Zoom lens and imaging device

Abstract

To provide a zoom lens capable of achieving high-definition and high-speed zoom operation while having a small size, a high variable power ratio and a large aperture ratio.SOLUTION: A zoom lens (L0a) consists of a first lens group (L1) having positive refractive power, a second lens group (L2) having negative refractive power and a subsequent group (LR) including at least four lens groups moving when zooming in this order from the object side to the image side. An interval between the lens groups adjacent to each other is changed when zooming. The first lens group avoids movement to an image surface when zooming and focusing. A distance Lw on the optical axis from a surface peak point position of the surface on the most object side in the zoom lens at a wide angle end to an image surface, a focal distance fw of the zoom lens at the wide angle end, a distance T2 on the optical axis from a surface peak point position of the surface on the most object side in the second lens group to a surface peak point position of the surface on the most image side and a focal distance f2 of the second lens group satisfy a predetermined conditional expression.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a zoom lens and an imaging apparatus. [Background Art]

[0002] As a zoom lens used in an imaging apparatus, there is a demand for a zoom lens that is small and lightweight, and has high optical performance that satisfactorily corrects various aberrations such as chromatic aberration. There is also a demand for a zoom lens that has a short focal length at the wide-angle end, a large zoom ratio, a small F-number, a large aperture ratio, and is easy to manufacture. Further, there is a demand for a zoom lens capable of high-speed zoom operation. Patent Document 1 discloses a zoom lens including, in order from the object side to the image side, a lens unit having positive refractive power, a lens unit having negative refractive power, and a rear group having a plurality of lens units. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2020-134807 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] With the zoom lens disclosed in Patent Document 1, it is difficult to achieve both high image quality and high-speed zoom operation while being compact, having a high zoom ratio and a large aperture ratio.

[0005] Accordingly, an object of the present invention is to provide a zoom lens that achieves both high image quality and high-speed zoom operation while being compact, having a high zoom ratio and a large aperture ratio. [Means for Solving the Problem]

[0006] A zoom lens according to one aspect of the present invention includes, in order from the object side to the image side PlacedA zoom lens comprising a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent group having at least four lens groups that move during zooming, wherein the spacing between adjacent lens groups changes during zooming, the first lens group does not move relative to the image plane during zooming and focusing, the first lens group has at least three lenses with positive refractive power, and the distance along the optical axis from the vertex position of the lens surface closest to the object in the zoom lens at the wide-angle end to the image plane is Lw, the focal length of the zoom lens at the wide-angle end is fw, and from the vertex position of the lens surface closest to the object in the second lens group In the second lens group T2 is the distance along the optical axis from the vertex of the lens surface closest to the image, f2 is the focal length of the second lens group, and skw is the distance along the optical axis from the vertex of the lens surface closest to the image to the image plane in the zoom lens at the wide-angle end. Let f1 be the focal length of the first lens group, T1 be the distance along the optical axis from the vertex position of the surface closest to the object in the first lens group to the vertex position of the surface closest to the image in the first lens group, MR be the maximum absolute value of the amount of movement of each lens group constituting the subsequent group when zooming from the wide-angle end to the telephoto end, and ft be the focal length of the zoom lens at the telephoto end. When, 7.5 <Lw / fw<15.0 0.20 <T2 / |f2|<0.85 0.20 <skw / fw<1.50 0.10 <T1 / f1<0.70 0.10 <MR / ft<0.5 The following condition is satisfied.

[0007] Other objects and features of the present invention are described in the following examples. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a zoom lens that is compact, has a high magnification ratio and a large aperture ratio, while achieving high image quality and fast zoom operation. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view of the zoom lens in Example 1. [Figure 2] This is an aberration diagram of the zoom lens in Example 1. [Figure 3] This is a cross-sectional view of the zoom lens in Example 2. [Figure 4] It is an aberration diagram of the zoom lens in Example 2. [Figure 5] It is a cross-sectional view of the zoom lens in Example 3. [Figure 6] It is an aberration diagram of the zoom lens in Example 3. [Figure 7] It is a cross-sectional view of the zoom lens in Example 4. [Figure 8] It is an aberration diagram of the zoom lens in Example 4. [Figure 9] It is a cross-sectional view of the zoom lens in Example 5. [Figure 10] It is an aberration diagram of the zoom lens in Example 5. [Figure 11] It is a schematic diagram of an image pickup apparatus provided with the zoom lens according to each example. DESCRIPTION OF EMBODIMENTS

[0010] Hereinafter, examples of the present invention will be described in detail with reference to the drawings.

[0011] To achieve high-speed zoom operation, it is preferable to reduce the mass and movement amount of a lens unit that moves during zooming. To suppress the mass of the moving lens unit, it is preferable to reduce the number of lenses constituting the moving lens unit. However, reducing the number of lenses in the moving lens unit makes aberration correction difficult, and thus makes it difficult to achieve high image quality. Further, reducing the movement amount of the moving lens unit makes it difficult to achieve high zoom ratio. In addition, when the refractive power of the lens units constituting the zoom lens is increased to reduce the movement amount of the moving lens unit, aberration correction becomes difficult, which makes high image quality difficult to achieve. Therefore, to obtain a zoom lens that is compact, has a high zoom ratio and a large aperture ratio, and achieves both high image quality and high-speed zoom operation, it is important to appropriately set the arrangement of the lenses and lens units constituting the zoom lens.

[0012] The zoom lens of each embodiment consists of, in order from the object side to the image side, a first lens group L1 having a positive refractive power, a second lens group L2 having a negative refractive power, and a subsequent group LR having at least four lens groups that move during zooming. During zooming, the distance between adjacent lens groups (the air distance in the direction along the optical axis OA) changes. In addition, during zooming and focusing, the first lens group L1 does not move relative to the image plane. A zoom lens with a high zoom ratio and a large aperture ratio tends to have a large front lens diameter and a large mass. Therefore, fixing the first lens group L1 relative to the image plane can facilitate high-speed zoom operation. In addition, when a plurality of lens groups move while changing their intervals, various aberrations during zooming, particularly zoom fluctuations of chromatic magnification difference and astigmatism, can be corrected favorably.

[0013] In the zoom lens of each embodiment, the following conditional expressions (1) and (2) are satisfied.

[0014] 7.50 < Lw / fw < 15.00 ···(1) 0.20 < T2 / |f2| < 0.85 ···(2) Here, Lw is the distance on the optical axis from the vertex position of the most object-side surface to the image plane of the zoom lens at the wide-angle end, and fw is the focal length of the entire zoom lens (the entire system) at the wide-angle end. T2 is the distance on the optical axis from the vertex position of the most object-side surface to the vertex position of the most image-side surface in the second lens group L2, and f2 is the focal length of the second lens group L2.

[0015] Conditional expression (1) defines the relationship between the distance on the optical axis from the vertex position of the most object-side surface to the image plane at the wide-angle end and the focal length of the entire zoom lens (the entire system) at the wide-angle end. If the upper limit of conditional expression (1) is exceeded, the lens diameter and mass of the second lens group L2 will increase, making it difficult to achieve high-speed zoom operation, which is not preferable. On the other hand, if the lower limit of conditional expression (1) is exceeded, the refractive power of each lens group becomes excessively strong, making it difficult to correct various aberrations, particularly spherical aberration and astigmatism, which is not preferable.

[0016] Conditional equation (2) defines the relationship between the thickness of the second lens group L2 along the optical axis and the focal length of the second lens group L2. If the thickness of the second lens group L2 exceeds the upper limit of conditional equation (2), the mass of the second lens group L2 increases, making it difficult to achieve high-speed zoom operation, which is undesirable. On the other hand, if the thickness of the second lens group L2 decreases beyond the lower limit of conditional equation (2), it becomes difficult to suppress aberrations occurring in the second lens group L2, and the correction of various aberrations, especially spherical aberration and astigmatism, becomes larger during zoom, which is also undesirable.

