Internal focusing lens group

Abstract

The invention provides an internal focusing lens group, which comprises a first lens cone, a second lens cone, a third lens cone, a third lens cone, a fourth lens cone and a fifth lens cone which are sequentially arranged along an optical axis, and a second lens cone is movably arranged between the first lens cone and the third lens cone; a first lens group, a second lens group, a third lens group and a fourth lens group are respectively and sequentially accommodated in each lens barrel, the first lens group comprises a first lens, the second lens group comprises a second lens, a third lens group and a fifth lens, the third lens group comprises a sixth lens and a seventh lens, and the focal power of the three lens groups is distributed according to positive-positive-negative; the focal power of the seven lenses is distributed according to positive-positive-negative-positive-positive-negative-negative; at least one spacing element is arranged between two adjacent lenses in the second lens group, and one spacing element is arranged between the sixth lens and the seventh lens; the internal focusing lens group also satisfies the following conditions: 11.90 lt; f1 / L1 < lt >; 15.70, 0.70 lt, 0.70 lt; f2 / (DT2s + DT2m) lt; 1.15,-6.80 lt, 1.15,-6.80 lt; f3 / (DT3m-DT3s) lt; and-3.60 DEG C.

Description

Technical Field

[0001] This application relates to the technical field of optical devices, and particularly to an internal focusing lens group. Background Art

[0002] In recent years, with the rapid development of smart phones, mobile phone photography has become popular among the general public. Users' demands for mobile phone photography are no longer satisfied with simple recording, and they begin to pursue higher imaging effects, including higher picture clarity, richer detail performance, and faster and more accurate focusing capabilities. This makes the importance of optical zoom technology increasingly prominent. Since an optical zoom lens system needs to be configured with multiple lens groups and the overall length of such a system is relatively long, it is mainly applied to periscope telephoto camera modules. The number of lens groups in the current optical zoom system has developed from a simple two-lens group to a three-lens group, and the corresponding zoom method has also developed from the external focusing of the two-lens group to the internal focusing of the three-lens group, as well as the continuous zoom technology in which two lens groups in the three-lens group cooperate for focusing.

[0003] Compared with the external focusing and continuous zoom lens systems, the overall length of the internal focusing lens system does not change, avoiding the problem of inhaling dust and impurities during the telescopic process of the external focusing and continuous zoom lens systems. At the same time, it has higher imaging quality than the traditional two-group external focusing system, shorter space occupancy than the three-group continuous zoom system, a simpler and more stable module zoom structure, and faster focusing speed. This makes the internal focusing lens system more favored by high-end flagship mobile phones.

[0004] With the market's pursuit of higher pixel and larger imaging size for mobile phone lenses, while also taking into account the smallest possible module height, the processing difficulty is relatively large in the actual production process, and the product yield is relatively low. Summary of the Invention

[0005] One advantage of this application is to provide an internal focusing lens group, which can ensure stable light flux during the zoom process and ensure that the lens in the third lens group has good structural space and manufacturability while taking into account the imaging quality and miniaturization design of the internal focusing lens group.

[0006] This application provides an internal focusing lens group, including a first lens barrel, a second lens barrel, and a third lens barrel arranged in sequence along the optical axis, wherein the second lens barrel is movably arranged between the first lens barrel and the third lens barrel;

[0007] The first lens barrel further accommodates a first lens group with positive optical power, and the first lens group includes a first lens with positive optical power;

[0008] The second lens barrel further houses a second lens group with positive optical power, the second lens group including a second lens with positive optical power, a third lens with negative optical power, a fourth lens with positive optical power, and a fifth lens with positive optical power;

[0009] The third lens barrel further houses a third lens group with negative optical power, the third lens group including a sixth lens with negative optical power and a seventh lens with negative optical power;

[0010] In the second lens group, there is at least one spacer element between any two lenses, and in the third lens group, there is a spacer element between the sixth lens and the seventh lens;

[0011] The internal focusing lens group satisfies:

[0012] 11.90 < F1 / L1 < 15.70;

[0013] 0.70 < F2 / (DT2s + DT2m) < 1.15; and

[0014] -6.80 < F3 / |(DT3m - DT3s)| < -3.60;

[0015] wherein, F1 is the effective focal length of the first lens group, F2 is the effective focal length of the second lens group, F3 is the effective focal length of the third lens group, L1 is the maximum height of the first lens barrel along the optical axis direction, DT2s is the clear aperture diameter on the object side of the second lens barrel, DT2m is the clear aperture diameter on the image side of the second lens barrel, DT3s is the clear aperture diameter on the object side of the third lens barrel, and DT3m is the clear aperture diameter on the image side of the third lens barrel.

[0016] In some embodiments of the present application, the internal focusing lens group further satisfies: 2.95 < R2 / R3 < 4.40; and 1.0 ≤ (d01m - DT2s) / ΔEP0 ≤ 2.20; where R2 is the radius of curvature of the image side surface of the first lens, R3 is the radius of curvature of the object side surface of the second lens, d01m is the inner diameter of the image side end face of the first lens barrel, DT2s is the clear aperture diameter on the object side of the second lens barrel, and ΔEP0 is the maximum movable distance of the second lens barrel along the optical axis direction.

[0017] In some embodiments of the present application, the internal focusing lens group further satisfies: 0.55 < (D01m - D02s) / (d01m - d02s) < 1.35; where D01m is the outer diameter of the image side end face of the first lens barrel, D02s is the outer diameter of the object side end face of the second lens barrel, d01m is the inner diameter of the image side end face of the first lens barrel, and d02s is the inner diameter of the object side end face of the second lens barrel.

[0018] In some embodiments of the present application, the internal focusing lens group further satisfies: 0.90 < D02m / D03s < 1.15; and 1.10 < (DT2m + DT3s) / EPD ≤ 2.25; where D02m is the outer diameter of the image-side end face of the second lens barrel, D03s is the outer diameter of the object-side end face of the third lens barrel, DT2m is the clear aperture diameter of the image side of the second lens barrel, DT3s is the clear aperture diameter of the object side of the third lens barrel, and EPD is the entrance pupil diameter of the internal focusing lens group when the object distance is infinite.

[0019] In some embodiments of the present application, the internal focusing lens group further satisfies: -32.75 < (f6 + f7) / L3 < -11.90; where f6 is the effective focal length of the sixth lens, f7 is the effective focal length of the seventh lens, and L3 is the maximum height of the third lens barrel along the optical axis direction.

[0020] In some embodiments of the present application, the internal focusing lens group further satisfies: -4.30 < f7 / DT3m ≤ -1.30; where f7 is the effective focal length of the seventh lens, and DT3m is the clear aperture diameter of the image side of the third lens barrel.

[0021] In some embodiments of the present application, the internal focusing lens group further satisfies: 0.30 < T67 / (ET6 + ET7) < 0.55; where T67 is the air gap between the sixth lens and the seventh lens on the optical axis, ET6 is the maximum thickness of the non-light-transmitting region of the sixth lens, and ET7 is the maximum thickness of the non-light-transmitting region of the seventh lens.

[0022] In some embodiments of the present application, the internal focusing lens group further satisfies: 1.80 < L3 / (CT6 + CT7) < 2.15; where L3 is the maximum height of the third lens barrel along the optical axis direction, CT6 is the central thickness of the sixth lens, and CT7 is the central thickness of the seventh lens.

[0023] In some embodiments of the present application, a sixth spacer element in contact with the image-side surface of the sixth lens is disposed on the image side of the sixth lens. The internal focusing lens group further satisfies: 1.30 < F3 / R11 < 2.15; and 0.95 < DT3s / d6s < 1.65; where F3 is the effective focal length of the third lens group, R11 is the curvature radius of the object-side surface of the sixth lens, DT3s is the clear aperture diameter of the object side of the third lens barrel, and d6s is the inner diameter of the object-side surface of the sixth spacer element.

[0024] In some embodiments of the present application, a second spacer element in contact with the image side surface of the second lens is disposed on the image side of the second lens, a third spacer element in contact with the image side surface of the third lens is disposed on the image side of the third lens, a fourth spacer element in contact with the image side surface of the fourth lens is disposed on the image side of the fourth lens, and the internal focusing lens group further satisfies: 0.90 ≤ (EP23 + EP34) / (CT3 + CT4) < 1.55; where EP23 is the distance along the optical axis from the image side surface of the second spacer element to the object side surface of the third spacer element, EP34 is the distance along the optical axis from the image side surface of the third spacer element to the object side surface of the fourth spacer element, CT3 is the central thickness of the third lens, and CT4 is the central thickness of the fourth lens.

