Zoom lens and image capturing device

Abstract

To provide a compact zoom lens capable of suppressing chromatic aberration.SOLUTION: A zoom lens disclosed herein comprises a positive first lens group, multiple movable lens groups configured to move while zooming, and a rear lens group with positive refractive power. The movable lens groups comprise a first negative lens group, a second negative lens group, and a positive lens group. The positive lens group comprises an aperture stop, one or more positive lenses, and one or more negative lenses. An average partial dispersion ratio θgFap and an average Abbe number νdap of positive lenses in the positive lens group, an average partial dispersion ratio θgFan and an average Abbe number νdan of negative lenses in the positive lens group, a distance dPw from the aperture stop to a most image-side lens surface of the rear lens group, and a distance dIE from a most image-side lens surface of the positive lens group to a most object-side lens surface of the rear group satisfy conditions expressed as: -2.0×10-3≤(θgFap-θgFan) / (νdap-νdan)<0, and 0.15≤dIE / dPw≤0.8.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a zoom lens. [Background technology]

[0002] Some zoom lenses have an aperture diaphragm provided in the lens group closest to the image side among a plurality of lens groups that move for zooming. Patent Document 1 discloses a zoom lens including three or more lens groups that move during zooming. This zoom lens is arranged in order from the object side to the image side, and each of the lens groups includes a fixed positive lens group, one or more lens groups that move including a negative lens group, a moving negative lens group, a moving positive lens group that includes an aperture, and a fixed positive lens group. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-032924 Summary of the Invention [Problem to be solved by the invention]

[0004] In the zoom lens disclosed in Patent Document 1, chromatic aberration becomes large and the size increases when a high zoom ratio is achieved.

[0005] The present invention provides a compact zoom lens capable of suppressing chromatic aberration, and an imaging device equipped with the same. [Means for solving the problem]

[0006] A zoom lens according to one aspect of the present invention has, as lens groups arranged in order from the object side, a first lens group having positive refractive power that does not move for zooming, a plurality of movable groups that each move for zooming, and a rear lens group having positive refractive power that does not move for zooming, and the interval between adjacent lens groups changes during zooming. The movable groups have, arranged in order from the object side to the image side, a first negative lens group, a second negative lens group, and a positive lens group. The positive lens group has an aperture stop, one or more positive lenses, and one or more negative lenses. The average partial dispersion ratios for the g-line and F-line of one or more positive lenses included in the positive lens group and the average Abbe numbers based on the d-line are respectively θgFap and νdap, the average partial dispersion ratios for the g-line and F-line of one or more negative lenses included in the positive lens group and the average Abbe numbers based on the d-line are respectively θgFan and νdan, the distance on the optical axis at the wide-angle end from the aperture stop to the lens surface in the rear lens group closest to the image side is dPw, and the distance on the optical axis from the lens surface in the positive lens group closest to the image side to the lens surface in the rear lens group closest to the object side is dIE. -2.0×10 -3 ≦(θgFap-θgFan) / (νdap-νdan)<0 0.15≦dIE / dPw≦0.8 The present invention is characterized in that the above conditions are satisfied. An image pickup apparatus including the above zoom lens also constitutes another aspect of the present invention. Effect of the Invention

[0007] According to the present invention, it is possible to provide a compact zoom lens capable of suppressing chromatic aberration. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a cross-sectional view of the zoom lens of the first embodiment at the wide-angle end. [Diagram 2] 5A to 5C are aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of the first embodiment. [Diagram 3] FIG. 11 is a cross-sectional view of a zoom lens at a wide-angle end according to a second embodiment. [Figure 4]11A to 11C are aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 2. [Diagram 5] FIG. 11 is a cross-sectional view of a zoom lens at a wide-angle end according to a third embodiment. [Figure 6] 11A to 11C are aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 3. [Figure 7] FIG. 11 is a cross-sectional view of a zoom lens at a wide-angle end according to a fourth embodiment. [Figure 8] 11A to 11C are aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 4. [Figure 9] FIG. 1 is a diagram showing an imaging device equipped with a zoom lens according to any one of the first to fourth embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0010] Prior to describing specific embodiments 1 to 4, matters common to embodiments 1 to 4 will be described with reference to Fig. 1. Fig. 1 shows a cross section of the zoom lens of embodiment 1 at the wide-angle end.

[0011] The zoom lens of each embodiment includes a first lens group G1 (L1) that does not move for zooming, a plurality of movable groups GZ (L2-L4) that move for zooming, and a rear lens group GE (L5) that does not move for zooming, as lens groups arranged in order from the object side to the image side. The first lens group G1 has a positive refractive power as a whole, and the rear lens group GE also has a positive refractive power as a whole.