[0017] In each embodiment, preferably, at least one numerical range of conditional expressions (1) and (2) is set as shown in the following conditional expressions (1a) and (2a), respectively.

[0018] 8.02 <Lw / fw<12.16 ···(1a) 0.38 <T2 / f2<0.84 ···(2a) In each embodiment, more preferably, at least one numerical range of conditional expressions (1) and (2) is set as shown in the following conditional expressions (1b) and (2b). 8.28 <Lw / fw<10.74 ···(1b) 0.47 <T2 / f2<0.83 ···(2b) Next, we will describe the preferred configuration of the zoom lens in each embodiment.

[0019] In each embodiment, preferably, the first lens group L1 has a lens (first lens) L11 with negative refractive power closest to the object. This makes it easier to suppress the front element diameter and facilitates miniaturization.

[0020] In each embodiment, the subsequent lens group LR has, in order from the object side to the image side, a third lens group L3 with positive refractive power and a fourth lens group L4 with positive refractive power. By changing the spacing between the positive refractive power lens groups, zoom fluctuations due to astigmatism are suppressed, and optical image quality is improved. Furthermore, by arranging multiple positive refractive power lens groups, the ray height of light rays incident on the lens groups positioned closer to the image than the fourth lens group L4 can be lowered, making it easier to reduce the diameter and size of the lens groups positioned closer to the image than the fourth lens group L4.

[0021] In each embodiment, preferably, when focusing from infinity to near distance (during focusing), a lens or lens group positioned closer to the image than the fourth lens group L4 moves. By fixing the larger diameter lens group positioned closer to the object during focusing, and configuring the system to use a smaller diameter lens or lens group positioned closer to the image than the fourth lens group L4 for focusing, the weight of the focusing lens group can be easily reduced, and the drive mechanism can be simplified. This facilitates miniaturization.

[0022] In each embodiment, the first lens group L1 has at least three lenses with positive refractive power. This makes it easy to achieve both high magnification and high performance.

[0023] In each embodiment, the second lens group L2 includes, in order from the object side to the image side, a lens with negative refractive power (second lens), a lens with negative refractive power, a lens with negative refractive power, and a lens with positive refractive power. By placing the negative lens on the object side in the second lens group L2, it becomes easy to achieve both wide-angle and suppression of the front lens diameter.

[0024] In each embodiment, preferably, at least one of the following conditional expressions (3) to (15) is satisfied.

[0025] 0.20 <skw / fw<1.50 ···(3) 1.50 < |f1 / f2| < 7.70 ... (4) 0.60 <M2 / fw<3.20 ···(5) -2.00<β2t<-0.30 ···(6) 0.10 <T1 / f1<0.70 ···(7) 0.40<|f11 / f1|<2.20 ···(8) -2.00<(r112+r111) / (r112-r111)<-0.20 ···(9) 0.10 <MR / ft<0.50 ···(10) 2.00 <f3 / fw<11.00 ···(11) 0.70 <f4 / fw<6.70 ···(12) 0.40<(D34w-D34t) / fw<1.80 ···(13) 0.60<|f21 / f2|<3.00 ···(14) -2.60<(r212+r211) / (r212-r211)<-0.50 ···(15) Here, skw is the distance along the optical axis from the vertex of the image-side surface of the zoom lens at the wide-angle end to the image plane (back focus). f1 is the focal length of the first lens group L1. f2 is the focal length of the second lens group L2. M2 is the absolute value of the amount of movement of the second lens group L2 when zooming from the wide-angle end to the telephoto end. β2T is the lateral magnification of the second lens group L2 at the telephoto end. T1 is the distance along the optical axis from the vertex of the object-side surface of the first lens group L1 to the vertex of the image-side surface. f11 is the focal length of the lens (first lens) L11. r111 is the radius of curvature of the object-side surface of lens L11, and r112 is the radius of curvature of the image-side surface of lens L11. MR is the maximum value of the absolute amount of movement of the lens groups constituting the subsequent group LR when zooming from the wide-angle end to the telephoto end. ft is the focal length of the zoom lens (entire system) at the telephoto end. f3 is the focal length of the third lens group L3, and f4 is the focal length of the fourth lens group L4. D34w is the distance along the optical axis from the vertex of the image-side surface of the third lens group L3 to the vertex of the object-side surface of the fourth lens group L4 at the wide-angle end. D34t is the distance along the optical axis from the vertex of the image-side surface of the third lens group L3 to the vertex of the object-side surface of the fourth lens group L4 at the telephoto end. f21 is the focal length of lens (second lens) L21. r211 is the radius of curvature of the object-side surface of lens L21, and r212 is the radius of curvature of the image-side surface of lens L21.

[0026] Conditional equation (3) defines the relationship between the back focus at the wide-angle end and the focal length of the zoom lens (entire system). If the back focus becomes longer than the upper limit of conditional equation (3), the front element diameter increases, resulting in a larger size, which is undesirable. On the other hand, if the back focus becomes shorter than the lower limit of conditional equation (3), the lens diameter of the lenses constituting the subsequent LR group increases, and the mass of the lenses constituting the subsequent LR group increases, making it difficult to achieve high-speed zoom operation, which is also undesirable.

[0027] Conditional equation (4) defines the relationship between the focal length of the first lens group L1 and the focal length of the second lens group L2. If the focal length of the first lens group L1 exceeds the upper limit of conditional equation (4), it is undesirable because it results in a larger size. On the other hand, if the focal length of the first lens group L1 exceeds the lower limit of conditional equation (4), it is undesirable because it becomes difficult to correct various aberrations, especially spherical aberration and chromatic aberration at the telephoto end.

[0028] Conditional equation (5) defines the relationship between the amount of movement of the second lens group L2 and the focal length at the wide-angle end. If the amount of movement of the second lens group L2 exceeds the upper limit of conditional equation (5), it becomes difficult to achieve high-speed zoom operation, which is undesirable. On the other hand, if the amount of movement of the second lens group L2 exceeds the lower limit of conditional equation (5), it becomes difficult to achieve high magnification, which is also undesirable.

[0029] Conditional equation (6) specifies the lateral magnification of the second lens group L2 at the telephoto end. If the absolute value of the lateral magnification of the second lens group L2 at the telephoto end becomes small beyond the upper limit of conditional equation (6), it becomes difficult to achieve high magnification, which is undesirable. On the other hand, if the absolute value of the lateral magnification of the second lens group L2 becomes large beyond the lower limit of conditional equation (6), the magnification contribution of the second lens group L2 becomes large. As a result, it becomes difficult to correct aberrations occurring in the second lens group L2, and it becomes particularly difficult to suppress zoom variations in spherical aberration and astigmatism, which is undesirable.

[0030] Conditional equation (7) defines the relationship between the thickness of the first lens group L1 and the focal length. If the thickness of the first lens group L1 exceeds the upper limit of conditional equation (7), the front element diameter increases and the lens becomes larger, which is undesirable. On the other hand, if the thickness of the first lens group L1 exceeds the lower limit of conditional equation (7), it becomes difficult to correct aberrations occurring in the first lens group L1, and it becomes particularly difficult to correct spherical aberration and chromatic aberration at the telephoto end, which is also undesirable.

[0031] Conditional equation (8) defines the relationship between the focal length of lens L11 and the focal length of the first lens group L1. If the absolute value of the focal length of lens L11 exceeds the upper limit of conditional equation (8), the front element diameter increases, which is undesirable. On the other hand, if the absolute value of the focal length of lens L11 exceeds the lower limit of conditional equation (8), it becomes difficult to correct aberrations occurring in lens L11, and it becomes particularly difficult to correct distortion and coma aberration at the wide-angle end, which is undesirable.