[0025] In some embodiments of the present application, a second spacer element in contact with the image side surface of the second lens is disposed on the image side of the second lens, a third spacer element in contact with the image side surface of the third lens is disposed on the image side of the third lens, and the internal focusing lens group further satisfies: -11.0 ≤ f3 / EP23 < -3.35; where EP23 is the distance along the optical axis from the image side surface of the second spacer element to the object side surface of the third spacer element, and f3 is the effective focal length of the third lens.

[0026] In some embodiments of the present application, the internal focusing lens group further satisfies: 1.25 < T23 / T45 < 2.70; and 2.55 ≤ L2 / (T23 + T45) < 5.90; where T23 is the air gap between the second lens and the third lens on the optical axis, T45 is the air gap between the fourth lens and the fifth lens on the optical axis, and L2 is the maximum height of the second lens barrel along the optical axis.

[0027] In some embodiments of the present application, the internal focusing lens group further satisfies: -2.55 ≤ R10 / R3 < -1.55; and 0.9 < Td2 / L2 ≤ 1.15; where R3 is the radius of curvature of the object side surface of the second lens, R10 is the radius of curvature of the image side surface of the fifth lens, Td2 is the distance on the optical axis from the object side surface of the second lens in the second lens group to the image side surface of the fifth lens, and L2 is the maximum height of the second lens barrel along the optical axis.

[0028] In some embodiments of the present application, the internal focusing lens group further satisfies: 1.70 < (L1 + L2 + L3) / |Δf| < 2.15; where L1 is the maximum height of the first lens barrel along the optical axis, L2 is the maximum height of the second lens barrel along the optical axis, L3 is the maximum height of the third lens barrel along the optical axis, and Δf is the change difference in the effective focal length of the internal focusing lens group when the second lens barrel moves from the closest to the first lens barrel to the closest to the third lens barrel.

[0029] In summary, the internal focusing lens group provided by the present application builds an optical system including three lens groups, where the second lens group is movably arranged between the first lens group and the third lens group along the optical axis. The first lens group has a positive optical power, the second lens group has a positive optical power, and the third lens group has a negative optical power. The optical powers of the seven lenses are distributed as "positive - positive - negative - positive - positive - negative - negative". Such an internal focusing lens group can balance the imaging performance of the telephoto, close-focus, and macro-focus focal lengths; by reasonably controlling the ratio of the effective focal length of the first lens group to the maximum height of the first lens barrel along the optical axis, the ratio of the effective focal length of the second lens group to the sum of the object-side and image-side clear apertures of the second lens barrel, and the ratio of the effective focal length of the third lens group to the difference between the object-side and image-side clear apertures of the third lens barrel, it not only maintains the stability of the light flux of the internal focusing lens group during the movement of the second lens group, avoiding obvious changes in illuminance during the zooming process; but also reserves sufficient space for the lens structure design in the third lens group, ensuring a reasonable layout of the lens components to improve the processability of the lenses. By synergistically optimizing the key dimensional relationships between the three lens groups and the corresponding lens barrels, it balances miniaturization while improving the production yield of the internal focusing lens group. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic structural diagram of an internal focusing lens group in an embodiment according to the present application;

[0031] Figure 2 is Figure 1 a schematic diagram of the structural parameters of the internal focusing lens group shown;

[0032] Figure 3A is a schematic structural diagram of the internal focusing lens group in working condition 1-1 of Embodiment 1 according to the present application;

[0033] Figure 3B is a schematic structural diagram of the internal focusing lens group in working condition 1-2 of Embodiment 1 according to the present application;

[0034] Figure 3C is a schematic structural diagram of the internal focusing lens group in working condition 1-3 of Embodiment 1 according to the present application;

[0035] Figure 4AShows the schematic diagram of the axial chromatic aberration curve of the internal focusing lens group under three working conditions of Embodiment 1 when the object distance is infinite;

[0036] Figure 4B Shows the schematic diagram of the astigmatism curve of the internal focusing lens group under three working conditions of Embodiment 1 when the object distance is infinite;

[0037] Figure 4C Shows the schematic diagram of the distortion curve of the internal focusing lens group under three working conditions of Embodiment 1 when the object distance is infinite;

[0038] Figure 5A Shows the schematic diagram of the axial chromatic aberration curve of the internal focusing lens group under three working conditions of Embodiment 1 when the object distance is 66.6675mm;

[0039] Figure 5B Shows the schematic diagram of the astigmatism curve of the internal focusing lens group under three working conditions of Embodiment 1 when the object distance is 66.6675mm;

[0040] Figure 5C Shows the schematic diagram of the distortion curve of the internal focusing lens group under three working conditions of Embodiment 1 when the object distance is 66.6675mm;

[0041] Figure 6A Is the schematic diagram of the structure of the internal focusing lens group in Working Condition 2-1 of Embodiment 2 according to the present application;

[0042] Figure 6B Is the schematic diagram of the structure of the internal focusing lens group in Working Condition 2-2 of Embodiment 2 according to the present application;

[0043] Figure 6C Is the schematic diagram of the structure of the internal focusing lens group in Working Condition 2-3 of Embodiment 2 according to the present application;

[0044] Figure 7A Shows the schematic diagram of the axial chromatic aberration curve of the internal focusing lens group under three working conditions of Embodiment 2 when the object distance is infinite;

[0045] Figure 7B Shows the schematic diagram of the astigmatism curve of the internal focusing lens group under three working conditions of Embodiment 2 when the object distance is infinite;

[0046] Figure 7C Shows the schematic diagram of the distortion curve of the internal focusing lens group under three working conditions of Embodiment 2 when the object distance is infinite;

[0047] Figure 8A Shows the schematic diagram of the axial chromatic aberration curve of the internal focusing lens group under three working conditions of Embodiment 2 when the object distance is 52.6455mm;

[0048] Figure 8BIt shows the schematic diagram of the astigmatism curve of the internal focusing lens group at an object distance of 52.6455 mm under three working conditions of Embodiment 2;

[0049] Figure 8C It shows the schematic diagram of the distortion curve of the internal focusing lens group at an object distance of 52.6455 mm under three working conditions of Embodiment 2;

[0050] Figure 9A It is the schematic diagram of the structure of the internal focusing lens group in Working Condition 3-1 of Embodiment 3 according to the present application;

[0051] Figure 9B It is the schematic diagram of the structure of the internal focusing lens group in Working Condition 3-2 of Embodiment 3 according to the present application;

[0052] Figure 9C It is the schematic diagram of the structure of the internal focusing lens group in Working Condition 3-3 of Embodiment 3 according to the present application;

[0053] Figure 10A It shows the schematic diagram of the axial chromatic aberration curve of the internal focusing lens group at an infinite object distance under three working conditions of Embodiment 3;

[0054] Figure 10B It shows the schematic diagram of the astigmatism curve of the internal focusing lens group at an infinite object distance under three working conditions of Embodiment 3;

[0055] Figure 10C It shows the schematic diagram of the distortion curve of the internal focusing lens group at an infinite object distance under three working conditions of Embodiment 3;

[0056] Figure 11A It shows the schematic diagram of the axial chromatic aberration curve of the internal focusing lens group at an object distance of 52.6455 mm under three working conditions of Embodiment 3;

[0057] Figure 11B It shows the schematic diagram of the astigmatism curve of the internal focusing lens group at an object distance of 52.6455 mm under three working conditions of Embodiment 3;

[0058] Figure 11C It shows the schematic diagram of the distortion curve of the internal focusing lens group at an object distance of 52.6455 mm under three working conditions of Embodiment 3.

[0059] Reference numerals

[0060] E1, the first lens; E2, the second lens; E3, the third lens; E4, the fourth lens; E5, the fifth lens; E6, the sixth lens; E7, the seventh lens; P01, the first lens barrel; P02, the second lens barrel; P03, the third lens barrel; P2, the second spacer element; P3, the third spacer element; P4, the fourth spacer element; P6, the sixth spacer element. Detailed Implementation Modes

[0061] To better understand the present application, more detailed descriptions of various aspects of the present application will be made with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary implementation modes of the present application, and do not limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0062] It should be noted that in this specification, the expressions such as first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teachings of the present application, the first lens E1 discussed below may also be referred to as the second lens E2 or the third lens E3.

[0063] In the drawings, for the sake of convenience of illustration, the thickness, size and shape of the lens have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are shown by way of example. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0064] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The judgment of the surface shape in the paraxial region can be carried out according to the general methods in the art. For example, the positive or negative value of the R value (R refers to the radius of curvature of the paraxial region) is used to judge the convexity and concavity. In this article, the surface of each lens closest to the object to be photographed is called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens. For the object side surface, when the R value is positive, it is judged to be convex, and when the R value is negative, it is judged to be concave; for the image side surface, when the R value is positive, it is judged to be concave, and when the R value is negative, it is judged to be convex.