[0012] In a zoom lens, a lens group is a group of one or more lenses that move together during zooming or focusing between the wide-angle end and the telephoto end. That is, the interval between adjacent lens groups changes during zooming or focusing. The lens group may include an aperture stop. The wide-angle end and the telephoto end respectively indicate the zoom states of the maximum angle of view (shortest focal length) and the minimum angle of view (maximum focal length) when the lens group that moves during zooming is located at both ends of the range that can be moved mechanically or controlled on the optical axis. In FIG. 1, the movement trajectory of each lens group during zooming from the wide-angle end to the telephoto end is shown below the multiple movable groups GZ (L2 to L4). Li (i=1, 2, 3, ...) indicates the i-th lens group, which is the i-th lens group counted from the object side, and SP indicates the aperture stop. I indicates an image plane. The imaging surface of an imaging element such as a CMOS sensor or the film surface of a silver halide film is arranged on the image plane I. GB denotes a glass block, such as a prism, that is disposed between the rear lens group GE (L5) and the image surface I and has no refractive power.

[0013] The multiple movable groups GZ include multiple lens groups arranged in order from the object side to the image side, which move as follows during zooming from the wide-angle end to the telephoto end: a first negative lens group GN1 (L2) that moves monotonically toward the image side, a second negative lens group GN2 (L3) that moves so as to be located closer to the image side than the wide-angle end at the telephoto end, and a positive lens group GP1 (L4) that moves toward the image side and the object side.

[0014] The positive lens group GP1, which is the movable group GZ closest to the image side, has one or more positive lenses and one or more negative lenses. The positive lens group GP1 moves to correct changes in the imaging position that accompany zooming and to suppress aberration fluctuations. When the zoom lens has a large magnification ratio, the refractive power of the positive lens group GP1 becomes stronger and the amount of movement increases, which tends to increase the fluctuation in chromatic aberration that accompanies zooming. For this reason, by arranging a positive lens and a negative lens in the positive lens group GP1, the fluctuation in chromatic aberration that accompanies zooming is suppressed.

[0015] Furthermore, an aperture stop SP is provided in the positive lens group GP1, which is particularly effective for making the first lens group G1 smaller in size compared to a zoom lens in which an aperture stop is provided closer to the image side than the movable groups.

[0016] Furthermore, at least one of the lens surfaces in the positive lens group GP1 is made aspheric, thereby suppressing aberration fluctuations that occur during zooming.

[0017] In the above configuration, the average value of the partial dispersion ratio θgF for the g-line and the F-line of one or more positive lenses included in the positive lens group GP1 and the average value of the Abbe number νd based on the d-line are respectively θgFap and νdap. The average value of the partial dispersion ratio θgF for the g-line and the F-line of one or more negative lenses included in the positive lens group GP1 and the average value of the Abbe number νd based on the d-line are respectively θgFan and νdan. The definitions of the partial dispersion ratio θgF and the Abbe number νd will be described later. In addition, when a cemented lens is included in the positive lens group GP1, each of the positive lens and the negative lens constituting the cemented lens is treated as one lens when calculating the above average value. This is also the case for the rear lens group GE described later. In addition, the distance on the optical axis from the aperture stop SP to the lens surface of the rear lens group GE that is closest to the image at the wide-angle end is dPw, and the distance on the optical axis from the lens surface of the positive lens group GP1 that is closest to the image to the lens surface of the rear lens group GE that is closest to the object is dIE. In this case, the zoom lens of each embodiment satisfies the conditions shown in the following expressions (1) and (2).

[0018] -2.0×10 -3 ≦(θgFap-θgFan) / (νdap-νdan)<0 (1) 0.15≦dIE / dPw≦0.80 (2) By making (θgFap-θgFan) / (νdap-νdan) equal to or greater than the lower limit of formula (1), a low-dispersion glass material with a high partial dispersion ratio θgF is used for the positive lens included in the positive lens group GP1, making it possible to suppress fluctuations in lateral chromatic aberration that accompanies zooming and axial chromatic aberration at the wide-angle end. Also, by making (θgFap-θgFan) / (νdap-νdan) equal to or less than the upper limit of formula (1), it is possible to suppress excessive correction of chromatic aberration. By making dIE / dPw equal to or greater than the lower limit of formula (2), it is possible to prevent the optical components to be inserted or removed from becoming too small, and to prevent changes in optical performance during insertion. Also, by making dIE / dPw equal to or less than the upper limit of formula (2), it is possible to prevent the zoom lens from becoming too large.