[0032] Conditional equation (9) defines the relationship between the radius of curvature of the object-side surface and the radius of curvature of the image-side surface in lens L11. Exceeding the upper limit of conditional equation (9) is undesirable because it makes it difficult to correct distortion aberration. On the other hand, exceeding the lower limit of conditional equation (9) is also undesirable because it increases the front element diameter and makes the lens larger.

[0033] Conditional equation (10) defines the relationship between the maximum absolute value of the amount of movement of the lenses constituting the subsequent LR group and the focal length of the focusing lens (entire system) at the telephoto end. If the maximum absolute value of the amount of movement of the lenses constituting the subsequent LR group becomes larger than the upper limit of conditional equation (10), it becomes difficult to achieve high-speed zoom operation, which is undesirable. On the other hand, if the maximum absolute value of the amount of movement of the lenses constituting the subsequent LR group becomes smaller than the lower limit of conditional equation (10), it becomes difficult to achieve high magnification, which is also undesirable.

[0034] Conditional equation (11) defines the relationship between the focal length of the third lens group L3 and the focal length of the zoom lens (entire system) at the wide-angle end. If the focal length of the third lens group L3 exceeds the upper limit of conditional equation (11), the diameter of the lens group positioned closer to the image than the third lens group L3 increases, resulting in a larger overall size, which is undesirable. On the other hand, if the focal length of the third lens group L3 exceeds the lower limit of conditional equation (11), correcting the aberrations occurring in the third lens group L3 becomes difficult, making it difficult to correct various aberrations, especially spherical aberration and axial chromatic aberration at the telephoto end, which is also undesirable.

[0035] Conditional equation (12) defines the relationship between the focal length of the fourth lens group L4 and the focal length of the zoom lens (entire system) at the wide-angle end. If the focal length of the fourth lens group L4 exceeds the upper limit of conditional equation (12), the diameter of the lens group positioned closer to the image than the fourth lens group L4 increases, resulting in a larger overall size, which is undesirable. On the other hand, if the focal length of the fourth lens group L4 decreases beyond the lower limit of conditional equation (12), it becomes difficult to correct the aberrations occurring in the fourth lens group L4, making it difficult to correct various aberrations, especially spherical aberration and astigmatism at the telephoto end, and coma aberration at the wide-angle end, which is undesirable.

[0036] Conditional equation (13) defines the relationship between the distance (air gap) between the third lens group L3 and the fourth lens group L4 at the wide-angle and telephoto ends, and the focal length of the zoom lens (entire system) at the wide-angle end. If the change in the distance becomes large beyond the upper limit of conditional equation (13), the amount of movement of the fourth lens group L4 becomes large, making it difficult to achieve high-speed zoom operation, which is undesirable. On the other hand, if the change in the distance becomes small beyond the lower limit of conditional equation (13), the zoom variation of astigmatism becomes large, making it difficult to achieve high image quality, which is also undesirable.

[0037] Conditional equation (14) defines the relationship between the focal length of lens L21 and the focal length of the second lens group L2. If the absolute value of the focal length of lens L21 exceeds the upper limit of conditional equation (14), the front element diameter increases, resulting in a larger size, which is undesirable. On the other hand, if the absolute value of the focal length of lens L21 exceeds the lower limit of conditional equation (14), correcting various aberrations, especially distortion and chromatic aberration at the wide-angle end, becomes difficult, which is also undesirable.

[0038] Conditional equation (15) defines the relationship between the radius of curvature of the object-side surface and the radius of curvature of the image-side surface in lens L21. Exceeding the upper limit of conditional equation (15) is undesirable because it makes it difficult to correct distortion aberration. On the other hand, exceeding the lower limit of conditional equation (15) is undesirable because it increases the diameter of the front element and makes the lens larger.

[0039] In each embodiment, more preferably, at least one numerical range of conditional expressions (3) to (15) is set as shown in the following conditional expressions (1a) to (15a).

[0040] 0.33 <skw / fw<1.13 ···(3a) 2.25 < |f1 / f2| < 5.79 ···(4a) 0.90 <M2 / fw<2.41 ···(5a) -1.05 < β2t < -0.60 ···(6a) 0.17 <T1 / f1<0.53 ···(7a) 0.60 < |f11 / f1| < 1.65 ···(8a) -1.50<(r112+r111) / (r112-r111)<-0.21 ···(9a) 0.17 <MR / ft<0.38 ···(10a) 2.97 <f3 / fw<8.26 ···(11a) 1.04 <f4 / fw<5.04 ···(12a) 0.58<(D34w-D34t) / fw<1.35 (13a) 0.94<|f21 / f2|<2.24 (14a) -1.49<(r212+r211) / (r212-r211)<-0.94 ···(15a) In each embodiment, more preferably, at least one of the numerical ranges in conditional expressions (3) to (15) is set as follows:

[0041] 0.40 <skw / fw<0.95 ···(3b) 2.62 < |f1 / f2| < 4.83 ···(4b) 1.05 <M2 / fw<2.01 ···(5b) -1.00 < β2t < -0.68 ···(6b) 0.21 <T1 / f1<0.44 ···(7b) 0.70 < |f11 / f1| < 1.37 ···(8b) -0.99<(r112+r111) / (r112-r111)<-0.22 ···(9b) 0.21 <MR / ft<0.32 ···(10b) 3.46 <f3 / fw<6.89 ···(11b) 1.21 <f4 / fw<4.21 ···(12b) 0.67<(D34w-D34t) / fw<1.10 (13b) 1.11<|f21 / f2|<1.86 (14b) -1.33<(r212+r211) / (r212-r211)<-0.95 (15b) The configuration of the zoom lens in each embodiment will be described in detail below. [Examples]

[0042] First, the zoom lens L0a in Example 1 will be described with reference to Figures 1 and 2(a) and (b). Figure 1 is a cross-sectional view of the zoom lens L0a at the wide-angle end when focused at infinity. In Figure 1, the left side is the object side (front) and the right side is the image side (rear). The aperture diaphragm SP determines (limits) the light beam at the open F number (Fno). When focusing from an object at infinity to the closest object, the focus lens group moves as shown by the arrow focus in Figure 1. When the zoom lens L0a is used as the imaging optical system of a digital still camera or digital video camera, the image plane IP becomes the imaging surface of an image sensor (photoelectric conversion element) such as a CCD sensor or CMOS sensor. When the zoom lens L0a is used as the imaging optical system of a silver halide film camera, the image plane IP corresponds to the film plane. The above explanation also applies to other cross-sectional views.

[0043] Figure 2(a) shows the aberration diagram of zoom lens L0a at the wide-angle end when focused at infinity, and Figure 2(b) shows the aberration diagram of zoom lens L0a at the telephoto end when focused at infinity. In the spherical aberration diagram, Fno is the F number and indicates the amount of spherical aberration for the d line (wavelength 587.56 nm) and the g line (wavelength 435.8 nm). In the astigmatism diagram, ΔS indicates the amount of astigmatism at the sagittal image plane, and ΔM indicates the amount of astigmatism at the meridional image plane. In the distortion diagram, the amount of distortion for the d line is shown. In the chromatic aberration diagram, the amount of chromatic aberration for the g line is shown. ω is the half-angle of view (°) of the image calculated paraxially. The above explanation also applies to the other aberration diagrams.

[0044] The zoom lens L0a in this embodiment is composed of a first lens group L1, a second lens group L2, and a successor group LR, in order from the object side to the image side. The successor group LR is composed of a third lens group L3 with positive refractive power, a fourth lens group L4 with positive refractive power, a fifth lens group L5 with negative refractive power, a sixth lens group L6 with positive refractive power, and a seventh lens group L7 with negative refractive power, in order from the object side to the image side. The first lens group L1 is fixed to the image plane IP during magnification (it does not move during zooming). Each lens group moves along a different trajectory (the trajectory shown by the arrows in Figure 1) while changing the distance between them during magnification. The third lens group L3 has an aperture diaphragm SP. When focusing from infinity to near distance, the fifth lens group L5 moves towards the image side, and the sixth lens group L6 also moves towards the image side. [Examples]

[0045] Next, the zoom lens L0b in Example 2 will be described with reference to Figures 3 and 4(a) and 4(b). Figure 3 is a cross-sectional view of the zoom lens L0b at the wide-angle end when focused at infinity. Figure 4(a) is an aberration diagram of the zoom lens L0b at the wide-angle end when focused at infinity, and Figure 4(b) is an aberration diagram of the zoom lens L0b at the telephoto end when focused at infinity.