[0065] It should also be understood that the terms "comprises", "comprising", "has", "including" and / or "including having", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when an expression such as "at least one of..." appears after the list of listed features, it modifies the entire list of listed features, rather than modifying the individual elements in the list. In addition, when describing the implementation modes of the present application, the use of "may" means "one or more implementation modes of the present application". And the term "exemplary" is intended to refer to an example or illustration.

[0066] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0067] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following embodiments only represent several implementation manners of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the patent scope of this application. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can still be made, and these all belong to the protection scope of this application. The following will describe this application in detail with reference to the drawings and in conjunction with the embodiments.

[0068] In this article, the non-transmissive area of the lens is the part on the lens that is mainly used to contact the lens barrel or the spacer element, and this part supports the lens and restricts the position of the lens in the lens barrel. In contrast, the transmissive area of the lens is the part on the lens that is mainly used to transmit light and polarize the light. The paraxial area of the lens is a special case of the transmissive area, mainly located in the part of the transmissive area near the optical axis and where the curvature does not change. It can be understood that for some lenses, there are inflection points, and the inflection point is the position where the sign of the radius of curvature on the transmissive area changes.

[0069] According to one aspect of this application, as Figure 1 and Figure 2 shown, an embodiment of this application provides an internally focusing lens group, including a first lens barrel P01, a second lens barrel P02, and a third lens barrel P03 arranged in sequence along the optical axis, wherein the second lens barrel P02 is movably disposed between the first lens barrel P01 and the third lens barrel P03;

[0070] The first lens barrel P01 houses a first lens group with positive optical power, and the first lens group includes a first lens E1 with positive optical power;

[0071] The second lens barrel P02 houses a second lens group with positive optical power, and the second lens group includes a second lens E2 with positive optical power, a third lens E3 with negative optical power, a fourth lens E4 with positive optical power, and a fifth lens E5 with positive optical power;

[0072] The third lens barrel P03 houses a third lens group with negative optical power, and the third lens group includes a sixth lens E6 with negative optical power and a seventh lens E7 with negative optical power;

[0073] In the second lens group, at least one spacer element is included between any two lenses. In the third lens group, a sixth spacer element P6 is included between the sixth lens E6 and the seventh lens E7.

[0074] The internal focusing lens group satisfies:

[0075] 11.90 < F1 / L1 < 15.70;

[0076] 0.70 < F2 / (DT2s + DT2m) < 1.15; and

[0077] -6.80 < F3 / |(DT3m - DT3s)| < -3.60;

[0078] Wherein, F1 is the effective focal length of the first lens group, F2 is the effective focal length of the second lens group, F3 is the effective focal length of the third lens group, L1 is the maximum height of the first lens barrel P01 along the optical axis direction, DT2s is the clear aperture diameter on the object side of the second lens barrel P02, DT2m is the clear aperture diameter on the image side of the second lens barrel P02, DT3s is the clear aperture diameter on the object side of the third lens barrel P03, and DT3m is the clear aperture diameter on the image side of the third lens barrel P03.

[0079] It should be noted that the internal focusing lens group provided in this application builds an optical system including three lens groups, wherein the second lens group is movably arranged between the first lens group and the third lens group along the optical axis. The first lens group has a positive optical power, the second lens group has a positive optical power, and the third lens group has a negative optical power. The optical powers of the seven lenses are distributed as "positive - positive - negative - positive - positive - negative - negative". Such an internal focusing lens group can take into account the imaging performance of the telephoto, short - focus, and macro - focus focal segments; by reasonably controlling the ratio of the effective focal length of the first lens group to the maximum height of the first lens barrel P01 along the optical axis direction, the ratio of the effective focal length of the second lens group to the sum of the clear aperture diameters on the object side and the image side of the second lens barrel, and the ratio of the effective focal length of the third lens group to the difference between the clear aperture diameters on the object side and the image side of the third lens barrel, it not only maintains the stability of the light flux of the internal focusing lens group during the movement of the second lens group, avoiding obvious changes in illuminance during the zooming process; but also reserves sufficient space for the lens structure design in the third lens group, ensuring the reasonable layout of the lens components to improve the processability of the lenses. By synergistically optimizing the key dimensional relationships between the three lens groups and the corresponding lens barrels, it takes into account miniaturization while improving the production yield of the internal focusing lens group.

[0080] Exemplarily, Table 1 below shows the product yield detection data when the internal focusing lens group satisfies F1 / L1 = 14.2 and F2 / (DT2s + DT2m) = 1.01. Table 2 below shows the product yield detection data when the internal focusing lens group satisfies F1 / L1 = 10.2 and F2 / (DT2s + DT2m) = 0.43. Table 3 below shows the product yield detection data when the internal focusing lens group satisfies F1 / L1 = 16.5 and F2 / (DT2s + DT2m) = 1.3. It can be seen from the three tables that when the range of the design parameter F1 / L1 of the internal focusing lens group satisfies 11.90 - 15.70 and the range of F2 / (DT2s + DT2m) satisfies 0.70 - 1.15, the product yield can be as high as 35.70%. When the design parameters F1 / L1 and F2 / (DT2s + DT2m) of the internal focusing lens group are lower than the lower limit of the range, the product yield is only 10.88%. When the design parameters F1 / L1 and F2 / (DT2s + DT2m) of the internal focusing lens group are higher than the upper limit of the range, the product yield is only 18.84%. Comparing the three detection results, it can be known that the internal focusing lens group designed based on the design parameters provided in this application can not only balance the optical imaging performance, miniaturization and light flux stability, but also improve the production yield of products and reduce the production cost.

[0081] Table 1 Product detection results when the internal focusing lens group satisfies F1 / L1 = 14.2 and F2 / (DT2s + DT2m) = 1.01

[0082]

[0083] Table 2 Product detection results when the internal focusing lens group satisfies F1 / L1 = 10.2 and F2 / (DT2s + DT2m) = 0.43

[0084]

[0085] Table 3 Product detection results when the internal focusing lens group satisfies F1 / L1 = 16.5 and F2 / (DT2s + DT2m) = 1.3

[0086]

[0087] Preferably, the internal focusing lens group satisfies: 11.93 ≤ F1 / L1 ≤ 15.66; 0.71 ≤ F2 / (DT2s + DT2m) ≤ 1.11; and -6.77 ≤ F3 / (DT3m - DT3s) ≤ -3.62.

[0088] According to some embodiments of the present application, the internal focusing lens group further satisfies: 2.95 < R2 / R3 < 4.40; and 1.0 ≤ (d01m - DT2s) / ΔEP0 ≤ 2.20; where R2 is the radius of curvature of the image side surface of the first lens E1, R3 is the radius of curvature of the object side surface of the second lens E2, d01m is the inner diameter of the image side end surface of the first lens barrel P01, DT2s is the clear aperture diameter of the object side of the second lens barrel P02, and ΔEP0 is the maximum movable distance of the second lens barrel P02 along the optical axis direction.

[0089] In this way, reasonably controlling the ratio range of the radius of curvature of the image side surface of the first lens E1 to the radius of curvature of the object side surface of the second lens E2 is beneficial to restricting the bending degree of the image side surface of the first lens E1 and ensuring that the light can be well converged and incident on the object side surface of the second lens E2 after exiting the first lens E1. At the same time, reasonably restricting the ratio of the maximum movable distance of the second lens barrel P02 along the optical axis direction to the difference between the inner diameter of the image side end surface of the first lens barrel P01 and the diameter of the object side of the second lens barrel P02 is beneficial to ensuring the optical zoom range of the internal focusing lens group, so that during the zooming process of the internal focusing lens group, the second lens barrel P02 will not have a problem of position interference with the first lens barrel P01 or the third lens barrel P03.

[0090] Preferably, the internal focusing lens group satisfies: 2.98 ≤ R2 / R3 ≤ 4.39; and 1.00 ≤ (d01m - DT2s) / ΔEP0 ≤ 2.20.

[0091] According to some embodiments of the present application, the internal focusing lens group further satisfies: 0.55 < (D01m - D02s) / (d01m - d02s) < 1.35; where D01m is the outer diameter of the image side end surface of the first lens barrel P01, D02s is the outer diameter of the object side end surface of the second lens barrel P02, d01m is the inner diameter of the image side end surface of the first lens barrel P01, and d02s is the inner diameter of the object side end surface of the second lens barrel P02.

