Zoom lens and image capturing device having the same

Abstract

To provide a zoom lens with a fixed total lengthy, which has a high zoom ratio and offers superior optical performance over an entire zoom range.SOLUTION: A zoom lens is provided, comprising a first lens group B1 having positive refractive power, a second lens group B2 having negative refractive power, a third lens group B3 having positive refractive power, a fourth lens group B4 having positive refractive power, and a fifth lens group B5 having negative refractive power arranged in order from the object side to the image side. When zooming from the wide-angle end to the telephoto end, the first and third lens groups are stationary while the second and fourth lens groups move. The third lens group comprises a negative lens and a positive lens. An imaging magnification β3w of the third lens group at the wide-angle end, and imaging magnification β3t of the third lens group at the telephoto end, a focal length f1 of the first lens group, and a focal length f2 of the second lens group satisfy predetermined conditional expressions.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a zoom lens suitable for use in imaging devices such as digital video cameras, digital still cameras, broadcast cameras, cameras for silver halide film, and surveillance cameras. [Background technology]

[0002] Fixed-length zoom lenses, in which the overall length of the lens does not change during zooming, are known. These zoom lenses are well-suited for video recording because their center of gravity changes little during zooming. Furthermore, in recent years, zoom lenses have been required to have a high zoom magnification and excellent optical performance throughout the entire zoom range for video recording.

[0003] Patent Documents 1 and 2 disclose fixed-length zoom lenses that are made up of a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, and a negative fifth lens group. In the zoom lenses described in Patent Documents 1 and 2, the second and fourth lens groups move during zooming. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-327903 [Patent Document 2] International Publication No. 2018 / 074413 Summary of the Invention [Problem to be solved by the invention]

[0005] However, although the zoom lens described in Patent Document 1 has the advantage of having fewer lens groups that move during zooming and focusing, improvements in optical performance are required in recent years as sensors have become higher resolution.

[0006] On the other hand, in the zoom lens described in Patent Document 2, high optical performance is achieved over the entire zoom range by increasing the number of lenses in each lens group, but there is a demand for even higher zoom magnification.

[0007] The present invention provides a fixed length zoom lens having a high zoom magnification and high optical performance throughout the entire zoom range. [Means for solving the problem]

[0008] A zoom lens according to one aspect of the present invention has, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power, wherein the spacing between adjacent lens groups changes during zooming from the wide-angle end to the telephoto end, and wherein, during zooming from the wide-angle end to the telephoto end, the first lens group and the third lens group are fixed, and the second lens group and the fourth lens group move, and the third lens group includes a negative lens and a positive lens, and when the imaging magnification of the third lens group at the wide-angle end is β3w, the imaging magnification of the third lens group at the telephoto end is β3t, the focal length of the first lens group is f1, and the focal length of the second lens group is f2, then: -3.50<β3w / β3t<-0.10 -10.0 <f1 / f2<-4.0 The present invention is characterized in that the following conditional expression is satisfied:

[0009] Other objects and features of the present invention will be described in the following embodiments. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a fixed length zoom lens having a high zoom magnification and high optical performance throughout the entire zoom range. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view of a zoom lens according to a first embodiment. [Figure 2] FIG. 10 is a cross-sectional view of a zoom lens according to a second embodiment. [Figure 3] FIG. 10 is a cross-sectional view of a zoom lens according to a third embodiment. [Figure 4] 1A and 1B are aberration diagrams of the zoom lens of Example 1 at the wide-angle end and the telephoto end, respectively. [Figure 5] 10A and 10B are aberration diagrams of the zoom lens of Example 2 at the wide-angle end and the telephoto end, respectively. [Figure 6] 10A and 10B are aberration diagrams of the zoom lens of Example 3 at the wide-angle end and the telephoto end, respectively. [Figure 7] FIG. 1 is a schematic diagram of an imaging device. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a zoom lens and an image pickup apparatus having the same according to the present invention will be described with reference to the accompanying drawings.

[0013] 1, 2, and 3 are cross-sectional views of the zoom lenses of Examples 1 to 3 when focused at infinity. The zoom lenses of each Example are used in imaging devices such as digital video cameras, digital still cameras, broadcast cameras, cameras for silver halide film, and surveillance cameras.

[0014] In each lens cross-sectional view, the left side is the object side and the right side is the image side. The zoom lens of each embodiment is configured with multiple lens groups. In this specification, a lens group refers to a group of lenses that move or remain stationary as a unit during zooming. That is, in the zoom lens of each embodiment, the spacing between adjacent lens groups changes during zooming from the wide-angle end to the telephoto end. Note that a lens group may be composed of a single lens or multiple lenses. A lens group may also include an aperture stop. The wide-angle end and telephoto end refer to the zoom states (zoom positions) when the lens group is located at either end of the range of mechanical movement of the lens group in the optical axis direction during zooming.

[0015] In each lens cross-sectional view, Bi represents the ith (i is a natural number) lens group included in the zoom lens, counting from the object side. L1i represents the ith (i is a natural number) lens included in the first lens group B1, counting from the object side. L1i represents the ith (i is a natural number) lens included in the first lens group B1, counting from the object side. L2i represents the ith (i is a natural number) lens included in the second lens group B2, counting from the object side. L3i represents the ith (i is a natural number) lens included in the third lens group B3, counting from the object side. L4i represents the ith (i is a natural number) lens included in the fourth lens group B4, counting from the object side. L5i represents the ith (i is a natural number) lens included in the fifth lens group B5, counting from the object side.

[0016] Moreover, the imaging magnification means the lateral magnification.

[0017] Additionally, STO denotes an aperture stop. IMG denotes an image plane, on which the imaging surface of a solid-state imaging element (photoelectric conversion element) such as a CCD sensor or CMOS sensor is placed when the zoom lens of each embodiment is used as the imaging optical system of a digital still camera or digital video camera. When the zoom lens of each embodiment is used as the imaging optical system of a silver halide film camera, a photosensitive surface equivalent to the film surface is placed on the image plane IMG.

[0018] In addition, in each lens cross-sectional view, the movement locus of the lens group that moves during zooming from the wide-angle end to the telephoto end is indicated by arrows. The solid arrows represent the movement of the lens group during zooming from the wide-angle end to the telephoto end when the object distance is infinity, while the dashed arrows represent the movement of the lens group during zooming from the wide-angle end to the telephoto end when the object distance is close. The focusing arrows indicate the movement direction of the lens group that moves during focusing from infinity to close range.

[0019] 4, 5, and 6 are aberration diagrams when the zoom lenses of Examples 1 to 3 are focused at infinity. In each aberration diagram, (A) is an aberration diagram at the wide-angle end, and (B) is an aberration diagram at the telephoto end.