[0046] The zoom lens L0b in this embodiment is composed of a first lens group L1, a second lens group L2, and a successor group LR, in order from the object side to the image side. The successor group LR is composed of a third lens group L3 with positive refractive power, a fourth lens group L4 with positive refractive power, a fifth lens group L5 with negative refractive power, a sixth lens group L6 with negative refractive power, a seventh lens group L7 with positive refractive power, and an eighth lens group L8 with positive refractive power, in order from the object side to the image side. The first lens group L1 is fixed to the image plane IP during magnification (it does not move during zooming). Each lens group moves along a different trajectory (the trajectory shown by the arrows in Figure 3) while changing the distance between them during magnification. The third lens group L3 has an aperture diaphragm SP. When focusing from infinity to near distance, the fifth lens group L5 moves towards the object side, and the sixth lens group L6 moves towards the image side. [Examples]

[0047] Next, the zoom lens L0c in Example 3 will be described with reference to Figures 5 and 6(a) and (b). Figure 5 is a cross-sectional view of the zoom lens L0c at the wide-angle end when focused at infinity. Figure 6(a) is an aberration diagram of the zoom lens L0c at the wide-angle end when focused at infinity, and Figure 6(b) is an aberration diagram of the zoom lens L0c at the telephoto end when focused at infinity.

[0048] The zoom lens L0c of this embodiment is composed of a first lens group L1, a second lens group L2, and a successor group LR, in order from the object side to the image side. The successor group LR is composed of a third lens group L3 with positive refractive power, a fourth lens group L4 with positive refractive power, a fifth lens group L5 with positive refractive power, a sixth lens group L6 with negative refractive power, and a seventh lens group L7 with negative refractive power, in order from the object side to the image side. The first lens group L1 is fixed to the image plane IP during magnification (it does not move during zooming). Each lens group moves along a different trajectory (the trajectory shown by the arrows in Figure 5) while changing the distance between them during magnification. The third lens group L3 has an aperture diaphragm SP. When focusing from infinity to near distance, the fifth lens group L5 moves towards the object side, and the sixth lens group L6 also moves towards the object side. [Examples]

[0049] Next, the zoom lens L0d in Example 4 will be described with reference to Figures 7 and 8(a) and 8(b). Figure 7 is a cross-sectional view of the zoom lens L0d at the wide-angle end when focused at infinity. Figure 8(a) is an aberration diagram of the zoom lens L0d at the wide-angle end when focused at infinity, and Figure 8(b) is an aberration diagram of the zoom lens L0d at the telephoto end when focused at infinity.

[0050] The zoom lens L0d in this embodiment is composed of a first lens group L1, a second lens group L2, and a successor group LR, in order from the object side to the image side. The successor group LR is composed of a third lens group L3 with positive refractive power, a fourth lens group L4 with positive refractive power, a fifth lens group L5 with negative refractive power, a sixth lens group L6 with positive refractive power, and a seventh lens group L7 with negative refractive power, in order from the object side to the image side. The first lens group L1 is fixed to the image plane IP during magnification (it does not move during zooming). Each lens group moves along a different trajectory (the trajectory shown by the arrows in Figure 7) while changing the distance between them during magnification. The third lens group L3 has an aperture diaphragm SP. When focusing from infinity to near distance, the fifth lens group L5 moves towards the image side, and the sixth lens group L6 also moves towards the image side. [Examples]

[0051] Next, the zoom lens L0e in Example 5 will be described with reference to Figures 9 and 10(a) and (b). Figure 9 is a cross-sectional view of the zoom lens L0e at the wide-angle end when focused at infinity. Figure 10(a) is an aberration diagram of the zoom lens L0e at the wide-angle end when focused at infinity, and Figure 10(b) is an aberration diagram of the zoom lens L0e at the telephoto end when focused at infinity.

[0052] The zoom lens L0e in this embodiment is composed of, in order from the object side to the image side, a first lens group L1, a second lens group L2, and a successor group LR. The successor group LR is composed of, in order from the object side to the image side, a third lens group L3 with positive refractive power, a fourth lens group L4 with positive refractive power, a fifth lens group L5 with negative refractive power, and a sixth lens group L6 with positive refractive power. The first lens group L1, the third lens group L3, and the sixth lens group L6 are fixed relative to the image plane IP during magnification (they do not move during zooming). Each lens group moves along a different trajectory (the trajectory shown by the arrows in Figure 9) while changing the distance between them during magnification. The third lens group L3 has an aperture diaphragm SP. When focusing from infinity to near distance, the fifth lens group L5 moves towards the image side.

[0053] In the zoom lenses of each embodiment, all surfaces with refractive power are composed of refractive surfaces. Compared to cases where diffractive optical elements or reflective surfaces are used, optical performance equivalent to or better than that of cases where diffractive optical elements or reflective surfaces are used can be easily obtained with lower manufacturing difficulty.

[0054] In the zoom lens of each embodiment, image shake correction may be performed by moving a part of the zoom lens in a direction that includes a component perpendicular to the optical axis OA. By making the part moved during image shake correction a lens group located on the image side with a relatively small diameter, the actuator for driving can be made smaller, and the lens device including the zoom lens can be miniaturized. For example, image shake correction may be performed by moving all or part of the third lens group L3 in a direction that includes a component perpendicular to the optical axis OA.

[0055] The numerical values ​​corresponding to each of Examples 1 to 5 are shown below.

[0056] In the surface data for each numerical example, r represents the radius of curvature of each optical surface, and d (mm) represents the on-axial spacing (distance along the optical axis) between the m-th surface and the (m+1)-th surface. Here, m is the surface number counted from the light incident side. Also, nd represents the refractive index of each optical component with respect to the d-line, and νd represents the Abbe number of the optical component with respect to the d-line. In this specification, the Abbe number νd of a certain material with respect to the d-line is given by Nd, NF, and NC, respectively, when the refractive indices of the Fraunhofer lines at d-line (587.6 nm), F-line (486.1 nm), C-line (656.3 nm), and g-line (wavelength 435.8 nm) are Nd, NF, and NC. νd = (Nd-1) / (NF-NC) It is represented as follows.

[0057] In each numerical example, d, focal length (mm), F-number, and half-angle of view (°) are all values ​​when the zoom lens of each example is in focus on an object at infinity. Back focus BF is the air-converted value of the distance from the final lens surface (the surface closest to the image) of the zoom lens to the image plane. The total length of the zoom lens is the distance from the first lens surface to the final lens surface plus the back focus.