[0092] In this way, reasonably restricting the ratio of the difference between the outer diameters of the image side end surface of the first lens barrel P01 and the object side end surface of the second lens barrel P02 to the difference between the inner diameters of the image side end surface of the first lens barrel P01 and the object side end surface of the second lens barrel P02 is beneficial to ensuring the width of the bearing end surfaces of the first lens barrel P01 and the second lens barrel P02 and the thickness of the lens barrel, so that the first lens barrel P01 and the second lens barrel P02 have better strength and processability; the assembly between the second lens barrel P02 and the second lens group is more firm, and when the second lens barrel P02 drives the second lens group to perform focusing movement, the movement path of the second lens group is more stable, avoiding the problem that the second lens group shakes during the focusing process and affecting the imaging quality.

[0093] Preferably, the internal focusing lens group satisfies: 0.57 ≤ (D01m - D02s) / (d01m - d02s) ≤ 1.32.

[0094] According to some embodiments of the present application, the internal focusing lens group further satisfies: 0.90 < D02m / D03s < 1.15; and 1.10 < (DT2m + DT3s) / EPD ≤ 2.25; where D02m is the outer diameter of the image side end face of the second lens barrel P02, D03s is the outer diameter of the object side end face of the third lens barrel P03, DT2m is the clear aperture diameter of the image side of the second lens barrel P02, DT3s is the clear aperture diameter of the object side of the third lens barrel P03, and EPD is the entrance pupil diameter of the internal focusing lens group when the object distance is infinite.

[0095] In this way, by reasonably restricting the ratio between the outer diameter of the image side end face of the second lens barrel P02 and the outer diameter of the object side end face of the third lens barrel P03, the second lens barrel and the third lens barrel can be better matched while saving space, and the change of light in the second lens barrel during the zoom process can be avoided. Specifically, the change of light includes the change of illuminance and image resolution. When these two changes are large, they will affect the imaging performance and the degree of detail expression of the image; by restricting the ratio of the sum of the clear aperture diameter of the image side of the second lens barrel P02 and the clear aperture diameter of the object side of the third lens barrel P03 to the entrance pupil diameter of the lens system, the problem of vignetting caused by the second lens barrel P02 and the third lens barrel P03 intercepting too much light during the zoom process of the internal focusing lens group can be prevented, and at the same time, the upper limits of the clear aperture diameter of the image side of the second lens barrel P02 and the clear aperture diameter of the object side of the third lens barrel P03 are restricted to avoid introducing excess light and generating stray light problems.

[0096] Preferably, the internal focusing lens group satisfies: 0.93 ≤ D02m / D03s ≤ 1.13, and 1.13 ≤ (DT2m + DT3s) / EPD ≤ 2.24.

[0097] According to some embodiments of the present application, the internal focusing lens group further satisfies: -32.75 < (f6 + f7) / L3 < -11.90; where f6 is the effective focal length of the sixth lens E6, f7 is the effective focal length of the seventh lens E7, and L3 is the maximum height of the third lens barrel P03 along the optical axis direction.

[0098] In this way, the ratio of the sum of the effective focal lengths of the sixth lens E6 and the seventh lens E7 to the maximum height of the third lens barrel P03 along the optical axis is reasonably limited. On the one hand, under the given limit of the maximum height of the lens barrel, the luminous flux passing through the sixth lens E6 and the seventh lens E7 can be effectively controlled, so that the illumination received by the image plane is distributed as evenly as possible, and the problems such as vignetting can be avoided; on the other hand, under the given chip model and image height, and the effective focal lengths of the sixth lens E6 and the seventh lens E7 meet the design requirements of the optical principal value parameters, the height of the third lens barrel P03 along the optical axis can be minimized, which can better adapt to the structural space requirements of the lens, facilitate the design layout of the internal structure of the inner focusing lens group, and help improve the product yield.

[0099] Preferably, the inner focus lens group satisfies: -32.73≤(f6+f7) / L3≤-11.91.

[0100] According to some embodiments of the present application, the inner focus lens group also satisfies: -4.30 <f7 / DT3m≤-1.30;其中,f7为所述第七透镜E7的有效焦距,DT3m为所述第三镜筒P03像侧的通光直径。

[0101] In this way, the reasonable control of the ratio range of the effective focal length of the seventh lens E7 and the light-clearance diameter on the image side of the third lens barrel P03 is conducive to controlling the light emission angle and the luminous flux, so that the light can converge at a more precise angle, so as to better match the incident angle required by the chip sensor, and finally present a clear and sharp image on the sensor. At the same time, the size of the light-clearance diameter of the lens barrel will also affect the contrast. If the light-clearance diameter is not designed reasonably, it may cause light scattering and reduce the contrast of the image. The intuitive performance is that the image presents a gray visual effect with poor layering.

[0102] Preferably, the inner focus lens group satisfies: -4.26≤f7 / DT3m≤-1.30.

[0103] According to some embodiments of the present application, the inner focus lens group also satisfies: 0.30 <T67 / (ET6+ET7)<0.55;其中,T67为所述第六透镜E6和所述第七透镜E7在光轴上的空气间隔,ET6为所述第六透镜E6非透光区域的最大厚度,ET7为所述第七透镜E7非透光区域的最大厚度。

[0104] In this way, reasonably restricting the ratio of the air interval between the sixth lens E6 and the seventh lens E7 on the optical axis to the sum of the maximum thicknesses of the non-transmissive regions of the sixth lens E6 and the seventh lens E7 is beneficial to restricting the proportion of the air gap between the sixth lens E6 and the seventh lens E7 in the third lens barrel. It should be noted that after the light passes through the sixth lens E6, if it propagates in a relatively long air interval, the possibility of being interfered by the outside world will also increase accordingly. At the same time, when the light enters the seventh lens E7, the incident angle of the light may also change greatly. Both the long propagation distance and the large change in the incident angle will affect the clarity and accuracy of imaging, specifically manifested as problems such as poor aberration or poor optical path control. These problems can also be avoided through the above conditional restrictions to ensure the quality of the photo.

[0105] Preferably, the internal focusing lens group satisfies: 0.34 ≤ T67 / (ET6 + ET7) ≤ 0.54.

[0106] According to some embodiments of the present application, the internal focusing lens group further satisfies: 1.80 < L3 / (CT6 + CT7) < 2.15; where L3 is the maximum height of the third lens barrel P03 along the optical axis direction, CT6 is the central thickness of the sixth lens E6, and CT7 is the central thickness of the seventh lens E7.

[0107] In this way, reasonably controlling the ratio of the maximum height of the third lens barrel P03 to the sum of the central thicknesses of the sixth lens E6 and the seventh lens E7 can ensure the central thicknesses of the sixth lens E6 and the seventh lens E7 when the height of the lens barrel is limited, so that they have sufficient strength and processability. If this ratio is too large, that is, the maximum height of the third lens barrel P03 is much larger than the sum of the central thicknesses of the sixth lens E6 and the seventh lens E7, it may make the internal space of the lens barrel too large, and the lens group is more likely to be interfered by factors such as external vibration and temperature change. If the ratio is too small, it may lead to insufficient lens installation space, or the support and fixing structure of the lens barrel for the lens is too compact, affecting the optical performance of the lens.

[0108] Preferably, the internal focusing lens group satisfies: 1.84 ≤ L3 / (CT6 + CT7) ≤ 2.14.

[0109] According to some embodiments of the present application, a sixth spacer element P6 in contact with the image side surface of the sixth lens E6 is disposed on the image side of the sixth lens E6, and the internal focusing lens group further satisfies: 1.30 < F3 / R11 < 2.15; and 0.95 < DT3s / d6s < 1.65; where F3 is the effective focal length of the third lens group, R11 is the curvature radius of the object side surface of the sixth lens E6, DT3s is the clear aperture diameter of the object side of the third lens barrel P03, and d6s is the inner diameter of the object side surface of the sixth spacer element P6.

[0110] In this way, by reasonably restricting the ratio range of the effective focal length of the third lens group and the curvature radius of the object side surface of the sixth lens E6, the transition degree of light rays exiting from the second lens barrel and entering the third lens barrel and the distribution of the light ray converging ability are restricted. This is beneficial to improving the zoom quality of the internal focusing lens group. Further controlling the ratio range of the light passing diameter on the object side of the third lens barrel P03 and the inner diameter of the object side surface of the sixth spacer element P6 can block excess light from entering the third lens barrel P03 and passing through the sixth spacer element P6 while ensuring sufficient illuminance, thereby avoiding the generation of stray light and affecting the imaging quality.

[0111] Preferably, the internal focusing lens group satisfies: 1.32 ≤ F3 / R11 ≤ 2.12, and 0.97 ≤ DT3s / d6s ≤ 1.61.