[0020] In the spherical aberration diagram, Fno is the F-number, and the amount of spherical aberration for the d-line (wavelength 587.56 nm), f-line (486.13 nm), C-line (656.27 nm), and g-line (wavelength 435.83 nm) is shown. The horizontal scale is the amount of defocus, shown from -0.4 to +0.4 mm. In the astigmatism diagram, dS is the amount of astigmatism on the sagittal image plane, and dM is the amount of astigmatism on the meridional image plane. The horizontal scale is the amount of defocus, shown from -0.4 to +0.4 mm. In the distortion diagram, the amount of distortion for the d-line is shown. In the distortion diagram, the horizontal scale is shown from -15 to +15%.

[0021] Next, the characteristic configuration of the zoom lens of each embodiment will be described.

[0022] The zoom lens of each embodiment has, arranged in order from the object side to the image side, a first lens unit B1 with positive refractive power, a second lens unit B2 with negative refractive power, a third lens unit B3 with positive refractive power, a fourth lens unit B4 with positive refractive power, and a fifth lens unit B5 with negative refractive power. In the zoom lens of each embodiment, the spacing between adjacent lens units changes during zooming from the wide-angle end to the telephoto end.

[0023] To achieve a high zoom magnification and high optical performance across the entire zoom range, it is advisable to construct a zoom lens using multiple lens groups and vary the spacing between adjacent lens groups, but using multiple lens groups makes the mechanical configuration more complex, making it difficult to achieve smooth zooming from the wide-angle end to the telephoto end using an electric actuator.

[0024] In the zoom lens of each embodiment, when zooming from the wide-angle end to the telephoto end, the first lens group B1 and the third lens group B3 are fixed, and the second lens group B2 and the fourth lens group B4 move in the optical axis direction. By limiting the number of lens groups that move during zooming to two, zooming is possible with a simple configuration. Because the first lens group B1 is the heaviest lens group, changing the center of gravity of the lens during zooming is suppressed by fixing it during zooming.

[0025] On the other hand, as the zoom configuration becomes simpler, it becomes more difficult to correct various aberrations throughout the entire zoom range, and fixing the first lens unit B1 poses the problem that the overall lens length tends to become longer.

[0026] Therefore, in the zoom lens of each embodiment, the third lens group includes a negative lens and a positive lens, which makes it easy to correct axial chromatic aberration and spherical aberration, and also makes it easy to arrange the image stabilization group.

[0027] Furthermore, the zoom lens of each embodiment satisfies the following conditional expressions (1) and (2).

[0028] -3.50<β3w / β3t<-0.10 (1) -10.0 <f1 / f2<-4.0 ···(2) Here, β3w is the imaging magnification of the third lens unit B3 at the wide-angle end, β3t is the imaging magnification of the third lens unit B3 at the telephoto end, f1 is the focal length of the first lens unit B1, and f2 is the focal length of the second lens unit B2.

[0029] Conditional formula (1) defines the change in the imaging magnification of the third lens group B3. When conditional formula (1) is satisfied, light emerging from the third lens group B3 may become parallel during zooming from the wide-angle end to the telephoto end, thereby minimizing the change in the angle of light rays incident on the fourth lens group B4. This reduces aberration fluctuations during zooming and focusing. When the upper limit of conditional formula (1) is exceeded, the angle of light rays incident on the fourth lens group B4 at the wide-angle end becomes stronger, making it more likely that changes in spherical aberration and axial chromatic aberration will occur. When the lower limit of conditional formula (1) is exceeded, the angle of light rays incident on the fourth lens group B4 at the telephoto end becomes stronger, making it more likely that changes in spherical aberration and axial chromatic aberration will occur.

[0030] Conditional expression (2) defines the ratio of the refractive powers of the first lens group B1 and the second lens group B2, and indicates a preferable range for the refractive power arrangement of the main variable magnification group. If the upper limit of conditional expression (2) is exceeded, the refractive power of the second lens group B2 becomes too strong, making it impossible to effectively correct fluctuations in field curvature and spherical aberration during zooming. If the lower limit of conditional expression (2) is exceeded, the difference in refractive power becomes too small, making it impossible to achieve the desired zoom magnification, or increasing the amount of movement of the second lens group B2 makes the overall lens length too long.

[0031] Furthermore, it is preferable that the numerical ranges of the conditional expressions (1) and (2) satisfy the ranges of the following conditional expressions (1a) and (2a).

[0032] -2.00<β3w / β3t<-0.15 (1a) -8.5 <f1 / f2<-4.5 ···(2a) Moreover, it is preferable that the numerical ranges of the conditional expressions (1) and (2) satisfy the ranges of the following conditional expressions (1b) and (2b).

[0033] -1.20<β3w / β3t<-0.20 (1b) -7.0 <f1 / f2<-5.0 ···(2b) Next, the configurations that are preferably satisfied in the zoom lens of each embodiment will be described.

[0034] The first lens unit B1 preferably comprises, arranged in order from the object side to the image side, a cemented lens of a negative lens L11 and a positive lens L12, and a positive lens L13, which makes it easier to ensure the amount of movement of the second lens unit B2 during zooming while shortening the overall lens length.

[0035] During zooming from the wide-angle end to the telephoto end, it is preferable that the second lens unit B2 move toward the image side and the fourth lens unit B4 move toward the object side. Main zooming is performed by significantly changing the distance between the first lens unit B1 and the second lens unit B2 while ensuring the amount of movement of the second lens unit B2, and auxiliary zooming and image point correction are performed by moving the fourth lens unit B4 toward the object side.

[0036] The second lens group B2 and the fourth lens group B4 may be moved using metal cams as in the past, but moving the second lens group B2 and the fourth lens group B4 using a linear actuator enables high-speed zooming and focusing. Therefore, the second lens group B2 and the fourth lens group B4 must be relatively lightweight. Therefore, it is preferable that the second lens group B2 be composed of four or fewer lenses. For example, the second lens group B2 may be composed of a negative lens L21, a negative lens L22, a positive lens L23, and a negative lens L24, arranged in that order from the object side to the image side. This reduces zoom fluctuations in field curvature and lateral chromatic aberration.

[0037] The third lens group B3 is fixed during zooming and focusing, and it is preferable that the aperture stop STO and the image stabilization subgroup be located in the third lens group B3. This improves image stabilization performance and simplifies the zoom lens configuration. By locating the aperture stop STO in the third lens group B3, which is always fixed, the lens barrel structure can be simplified.

[0038] By moving an image stabilization subgroup, which is part of the third lens group B3, in a direction including a component perpendicular to the optical axis during image stabilization, it is possible to reduce image plane fluctuations during image stabilization. The third lens group B3 preferably comprises, arranged in order from the object side to the image side, a first subgroup 3a with positive refractive power, a second subgroup 3b with positive refractive power, and a third subgroup 3c with negative refractive power. Image stabilization is performed by moving the second subgroup 3b as the image stabilization subgroup in a direction including a component perpendicular to the optical axis. In order to reduce color shift during image stabilization, the second subgroup 3b is preferably a cemented lens consisting of a negative lens and a positive lens arranged in order from the object side to the image side.