[0058] [Numerical Example 1] Unit: mm Surface data Face number rd nd νd 1 -207.425 1.70 1.83481 42.7 2 95.825 4.21 3 393.916 2.00 1.72047 34.7 4 105.832 8.46 1.59522 67.7 5 -203.044 0.15 6 124.562 5.68 1.72916 54.7 7 -487.042 0.15 8 78.249 6.74 1.72916 54.7 9 -444.181 (variable) 10 8601.520 1.20 1.80400 46.5 11 28.416 5.54 12 -738.337 1.00 1.49700 81.5 13 63.533 3.06 14 -115.610 1.00 1.49700 81.5 15 35.816 3.84 1.90366 31.3 16 169.674 (variable) 17 (aperture) ∞ 1.00 18 67.476 3.22 1.84666 23.8 19 -1153.421 0.60 20 55.893 1.20 2.00100 29.1 21 34.548 6.77 1.51742 52.4 22 -82.213 3.04 23* -43.690 0.05 1.59022 30.1 24 -46.141 1.20 1.72916 54.7 25 4358.607 (variable) 26 172.999 7.58 1.49700 81.5 27 -27.250 1.19 1.83400 37.2 28 231.097 0.15 29 48.103 7.69 1.48749 70.2 30 -81.882 0.15 31 42.435 9.37 1.43875 94.7 32 -82.878 0.15 33* 78.425 2.40 1.85400 40.4 34 37.200 9.41 1.61800 63.4 35 -70.814 (variable) 36 161.341 1.20 1.77250 49.6 37 28.989 (Variable) 38* 48.348 3.91 1.58313 59.4 39 95.150 (Variable) 40 224.141 7.07 1.80810 22.8 41 -35.894 1.50 1.49700 81.5 42 361.709 7.03 43 -34.951 1.50 1.92286 20.9 44 -125.011 (variable) Image plane ∞ Aspherical data Page 23 K = 0.00000e+00 A 4= 3.79285e-06 A 6=-1.22591e-10 A 8= 5.46760e-13 Page 33 K = 0.00000e+00 A 4=-7.34648e-06 A 6=-3.52185e-09 A 8= 3.20919e-13 Page 38 K = 0.00000e+00 A 4= 1.44392e-06 A 6= 4.53989e-09 A 8=-1.13675e-13 A10 = -4.07591e-15 Various data Zoom ratio 4.12 Wide-angle, Medium, Telephoto Focal length 24.72 50.19 101.86 F-number 2.90 2.90 2.90 Half-angle 41.19 23.32 11.99 Lens length 212.40 212.40 212.40 BF 11.98 26.45 21.74 d 9 0.80 16.04 34.02 d16 41.01 21.11 2.98 d25 19.68 9.87 0.79 d35 2.80 1.19 1.18 d37 7.64 6.92 6.23 d39 6.39 8.72 23.36 d44 11.98 26.45 21.74 Zoom lens group data Group starting plane focal length 1 1 83.05 2 10 -27.72 3 17 106.51 4 26 34.04 5 36 -45.93 6 38 163.53 7 40 -161.55 [Numerical Example 2] Unit: mm Surface data Face number rd nd νd 1 -208.117 2.00 2.00100 29.1 2 125.012 1.73 3 201.666 6.72 1.59522 67.7 4 -188.208 0.13 5 120.220 5.48 1.83481 42.7 6 -1189.696 0.15 7 69.551 5.71 1.83481 42.7 8 436.182 (variable) 9 214.024 1.20 1.90043 37.4 10 26.866 6.02 11 -282.246 1.20 1.59522 67.7 12 48.782 4.24 13 -64.715 1.20 1.49700 81.5 14 39.804 4.37 1.85025 30.1 15 -376.767 (variable) 16 (aperture) ∞ 1.00 17 76.845 3.20 1.84666 23.8 18 -332.575 0.50 19 56.009 0.90 2.00100 29.1 20 34.921 6.63 1.51742 52.4 21 -82.324 3.17 22* -40.899 0.05 1.59022 30.1 23 -43.512 1.20 1.72916 54.7 24 -438.046 (variable) 25 107.656 9.03 1.49700 81.5 26 -23.891 1.19 1.95375 32.3 27 -1561.807 0.15 28 57.153 9.76 1.43875 94.7 29 -41.965 0.15 30* 84.677 7.95 1.80400 46.5 31* -52.890 (variable) 32 185.555 2.58 1.89286 20.4 33 -333.256 1.20 1.61800 63.4 34 46.156 (Variable) 35 77.039 1.20 2.00100 29.1 36 30.744 (Variable) 37* 37.408 4.07 1.58313 59.4 38* 53.618 0.13 39 47.870 1.39 2.00069 25.5 40 25.731 9.31 1.61800 63.4 41 176.934 (variable) 42 54.577 7.41 1.84666 23.8 43 -80.249 1.50 1.48749 70.2 44 42.160 7.49 45 -49.214 1.50 1.92286 20.9 46 -97.002 (variable) Image plane ∞ Aspherical data Page 22 K = 0.00000e+00 A 4= 4.39269e-06 A 6= 1.10097e-09 A 8= 6.31456e-13 Page 30 K = 0.00000e+00 A 4=-5.80494e-06 A 6=-2.08319e-09 A 8=-2.99833e-12 Page 31 K = 0.00000e+00 A 4= 1.13763e-06 A 6=-3.28114e-09 Page 37 K = 0.00000e+00 A 4= 2.38842e-06 A 6=-2.70374e-09 A 8=-1.84658e-11 A10 = 2.89507e-14 Page 38 K = 0.00000e+00 A 4= 6.75134e-08 A 6=-3.59874e-09 A 8=-2.39776e-11 A10 = 3.36099e-14 Various data Zoom ratio 4.13 Wide-angle, Medium, Telephoto Focal length 24.73 50.23 102.12 F-number 2.90 2.90 2.90 Half-angle 41.19 23.30 11.96 Lens length 211.51 211.51 211.51 BF 11.80 26.61 26.29 d 8 0.80 15.28 30.36 d15 39.32 19.23 2.99 d24 19.57 9.93 0.78 d31 4.00 1.22 2.88 d34 4.47 7.50 6.25 d36 7.75 7.49 7.08 d41 1.00 1.44 12.05 d46 11.80 26.61 26.29 Zoom lens group data Group starting plane focal length 1 1 79.54 2 9 -24.54 3 16 97.60 4 25 34.35 5 32 -131.33 6 35 -51.78 7 37 123.01 8 42 770.84 [Numerical Example 3] Unit: mm Surface data Face number rd nd νd 1 -181.919 1.70 1.90043 37.4 2 111.072 3.71 3 364.499 5.59 1.59522 67.7 4 -177.536 0.14 5 154.743 4.78 1.75500 52.3 6 -870.763 0.15 7 84.502 7.28 1.75500 52.3 8 -367.735 (variable) 9 -2513.905 1.30 1.72916 54.7 10 27.941 6.20 11 -452.183 1.20 1.59522 67.7 12 68.302 2.86 13 -147.630 1.20 1.49700 81.5 14 37.027 4.02 1.90043 37.4 15 197.666 (variable) 16 (aperture) ∞ 1.00 17 70.360 3.19 1.84666 23.8 18 -1084.899 0.60 19 62.970 1.20 2.05090 26.9 20 36.953 6.53 1.56732 42.8 21 -87.660 3.17 22* -43.587 0.05 1.59022 30.1 23 -46.864 1.40 1.77250 49.6 24 3434.700 (Variable) 25 68.421 7.75 1.49700 81.5 26 -34.337 1.19 1.83400 37.2 27 94.819 0.15 28 45.071 5.49 1.49700 81.5 29 1775.190 0.15 30 38.956 9.94 1.49700 81.5 31 -94.914 2.39 32* 78.620 2.50 