[0112] According to some embodiments of the present application, a second spacer element P2 in contact with the image side surface of the second lens E2 is disposed on the image side of the second lens E2, a third spacer element P3 in contact with the image side surface of the third lens E3 is disposed on the image side of the third lens E3, a fourth spacer element P4 in contact with the image side surface of the fourth lens E4 is disposed on the image side of the fourth lens E4, and the internal focusing lens group further satisfies: 0.90 ≤ (EP23 + EP34) / (CT3 + CT4) < 1.55; where EP23 is the distance along the optical axis direction from the image side surface of the second spacer element P2 to the object side surface of the third spacer element P3, EP34 is the distance along the optical axis direction from the image side surface of the third spacer element P3 to the object side surface of the fourth spacer element P4, CT3 is the central thickness of the third lens E3, and CT4 is the central thickness of the fourth lens E4.

[0113] In this way, by reasonably restricting the distance along the optical axis direction from the image side surface of the second spacer element P2 to the object side surface of the third spacer element P3, the distance along the optical axis direction from the image side surface of the third spacer element P3 to the object side surface of the fourth spacer element P4, the central thickness of the third lens E3, and the central thickness of the fourth lens E4, the edge thickness and central thickness of the third lens E3 and the fourth lens E4 are ensured to be relatively uniform, with a good thickness ratio, avoiding the occurrence of two extreme lens shapes where the edge is thick and the middle is very thin and where the edge is thin and the middle is very thick. A better thickness distribution is also beneficial to the lens forming, avoiding forming appearance problems such as weld lines and appearance flow marks, and also avoiding problems such as difficult demolding and difficult control of the surface shape during the lens forming process. By restricting the thickness distribution of the lens through the above conditional constraints to optimize the lens shape, the third lens E3 and the fourth lens E4 have better manufacturability.

[0114] Preferably, the internal focusing lens group satisfies: 0.90 ≤ (EP23 + EP34) / (CT3 + CT4) ≤ 1.54.

[0115] According to some embodiments of the present application, a second spacer element P2 in contact with the image side surface of the second lens E2 is disposed on the image side of the second lens E2, and a third spacer element P3 in contact with the image side surface of the third lens E3 is disposed on the image side of the third lens E3. The internal focusing lens group further satisfies: -11.0 ≤ f3 / EP23 < -3.35; where EP23 is the distance along the optical axis from the image side surface of the second spacer element P2 to the object side surface of the third spacer element P3, and f3 is the effective focal length of the third lens E3.

[0116] In this way, by reasonably restricting the ratio between the effective focal length of the third lens E3 and the distance along the optical axis from the image side surface of the second spacer element P2 to the object side surface of the third spacer element P3, on the one hand, the imaging quality can be guaranteed. When the ratio is too large or too small, the light may be too divergent or too convergent when propagating between the lenses, resulting in problems such as an increase in aberrations such as spherical aberration and coma. The intuitive manifestation is that the imaging becomes blurred, the resolution decreases, and the clarity of the imaging decreases. On the other hand, the overall thickness and surface profile ratio of the third lens E3 can be ensured to be appropriate, making it have better processability.

[0117] Preferably, the internal focusing lens group satisfies: -11.00 ≤ f3 / EP23 ≤ -3.39.

[0118] According to some embodiments of the present application, the internal focusing lens group further satisfies: 1.25 < T23 / T45 < 2.70; and 2.55 ≤ L2 / (T23 + T45) < 5.90; where T23 is the air gap between the second lens E2 and the third lens E3 on the optical axis, T45 is the air gap between the fourth lens E4 and the fifth lens E5 on the optical axis, and L2 is the maximum height of the second lens barrel P02 along the optical axis direction.

[0119] In this way, reasonably restricting the ratio of the air gap between the second lens E2 and the third lens E3 on the optical axis and the sum of the air gaps between the fourth lens E4 and the fifth lens E5 on the optical axis to the maximum height of the second lens barrel P02 in the optical axis direction is beneficial to balancing the optical performance, mechanical structure, and thermal stability of the second lens group. In terms of optical performance, an appropriate air gap can control the propagation and convergence or divergence degree of light. When the total air gap is too large relative to the lens barrel height, it may be difficult to correct aberrations such as chromatic aberration and spherical aberration, affecting the imaging clarity and color reproduction. In terms of mechanical stability, when the total air gap is too large relative to the lens barrel height, the support structure of the lens in the lens barrel becomes complex. It should be noted that while ensuring the lens barrel has sufficient strength, an appropriate space for light propagation also needs to be reserved. If the ratio is unreasonable, it may lead to a bulky or insufficiently strong lens barrel structure. In terms of thermal stability, different ratios of air gap to lens barrel height affect the thermal stability of the system. When the ambient temperature changes, the thermal expansion coefficients of the air gap and the lens barrel are different. If the ratio is unreasonable, temperature changes may cause a large change in the relative position between the lenses, thus affecting the focal length and imaging quality of the optical system.

[0120] Preferably, the internal focusing lens group satisfies: 1.29 ≤ T23 / T45 ≤ 2.66, and 2.55 ≤ L2 / (T23 + T45) ≤ 5.87.

[0121] According to some embodiments of the present application, the internal focusing lens group further satisfies: -2.55 ≤ R10 / R3 < -1.55; and 0.9 < Td2 / L2 ≤ 1.15; where R3 is the curvature radius of the object side of the second lens E2, R10 is the curvature radius of the image side of the fifth lens E5, Td2 is the distance on the optical axis from the object side of the second lens E2 to the image side of the fifth lens E5 in the second lens group, and L2 is the maximum height of the second lens barrel P02 in the optical axis direction.

[0122] In this way, reasonably controlling the ratio range of the curvature radius of the image side of the fifth lens E5 and the curvature radius of the object side of the second lens E2 can effectively control the propagation directions of the incident light and the outgoing light, enabling the imaging change to be more gentle and the imaging transition to be more delicate during the zooming process of the internal focusing lens group, and can also well balance aberrations such as spherical aberration and coma, ensuring imaging clarity; further restricting the ratio of the distance on the optical axis from the object side of the second lens E2 to the image side of the fifth lens E5 to the maximum height of the second lens barrel P02, while ensuring the imaging quality, also controls the spatial proportion of the second lens barrel, making the arrangement of multiple lenses in the second lens group more compact and reducing the spatial occupancy of the second lens barrel in the entire internal focusing lens group.

[0123] Preferably, the internal focusing lens group satisfies: -2.55 ≤ R10 / R3 ≤ -1.59, and 0.94 ≤ Td2 / L2 ≤ 1.15.

[0124] According to some embodiments of the present application, the internal focusing lens group further satisfies: 1.70 < (L1 + L2 + L3) / |Δf| < 2.15; where L1 is the maximum height of the first lens barrel P01 along the optical axis direction, L2 is the maximum height of the second lens barrel P02 along the optical axis direction, L3 is the maximum height of the third lens barrel P03 along the optical axis direction, and Δf is the change difference of the effective focal length of the internal focusing lens group when the second lens barrel P02 moves from the closest to the first lens barrel P01 to the closest to the third lens barrel P03.

[0125] In this way, reasonably restricting the sum of the maximum heights of the first lens barrel P01, the second lens barrel P02, and the third lens barrel P03 and the change difference of the effective focal length of the internal focusing lens group when the second lens barrel P02 moves from the closest to the first lens barrel P01 to the closest to the third lens barrel P03 can well constrain the moving range of the second lens barrel during the zooming process. While pursuing a smaller space occupancy ratio, it not only ensures the feasibility of internal focusing but also leaves enough safety distance between the second lens barrel and the first lens barrel and the third lens barrel, ensuring that the second lens barrel P02 will not collide with the first lens barrel P01 or the second lens barrel P02 when moving back and forth during internal focusing, and avoiding the problem of damage to the internal focusing lens group due to collision. At the same time, it restricts the phenomenon that the effective focal length of the internal focusing lens group changes violently during the internal focusing process, avoiding sudden changes in image quality and unsmooth problems during the zoom shooting process.

[0126] Preferably, the internal focusing lens group satisfies: 1.73 ≤ (L1 + L2 + L3) / |Δf| ≤ 2.11.

[0127] It should be noted that those skilled in the art should understand that without departing from the technical solutions required to be protected by the present application, the number of spacer elements constituting the internal focusing lens group can be changed to obtain the various results and advantages described in this specification, and the present application does not make specific limitations in this regard. For example, according to needs, the internal focusing lens group may also include other numbers of spacer elements different from those described in the above embodiments.