[0039] For weight reduction, the fourth lens group B4 is preferably composed of three or four lenses. For example, the fourth lens group B4 may be composed of, in order from the object side to the image side, a positive lens L41, a positive lens L42, a negative lens L43, and a positive lens L44. This reduces fluctuations in field curvature and spherical aberration during zooming and focusing.

[0040] The fifth lens group B5 is preferably composed of at least four lenses. For example, the fifth lens group B5 may be composed of, in order from the object side to the image side, a negative lens L51, a positive lens L52, a negative lens L53, and a positive lens L54. By arranging the refractive power of the fifth lens group B5 in this manner, the exit pupil position can be moved toward the object side, thereby achieving a compact zoom lens and a reduced image plane incident angle.

[0041] When focusing from infinity to a close distance, it is preferable that the fourth lens unit B4 move toward the object side. By performing focusing using the fourth lens unit B4, which moves during zooming, zooming and focusing can be performed with a simple configuration.

[0042] Next, conditions that the zoom lens of each embodiment should preferably satisfy will be described. The zoom lens of each embodiment should preferably satisfy one or more of the following conditional expressions (3) to (12).

[0043] 0.2 <BF / fw<1.2 ···(3) 0.8 <M2 / D1<3.0 ···(4) 2.0 <f1 / fw<12.0 ···(5) -0.8 <f2 / f4<-0.3 ···(6) 1.0 <f3 / f4<2.0 ···(7) 1.5 <f5 / f2<10.0 ···(8) -6.0 <M2 / M4<0.0 ···(9) 1.2 <fis / f3<2.0 ···(10) -0.00163×νd+0.65800<θgf<-0.00163×νd+0.7500 (11) 15.0<νd<24.2 (12) Here, BF is the air-equivalent back focus (the distance on the optical axis from the lens surface closest to the image at the wide-angle end to the image plane IMG in a zoom lens. fw is the focal length of the zoom lens at the wide-angle end. M2 is the amount of movement of the second lens unit B2 when zooming from the wide-angle end to the telephoto end. The amount of movement of a lens unit corresponds to the difference between its axial position at the wide-angle end and its axial position at the telephoto end. The sign of the amount of movement is positive when the lens unit is closer to the image at the telephoto end than at the wide-angle end, and negative when the lens unit is closer to the object at the telephoto end than at the wide-angle end. D1 is the axial distance from the lens surface closest to the object in the first lens unit B1 to the lens surface closest to the image in the first lens unit B1 (the thickness of the first lens unit on the optical axis). f4 is the focal length of the fourth lens unit B4. f3 is the focal length of the third lens unit B3. f5 is the focal length of the fifth lens unit B5. M4 is the amount of movement of the fourth lens unit B4 during zooming from the wide-angle end to the telephoto end. fis is the focal length of the image stabilization subunit included in the third lens unit B3. θgf is the partial dispersion ratio for the g-line and f-line of the positive lens included in the fifth lens unit B5. νd is the Abbe number for the d-line of the positive lens included in the fifth lens unit B5.

[0044] Conditional expression (3) defines the ratio of the focal length of the zoom lens at the wide-angle end to the back focal length of the zoom lens. By satisfying conditional expression (3), the overall lens length can be shortened. If the upper limit of conditional expression (3) is exceeded, the back focal length of the zoom lens becomes too long compared to the focal length of the zoom lens at the wide-angle end, and the overall lens length becomes long in order to ensure the movement amount of the moving lens group, which is undesirable. If the lower limit of conditional expression (3) is exceeded, the final lens element becomes too close to the image plane IMG, which increases the lens diameter of the final lens element, and the final lens element will no longer fit within the specified lens mount diameter, which is undesirable.

[0045] Conditional expression (4) defines a desirable condition for achieving compactness of the zoom lens. If the upper limit of conditional expression (4) is exceeded, the movement amount of the second lens unit B2 becomes too large, which is undesirable because the overall lens length becomes long. If the lower limit of conditional expression (4) is not exceeded, the movement amount of the second lens unit B2 becomes too small, which worsens various aberrations, or the overall lens length becomes long and the lens diameter of the first lens unit B1 becomes too large, which is undesirable.

[0046] Conditional expression (5) defines the ratio of the focal length of the first lens group B1 to the focal length of the zoom lens at the wide-angle end, and defines a preferable range for the first lens group B1. If the upper limit of conditional expression (5) is exceeded, the refractive power of the first lens group B1 becomes too weak, which is undesirable because the desired zoom ratio cannot be achieved. If the lower limit of conditional expression (5) is exceeded, the refractive power of the first lens group B1 becomes too strong, which is undesirable because spherical aberration and axial chromatic aberration at the telephoto end tend to worsen.

[0047] Conditional expression (6) defines a preferable range for the ratio of the focal lengths of the second lens group B2 and the fourth lens group B4, which are two moving groups. If the upper limit of conditional expression (6) is exceeded, the refractive power of the second lens group B2 becomes too strong relative to the refractive power of the fourth lens group B4, which is undesirable because fluctuations in field curvature and spherical aberration during zooming cannot be fully corrected. If the lower limit of conditional expression (6) is exceeded, the refractive power of the second lens group B2 becomes too weak, which is undesirable because it becomes difficult to achieve high zoom levels.

[0048] Conditional expression (7) defines a preferable range for the ratio of the focal lengths of the third lens group B3 and the fourth lens group B4. If the upper limit of conditional expression (7) is exceeded, the refractive power of the third lens group B3 becomes too weak, reducing the zoom ratio contribution of the third lens group B3 and making it more likely that various aberrations will worsen, which is undesirable. If the lower limit of conditional expression (7) is exceeded, the refractive power of the fourth lens group B4 becomes too weak, increasing the amount of movement of the fourth lens group B4 and making the overall lens length longer, which is undesirable.

[0049] Conditional expression (8) defines a preferred range for the ratio of the focal lengths of the fifth lens group B5 and the second lens group B2. The fifth lens group B5 includes a subgroup consisting of a negative lens and a positive lens, arranged in order from the object side to the image side, which has the effect of magnifying the image. The larger the value of f5 / f2 in conditional expression (8), the smaller the angle of incidence on the image plane. Exceeding the upper limit of conditional expression (8) is undesirable because the angle of incidence on the image plane becomes too small, increasing the diameter of the final lens element, and making it impossible for the final lens element to fit within a specified lens mount diameter. Falling below the lower limit of conditional expression (8) is undesirable because the refractive power of the fifth lens group B5 becomes too strong, which tends to worsen curvature of field and chromatic aberration of magnification.