[0019] It is more preferable that the numerical ranges of the formulas (1) and (2) are as follows:

[0020] -1.8×10 -3 ≦(θgFap-θgFan) / (νdap-νdan) ≦-0.2×10 -3 (1a) 0.20≦dIE / dPw≦0.75 (2a) It is more preferable that the numerical ranges of the formulas (1) and (2) are as follows:

[0021] -1.6×10 -3 ≦(θgFap-θgFan) / (νdap-νdan) ≦-0.3×10 -3 (1b) 0.30≦dIE / dPw≦0.70 (2b) It is even more preferable that the numerical ranges of the formulas (1) and (2) are as follows:

[0022] -1.5×10 -3 ≦(θgFap-θgFan) / (νdap-νdan) ≦-0.4×10 -3 (1c) 0.40≦dIE / dPw≦0.65 (2c) It is preferable that the zoom lens of each embodiment satisfies at least one of the conditions shown in the following expressions (3) to (7).

[0023] When the lateral magnification of the positive rear lens group GE is β5R, it is preferable that the condition shown in the following formula (3) be satisfied.

[0024] -0.2≦β5R≦0.5 (3) An optical member such as an extender can be inserted or removed between the movable group GZ and the rear lens group GE (at the distance dIE). If β5R exceeds the upper limit or falls below the lower limit of formula (3), the light beam passing through the portion at the distance dIE becomes a convergent or divergent light beam, which is undesirable because the fluctuation in optical performance due to the insertion or removal of the optical member increases.

[0025] It is more preferable to set the numerical range of the formula (3) as follows:

[0026] -0.18≦β5R≦0.48 (3a) It is more preferable that the numerical range of the formula (3) is as follows:

[0027] -0.15≦β5R≦0.45 (3b) It is even more preferable to set the numerical range of the formula (3) as follows:

[0028] -0.13≦β5R≦0.40 (3c) It is preferable that the first lens group G1 has, arranged in order from the object side to the image side, a negative lens group that does not move for focus adjustment (focusing), a positive lens group as a focus group that moves during focusing, and a positive lens group that does not move for focusing. In Fig. 1, the movement direction of the positive lens group during focusing from infinity to a close distance is indicated by an arrow below the positive lens group as the focus group. This configuration can reduce the weight of the focus group and suppress the fluctuation of the angle of view during focusing.

[0029] The distance on the optical axis from the lens surface of the first lens group G1 closest to the object to the lens surface of the first lens group G1 closest to the image is dG1, and the total length of the zoom lens (the distance on the optical axis from the lens surface of the first lens group G1 closest to the object to the lens surface of the rear lens group GE closest to the image) is dz. In this case, it is preferable to satisfy the condition of the following formula (4).

[0030] 0.3≦dG1 / dz≦0.5 (4) If dG1 / dz exceeds the upper limit of formula (4), the first lens group G1 becomes large, which results in an increase in the size of the entire zoom lens, which is undesirable. Also, if dG1 / dz falls below the lower limit of formula (4), it is necessary to either increase the refractive power of the first lens group G1 or narrow the focusing range to reduce the amount of movement of the focus group, which makes it difficult to obtain sufficient optical performance, which is undesirable.

[0031] It is more preferable to set the numerical range of the formula (4) as follows:

[0032] 0.31≦dG1 / dz≦0.45 (4a) It is more preferable that the numerical range of the formula (4) is as follows:

[0033] 0.32≦dG1 / dz≦0.40 (4b) The movement amount of the positive lens group GP1 that moves during zooming between the wide-angle end and the telephoto end over the entire zoom range (the distance between the position closest to the object side and the position closest to the image side during zooming) is dGP1z, and the movement amount of the first negative lens group GN1 that moves during zooming over the entire zoom range is dGN1z. The movement amount is a positive movement amount (distance) when each lens group is located closer to the image side at the telephoto end than the wide-angle end. In this case, it is preferable to satisfy the condition shown in the following formula (5).

[0034] 0.02≦dGP1z / dGN1z≦0.40 (5) In order to increase the magnification of the zoom lens, it is necessary to increase the amount of movement dGP1z. However, if the aperture stop is disposed closer to the image side than the positive lens group GP1, the effective diameter of the first lens group G1 increases due to the increase in the amount of movement dGP1z, and the first lens group G1 becomes larger. Therefore, by disposing the aperture stop SP in the positive lens group GP1, it is possible to realize a high magnification of the zoom lens while suppressing the increase in size of the first lens group G1. If dGP1z / dGN1z is below the lower limit of formula (5), the zoom ratio of the zoom lens becomes small, or the refractive power of the positive lens group GP1 becomes too strong, making it impossible to satisfy the optical performance, which is not preferable. If dGP1z / dGN1z is above the upper limit of formula (5), the zoom lens becomes large, or the change in optical performance due to zooming becomes too large, which is not preferable.