[0128] Refer to the appendix Figure 1Some specific but non-limiting embodiments of the above-described embodiments of the present application will be described in more detail. For ease of description, in the following embodiments, OBJ represents the object plane of the internal focusing lens group, STO represents the surface of the aperture stop, S1 represents the object side surface of the first lens E1, S2 represents the image side surface of the first lens E1, S3 represents the object side surface of the second lens E2, S4 represents the image side surface of the second lens E2, S5 represents the object side surface of the third lens E3, S6 represents the image side surface of the third lens E3, S7 represents the object side surface of the fourth lens E4, S8 represents the image side surface of the fourth lens E4, S9 represents the object side surface of the fifth lens E5E4, S10 represents the image side surface of the fifth lens E5, S11 represents the object side surface of the sixth lens E6, S12 represents the image side surface of the sixth lens E6, S13 represents the object side surface of the seventh lens E7, S14 represents the image side surface of the seventh lens E7, S15 represents the object side surface of the prism E8, S16 represents the image side surface of the prism E8, S17 represents the object side surface of the filter E9, S18 represents the image side surface of the filter E9, and S19 represents the image plane.

[0129] In the following embodiments, the surface profile x of each aspherical lens can be defined by, but not limited to, the following aspherical formula:

[0130] ;

[0131] Furthermore, where x is the sagitta of the distance from the vertex of the aspherical surface at a position with a height of h along the optical axis direction of the aspherical surface; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1 above); k is the conic coefficient; Ai is the correction coefficient of the i-th order of the aspherical surface, i = 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30.

[0132] It should be noted that each of the following embodiments includes multiple working conditions, and the difference between multiple working conditions lies in some structural dimension parameters of the lens barrel and the spacer elements, as shown in Table 11 specifically.

[0133] Embodiment 1

[0134] As Figure 1 、 Figure 2 and Figures 3A to 3CAs shown, in this embodiment, the internal focusing lens group includes a first lens barrel P01, a second lens barrel P02, and a third lens barrel P03 arranged in sequence along the optical axis. The second lens barrel is movably disposed between the first lens barrel and the third lens barrel. The first lens barrel P01 houses a first lens group with a positive optical power, and the first lens group includes a first lens E1. The second lens barrel P02 houses a second lens group with a positive optical power, and the second lens group includes a second lens E2, a third lens E3, a fourth lens E4, and a fifth lens E5. The second lens barrel P02 also includes a second spacer element P2 disposed on the image side of the second lens E2 and in contact with the image side surface of the second lens E2, a third spacer element P3 disposed on the image side of the third lens E3 and in contact with the image side surface of the third lens E3, and a fourth spacer element P4 disposed on the image side of the fourth lens E4 and in contact with the image side surface of the fourth lens E4. The third lens barrel P03 houses a third lens group with a negative optical power, and the third lens group includes a sixth lens E6 and a seventh lens E7. The third lens barrel P03 also includes a sixth spacer element P6 disposed on the image side of the sixth lens E6 and in contact with the image side surface of the sixth lens E6.

[0135] In this embodiment, the first lens group has a positive optical power, the second lens group has a positive optical power, and the third lens group has a negative optical power. The first lens E1 has a positive optical power, the object side surface S1 of the first lens E1 is convex, and the image side surface S2 is concave. The second lens E2 has a positive optical power, the object side surface S3 of the second lens E2 is convex, and the image side surface S4 is concave. The third lens E3 has a negative optical power, the object side surface S5 of the third lens E3 is convex, and the image side surface S6 is concave. The fourth lens E4 has a positive optical power, the object side surface S7 of the fourth lens E4 is convex, and the image side surface S8 is concave. The fifth lens E5 has a positive optical power, the object side surface S9 of the fifth lens E5 is concave, and the image side surface S10 is convex. The sixth lens E6 has a negative optical power, the object side surface S11 of the sixth lens E6 is concave, and the image side surface S12 is convex. The seventh lens E7 has a negative optical power, the object side surface S13 of the seventh lens E7 is convex, and the image side surface S14 is concave.

[0136] It should be noted that, in this embodiment, the first lens E1 is made of glass, and the second lens E2 to the seventh lens E7 are made of plastic, which helps to reduce the weight of the entire internal focusing lens group.

[0137] In addition, Table 4 shows the basic optical parameters of the internal focusing lens group under three working conditions in Embodiment 1. Among them, the units of the radius of curvature, thickness / distance, and effective radius are all millimeters (mm).

[0138] Table 4: Basic Optical Parameter Table of the Internal Focusing Lens Group in Embodiment 1

[0139]

[0140] It should be noted that the materials in Table 4 include the refractive index and Abbe number. For example, the materials of S1 in Table 1, 1.498 and 70.42, represent that the refractive index of the first lens E1 is 1.498 and the Abbe number is 70.42 in sequence.

[0141] The following Table 5 gives the high-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, A30 for each aspheric surface S1 to S14 in Example 1.

[0142] Table 5: Aspheric Coefficient Table of the Inner Focus Lens Group in Example 1

[0143]

[0144]

[0145] As Figures 4A to 4C and Figures 5A to 5C shown, Figure 4A shows the schematic diagram of the axial chromatic aberration curve of the inner focus lens group under three working conditions in Example 1 when the object distance is infinity; Figure 4B shows the schematic diagram of the astigmatism curve of the inner focus lens group under three working conditions in Example 1 when the object distance is infinity; Figure 4C shows the schematic diagram of the distortion curve of the inner focus lens group under three working conditions in Example 1 when the object distance is infinity; Figure 5A shows the schematic diagram of the axial chromatic aberration curve of the inner focus lens group under three working conditions in Example 1 when the object distance is 66.6675 mm; Figure 5B shows the schematic diagram of the astigmatism curve of the inner focus lens group under three working conditions in Example 1 when the object distance is 66.6675 mm; Figure 5C shows the schematic diagram of the distortion curve of the inner focus lens group under three working conditions in Example 1 when the object distance is 66.6675 mm. According to Figures 4A to 4C and Figures 5A to 5C the test results of the inner focus lens group shown, the inner focus lens group under various working conditions in Example 1 has good imaging performance.

[0146] Example 2

[0147] As Figure 1 , Figure 2 and Figures 6A to 6CAs shown, in this embodiment, the internal focusing lens group includes a first lens barrel P01, a second lens barrel P02, and a third lens barrel P03 arranged in sequence along the optical axis. The second lens barrel P02 is movably disposed between the first lens barrel P01 and the third lens barrel P03. The first lens barrel P01 houses a first lens group with positive optical power, and the first lens group includes a first lens E1. The second lens barrel P02 houses a second lens group with positive optical power, and the second lens group includes a second lens E2, a third lens E3, a fourth lens E4, and a fifth lens E5. The second lens barrel also includes a second spacer element P2 disposed on the image side of the second lens E2 and in contact with the image side surface of the second lens E2, a third spacer element P3 disposed on the image side of the third lens E3 and in contact with the image side surface of the third lens E3, and a fourth spacer element P4 disposed on the image side of the fourth lens E4 and in contact with the image side surface of the fourth lens E4. The third lens barrel P03 houses a third lens group with negative optical power, and the third lens group includes a sixth lens E6 and a seventh lens E7. The third lens barrel also includes a sixth spacer element P6 disposed on the image side of the sixth lens E6 and in contact with the image side surface of the sixth lens E6.

[0148] In this embodiment, the first lens group has positive optical power, the second lens group has positive optical power, and the third lens group has negative optical power. The first lens E1 has positive optical power, the object side surface S1 of the first lens E1 is convex, and the image side surface S2 is concave. The second lens E2 has positive optical power, the object side surface S3 of the second lens E2 is convex, and the image side surface S4 is concave. The third lens E3 has negative optical power, the object side surface S5 of the third lens E3 is convex, and the image side surface S6 is concave. The fourth lens E4 has positive optical power, the object side surface S7 of the fourth lens E4 is convex, and the image side surface S8 is concave. The fifth lens E5 has positive optical power, the object side surface S9 of the fifth lens E5 is concave, and the image side surface S10 is convex. The sixth lens E6 has negative optical power, the object side surface S11 of the sixth lens E6 is concave, and the image side surface S12 is convex. The seventh lens E7 has negative optical power, the object side surface S13 of the seventh lens E7 is convex, and the image side surface S14 is concave.

[0149] It should be noted that, in this embodiment, the first lens E1 is a glass component, and the second lens E2 to the seventh lens E7 are plastic components, which is beneficial to reducing the weight of the entire internal focusing lens group.

