen that the internal focusing lens of the sixth preferred embodiment of the present invention effectively improves the astigmatism and chromatic aberration performance of the lens, which is beneficial to improving the imaging quality of the camera module.

[0165] Referring to the accompanying drawings of this invention Figure 25As shown, a camera module according to another aspect of the present invention is illustrated in the following description. The camera module includes an internal focusing lens 300 as described above, a photosensitive element 400, and at least one internal focusing motor 500. The internal focusing lens 300 is disposed along a photosensitive path of the photosensitive element 400. The internal focusing motor 500 is connected to at least one movable lens of the internal focusing lens 300, and the internal focusing motor 300 drives the movable lens so that the imaging position of the internal focusing lens 300 remains unchanged when the object distance captured by the camera module changes. It is worth noting that in this preferred embodiment of the present invention, the internal focusing motor 500 is the same as the internal focusing motor in the aforementioned preferred embodiment.

[0166] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments, and any variations or modifications may be made to the implementation of the present invention without departing from the stated principles.

Claims

1. An internal focusing lens, characterized in that, The internal focusing lens is an optical system consisting of seven lenses, including: A first lens with a positive focal length, wherein the object side of the first lens is convex and the image side of the first lens is concave. A second lens with a negative focal length, wherein the object side of the second lens is convex and the image side of the second lens is concave. A third lens with a positive focal length, wherein the object-side surface of the third lens is convex and the image-side surface of the third lens is concave. A fourth lens with a negative focal length, wherein the object-side surface of the fourth lens is concave and the image-side surface of the fourth lens is convex. A fifth lens with a positive focal length, wherein the object-side surface of the fifth lens is concave and the image-side surface of the fifth lens is concave. A sixth lens having a positive focal length, wherein the object-side surface of the sixth lens is convex, and the image-side surface of the sixth lens is convex; and A seventh lens with a negative focal length, wherein the object-side surface of the seventh lens is concave and the image-side surface of the seventh lens is concave, wherein the first lens, the second lens, the third lens, the fourth lens, and the fifth lens constitute the upper lens group, and the sixth lens and the seventh lens constitute the lower lens group, wherein the upper lens group is a movable lens group, and focusing is achieved by moving the upper lens group, while the lower lens group remains in a fixed position during focusing. 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, and the half-image height of the image plane is ImgeH, satisfying the following condition: 0.05 <CT1 / TTL<0.15;0.6<TTL / (2 ImgeH) < 0.8; The focal length of the internal focusing lens is f, the focal length of the movable lens group is fM, and the maximum travel of the movable lens group is AFD, which satisfies the following condition: 0.8 <fM / f<2.9;0.09<AFD<0.5。 2. The internal focusing lens according to claim 1, wherein the seventh lens is in the shape of an M-type lens.

3. The internal focusing lens according to claim 1, wherein the focal length of the nth lens is fn, the radius of curvature of the nth lens near the object side is RLnS1, and the radius of curvature of the nth lens near the image side is RLnS2, which satisfy the following conditions: 2.76 < |∑fn| / f < 8.5; 2.40 < ∑RLnS1 / RLnS2 < 3.14; and the upper lens group provides positive optical power.

4. The internal focusing lens according to claim 1, wherein the aspherical curve equation of each lens of the internal focusing lens is expressed as follows: in: X is the relative distance between a point on the aspherical surface at a distance Y from the optical axis and the tangent plane at the intersection point on the optical axis of the aspherical surface; Y is the perpendicular distance between a point on the aspherical curve and the optical axis; R is the radius of curvature; k is the conic coefficient; Ai is the i-th order aspherical coefficient.

5. A camera module, characterized in that, include: An internal focusing lens, wherein the internal focusing lens is an optical system consisting of seven lenses; A photosensitive assembly, wherein the internal focusing lens is disposed on the photosensitive assembly; as well as At least one internal focusing motor, wherein the internal focusing lens includes: A first lens with a positive focal length, wherein the object side of the first lens is convex and the image side of the first lens is concave. A second lens with a negative focal length, wherein the object side of the second lens is convex and the image side of the second lens is concave. A third lens with a positive focal length, wherein the object-side surface of the third lens is convex and the image-side surface of the third lens is concave. A fourth lens with a negative focal length, wherein the object-side surface of the fourth lens is concave and the image-side surface of the fourth lens is convex. A fifth lens with a positive focal length, wherein the object-side surface of the fifth lens is concave and the image-side surface of the fifth lens is concave. A sixth lens having a positive focal length, wherein the object-side surface of the sixth lens is convex, and the image-side surface of the sixth lens is convex; and A seventh lens with a negative focal length, wherein the object-side surface of the seventh lens is concave and the image-side surface of the seventh lens is concave, wherein the first lens, the second lens, the third lens, the fourth lens, and the fifth lens constitute the upper lens group, and the sixth lens and the seventh lens constitute the lower lens group, wherein the upper lens group is a movable lens group, and focusing is achieved by moving the upper lens group, while the lower lens group remains in a fixed position during focusing. 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, and the half-image height of the image plane is ImgeH, satisfying the following condition: 0.05 <CT1 / TTL<0.15;0.6<TTL / (2 ImgeH) < 0.8; The focal length of the internal focusing lens is f, the focal length of the movable lens group is fM, and the maximum travel of the movable lens group is AFD, which satisfies the following conditions: 0.8 <fM / f<2.9;0.09<AFD<0.5。 6. The camera module according to claim 5, wherein the seventh lens is in the shape of an M-type lens.

7. The camera module according to claim 6, wherein the focal length of the nth lens is fn, the radius of curvature of the nth lens near the object side is RLnS1, and the radius of curvature of the nth lens near the image side is RLnS2, which satisfy the following conditions: 2.76 < |∑fn| / f < 8.5; 2.40 < ∑RLnS1 / RLnS2 < 3.14; and the upper lens group provides positive optical power.

8. The camera module according to claim 5, wherein the aspherical curve equation of each lens of the internal focusing lens is expressed as follows: in: X is the relative distance between a point on the aspherical surface at a distance Y from the optical axis and the tangent plane at the intersection point on the optical axis of the aspherical surface; Y is the perpendicular distance between a point on the aspherical curve and the optical axis; R is the radius of curvature; k is the conic coefficient; Ai is the i-th order aspherical coefficient.

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