[0035] It is more preferable to set the numerical range of the formula (5) as follows:

[0036] 0.03≦dGP1z / dGN1z≦0.35 (5a) It is more preferable that the numerical range of the formula (5) is as follows:

[0037] 0.04≦dGP1z / dGN1z≦0.34 (5b) When the average value of the refractive index Nd at the d-line of one or more positive lenses included in the positive lens group GP1 is Ndap and the average value of the refractive index Nd at the d-line of one or more negative lenses included in the positive lens group GP1 is Ndan, it is preferable to satisfy the condition shown in the following equation (6).

[0038] 0.1≦Ndan-Ndap≦0.5 (6) The condition of formula (6) indicates an appropriate refractive index difference between the positive lens and the negative lens in the positive lens group GP1. By providing a refractive index difference that satisfies the condition of formula (6), it is possible to satisfactorily correct the field curvature. If Ndan-Ndap is below the lower limit of formula (6), the field curvature will be undercorrected, and if it exceeds the upper limit, the field curvature will be overcorrected, which is not preferable.

[0039] It is more preferable to set the numerical range of the formula (6) as follows:

[0040] 0.15≦Ndan-Ndap≦0.45 (6a) It is more preferable that the numerical range of the formula (6) is as follows:

[0041] 0.2≦Ndan-Ndap≦0.4 (6b) The average value of the partial dispersion ratio θgF for the g-line and F-line of one or more positive lenses included in the rear lens group GE is denoted as θgFbp, and the average value of the partial dispersion ratio θgF for the g-line and F-line of one or more negative lenses included in the rear lens group GE is denoted as θgFbn. In this case, it is preferable to satisfy the condition of the following formula (7).

[0042] -0.07≦θgFbp-θgFbn≦-0.02 (7) When θgFbp-θgFbn satisfies the condition of formula (7), it can have an effect particularly on the correction of lateral chromatic aberration, and when combined with satisfying the condition of formula (1), it is possible to satisfactorily correct both the axial chromatic aberration and the lateral chromatic aberration.

[0043] It is more preferable to set the numerical range of the formula (7) as follows:

[0044] -0.060≦θgFbp-θgFbn≦-0.025 (7a) It is more preferable that the numerical range of the formula (7) is as follows:

[0045] -0.05≦θgFbp-θgFbn≦-0.03 (7b) In addition, in the positive lens group GP1 of the zoom lens of each embodiment, it is preferable to place the aperture stop SP closest to the object side, which allows the lens diameter of the first positive lens group G1 to be reduced, thereby making it possible to miniaturize the zoom lens.

[0046] Below, examples 1 to 4 will be described. After example 4, numerical examples 1 to 4 corresponding to examples 1 to 4, respectively, are shown.

[0047] In each numerical example, surface number i indicates the order of the surface when counted from the object side. r indicates the radius of curvature (mm) of the i-th surface from the object side, and d indicates the lens thickness or air space (mm) between the i-th and (i+1)-th surfaces. The (variable) in d indicates that the air space changes during zooming, and the correspondence between the air space and the focal length is shown in a separate table. Nd is the refractive index at the d-line (wavelength 587.6 nm) of the optical material between the i-th and (i+1)-th surfaces. νd is the Abbe number based on the d-line of the optical material between the i-th and (i+1)-th surfaces. θgF is the partial dispersion ratio for the g-line (wavelength 435.8 nm) and the F-line (wavelength 486.1 nm).

[0048] The Abbe number νd based on the d-line is expressed as νd=(Nd-1) / (NF-NC), where Nd, NF, and NC are the refractive indices at the d-line, F-line, and C-line (656.3 nm), respectively. Additionally, the partial dispersion ratio θgF for the g-line and F-line is expressed as θgF=(Ng-NF) / (NF-NC), where Ng is the refractive index at the g-line. The effective diameter is the radius (mm) of the area of ​​the i-th lens surface through which light rays that contribute to imaging pass.

[0049] An "*" next to a surface number means that the surface has an aspheric shape. An aspheric shape is expressed by the following formula, where X is the displacement from the apex of the surface in the optical axis direction, H is the height from the optical axis in a direction perpendicular to the optical axis, the light traveling direction is positive, R is the paraxial radius of curvature, K is the conic constant, and A2 to A16 are aspheric coefficients. The conic constant and the aspheric coefficients "e±x" are ×10 ±x means.