1.85400 40.4 33 * 49.978 (variable) 34* 37.006 8.81 1.58313 59.4 35* -88.576 (variable) 36 123.459 1.20 2.00100 29.1 37 40.182 (Variable) 38 73.297 8.72 1.84666 23.8 39 -41.340 1.40 1.60311 60.6 40 49.128 8.20 41 -33.125 1.40 1.92286 20.9 42 -59.144 (variable) Image plane ∞ Aspherical data Page 22 K = 0.00000e+00 A 4= 3.89058e-06 A 6= 6.70856e-10 A 8=-1.58188e-12 Page 32 K = 0.00000e+00 A 4= 4.26123e-06 A 6=-9.76054e-09 A 8=-4.97564e-12 Page 33 K = 0.00000e+00 A 4= 1.08509e-05 A 6=-5.04108e-09 A 8=-2.02185e-12 A10 = 5.27144e-15 Page 34 K = 0.00000e+00 A 4=-1.80819e-06 A 6=-1.87700e-09 A 8= 3.87938e-13 Page 35 K = 0.00000e+00 A 4= 4.45032e-06 A 6=-4.27576e-09 A 8= 3.65399e-12 Various data Zoom ratio 4.12 Wide-angle, Medium, Telephoto Focal length 24.72 50.22 101.96 F-number 2.90 2.90 2.90 Half-angle 41.19 23.31 11.98 Lens length 211.02 211.02 211.02 BF 11.85 26.68 22.74 d 8 0.80 16.99 35.41 d15 44.29 21.72 3.00 d24 20.71 11.73 0.78 d33 4.43 7.45 8.57 d35 2.11 1.69 3.52 d37 10.27 8.21 20.44 d42 11.85 26.68 22.74 Zoom lens group data Group starting plane focal length 1 1 94.31 2 9 -29.02 3 16 127.17 4 25 83.32 5 34 45.95 6 36 -59.94 7 38 -203.31 [Numerical Example 4] Unit: mm Surface data Face number rd nd νd 1 -266.746 1.60 1.90043 37.4 2 98.340 2.81 3 192.058 6.58 1.53775 74.7 4 -241.263 0.15 5 119.575 5.31 1.72916 54.7 6 -1682.093 0.15 7 76.157 6.72 1.72916 54.7 8 -880.300 (variable) 9 915.083 1.20 1.88300 40.8 10 29.841 5.73 11 -218.330 1.00 1.59522 67.7 12 63.389 3.69 13 -74.215 1.10 1.49700 81.5 14 41.057 4.98 1.77047 29.7 15 -204.631 (variable) 16 (aperture) ∞ 1.00 17 78.578 3.15 1.84666 23.8 18 -594.031 0.60 19 59.615 1.20 2.00100 29.1 20 36.734 7.47 1.51742 52.4 21 -83.322 3.11 22* -44.261 0.05 1.59022 30.1 23 -47.091 1.20 1.77250 49.6 24 -640.625 (variable) 25 255.634 8.10 1.49700 81.5 26 -27.474 1.30 1.90043 37.4 27 -222.061 0.15 28 41.537 8.18 1.49700 81.5 29 -105.932 2.30 30 63.231 6.49 1.49700 81.5 31 -97.379 0.15 32* 85.354 2.40 1.85400 40.4 33 34.925 8.89 1.60311 60.6 34 -78.017 (variable) 35 157.315 1.20 1.72916 54.7 36 28.256 (Variable) 37* 47.159 4.54 1.58313 59.4 38 160.935 (variable) 39 210.344 5.69 1.80518 25.4 40 -46.896 1.50 1.48749 70.2 41 59.110 9.57 42 -33.883 1.20 2.00069 25.5 43 -66.006 (variable) Image plane ∞ Aspherical data Page 22 K = 0.00000e+00 A 4= 3.72124e-06 A 6= 3.39835e-10 A 8= 6.96887e-13 Page 32 K = 0.00000e+00 A 4=-7.10364e-06 A 6=-3.27713e-09 A 8=-1.38031e-12 Page 37 K = 0.00000e+00 A 4= 1.68172e-06 A 6= 3.21879e-09 A 8= 5.86323e-12 A10 = -1.26470e-14 Various data Zoom ratio 4.12 Wide-angle, Medium, Telephoto Focal length 24.78 50.31 102.06 F-number 2.90 2.90 2.90 Half-angle 41.12 23.27 11.97 Lens length 211.98 211.98 211.98 BF 11.63 25.76 19.01 d 8 0.80 16.58 34.70 d15 42.76 21.90 2.98 d24 19.63 10.61 0.79 d34 2.50 1.78 1.10 d36 8.07 7.90 7.19 d38 6.12 7.00 25.75 d43 11.63 25.76 19.01 Zoom lens group data Group starting plane focal length 1 1 90.57 2 9 -27.00 3 16 119.23 4 25 35.02 5 35 -47.42 6 37 112.74 7 39 -90.78 [Numerical Example 5] Unit: mm Surface data Face number rd nd νd 1 -8741.959 1.40 2.00100 29.1 2 77.425 2.07 3 132.828 5.55 1.48749 70.2 4 -278.544 0.15 5 81.695 4.36 1.72916 54.7 6 698.842 0.15 7 52.270 5.59 1.72916 54.7 8 496.392 (variable) 9 231.928 0.90 1.80400 46.6 10 19.761 4.24 11 -78.088 0.80 1.59282 68.6 12 53.314 3.20 13 -27.410 0.80 1.49700 81.5 14 57.444 2.55 15 69.921 2.53 1.85025 30.1 16 -72.259 (variable) 17 (aperture) ∞ 1.00 18 104.572 2.48 1.84666 23.8 19 -84.594 0.60 20 55.992 1.00 1.90043 37.4 21 31.491 4.61 1.49700 81.5 22 -70.253 3.02 23* -28.727 0.05 1.59022 30.1 24 -29.778 0.80 1.80518 25.4 25 -100.170 (variable) 26 18.384 6.47 1.49700 81.5 27 -138.084 2.89 28* 35.239 2.00 1.85400 40.4 29 12.971 8.26 1.53775 74.7 30 -46.153 (variable) 31 168.469 0.80 1.69680 55.5 32 16.983 3.73 33* 31.760 0.05 1.59022 30.1 34 29.014 3.06 1.59551 39.2 35 123.379 (variable) 36 -344.548 7.53 1.90366 31.3 37 -18.233 1.20 1.84666 23.8 38 -96.734 (variable) Image plane ∞ Aspherical data Page 23 K = 0.00000e+00 A 4= 8.09779e-06 A 6=-1.18636e-08 A 8= 6.70206e-11 Page 28 K = 0.00000e+00 A 4=-2.83986e-05 A 6=-4.36898e-08 A 8=-1.47706e-10 Page 33 K = 0.00000e+00 A 4= 7.39408e-06 A 6= 5.64098e-08 A 8= 1.50619e-10 A10 = -4.36865e-13 Various data Zoom ratio 3.77 Wide-angle, Medium, Telephoto Focal length 15.45 30.00 58.20 F-number 2.90 2.90 2.90 Half-angle 41.48 24.48 13.21 Lens length 143.99 143.99 143.99 BF 11.90 11.90 11.90 d 8 0.80 12.86 25.80 d16 27.48 15.42 2.48 d25 14.75 4.45 0.78 d30 2.62 1.54 5.64 d35 2.60 13.97 13.54 d38 11.90 11.90 11.90 Zoom lens group data Group starting plane focal length 1 1 70.23 2 9 -18.13 3 17 85.18 4 26 26.26 5 31 -47.32 6 36 106.66 Table 1 shows the values ​​corresponding to conditional expressions (1) to (15) in numerical examples 1 to 5.