[0150] In addition, Table 6 shows the basic optical parameters of the internal focusing lens group under three working conditions in the second embodiment, where the units of the radius of curvature, thickness / distance, and effective radius are all millimeters (mm).

[0151] Table 6: Basic Optical Parameter Table of the Internal Focusing Lens Group in the Second Embodiment

[0152]

[0153] It should be noted that the materials in Table 6 include the refractive index and Abbe number. For example, for Material 1.498 and 81.56 of S1 in Table 6, they respectively represent that the refractive index of the first lens E1 is 1.498 and the Abbe number is 81.56.

[0154] The following Table 7 gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, A30 for each aspherical surface S1 to S14 in Example 2.

[0155] Table 7: Aspherical Coefficient Table of the Inner Focus Lens Group in Example 2

[0156]

[0157]

[0158] As Figures 7A to 7C and Figures 7A to 7C shown, Figure 7A it shows the schematic diagram of the axial chromatic aberration curve of the inner focus lens group under three working conditions in Example 2 when the object distance is infinity; Figure 7B it shows the schematic diagram of the astigmatism curve of the inner focus lens group under three working conditions in Example 2 when the object distance is infinity; Figure 7C it shows the schematic diagram of the distortion curve of the inner focus lens group under three working conditions in Example 2 when the object distance is infinity; Figure 8A it shows the schematic diagram of the axial chromatic aberration curve of the inner focus lens group under three working conditions in Example 2 when the object distance is 52.6455 mm; Figure 8B it shows the schematic diagram of the astigmatism curve of the inner focus lens group under three working conditions in Example 2 when the object distance is 52.6455 mm; Figure 8C it shows the schematic diagram of the distortion curve of the inner focus lens group under three working conditions in Example 2 when the object distance is 52.6455 mm. According to Figures 7A to 7C and Figures 8A to 8C the test results of the inner focus lens group shown, the inner focus lens group under various working conditions in Example 2 has good imaging performance.

[0159] Example 3

[0160] As Figure 1 , Figure 2 and Figures 6A to 6CAs shown, in this embodiment, the internal focusing lens group includes a first lens barrel P01, a second lens barrel P02, and a third lens barrel P03 arranged in sequence along the optical axis. The second lens barrel P02 is movably disposed between the first lens barrel P01 and the third lens barrel P03. The first lens barrel P01 houses a first lens group with positive optical power, and the first lens group includes a first lens E1. The second lens barrel P02 houses a second lens group with positive optical power, and the second lens group includes a second lens E2, a third lens E3, a fourth lens E4, and a fifth lens E5. The second lens barrel P02 further includes a second spacer element P2 disposed on the image side of the second lens E2 and in contact with the image side surface of the second lens E2, a third spacer element P3 disposed on the image side of the third lens E3 and in contact with the image side surface of the third lens E3, and a fourth spacer element P4 disposed on the image side of the fourth lens E4 and in contact with the image side surface of the fourth lens E4. The third lens barrel P03 houses a third lens group with negative optical power, and the third lens group includes a sixth lens E6 and a seventh lens E7. The third lens barrel P03 further includes a sixth spacer element P6 disposed on the image side of the sixth lens E6 and in contact with the image side surface of the sixth lens E6.

[0161] In this embodiment, the first lens group has positive optical power, the second lens group has positive optical power, and the third lens group has negative optical power. The first lens E1 has positive optical power, the object side surface S1 of the first lens E1 is convex, and the image side surface S2 is concave. The second lens E2 has positive optical power, the object side surface S3 of the second lens E2 is convex, and the image side surface S4 is concave. The third lens E3 has negative optical power, the object side surface S5 of the third lens E3 is concave, and the image side surface S6 is concave. The fourth lens E4 has positive optical power, the object side surface S7 of the fourth lens E4 is convex, and the image side surface S8 is concave. The fifth lens E5 has positive optical power, the object side surface S9 of the fifth lens E5 is convex, and the image side surface S10 is convex. The sixth lens E6 has negative optical power, the object side surface S11 of the sixth lens E6 is concave, and the image side surface S12 is convex. The seventh lens E7 has negative optical power, the object side surface S13 of the seventh lens E7 is convex, and the image side surface S14 is concave.

[0162] It should be noted that, in this embodiment, the first lens E1 is a glass component, and the second lens E2 to the seventh lens E7 are plastic components, which is beneficial to reducing the weight of the entire internal focusing lens group.

[0163] In addition, Table 8 shows the basic optical parameters of the internal focusing lens group under three working conditions in Embodiment 3, where the units of the radius of curvature, thickness / distance, and effective radius are all millimeters (mm).

[0164] Table 8: Basic Optical Parameter Table of the Internal Focusing Lens Group in Embodiment 3

[0165]

[0166] It should be noted that the materials in Table 8 include the refractive index and Abbe number. For example, for Material 1.498 and 70.42 of S1 in Table 8, they respectively represent that the refractive index of the first lens E1 is 1.498 and the Abbe number is 70.42.

[0167] The following Table 9 gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, A30 for each aspheric surface S1 to S14 in Example 3.

[0168] Table 9: Aspheric Coefficient Table of the Inner Focus Lens Group in Example 3

[0169]

[0170]

[0171] As Figures 10A to 10C and Figures 11A to 11C shown, Figure 10A shows the schematic diagram of the axial chromatic aberration curve of the inner focus lens group under three working conditions in Example 3 when the object distance is infinity; Figure 10B shows the schematic diagram of the astigmatism curve of the inner focus lens group under three working conditions in Example 3 when the object distance is infinity; Figure 10C shows the schematic diagram of the distortion curve of the inner focus lens group under three working conditions in Example 3 when the object distance is infinity; Figure 11A shows the schematic diagram of the axial chromatic aberration curve of the inner focus lens group under three working conditions in Example 3 when the object distance is 52.6455 mm; Figure 11B shows the schematic diagram of the astigmatism curve of the inner focus lens group under three working conditions in Example 3 when the object distance is 52.6455 mm; Figure 11C shows the schematic diagram of the distortion curve of the inner focus lens group under three working conditions in Example 3 when the object distance is 52.6455 mm. According to Figures 10A to 10C and Figures 11A to 11C the test results of the inner focus lens group shown, the inner focus lens group under various working conditions in Example 3 has good imaging performance.

[0172] In summary, in Examples 1 to 3, the effective focal lengths f1, f2, f3 of the first lens group, the second lens group, and the third lens group in the inner focus lens group, the effective focal length f of the inner focus lens group when the object distance is infinity and at close range, and the aperture coefficient Fno of the inner focus lens group are as shown in the following Table 10.

[0173] Table 10 System Optical Parameter Table of the Inner Focus Lens Group

[0174]

[0175] In addition, partial structural parameters of the lens barrel and spacer elements of the internal focusing lens group in Embodiments 1 to 3 are shown in Table 11. Refer to Figure 2 , and the specific structural parameters are as follows: d01m (inner diameter of the image-side end face of the first lens barrel P01), D01m (outer diameter of the image-side end face of the first lens barrel P01), d02s (inner diameter of the object-side end face of the second lens barrel P02), D02s (outer diameter of the object-side end face of the second lens barrel P02), D02m (outer diameter of the image-side end face of the second lens barrel P02), DT2s (clear aperture diameter of the object side of the second lens barrel P02), DT2m (clear aperture diameter of the image side of the second lens barrel P02), D03s (outer diameter of the object-side end face of the third lens barrel P03), DT3s (clear aperture diameter of the object side of the third lens barrel P03), DT3m (clear aperture diameter of the image side of the third lens barrel P03), d6s (inner diameter of the object side face of the sixth spacer element P6), EP23 (spacing along the optical axis from the image side face of the second spacer element P2 to the object side face of the third spacer element P3), EP34 (spacing along the optical axis from the image side face of the third spacer element P3 to the object side face of the fourth spacer element P4), L1 (maximum height of the first lens barrel P01 along the optical axis), L2 (maximum height of the second lens barrel P02 along the optical axis), L3 (maximum height of the third lens barrel P03 along the optical axis), ΔEP0 (maximum movable distance of the second lens barrel P02 along the optical axis), ET6 (maximum thickness of the non-transmissive region of the sixth lens E6), ET7 (maximum thickness of the non-transmissive region of the seventh lens E7).

[0176] Table 11 Partial Structural Parameter Table of the Internal Focusing Lens Group

[0177]

[0178] In summary, the internal focusing lens groups in Embodiments 1 to 3 satisfy the relational expressions shown in Table 12, as specifically shown in Table 12.