[0050]

number

[0051] In each numerical example, the zoom ratio (variable magnification ratio), focal length (mm), F-number, and half angle of view (°) of the zoom lens are shown, and the maximum image height corresponding to the half angle of view is shown as "image height." The focal length is the focal length at the d-line (587.6 nm). BF stands for back focus (mm). The back focus is the distance on the optical axis from the final surface (lens surface closest to the image) of the zoom lens to the paraxial image surface expressed as an air-equivalent length. The total lens length is the distance on the optical axis from the foreground (lens surface closest to the object) of the zoom lens to the final surface plus the back focus. In addition, the surface number of the surface (starting surface) closest to the object of each lens group and the focal length of each lens group are shown as lens group data. EXAMPLES

[0052] In the zoom lens of Example 1 shown in FIG. 1, the first lens group G1 (L1) is composed of 10 lenses, of which the eighth lens from the object side is a cemented lens. The second lens group L2 as the first negative lens group GN1 is composed of four lenses, of which the third lens from the object side is a cemented lens. The third lens group L3 as the second negative lens group GN2 is composed of one cemented lens. The fourth lens group L4 as the positive lens group GP1 is composed of an aperture stop SP, a positive lens, and a cemented lens in which a positive lens and a negative lens are cemented together, arranged in order from the object side. The fifth lens group L5 as the rear lens group GE is composed of a positive lens, a cemented lens in which a negative lens and a positive lens are cemented together, a cemented lens in which a positive lens and a negative lens are cemented together, and a positive lens, arranged in order from the object side.

[0053] During zooming from the wide-angle end to the telephoto end, the first negative lens group GN1 moves monotonically toward the image side, the second negative lens group GN1 moves to describe a convex locus toward the object side so that the telephoto end is closer to the image side than the wide-angle end, and the positive lens group GP1 moves to describe a convex locus toward the object side and then moves toward the object side.

[0054] The values ​​corresponding to the above-mentioned formulas (1) to (7) in Numerical Example 1 are summarized in Table 1. In Table 1, "E-XX" stands for ×10 -XXThe zoom lens of Numerical Example 1 satisfies all of the conditions in expressions (1) to (7). Therefore, even though it is a small zoom lens, it is possible to effectively suppress chromatic aberration.

[0055] 2(A) and (B) respectively show the longitudinal aberration (spherical aberration, astigmatism, distortion, and chromatic aberration) of the zoom lens of Numerical Example 1 at the wide-angle end and the telephoto end. In the spherical aberration diagram, Fno indicates the F-number, the solid line indicates the spherical aberration for the d-line (wavelength 587.6 nm), and the two-dot chain line indicates the spherical aberration for the g-line (wavelength 435.8 nm). In the astigmatism diagram, the solid line S indicates the astigmatism at the sagittal image plane, and the dashed line M indicates the astigmatism at the meridional image plane. The distortion aberration diagram shows the distortion aberration at the d-line. The chromatic aberration diagram shows the chromatic aberration of magnification at the g-line. ω is the half angle of view (°). EXAMPLES

[0056] FIG. 3 shows a cross section of the zoom lens of Example 2 at the wide-angle end. In the zoom lens of Example 2, the first lens group G1 (L1) is composed of eight lenses, of which the fifth and sixth lenses from the object side are cemented lenses. The second lens group L2 as the first negative lens group GN1 is composed of three lenses, of which the second lens from the object side is a cemented lens. The third lens group L3 as the second negative lens group GN2 is composed of one cemented lens. The fourth lens group L4 as the positive lens group GP1 is composed of an aperture stop SP, a positive lens, and a cemented lens in which a negative lens and a positive lens are cemented together, arranged in order from the object side. The fifth lens group L5 as the rear lens group GE is composed of a positive lens, a cemented lens in which a positive lens and a negative lens are cemented together, a cemented lens in which a positive lens and a negative lens are cemented together, and a positive lens, arranged in order from the object side.

[0057] During zooming from the wide-angle end to the telephoto end, the first negative lens group GN1 moves monotonically toward the image side, and the second negative lens group GN1 moves to describe a locus convex toward the object side so that the telephoto end is closer to the image side than the wide-angle end. The positive lens group GP1 moves in the order of the image side, object side, image side, and object side.

[0058] Table 1 shows the values ​​corresponding to the above-mentioned expressions (1) to (7) in Numerical Example 2. The zoom lens of Numerical Example 2 satisfies all of the conditions of expressions (1) to (7). Therefore, chromatic aberration can be effectively suppressed even though it is a compact zoom lens.