[0059] [Table 1]

[0060] (Imaging device) Next, with reference to Figure 11, an imaging device (digital still camera) 10 equipped with a zoom lens of each embodiment will be described. Figure 11 is a schematic diagram of the imaging device 10. The imaging device 10 comprises a camera body 13, a lens device 11 including a zoom lens (L0a to L0e) of any of Embodiments 1 to 5, and an image sensor (light-receiving element) 12 that photoelectrically converts the image formed by the zoom lens. The image sensor 12 is a photoelectric conversion element such as a CCD sensor or a CMOS sensor. The lens device 11 and the camera body 13 may be configured as a single unit or may be configured to be detachable. The imaging device 10 is small, lightweight, and can achieve high optical performance. Note that the zoom lenses of each embodiment are not limited to the imaging device 10 shown in Figure 11, but can also be applied to various imaging devices such as broadcast cameras, silver halide film cameras, and surveillance cameras.

[0061] According to each embodiment, it is possible to provide a zoom lens and imaging device that are compact, have a high magnification ratio and a large aperture ratio, while achieving high image quality and high-speed zoom operation.

[0062] Each embodiment disclosed includes the following configuration:

[0063] (Composition 1) A zoom lens comprising, in order from the object side to the image side, a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent group having at least four lens groups that move during zooming, During zooming, the spacing between adjacent lens groups changes. During zooming and focusing, the first lens group does not move relative to the image plane. When Lw is the distance along the optical axis from the vertex of the surface closest to the object in the zoom lens at the wide-angle end to the image plane, fw is the focal length of the zoom lens at the wide-angle end, T2 is the distance along the optical axis from the vertex of the surface closest to the object in the second lens group to the vertex of the surface closest to the image, and f2 is the focal length of the second lens group, 7.50 <Lw / fw<15.00 0.20 <T2 / |f2|<0.85 A zoom lens characterized by satisfying the following conditional equation. (Configuration 2) When skw is the distance along the optical axis from the vertex of the image-side surface of the zoom lens at the wide-angle end to the image plane, 0.20 <skw / fw<1.50 A zoom lens according to configuration 1, characterized in that it satisfies the following condition. (Composition 3) When the focal length of the first lens group is f1 and the focal length of the second lens group is f2, 1.50 < |f1 / f2| < 7.70 A zoom lens according to configuration 1 or 2, characterized by satisfying the following conditional expression. (Composition 4) When M2 is the absolute value of the amount of movement of the second lens group when zooming from the wide-angle end to the telephoto end, 0.60 <M2 / fw<3.20 A zoom lens according to any one of configurations 1 to 3, characterized by satisfying the following conditional expression. (Composition 5) When the lateral magnification of the second lens group at the telephoto end is β2T, -2.00 < β2t < -0.30 A zoom lens according to any one of configurations 1 to 4, characterized by satisfying the following conditional expression. (Composition 6) When the focal length of the first lens group is f1, and the distance along the optical axis from the vertex position of the surface closest to the object in the first lens group to the vertex position of the surface closest to the image is T1, 0.10 <T1 / f1<0.70 A zoom lens according to any one of configurations 1 to 5, characterized in that it satisfies the following conditional expression. (Composition 7) The zoom lens according to any one of configurations 1 to 6, characterized in that the first lens group has a first lens with negative refractive power closest to the object. (Composition 8) When the focal length of the first lens group is f1 and the focal length of the first lens is f11, 0.40 < |f11 / f1| < 2.20 The zoom lens according to configuration 7, characterized in that it satisfies the following conditional expression. (Composition 9) When the radius of curvature of the object-side surface of the first lens is r111 and the radius of curvature of the image-side surface of the first lens is r112, A zoom lens according to configuration 7 or 8, characterized in that it satisfies the condition -2.00 < (r112 + r111) / (r112 - r111) < -0.20. (Composition 10) When zooming from the wide-angle end to the telephoto end, the maximum value of the absolute amount of movement of the lens group constituting the subsequent group is MR, and the focal length of the zoom lens at the telephoto end is ft, 0.10 <MR / ft<0.50 A zoom lens according to any one of configurations 1 to 9, characterized by satisfying the following conditional expression. (Composition 11) The zoom lens according to any one of configurations 1 to 10, characterized in that the subsequent group has, in order from the object side to the image side, a third lens group with positive refractive power and a fourth lens group with positive refractive power. (Composition 12) When the focal length of the third lens group is f3, 2.00 <f3 / fw<11.00 A zoom lens according to configuration 11, characterized by satisfying the following conditional expression. (Composition 13) When the focal length of the fourth lens group is f4, 0.70 <f4 / fw<6.70 A zoom lens according to configuration 11 or 12, characterized by satisfying the following conditional expression. (Composition 14) When D34w is the distance along the optical axis from the vertex position of the image-side face in the third lens group to the vertex position of the object-side face in the fourth lens group at the wide-angle end, and D34t is the distance along the optical axis from the vertex position of the image-side face in the third lens group to the vertex position of the object-side face in the fourth lens group at the telephoto end, 0.40 < (D34w - D34t) / fw < 1.80 A zoom lens according to any one of configurations 11 to 13, characterized by satisfying the following conditional expression. (Composition 15) A zoom lens according to any one of configurations 11 to 14, characterized in that, when focusing, only the lens group positioned on the image side of the fourth lens group moves. (Composition 16) The zoom lens according to any one of configurations 1 to 15, characterized in that the first lens group has at least three lenses with positive refractive power. (Composition 17) The zoom lens according to any one of configurations 1 to 16, characterized in that the second lens group has a second lens with negative refractive power closest to the object. (Composition 18) When the focal length of the second lens is f21, 0.60 < |f21 / f2| < 3.00 A zoom lens according to configuration 17, characterized by satisfying the following conditional expression. (Composition 19) When the radius of curvature of the object-side surface in the second lens is r211 and the radius of curvature of the image-side surface in the second lens is r212, -2.60<(r212+r211) / (r212-r211)<-0.50 A zoom lens according to configuration 17 or 18, characterized by satisfying the following conditional expression. (Composition 20) The zoom lens according to any one of configurations 1 to 19, characterized in that the second lens group comprises, in order from the object side to the image side, a lens with negative refractive power, a lens with negative refractive power, a lens with negative refractive power, and a lens with positive refractive power. (Composition 21) A zoom lens as described in any of configurations 1 to 20, An imaging device characterized by having an image sensor that receives light from an image formed by the zoom lens.

[0064] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its essence. [Explanation of symbols]

[0065] L0a~L0e Zoom Lens L1 First lens group L2 Second lens group LR successor group

Claims

1. A zoom lens comprising a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent group having at least four lens groups that move during zooming, arranged in order from the object side to the image side, During zooming, the spacing between adjacent lens groups changes. During zooming and focusing, the first lens group does not move relative to the image plane. The first lens group has at least three lenses with positive refractive power, When Lw is the distance along the optical axis from the vertex position of the lens surface closest to the object in the zoom lens at the wide-angle end to the image plane, fw is the focal length of the zoom lens at the wide-angle end, T2 is the distance along the optical axis from the vertex position of the lens surface closest to the object in the second lens group to the vertex position of the lens surface closest to the image in the second lens group, f2 is the focal length of the second lens group, skw is the distance along the optical axis from the vertex position of the lens surface closest to the image in the zoom lens at the wide-angle end to the image plane, f1 is the focal length of the first lens group, T1 is the distance along the optical axis from the vertex position of the surface closest to the object in the first lens group to the vertex position of the surface closest to the image in the first lens group, MR is the maximum value of the absolute amount of movement of each lens group constituting the subsequent group when zooming from the wide-angle end to the telephoto end, and ft is the focal length of the zoom lens at the telephoto end, 7.50<Lw / fw<15.00 0.20<T2 / |f2|<0.85 0.20<skw / fw<1.50 0.10<T1 / f1<0.70 0.10<MR / ft<0.5 A zoom lens characterized by satisfying the following conditional equation.

2. 1.50<|f1 / f2|<7.70 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

3. When M2 is the absolute value of the amount of movement of the second lens group when zooming from the wide-angle end to the telephoto end, 0.60<M2 / fw<3.20 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

4. When the lateral magnification of the second lens group at the telephoto end is β2T, -2.00<β2t<-0.30 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

5. The zoom lens according to claim 1, characterized in that the first lens group has a first lens with negative refractive power closest to the object.

6. When the focal length of the first lens is f11, 0.40<|f11 / f1|<2.20 The zoom lens according to claim 5, characterized in that it satisfies the following condition.

7. The zoom lens according to claim 1, characterized in that the second lens group has a second lens with negative refractive power closest to the object.