[0050] Conditional expression (9) defines a preferable range of the movement ratio between the second lens group B2 and the fourth lens group B4, which are two moving groups. If the upper limit of conditional expression (9) is exceeded, the amount of movement of the second lens group B2 becomes too small, which is undesirable because the refractive power of the second lens group B2 needs to be increased. If the lower limit of conditional expression (9) is not exceeded, the amount of movement of the fourth lens group B4 becomes too small, which is undesirable because the refractive power of the fourth lens group B4 needs to be increased.

[0051] Conditional expression (10) defines the ratio of the focal length of the image blur correction subgroup to the focal length of the third lens group B3, and defines a preferred range for the refractive power of the image blur correction subgroup. Exceeding the upper limit of conditional expression (10) is undesirable because the refractive power of the image blur correction subgroup is too weak, resulting in excessive movement of the image blur correction subgroup during image blur correction. Falling below the lower limit of conditional expression (10) is undesirable because the refractive power of the image blur correction subgroup is too strong, resulting in increased coma during image blur correction.

[0052] Conditional expressions (11) and (12) define conditions for favorable correction of axial chromatic aberration and lateral chromatic aberration. Exceeding the upper limit of conditional expression (11) is undesirable because a stable optical glass cannot be obtained. Falling below the lower limit of conditional expression (11) is undesirable because the chromatic aberration correction effect cannot be obtained. Exceeding the upper limit of conditional expression (12) is undesirable because the chromatic aberration correction effect decreases. Falling below the lower limit of conditional expression (12) is undesirable because a stable optical glass cannot be obtained.

[0053] Furthermore, by making the positive lens included in the fifth lens unit B5, which satisfies the conditional expressions (11) and (12), have a meniscus shape convex toward the image side, it is possible to effectively correct secondary chromatic aberration.

[0054] It is more preferable that the numerical ranges of the conditional expressions (3) to (12) be within the ranges of the following conditional expressions (3a) to (12a).

[0055] 0.3 <BF / fw<1.0 ···(3a) 0.8 <M2 / D1<2.0 ···(4a) 3.0 <f1 / fw<10.0 ···(5a) -0.70 <f2 / f4<-0.35 ···(6a) 1.2 <f3 / f4<1.8 ···(7a) 1.8 <f5 / f2<9.0 ···(8a) -4.5 <M2 / M4<-1.5 ···(9a) 1.3 <fis / f3<1.9 ···(10a) -0.00163×νd+0.66000<θgf<-0.00163×νd+0.7300 (11a) 15.0<νd<23.5 (12a) It is more preferable that the numerical ranges of the conditional expressions (3) to (12) be within the ranges of the following conditional expressions (3b) to (12b).

[0056] 0.5 <BF / fw<0.9 ···(3b) 0.8 <M2 / D1<1.5 ···(4b) 5.0 <f1 / fw<9.0 ···(5b) -0.6 <f2 / f4<-0.4 ···(6b) 1.3 <f3 / f4<1.7 ···(7b) 2.0 <f5 / f2<8.0 ···(8b) -3.5 <M2 / M4<-2.0 ···(9b) 1.4 <fis / f3<1.8 ···(10b) -0.00163×νd+0.66400<θgf<-0.00163×νd+0.7100 (11b) 15.0<νd<23.0 (12b) Next, the zoom lens of each embodiment will be described in detail.

[0057] The zoom lens in Example 1 is made up of a first lens unit B1, a second lens unit B2, a third lens unit B3, a fourth lens unit B4, and a fifth lens unit B5, arranged in this order from the object side to the image side.

[0058] The zoom lens in Example 2 is composed of, in order from the object side to the image side, a first lens group B1, a second lens group B2, a third lens group B3, a fourth lens group B4, and a fifth lens group B5. The zoom lens in Example 2 is configured so that the focal length of the zoom lens at the telephoto end is longer than that of the zoom lens in Example 1. Even in this case, good imaging performance can be ensured by satisfying the above-mentioned conditions.

[0059] The zoom lens in Example 3 is composed of, in order from the object side to the image side, a first lens group B1, a second lens group B2, a third lens group B3, a fourth lens group B4, and a fifth lens group B5. The zoom lens in Example 3 is configured so that the focal length of the zoom lens at the wide-angle end is shorter than that of the zoom lens in Example 1. Even in this case, good imaging performance can be ensured by satisfying the above-mentioned conditions.

[0060] Although each embodiment shows a zoom lens with a five-group configuration, a lens group with weak refractive power may be arranged on the object side or image side of the zoom lens of each embodiment as long as the same effect as that of each embodiment can be obtained.Furthermore, an element with extremely weak refractive power (effectively no refractive power) may be arranged on the object side or image side of the zoom lens of each embodiment.

[0061] Numerical Examples 1 to 3 corresponding to Examples 1 to 3, respectively, are shown below.

[0062] In each numerical example, |f| is the focal length (mm), F is the F-number, img is the image circle diameter (mm), and ang is the half angle of view (°). B indicates the number of the lens group counted from the object side to the image side. S is the surface number assigned to the lens surface or diaphragm surface counted from the object side to the image side. The s to the left of the surface number indicates that the surface is the aperture stop STO. EA is the effective diameter of the lens (mm), r is the radius of curvature of each lens surface (mm), d is the distance on the optical axis between the i-th surface and the (i+1)-th surface (mm), and the distance in parentheses indicates the distance between the lens groups. glass indicates the name of the glass material. nd is the refractive index at the d-line of the material of the i-th optical element. νd is the Abbe number based on the d-line of the material of the i-th optical element. The Abbe number νd is given by the following formula, where Nd, NF, and NC are the refractive indices at the d-line (587.6 nm), F-line (486.1 nm), and C-line (656.3 nm) of the Fraunhofer lines: νd=(Nd-1) / (NF-NC) It is expressed as:

[0063] Lens surfaces with an asterisk (*) to the right of the surface number have aspheric shapes that conform to the following functions, and the coefficients in the functions are shown in each numerical example. The aspheric coefficient "ex" is x10 -x The aspherical shape is expressed by the following equation, where x is the coordinate in the optical axis direction based on the vertex of the lens surface, y is the coordinate in the radial direction based on the vertex of the lens surface, the direction of light travel is positive, r is the paraxial radius of curvature, K is the conic constant, and A to F are aspherical coefficients.