[0059] 4A and 4B show longitudinal aberrations of the zoom lens of Numerical Example 2 at the wide-angle end and the telephoto end, respectively. EXAMPLES

[0060] FIG. 5 shows a cross section of the zoom lens of Example 3 at the wide-angle end. In the zoom lens of Example 3, the first lens group G1 (L1) is composed of 10 lenses, of which the eighth lens from the object side is a cemented lens. The second lens group L2 as the first negative lens group GN1 is composed of four lenses, of which the third lens from the object side is a cemented lens. The third lens group L3 as the second negative lens group GN2 is composed of one cemented lens. The fourth lens group L4 as the positive lens group GP1 is composed of an aperture stop SP, a positive lens, and a cemented lens in which a negative lens and a positive lens are cemented together, arranged in order from the object side. The fifth lens group L5 as the rear lens group GE is composed of a positive lens, a cemented lens in which a positive lens and a negative lens are cemented together, a cemented lens in which a positive lens and a negative lens are cemented together, and a positive lens, arranged in order from the object side.

[0061] During zooming from the wide-angle end to the telephoto end, the first negative lens group GN1 moves monotonically toward the image side, and the second negative lens group GN1 moves to describe a curved locus so that it is located closer to the image side at the telephoto end than at the wide-angle end. The positive lens group GP1 moves toward the image side and then moves toward the object side.

[0062] Table 1 shows the values ​​corresponding to the above-mentioned expressions (1) to (7) in Numerical Example 3. The zoom lens of Numerical Example 3 satisfies all of the conditions of expressions (1) to (7). Therefore, chromatic aberration can be effectively suppressed even though it is a compact zoom lens.

[0063] 6A and 6B show longitudinal aberrations of the zoom lens of Numerical Example 3 at the wide-angle end and the telephoto end, respectively. EXAMPLES

[0064] FIG. 7 shows a cross section of the zoom lens of Example 4 at the wide-angle end. In the zoom lens of Example 4, the first lens group G1 (L1) is composed of 10 lenses, of which the eighth lens from the object side is a cemented lens. The second lens group L2 as the first negative lens group GN1 is composed of four lenses, of which the third lens from the object side is a cemented lens. The third lens group L3 as the second negative lens group GN2 is composed of one cemented lens. The fourth lens group L4 as the positive lens group GP1 is composed of an aperture stop SP, a positive lens, and a cemented lens in which a positive lens and a negative lens are cemented together, arranged in order from the object side. The fifth lens group L5 as the rear lens group GE is composed of a positive lens, a cemented lens in which a negative lens and a positive lens are cemented together, a cemented lens in which a positive lens and a negative lens are cemented together, and a positive lens, arranged in order from the object side.

[0065] During zooming from the wide-angle end to the telephoto end, the first negative lens group GN1 moves monotonically toward the image side, and the second negative lens group GN1 moves in the order of the image side, object side, and image side so that the telephoto end is closer to the image side than the wide-angle end. The positive lens group GP1 moves toward the image side and then toward the object side.

[0066] Table 1 shows the values ​​corresponding to the above-mentioned expressions (1) to (7) in Numerical Example 4. The zoom lens of Numerical Example 4 satisfies all of the conditions of expressions (1) to (7). Therefore, chromatic aberration can be effectively suppressed even though it is a compact zoom lens.

[0067] 8A and 8B show longitudinal aberrations of the zoom lens of Numerical Example 4 at the wide-angle end and the telephoto end, respectively.