8. When the focal length of the second lens is f21, 0.60<|f21 / f2|<3.00 The zoom lens according to claim 7, characterized in that it satisfies the following condition.

9. When the radius of curvature of the object-side surface of the second lens is r211 and the radius of curvature of the image-side surface of the second lens is r212, -2.60<(r212+r211) / (r212-r211)<-0.50 The zoom lens according to claim 7, characterized in that it satisfies the following condition.

10. The zoom lens according to claim 1, characterized in that the second lens group comprises, in order from the object side to the image side, a lens with negative refractive power, a lens with negative refractive power, a lens with negative refractive power, and a lens with positive refractive power.

11. A zoom lens comprising a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent group having at least four lens groups that move during zooming, arranged in order from the object side to the image side, During zooming, the spacing between adjacent lens groups changes. During zooming and focusing, the first lens group does not move relative to the image plane. The first lens group comprises a first lens with negative refractive power positioned closest to the object, and at least three lenses with positive refractive power. When Lw is the distance along the optical axis from the vertex position of the lens surface closest to the object in the zoom lens at the wide-angle end to the image plane, fw is the focal length of the zoom lens at the wide-angle end, T2 is the distance along the optical axis from the vertex position of the lens surface closest to the object in the second lens group to the vertex position of the lens surface closest to the image in the second lens group, f2 is the focal length of the second lens group, skw is the distance along the optical axis from the vertex position of the lens surface closest to the image in the zoom lens at the wide-angle end to the image plane, r111 is the radius of curvature of the object-side surface in the first lens, and r112 is the radius of curvature of the image-side surface in the first lens, 7.50<Lw / fw<15.00 0.20<T2 / |f2|<0.85 0.20<skw / fw<1.50 -2.00<(r112+r111) / (r112-r111)<-0.20 A zoom lens characterized by satisfying the following conditional equation.

12. A zoom lens comprising a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent group having at least four lens groups that move during zooming, arranged in order from the object side to the image side, During zooming, the spacing between adjacent lens groups changes. During zooming and focusing, the first lens group does not move relative to the image plane. The first lens group has at least three lenses with positive refractive power, The subsequent group comprises a third lens group with positive refractive power and a fourth lens group with positive refractive power, arranged in order from the object side to the image side. When Lw is the distance along the optical axis from the vertex of the lens surface closest to the object in the zoom lens at the wide-angle end to the image plane, fw is the focal length of the zoom lens at the wide-angle end, T2 is the distance along the optical axis from the vertex of the lens surface closest to the object in the second lens group to the vertex of the lens surface closest to the image in the second lens group, f2 is the focal length of the second lens group, and skw is the distance along the optical axis from the vertex of the lens surface closest to the image in the zoom lens at the wide-angle end to the image plane, 7.50<Lw / fw<15.00 0.20<T2 / |f2|<0.85 0.20<skw / fw<1.50 A zoom lens characterized by satisfying the following conditional equation.

13. A zoom lens comprising a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent group having at least four lens groups that move during zooming, arranged in order from the object side to the image side, During zooming, the spacing between adjacent lens groups changes. During zooming and focusing, the first lens group does not move relative to the image plane. The first lens group has at least three lenses with positive refractive power, The subsequent group comprises a third lens group with positive refractive power and a fourth lens group with positive refractive power, arranged in order from the object side to the image side. When Lw is the distance along the optical axis from the vertex position of the lens surface closest to the object in the zoom lens at the wide-angle end to the image plane, fw is the focal length of the zoom lens at the wide-angle end, T2 is the distance along the optical axis from the vertex position of the lens surface closest to the object in the second lens group to the vertex position of the lens surface closest to the image in the second lens group, f2 is the focal length of the second lens group, skw is the distance along the optical axis from the vertex position of the lens surface closest to the image in the zoom lens at the wide-angle end to the image plane, and f3 is the focal length of the third lens group, 7.50<Lw / fw<15.00 0.20<T2 / |f2|<0.85 0.20<skw / fw<1.50 2.00<f3 / fw<11.00 A zoom lens characterized by satisfying the following conditional equation.

14. A zoom lens comprising a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent group having at least four lens groups that move during zooming, arranged in order from the object side to the image side, During zooming, the spacing between adjacent lens groups changes. During zooming and focusing, the first lens group does not move relative to the image plane. The first lens group has at least three lenses with positive refractive power, The subsequent group comprises a third lens group with positive refractive power and a fourth lens group with positive refractive power, arranged in order from the object side to the image side. When Lw is the distance along the optical axis from the vertex of the lens surface closest to the object in the zoom lens at the wide-angle end to the image plane, fw is the focal length of the zoom lens at the wide-angle end, T2 is the distance along the optical axis from the vertex of the lens surface closest to the object in the second lens group to the vertex of the lens surface closest to the image in the second lens group, f2 is the focal length of the second lens group, skw is the distance along the optical axis from the vertex of the lens surface closest to the image in the zoom lens at the wide-angle end to the image plane, and f4 is the focal length of the fourth lens group, 7.50<Lw / fw<15.00 0.20<T2 / |f2|<0.85 0.20<skw / fw<1.50 0.70<f4 / fw<6.70 A zoom lens characterized by satisfying the following conditional equation.

15. A zoom lens comprising a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent group having at least four lens groups that move during zooming, arranged in order from the object side to the image side, During zooming, the spacing between adjacent lens groups changes. During zooming and focusing, the first lens group does not move relative to the image plane. The first lens group has at least three lenses with positive refractive power, The subsequent group comprises a third lens group with positive refractive power and a fourth lens group with positive refractive power, arranged in order from the object side to the image side. When Lw is the distance along the optical axis from the vertex position of the lens surface closest to the object in the zoom lens at the wide-angle end to the image plane, fw is the focal length of the zoom lens at the wide-angle end, T2 is the distance along the optical axis from the vertex position of the lens surface closest to the object in the second lens group to the vertex position of the lens surface closest to the image in the second lens group, f2 is the focal length of the second lens group, skw is the distance along the optical axis from the vertex position of the lens surface closest to the image in the zoom lens at the wide-angle end to the image plane, D34w is the distance along the optical axis from the vertex position of the image-side surface in the third lens group at the wide-angle end to the vertex position of the object-side surface in the fourth lens group, and D34t is the distance along the optical axis from the vertex position of the image-side surface in the third lens group at the telephoto end to the vertex position of the object-side surface in the fourth lens group, 7.50<Lw / fw<15.00 0.20<T2 / |f2|<0.85 0.20<skw / fw<1.50 0.40<(D34w-D34t) / fw<1.80 A zoom lens characterized by satisfying the following conditional equation.

16. A zoom lens comprising a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent group having at least four lens groups that move during zooming, arranged in order from the object side to the image side, During zooming, the spacing between adjacent lens groups changes. During zooming and focusing, the first lens group does not move relative to the image plane. The first lens group has at least three lenses with positive refractive power, The subsequent group comprises a third lens group with positive refractive power and a fourth lens group with positive refractive power, arranged in order from the object side to the image side. During focusing, only the lens group positioned closer to the image than the fourth lens group moves. When Lw is the distance along the optical axis from the vertex of the lens surface closest to the object in the zoom lens at the wide-angle end to the image plane, fw is the focal length of the zoom lens at the wide-angle end, T2 is the distance along the optical axis from the vertex of the lens surface closest to the object in the second lens group to the vertex of the lens surface closest to the image in the second lens group, f2 is the focal length of the second lens group, and skw is the distance along the optical axis from the vertex of the lens surface closest to the image in the zoom lens at the wide-angle end to the image plane, 7.50<Lw / fw<15.00 0.20<T2 / |f2|<0.85 0.20<skw / fw<1.50 A zoom lens characterized by satisfying the following conditional equation.

17. A zoom lens according to any one of claims 1 to 16, An imaging device characterized by having an image sensor that receives light from an image formed by the zoom lens.

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