[0064] x=(y 2 / r) / [1+{1-(1+K)(y 2 / r 2 )} 1 / 2 ]+Ay 4 +By 6 +Cy 8 +Dy 10 +Ey 12 +Fy 14 In the various data, the focal length (mm) and F-number (FNO) are values ​​when the lens is focused on an object at infinity. The real image height (mm) represents the image height including image distortion. In each embodiment, it is assumed that image distortion due to distortion is corrected by image processing of the captured image. The total length (mm) of the lens refers to the distance on the optical axis from the first surface, which is the lens surface closest to the object, to the image plane IMG. The back focus BF (mm) is the distance on the optical axis from the lens surface closest to the image (the final lens surface) to the image plane IMG. If there is an element without refractive power, such as a flat plate, between the final lens surface and the image plane IMG, this is the calculated air-equivalent length. The total length is the distance on the optical axis from the first surface to the final lens surface plus the back focus. In the distance data, OBJ represents the object distance, and in each embodiment, it is expressed as the distance from the object position to the image plane IMG.

[0065] (Numerical Example 1) |f|=20.01-119.99 F / 4.08-4.08 img=27.32 ang=34.4-15.2 BS EA R d glass nd νd OBJ 1 1 66.03 97.1682 1.5000 SLAH95 1.90366 31.34 2 62.85 57.4857 11.0700 SFPL51 1.49700 81.54 3 61.81 828.7642 0.3000 4 56.67 53.1290 9.1500 SFPM2 1.59522 67.73 5 55.00 287.2910 (0.9367) 2 6* 26.01 -1383.4788 1.2000 TAFD45 1.95375 32.32 7 21.97 20.5219 5.2000 8 21.84 -33.8748 1.0000 SLAL14 1.69680 55.53 9 21.63 78.3769 0.3000 10 21.71 44.9883 5.6000 STIH53 1.84666 23.78 11 21.36 -26.0967 0.5150 12 20.92 -22.7801 1.0000 SLAH89 1.85150 40.78 13 20.62 -237.1036 (41.2153) 3 s14 14.94 1e+018 1.0000 15* 19.16 29.9339 3.6000 SFPL51 1.49700 81.54 16 19.40 -566.8117 0.8000 17 20.47 59.1528 1.0000 TAFD45 1.95375 32.32 18 20.27 25.9450 4.0000 SLAL58 1.69350 50.81 19 20.30 -126.1091 0.8000 20 19.53 45.6683 1.2000 SLAL14 1.69680 55.53 21 19.14 26.8471 (22.6407) 4 22 20.08 20.0576 5.0000 SFPL51 1.49700 81.54 23 19.52 -151.5934 0.3000 24 18.45 28.3488 3.3000 SFPL51 1.49700 81.54 25 17.60 -163.5093 1.0000 SLAH52 1.79952 42.22 26 16.48 26.5017 0.8000 27* 16.24 28.1092 2.4000 SBAL42 1.58313 59.37 28* 15.54 113.7278 (1.4205) 5 29 14.50 109.2493 1.0000 SLAH89 1.85150 40.78 30 14.32 18.8346 2.3000 31 14.46 -39.5201 2.1000 EFDS1W 1.92286 20.88 32 15.23 -24.4137 9.0000 33 18.03 -17.8671 1.0000 TAFD45 1.95375 32.32 34 19.85 -51.4100 0.3000 35 23.19 40.3016 6.0000 SBSL7 1.51633 64.14 36 24.00 -32.1527 IMG Aspheric data Surface 6 r =-1.38348e+003 K = 0.00000e+000 A = 4.45817e-006 B =-2.62754e-009 C =-7.55319e-012 D = 1.11792e-013 E = 0.00000e+000 F = 0.00000e+000 Surface 15 r = 2.99339e+001 K = 0.00000e+000 A =-9.27353e-006 B = 6.66006e-009 C =-8.70310e-011 D = 4.89575e-013 E = 0.00000e+000 F = 0.00000e+000 Surface 27 r = 2.81092e+001 K = 0.00000e+000 A = 2.56153e-005 B = 3.66705e-007 C = 3.10854e-010 D = 2.63528e-011 E = 0.00000e+000 F = 0.00000e+000 surface 28 r = 1.13728e+002 K = 0.00000e+000 A = 5.80405e-005 B = 5.18295e-007 C =-6.86215e-010 D = 4.96736e-011 E = 0.00000e+000 F = 0.00000e+000 Various データ WIDE MIDDLE TELE WIDE to near MIDDLE to near TELE to near Focal distance: 20.02, 50.03, 119.95 FNO 4.08 4.08 4.08 Half painting angle (°) 34.40 15.16 6.31 The height of the statue is 12.33 13.66 13.66 Total length 165.00 165.00 165.00 BF 13.54 13.54 13.54 d0 INF INF INF 235 635 1035 d6 0.9367 26.2908 41.1559 d14 41.2153 15.8301 1.0000 d22 22.6407 15.2078 6.7729 22.2066 14.2079 2.2200 d29 1.4205 8.8815 17.2859 1.8546 9.8792 21.8418 Lens group data Group Starting plane Focal length B1 1 93.0357 B2 7 -16.2313 B3 15 50.4265 B4 23 32.4957 B5 30 -47.1450 (Numerical Example 2) |f|=20.01-134.95 F / 4.08-4.08 img=27.32 ang=34.3-15.1 BS EA R d glass nd νd OBJ 1 1 63.83 107.8167 1.5000 SLAH95 1.90366 31.34 2 61.19 62.7045 10.7000 SFPL51 1.49700 81.54 3 60.21 -976.9606 0.3000 4 54.46 53.6503 8.2000 SFPM2 1.59522 67.73 5 52.69 234.6119 (1.0633) 2 6* 26.99 484.0341 1.0000 TAFD45 1.95375 32.32 7 22.73 20.0167 5.6000 8 22.63 -34.3423 1.0000 SLAL14 1.69680 55.53 9 22.33 57.7374 0.3000 10 22.47 38.4457 6.0500 STIH53 1.84666 23.78 11 22.09 -26.4360 0.6500 12 21.53 -22.2250 1.0000 SLAH89 1.85150 40.78 13 21.27 -212.5288 (44.6455) 3 s14 15.63 1e+018 1.0000 15* 19.12 25.1590 3.6000 SFPL51 1.49700 81.54 16 19.20 116.8660 1.0900 17 20.60 64.0886 1.0000 TAFD45 1.95375 32.32 18 20.42 25.6060 4.3500 SBAH10 1.67003 47.23 19 20.50 -70.4913 0.6000 20 19.01 30.4363 1.0000 SLAL14 1.69680 55.53 21 18.53 21.8889 (20.6049) 4 22 19.12 19.4437 5.0000 SFPL51 1.49700 81.54 23 18.52 -141.0547 0.3000 24 17.86 35.5865 3.3000 SFPL51 1.49700 81.54 25 17.21 -73.8414 1.0000 SLAM66 1.80100 34.97 26 16.49 32.0389 0.3200 27* 16.47 35.9616 2.3000 SBAL42 1.58313 59.37 28* 16.01 256.0985 (1.1007) 5 29 15.54 115.0194 1.0000 SLAH89 1.85150 40.78 30 15.16 21.9152 2.5000 31 15.20 -28.9868 2.4000 SNPH1 1.80809 22.76 32 15.82 -17.4279 4.6000 33 15.73 -13.8276 1.0000 SLAH89 1.85150 40.78 34 17.90 -543.8315 3.2000 35 22.62 252.1738 4.6000 SFPL51 1.49700 81.54 36 24.15 -32.5503 0.3000 37 28.10 38.0000 6.5000 STIL1 1.54814 45.78 38 28.38 -59.9389 IMG Aspheric data Surface 6 r = 4.84034e+002 K = 0.00000e+000 A = 3.08024e-006 B =-3.40028e-010 C =-6.39982e-012 D = 1.25935e-013 E = 0.00000e+000 F = 0.00000e+000 Surface 15 r = 2.51590e+001 K = 0.00000e+000 A =-1.16571e-005 B =-8.07396e-009 C = 3.66989e-011 D =-7.95149e-014 E = 0.00000e+000 F = 0.00000e+000 Surface 27 r = 3.59616e+001 K = 0.00000e+000 A = 2.90954e-005 B = 4.47229e-007 C = 3.91657e-010 D = 2.38388e-011 E = 0.00000e+000 F = 0.00000e+000 Surface 28 r = 2.56099e+002 K = 0.00000e+000 A = 5.94204e-005 B = 5.77129e-007 C = -2.56978e-010 D = 4.58233e-011 E = 0.00000e+000 F = 0.00000e+000 Various data WIDE MIDDLE TELE WIDE closest MIDDLE closest TELE closest Focal length 20.01 50.01 134.95 FNO 4.08 4.08 4.08 Half angle of view (°) 34.29 15.08 5.61 Real image height 12.33 13.66 13.66 Overall length 168.51 168.47 168.50 BF 13.82 13.82 13.82 ]>d0 INF INF INF 230 630 1030 d5 1.0633 26.8834 44.7092 d13 44.6455 18.7996 1.0000 d