[0179] Table 12: Table of Relational Expressions Satisfied by the Internal Focusing Lens Group

[0180]

[0181] It is worth mentioning that, according to one aspect of the present application, an embodiment of the present application further provides an imaging module, which may include the above-mentioned internal focusing lens group and a photosensitive element, and the photosensitive element is disposed on the image side of the internal focusing lens group for imaging. It can be understood that the photosensitive element mentioned in the present application can be, but is not limited to, implemented as a Charge Coupled Device (CCD) or a Complementary Metal Oxide Semiconductor (CMOS) element, and the present application will not elaborate on this.

[0182] In addition, according to another aspect of the present application, an embodiment of the present application further provides an electronic device, which may include the above-mentioned imaging module and a processor configured thereto, and the imaging module is communicatively connected to the processor for acquiring image data and inputting the image data into the processor for processing. It can be understood that the electronic device mentioned in the present application can be, but is not limited to, implemented as a device such as a mobile phone equipped with the imaging module, and the present application will not elaborate on this.

[0183] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0184] The above embodiments only represent several implementation manners of the present application, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. Internal focusing lens group, characterized in that: It includes a first lens barrel, a second lens barrel, and a third lens barrel arranged in sequence along the optical axis, wherein the second lens barrel is movably disposed between the first lens barrel and the third lens barrel; The first lens barrel further houses a first lens group with positive optical power, and the first lens group includes a first lens with positive optical power; The second lens barrel further houses a second lens group with positive optical power, and the second lens group includes a second lens with positive optical power, a third lens with negative optical power, a fourth lens with positive optical power, and a fifth lens with positive optical power; The third lens barrel further houses a third lens group with negative optical power, and the third lens group includes a sixth lens with negative optical power and a seventh lens with negative optical power; In the second lens group, at least one spacer element is included between any two lenses, and in the third lens group, a spacer element is included between the sixth lens and the seventh lens; The internal focusing lens group satisfies: 11.90 < F1 / L1 < 15.70; 0.70 < F2 / (DT2s + DT2m) < 1.15; and -6.80 < F3 / |(DT3m - DT3s)| < -3.60; Wherein, F1 is the effective focal length of the first lens group, F2 is the effective focal length of the second lens group, F3 is the effective focal length of the third lens group, L1 is the maximum height of the first lens barrel along the optical axis direction, DT2s is the clear aperture diameter on the object side of the second lens barrel, DT2m is the clear aperture diameter on the image side of the second lens barrel, DT3s is the clear aperture diameter on the object side of the third lens barrel, and DT3m is the clear aperture diameter on the image side of the third lens barrel.

2. The internal focusing lens group according to claim 1, wherein The internal focusing lens group further satisfies: 2.95 < R2 / R3 < 4.40; and 1.0 ≤ (d01m - DT2s) / ΔEP0 ≤ 2.20; Wherein, R2 is the curvature radius of the image side surface of the first lens, R3 is the curvature radius of the object side surface of the second lens, d01m is the inner diameter of the image side end face of the first lens barrel, DT2s is the clear aperture diameter on the object side of the second lens barrel, and ΔEP0 is the maximum movable distance of the second lens barrel along the optical axis direction.

3. The internal focusing lens group according to claim 1, characterized in that, The internal focusing lens group further satisfies: 0.55 < (D01m - D02s) / (d01m - d02s) < 1.35; Wherein, D01m is the outer diameter of the image side end face of the first lens barrel, D02s is the outer diameter of the object side end face of the second lens barrel, d01m is the inner diameter of the image side end face of the first lens barrel, and d02s is the inner diameter of the object side end face of the second lens barrel.

4. The internal focusing lens group according to claim 1, characterized in that, The internal focusing lens group further satisfies: 0.90 < D02m / D03s < 1.15; and 1.10 < (DT2m + DT3s) / EPD ≤ 2.25; Wherein, D02m is the outer diameter of the image side end face of the second lens barrel, D03s is the outer diameter of the object side end face of the third lens barrel, DT2m is the clear aperture diameter on the image side of the second lens barrel, DT3s is the clear aperture diameter on the object side of the third lens barrel, and EPD is the entrance pupil diameter of the internal focusing lens group when the object distance is infinity.

5. The internal focusing lens group according to claim 1, wherein The internal focusing lens group further satisfies: -32.75 < (f6 + f7) / L3 < -11.90; Wherein, f6 is the effective focal length of the sixth lens, f7 is the effective focal length of the seventh lens, and L3 is the maximum height of the third lens barrel along the optical axis direction.

6. The internal focusing lens group according to claim 1, wherein The internal focusing lens group further satisfies: -4.30 < f7 / DT3m ≤ -1.30; Wherein, f7 is the effective focal length of the seventh lens, and DT3m is the clear aperture diameter on the image side of the third lens barrel.

7. The internal focusing lens group according to claim 1, wherein, The internal focusing lens group further satisfies: 0.30 < T67 / (ET6 + ET7) < 0.55; Wherein, T67 is the air gap between the sixth lens and the seventh lens on the optical axis, ET6 is the maximum thickness of the non-transmissive area of the sixth lens, and ET7 is the maximum thickness of the non-transmissive area of the seventh lens.

8. The internal focusing lens group according to claim 1, wherein, The internal focusing lens group further satisfies: 1.80 < L3 / (CT6 + CT7) < 2.15; Wherein, L3 is the maximum height of the third lens barrel along the optical axis direction, CT6 is the center thickness of the sixth lens, and CT7 is the center thickness of the seventh lens.

9. The internal focusing lens group according to claim 1, wherein, A sixth spacer element in contact with the image side surface of the sixth lens is disposed on the image side of the sixth lens. The internal focusing lens group further satisfies: 1.30 < F3 / R11 < 2.15; and 0.95 < DT3s / d6s < 1.65; Wherein, F3 is the effective focal length of the third lens group, R11 is the curvature radius of the object side surface of the sixth lens, DT3s is the clear aperture diameter on the object side of the third lens barrel, and d6s is the inner diameter of the object side surface of the sixth spacer element.

10. The internal focusing lens group according to claim 1, wherein A second spacer element in contact with the image side surface of the second lens is disposed on the image side of the second lens. A third spacer element in contact with the image side surface of the third lens is disposed on the image side of the third lens. A fourth spacer element in contact with the image side surface of the fourth lens is disposed on the image side of the fourth lens. The internal focusing lens group further satisfies: 0.90 ≤ (EP23 + EP34) / (CT3 + CT4) < 1.55; Wherein, EP23 is the distance along the optical axis from the image side surface of the second spacer element to the object side surface of the third spacer element, EP34 is the distance along the optical axis from the image side surface of the third spacer element to the object side surface of the fourth spacer element, CT3 is the center thickness of the third lens, and CT4 is the center thickness of the fourth lens.

11. The internal focusing lens group according to claim 1, characterized in that, A second spacer element in contact with the image side surface of the second lens is disposed on the image side of the second lens. A third spacer element in contact with the image side surface of the third lens is disposed on the image side of the third lens. The internal focusing lens group further satisfies: -11.0 ≤ f3 / EP23 < -3.35; Wherein, EP23 is the distance along the optical axis from the image side surface of the second spacer element to the object side surface of the third spacer element, and f3 is the effective focal length of the third lens.

12. The internal focusing lens group according to any one of claims 1 to 11, characterized in that, The internal focusing lens group further satisfies: 1.25 < T23 / T45 < 2.70; and 2.55 ≤ L2 / (T23 + T45) < 5.90; Wherein, T23 is the air gap between the second lens and the third lens on the optical axis, T45 is the air gap between the fourth lens and the fifth lens on the optical axis, and L2 is the maximum height of the second lens barrel along the optical axis direction.

13. The internal focusing lens group according to any one of claims 1 to 11, wherein The internal focusing lens group further satisfies: -2.55 ≤ R10 / R3 < -1.55; and 0.9 < Td2 / L2 ≤ 1.15; Wherein, R3 is the curvature radius of the object side surface of the second lens, R10 is the curvature radius of the image side surface of the fifth lens, Td2 is the distance on the optical axis from the object side surface of the second lens in the second lens group to the image side surface of the fifth lens, and L2 is the maximum height of the second lens barrel along the optical axis direction.

14. The internal focusing lens group according to any one of claims 1 to 11, wherein The internal focusing lens group further satisfies: 1.70 < (L1 + L2 + L3) / |Δf| < 2.15; Wherein, L1 is the maximum height of the first lens barrel along the optical axis direction, L2 is the maximum height of the second lens barrel along the optical axis direction, L3 is the maximum height of the third lens barrel along the optical axis direction, and △f is the change difference of the effective focal length of the internal focusing lens group when the second lens barrel moves from the position closest to the first lens barrel to the position closest to the third lens barrel.

Images