[0068] [Numerical example 1] Unit: mm Surface Data Surface number rd Nd νd θgF Effective diameter 1* -651.846 2.50 1.83481 42.7 0.5648 80.83 2 29.886 17.96 54.93 3* 205.029 2.00 1.83481 42.7 0.5648 54.39 4 133.762 8.37 53.04 5 -93.844 1.80 1.83481 42.7 0.5648 52.38 6 -529.040 0.15 52.82 7 94.300 3.70 1.92286 18.9 0.6495 53.20 8 254.951 1.67 52.90 9 137.316 7.43 1.60300 65.4 0.5401 52.15 10* -129.387 4.41 51.25 11 -3986.720 6.22 1.43387 95.1 0.5373 51.04 12 -72.185 0.30 51.43 13 -68.763 1.70 1.80000 29.8 0.6017 51.43 14 -129.110 0.18 52.89 15 177.001 1.70 1.91650 31.6 0.5911 54.56 16 53.973 15.73 1.43875 94.7 0.5340 54.69 17 -72.950 0.40 55.94 18 145.677 9.06 1.43387 95.1 0.5373 58.68 19 -98.739 0.40 58.81 20 198.764 6.83 1.76385 48.5 0.5589 57.74 21 -143.417 (variable) 57.35 22 109.025 0.70 2.00100 29.1 0.5997 20.35 23 17.638 3.22 18.16 24 -147.134 0.70 1.43875 94.7 0.5340 17.98 25 52.607 2.33 17.53 26 -222.929 5.23 1.85478 24.8 0.6122 17.21 27 -13.213 0.70 1.88300 40.8 0.5667 17.04 28 124.147 0.21 17.90 29 32.929 2.64 1.64769 33.8 0.5938 18.56 30 640.048 (variable) 18.66 31 -29.435 0.80 1.72916 54.7 0.5444 18.90 32 42.341 2.57 1.84666 23.8 0.6205 20.20 33 558.323 (variable) 20.64 34(Aperture) ∞ 1.20 27.23 35* 66.693 6.40 1.59522 67.7 0.5442 28.92 36 -55.306 0.20 29.53 37 129.439 6.58 1.53172 48.8 0.5631 29.55 38 -31.398 1.00 1.88300 40.8 0.5667 29.40 39 -87.887 (variable) 29.86 40 65.836 5.42 1.63980 34.5 0.5922 27.58 41 -55.379 3.39 27.13 42 -71.478 0.90 1.88300 40.8 0.5667 24.95 43 30.858 5.07 1.48749 70.2 0.5300 24.66 44 -107.443 0.20 24.93 45 51.336 7.84 1.43875 94.7 0.5340 25.21 46 -21.995 0.90 2.00100 29.1 0.5997 25.04 47 -59.375 0.13 26.13 48 92.546 5.49 1.48749 70.2 0.5300 26.63 49 -34.223 3.27 26.70 50 ∞ 33.00 1.60859 46.4 0.5664 40.00 51 ∞ 13.20 1.51680 64.2 0.5347 40.00 52 ∞ (variable) 40.00 Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 6.48442e-06 A 6= 2.19226e-09 A 8= 6.50797e-12 A10= 8.92330e-14 A12= 1.11240e-16 A14= 1.77070e-20 A16= 3.15292e-25 A 3= 8.54799e-06 A 5=-1.41802e-07 A 7=-4.53639e-11 A 9=-1.10620e-12 A11=-4.05612e-15 A13=-1.83948e-18 A15=-9.72378e-23 3rd page K = 0.00000e+00 A 4=-3.35608e-06 A 6=-7.00472e-08 A 8=-7.37142e-10 A10=-3.24129e-13 A12= 1.58966e-15 A14=-6.55545e-19 A16=-2.03600e-22 A 3=-8.90697e-07 A 5= 3.79740e-07 A 7= 9.30814e-09 A 9= 3.11630e-11 A11=-3.28771e-14 A13=-1.76087e-17 A15= 2.23720e-20 Side 10 K = 0.00000e+00 A 4= 1.29716e-06 A 6= 1.84566e-08 A 8= 2.81340e-10 A10= 2.05135e-13 A12=-7.68327e-16 A14= 1.04059e-18 A16= 2.18082e-22 A 3= 3.31773e-07 A 5=-5.38599e-08 A 7=-2.96537e-09 A 9=-1.45178e-11 A11= 1.68411e-14 A13=-4.57121e-18 A15=-2.62172e-20 Page 35 K = 6.60773e+00 A 4=-4.74213e-06 A 6=-9.99912e-11 A 8=-7.56379e-12 Various data Zoom ratio 15.32 Wide Angle Mid-Telephoto Focal length 4.26 15.50 65.32 F-number 1.87 1.86 3.05 Half angle of view (°) 52.22 19.53 4.81 Image height 5.50 5.50 5.50 Lens total length 296.34 296.34 296.34 BF 39.08 39.08 39.08 d21 0.47 36.42 53.16 d30 39.91 5.86 3.67 d33 14.99 17.75 2.07 d39 45.53 40.87 42.01 d52 6.60 6.60 6.60 Lens Group Data Group starting plane focal length 1 1 29.67 2 22 -19.60 3 