[21] ] 20.6049 14.0010 7.1139 20.1904 13.0987 2.6000 d28 1.1007 7.7299 14.5916 1.5151 8.6322 19.1059 Lens group data Group Starting surface Focal length B1 1 91.0192 B2 6 -16.36

[40] ] B3 14 47.7245 0]]B4 22 34.0997 B5 29 -125.5530 (Numerical Example 3) |f| = 18.41 - 101.96 F / 4.08 - 4.08 img = 27.32 ang = 36.6 - 15.1 B S EA R d glass nd νd OBJ 1 1 65.93 98.2076 1.5000 SLAH95 1.90366 31.34 2 62.69 56.6607 12.3000 SFPL51 1.49700 81.54 3 61.69 -848.7753 0.3000 4 54.91 48.3997 9.2500 SFPM2 1.59522 67.73 5 52.88 225.6590 (1.1932) 2 6 28.20 196.5503 1.2000 TAFD45 1.95375 32.32 7 22.58 17.3966 6.1000 8 22.44 -37.0226 1.0000 SLAL14 1.69680 55.53 9 21.98 49.1838 0.3000 10 22.12 31.3584 5.9200 STIH53 1.84666 23.78 11 21.59 -30.3809 0.5400 12 21.09 -25.8740 1.0000 SLAH89 1.85150 40.78 13 20.45 464.2321 (35.2668) 3 s14 12.80 1e+018 1.0000 15* 15.92 21.3480 3.1500 SFPL51 1.49700 81.54 16 15.97 102.3225 0.8000 17 17.27 54.7871 1.0000 TAFD45 1.95375 32.32 18 17.08 21.1227 3.6100 SLAM3 1.71700 47.93 19 17.10 -94.4947 0.6000 20 15.88 37.7066 1.0000 SBSL7 1.51633 64.14 21 15.57 20.2630 (15.7146) 4 22 16.14 15.1244 5.3000 SFPL51 1.49700 81.54 23 15.39 -41.0161 1.1000 24 14.42 -48.0462 1.0000 SNBH58 1.78880 28.43 25 14.00 169.2232 0.3000 26* 13.77 61.0313 2.2000 SBAL42 1.58313 59.37 27* 13.44 -367.6149 (0.6935) 5 28 13.80 36.2844 0.8000 SLAH65V 1.80400 46.58 29 13.56 16.8380 2.6650 30 13.79 -31.9424 2.2000 SNPH1 1.80809 22.76 31 14.49 -19.4468 5.5500 32* 15.29 -12.3340 1.0000 LLAH94 1.86100 37.10 33* 17.67 -85.0553 0.6650 34 20.96 45.1615 6.5000 SFSL5 1.48749 70.24 35 22.17 -20.4356 IMG Aspheric data Surface 15 r = 2.13480e+001 K = 0.00000e+000 A =-1.73848e-005 B =-2.50756e-008 C = 4.72402e-011 D =-3.38022e-013 E = 0.00000e+000 F = 0.00000e+000 Surface 26 r = 6.10313e+001 K = 0.00000e+000 A = 3.96721e-005 B = 6.09374e-007 C = 5.15667e-009 D =-4.54825e-011 E = 0.00000e+000 F = 0.00000e+000 Surface 27 r =-3.67615e+002 K = 0.00000e+000 A = 1.01834e-004 B = 9.00877e-007 C = 5.38464e-009 D =-6.24767e-012 E = 0.00000e+000 F = 0.00000e+000 surface 32 r =-1.23340e+001 K = 0.00000e+000 A = 5.07317e-006 B = 2.81676e-007 C =-3.46058e-009 D = 2.65520e-011 E = 0.00000e+000 F = 0.00000e+000 surface 33 r =-8.50553e+001 K = 0.00000e+000 A =-1.07295e-006 B = 1.76138e-007 C =-2.91744e-009 D = 2.46938e-011 E =-6.39575e-014 F = 0.00000e+000 Various データ WIDE MIDDLE TELE WIDE to near MIDDLE to near TELE to near Focal distance: 18.41 50.02 101.96 FNO 4.08 4.08 4.08 Half painting angle (°) 36.59 15.05 7.42 The height of the statue is 12.33 13.66 13.66 Total length: 146.50 146.48 146.49 BF 13.77 13.77 13.77 d0 INF INF INF 252 652 1052 d5 1.1932 24.4220 35.4608 d13 35.2668 12.0118 1.0000 d21 15.7146 9.5071 4.9651 15.3646 8.5117 2.0250 d27 0.6935 6.9267 11.4424 1.0435 7.9217 14.3833 Lens group data Group starting plane focal length B1 1 81.3708 B2 6 -14.8663 B3 14 45.5203 B4 22 28.5770 B5 28 -41.5130 The various values ​​in each numerical example are summarized in Table 1 below.

[0066] [Table 1]

[0067] [Imaging device] Next, an embodiment of a digital still camera (imaging device) using a zoom lens of the present invention as an imaging optical system will be described with reference to FIG. 7. FIG. 7 is a diagram showing the configuration of an imaging device 10. In FIG. 7, the imaging device 10 includes a camera body 13, a lens device 11 including any of the zoom lenses described in Examples 1 to 3, and an imaging element (light receiving element) 12 that receives and photoelectrically converts an optical image formed by the zoom lens. The imaging element 12 is built into the camera body 13. A solid-state imaging element (photoelectric conversion element) such as a CCD sensor or a CMOS sensor can be used as the imaging element 12. The lens device 11 and the camera body 13 may be configured as an integrated unit, or may be configured as detachable components. The camera body 13 may be a so-called single-lens reflex camera with a quick-turn mirror, or a so-called mirrorless camera without a quick-turn mirror.

[0068] In this way, by applying the zoom lens of each embodiment to an imaging device such as a digital still camera, it is possible to obtain an imaging device 10 that has a high zoom magnification and high optical performance over the entire zoom range.

[0069] The imaging device 10 of this embodiment is not limited to the digital still camera shown in FIG. 7, but can be applied to various imaging devices such as broadcast cameras, cameras for silver halide film, and surveillance cameras.

[0070] [Imaging system] An imaging system (surveillance camera system) may be configured that includes the zoom lens of each embodiment and a control unit that controls the zoom lens. In this case, the control unit can control the zoom lens so that each lens group moves as described above during zooming, focusing, and image stabilization. In this case, the control unit does not need to be configured integrally with the zoom lens; the control unit may be configured separately from the zoom lens. For example, a control unit (control device) located far from the drive units that drive each lens of the zoom lens may include a transmission unit that sends control signals (commands) to control the zoom lens. Such a control unit allows the zoom lens to be remotely controlled.

[0071] Alternatively, the control unit may be provided with an operation unit such as a controller or buttons for remotely operating the zoom lens, so that the zoom lens can be controlled in response to user input to the operation unit. For example, the operation unit may be provided with a zoom-in button and a zoom-out button. The control unit may then send a signal to the drive unit of the zoom lens L0 so that the magnification of the zoom lens increases when the user presses the zoom-in button, and decreases when the user presses the zoom-out button.

[0072] The imaging system may also have a display unit such as a liquid crystal panel that displays information (movement state) related to the zoom of the zoom lens. Information related to the zoom of the zoom lens may be, for example, the zoom magnification (zoom state) or the movement amount (movement state) of each lens group. In this case, the user can remotely operate the zoom lens via the operation unit while viewing the information related to the zoom of the zoom lens displayed on the display unit. In this case, the display unit and operation unit may be integrated by using, for example, a touch panel.

[0073] The disclosure of each of the above embodiments includes the following configurations. (Configuration 1) A zoom lens having, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power, wherein the spacing between adjacent lens groups changes during zooming from the wide-angle end to the telephoto end, During zooming from the wide-angle end to the telephoto end, the first lens group and the third lens group are fixed, and the second lens group and the fourth lens group are moved, the third lens group includes a negative lens and a positive lens, When the imaging magnification of the third lens group at the wide-angle end is β3w, the imaging magnification of the third lens group at the telephoto end is β3t, the focal length of the first lens group is f1, and the focal length of the second lens group is f2, -3.50<β3w / β3t<-0.10 -10.0 <f1 / f2<-4.0 A zoom lens characterized by satisfying the following conditional expressions: (Configuration 2) When the air-equivalent length of the distance on the optical axis from the lens surface closest to the image side at the wide-angle end of the zoom lens to the image plane is BF and the focal length of the zoom lens at the wide-angle end is fw, 0.2 <BF / fw<1.2 2. The zoom lens according to claim 1, wherein the following condition is satisfied: (Configuration 3) During zooming from the wide-angle end to the telephoto end, the second lens group moves toward the image side, When the amount of movement of the second lens group during zooming from the wide-angle end to the telephoto end is M2 and the distance on the optical axis from the lens surface of the first lens group closest to the object side to the lens surface of the first lens group closest to the image side is D1, 0.8 <M2 / D1<3.0 3. The zoom lens according to configuration 1 or 2, wherein the following condition is satisfied: (Configuration 4) When the focal length of the zoom lens at the wide-angle end is fw, 2.0 <f1 / fw<12.0 4. The zoom lens according to any one of configurations 1 to 3, wherein the following condition is satisfied: (Configuration 5) When the focal length of the fourth lens group is f4, -0.8 <f2 / f4<-0.3 5. A zoom lens according to any one of configurations 1 to 4, characterized in that the following conditional expression is satisfied: (Configuration 6) When the focal length of the third lens group is f3 and the focal length of the fourth lens group is f4, 1.0 <f3 / f4<2.0 6. A zoom lens according to any one of configurations 1 to 5, characterized in that the following conditional expression is satisfied: (Configuration 7) When the focal length of the fifth lens group is f5, 1.5 <f5 / f2<10.0 7. The zoom lens according to any one of configurations 1 to 6, wherein the following condition is satisfied: (Configuration 8) During zooming from the wide-angle end to the telephoto end, the second lens group moves toward the image side, and the fourth lens group moves toward the object side, When the amount of movement of the second lens group during zooming from the wide-angle end to the telephoto end is M2 and the amount of movement of the fourth lens group during zooming from the wide-angle end to the telephoto end is M4, -6.0 <M2 / M4<0.0 8. The zoom lens according to any one of configurations 1 to 7, wherein the following condition is satisfied: (Configuration 9) the third lens group includes an image blur correction subgroup that moves in a direction including a component perpendicular to the optical axis during image blur correction, When the focal length of the image stabilization subgroup is fis and the focal length of the third lens group is f3, 1.2 <fis / f3<2.0 9. A zoom lens according to any one of configurations 1 to 8, characterized in that the following conditional expression is satisfied: (Configuration 10) the third lens group comprises, arranged in order from the object side to the image side, a first sub-group having positive refractive power, a second sub-group having positive refractive power, and a third sub-group having negative refractive power; the second sub-group is a cemented lens including a negative lens and a positive lens arranged in this order from the object side to the image side, 10. The zoom lens according to any one of configurations 1 to 9, wherein the second subgroup moves in a direction including a component perpendicular to the optical axis during image blur correction. (Configuration 11) the fifth lens group includes a positive lens, When the partial dispersion ratio of the positive lens for the g-line and the f-line is θgf and the Abbe number of the positive lens for the d-line is νd, -0.00163×νd+0.65800<θgf<-0.00163×νd+0.7500 11. The zoom lens according to any one of configurations 1 to 10, wherein the following condition is satisfied: (Configuration 12) the positive lens included in the fifth lens group has a meniscus shape convex toward the image side, 15.0<νd<24.2 12. The zoom lens according to configuration 11, wherein the following condition is satisfied: (Configuration 13) The zoom lens according to any one of configurations 1 to 12, characterized in that the zoom lens comprises the first lens group, the second lens group, the third lens group, the fourth lens group, and the fifth lens group, arranged in this order from the object side to the image side. (Configuration 14) 14. The zoom lens according to any one of configurations 1 to 13, wherein the first lens group consists of, arranged in order from the object side to the image side, a cemented lens of a negative lens and a positive lens, and a positive lens. (Configuration 15) 15. A zoom lens according to any one of configurations 1 to 14, wherein the second lens group is made up of four or less lenses. (Configuration 16) 16. The zoom lens according to configuration 15, wherein the second lens group is composed of a negative lens, a negative lens, a positive lens, and a negative lens arranged in this order from the object side to the image side. (Configuration 17) 17. The zoom lens according to any one of configurations 1 to 16, wherein the third lens group includes an aperture stop. (Configuration 18) 18. A zoom lens according to any one of configurations 1 to 17, wherein the fourth lens group is made up of three or four lenses. (Configuration 19) 19. The zoom lens according to configuration 18, wherein the fourth lens group comprises, in order from the object side to the image side, a positive lens, a positive lens, a negative lens, and a positive lens. (Configuration 20) 20. A zoom lens according to any one of configurations 1 to 19, wherein the fifth lens group is made up of at least four lenses. (Configuration 21) 21. The zoom lens according to configuration 20, wherein the fifth lens group consists of a negative lens, a positive lens, a negative lens, and a positive lens arranged in this order from the object side to the image side. (Configuration 22) 22. A zoom lens according to any one of configurations 1 to 21, wherein the fourth lens group moves toward the object side during focusing from infinity to a close distance. (Configuration 23) a zoom lens according to any one of configurations 1 to 22; an imaging device having an imaging element that receives an image formed by the zoom lens;

[0074] Although the 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 the gist of the present invention. [Explanation of symbols]

[0075] First lens group B1 Second lens group B2 Third lens group B3 Fourth lens group B4 Fifth lens group B5

Claims

1. A zoom lens having, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power, wherein the spacing between adjacent lens groups changes during zooming from a wide-angle end to a telephoto end, During zooming from the wide-angle end to the telephoto end, the first lens group and the third lens group are fixed, and the second lens group and the fourth lens group are moved, the third lens group includes a negative lens and a positive lens, When the imaging magnification of the third lens group at the wide-angle end is β3w, the imaging magnification of the third lens group at the telephoto end is β3t, the focal length of the first lens group is f1, and the focal length of the second lens group is f2, -3.50<β3w / β3t<-0.10 -10.0<f1 / f2<-4.0 A zoom lens characterized by satisfying the following conditional expressions:

2. When the air-equivalent length of the distance on the optical axis from the lens surface closest to the image side at the wide-angle end of the zoom lens to the image plane is BF and the focal length of the zoom lens at the wide-angle end is fw, 0.2<BF / fw<1.2 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

3. During zooming from the wide-angle end to the telephoto end, the second lens group moves toward the image side, When the amount of movement of the second lens group during zooming from the wide-angle end to the telephoto end is M2 and the distance on the optical axis from the lens surface of the first lens group closest to the object side to the lens surface of the first lens group closest to the image side is D1, 0.8<M2 / D1<3.0 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

4. When the focal length of the zoom lens at the wide-angle end is fw, 2.0<f1 / fw<12.0 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

5. When the focal length of the fourth lens group is f4, -0.8<f2 / f4<-0.3 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

6. When the focal length of the third lens group is f3 and the focal length of the fourth lens group is f4, 1.0<f3 / f4<2.0 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

7. When the focal length of the fifth lens group is f5, 1.5<f5 / f2<10.0 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

8. During zooming from the wide-angle end to the telephoto end, the second lens group moves toward the image side, and the fourth lens group moves toward the object side, When the amount of movement of the second lens group during zooming from the wide-angle end to the telephoto end is M2 and the amount of movement of the fourth lens group during zooming from the wide-angle end to the telephoto end is M4, -6.0<M2 / M4<0.0 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

9. the third lens group includes an image blur correction subgroup that moves in a direction including a component perpendicular to the optical axis during image blur correction, When the focal length of the image blur correction subgroup is fis and the focal length of the third lens group is f3, 1.2<fis / f3<2.0 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

10. the third lens group comprises, arranged in order from the object side to the image side, a first sub-group having positive refractive power, a second sub-group having positive refractive power, and a third sub-group having negative refractive power; the second sub-group is a cemented lens including a negative lens and a positive lens arranged in this order from the object side to the image side, 2. The zoom lens according to claim 1, wherein the second sub-group moves in a direction including a component perpendicular to the optical axis during image blur correction.

11. the fifth lens group includes a positive lens, When the partial dispersion ratio of the positive lens with respect to the g-line and the f-line is θgf and the Abbe number of the positive lens with respect to the d-line is νd, -0.00163×νd+0.65800<θgf<-0.00163×νd+0.7500 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

12. the positive lens included in the fifth lens group has a meniscus shape convex toward the image side, 15.0<νd<24.2 12. The zoom lens according to claim 11, wherein the following condition is satisfied:

13. 2. The zoom lens according to claim 1, wherein the zoom lens comprises, in order from the object side to the image side, the first lens group, the second lens group, the third lens group, the fourth lens group, and the fifth lens group.

14. 2. The zoom lens according to claim 1, wherein the first lens group comprises, in order from the object side to the image side, a cemented lens of a negative lens and a positive lens, and a positive lens.

15. 3. The zoom lens according to claim 1, wherein the second lens group is made up of four or less lenses.

16. 16. The zoom lens according to claim 15, wherein the second lens group comprises, in order from the object side to the image side, a negative lens, a negative lens, a positive lens, and a negative lens.

17. 3. The zoom lens according to claim 1, wherein the third lens group includes an aperture stop.

18. 3. The zoom lens according to claim 1, wherein the fourth lens group is made up of three or four lenses.

19. 19. The zoom lens according to claim 18, wherein the fourth lens group consists of a positive lens, a positive lens, a negative lens, and a positive lens arranged in this order from the object side to the image side.

20. 3. The zoom lens according to claim 1, wherein the fifth lens group is made up of at least four lenses.

21. 21. The zoom lens according to claim 20, wherein the fifth lens group consists of a negative lens, a positive lens, a negative lens, and a positive lens arranged in this order from the object side to the image side.

22. 2. The zoom lens according to claim 1, wherein the fourth lens group moves toward the object side during focusing from infinity to a close distance.

23. a zoom lens according to any one of claims 1 to 14; an imaging device having an imaging element that receives an image formed by the zoom lens;

Images