31 -42.47 4 34 45.06 5 40 52.58 [Numerical example 2] Unit: mm Surface Data Surface number rd Nd νd θgF Effective diameter 1* 609.605 2.80 1.80100 35.0 0.5864 90.25 2 41.686 27.30 69.09 3 -82.104 2.20 1.69680 55.5 0.5434 68.65 4 205.639 0.15 71.18 5 141.997 9.90 1.92286 18.9 0.6495 72.25 6 -385.910 2.75 72.40 7 165.180 12.55 1.49700 81.5 0.5375 73.86 8* -112.941 5.88 73.86 9 -454.766 8.26 1.43387 95.1 0.5373 71.90 10 -83.798 2.10 1.84666 23.8 0.6205 71.85 11 -111.471 0.20 72.66 12 195.818 2.10 1.80518 25.4 0.6161 71.94 13 61.220 9.32 1.43875 94.7 0.5340 70.04 14 171.312 0.21 70.64 15 131.511 9.95 1.43387 95.1 0.5373 71.64 16 -207.707 0.21 72.10 17 177.243 11.35 1.76385 48.5 0.5589 73.64 18 -122.604 (variable) 73.52 19* 70.794 1.25 2.00100 29.1 0.5997 35.82 20 28.534 10.84 31.93 21 -36.627 0.90 1.59522 67.7 0.5442 29.52 22 47.473 6.75 1.85478 24.8 0.6122 28.78 23 -69.378 4.72 28.54 24 -29.917 0.90 1.83481 42.7 0.5648 28.15 25 -46.686 (variable) 28.99 26 -49.809 0.90 1.60300 65.4 0.5401 29.23 27 136.391 2.68 1.85478 24.8 0.6122 30.60 28 7045.438 (variable) 31.09 29(Aperture) ∞ 0.00 37.90 30* 66.036 7.74 1.59522 67.7 0.5442 39.29 31 -93.835 0.20 39.62 32 76.450 1.20 2.00100 29.1 0.5997 39.24 33 48.181 7.27 1.43875 94.7 0.5340 38.44 34 -2787.171 (variable) 38.16 35 78.338 9.95 1.43875 94.7 0.5340 37.31 36 -51.850 4.20 37.15 37 84.735 6.06 1.80810 22.8 0.6307 33.29 38 -54.415 1.10 2.00100 29.1 0.5997 32.50 39 81.094 1.00 30.97 40 52.022 10.68 1.43875 94.7 0.5340 30.58 41 -26.960 1.20 1.89190 37.1 0.5780 29.22 42 53.200 1.97 29.77 43 38.195 8.26 1.48749 70.2 0.5300 32.29 44 -64.588 (variable) 32.60 Image plane ∞ Aspheric Data Front page K =-2.00000e+00 A 4= 6.65999e-07 A 6=-1.64676e-09 A 8= 2.69957e-12 A10= 9.11155e-15 A12=-9.78815e-19 A14=-2.49323e-21 A16=-8.75802e-26 A 3=-1.84870e-06 A 5= 1.98122e-08 A 7= 3.48096e-11 A 9=-2.42371e-13 A11=-1.59410e-16 A13= 1.15579e-19 A15= 2.39918e-23 Side 8 K =-1.21910e+01 A 4=-1.76701e-07 A 6= 2.22979e-09 A 8= 3.88179e-12 A10=4.17512e-16 A12=-2.85268e-20 A 3=-9.15088e-07 A 5=-1.50223e-08 A 7=-1.18303e-10 A 9=-6.90664e-14 A11 = 2.72454e-18 Page 19 K = 1.05505e+01 A 4=-2.14678e-06 A 6=-2.20721e-07 A 8=-5.48011e-09 A10=-2.19729e-11 A12=-7.61872e-15 A 3= 9.51044e-07 A 5= 5.84754e-07 A 7= 4.35486e-08 A 9= 4.40162e-10 A11= 6.20031e-13 Page 30 K = 5.49979e+00 A 4=-2.16242e-06 A 6=-4.40886e-09 A 8=-1.99416e-09 A10=-1.13469e-11 A12= 5.36967e-15 A14= 1.02287e-17 A16=-1.64191e-21 A 3=-5.17826e-06 A 5=-3.36916e-07 A 7= 1.01936e-08 A 9= 2.01832e-10 A11= 2.69566e-13 A13=-5.02520e-16 A15=-6.19408e-22 Various data Zoom ratio 7.79 Wide Angle Mid-Telephoto Focal length 15.40 45.00 120.00 F-number 2.72 2.70 3.65 Half angle of view (°) 43.86 18.21 7.03 Image height 14.80 14.80 14.80 Lens total length 364.15 364.15 364.15 BF 42.00 42.00 42.00 d18 1.15 43.84 64.29 d25 50.00 3.95 3.86 d28 20.54 25.49 3.01 d34 53.46 51.86 53.98 d44 42.00 42.00 42.00 Lens Group Data Group starting plane focal length 1 1 51.93 2 19 -32.49 3 26 -96.42 4 29 59.65 5 35 139.13 [Numerical example 3] Unit: mm Surface Data Surface number rd Nd νd θgf Effective diameter 1* -945.881 2.50 1.83481 42.7 0.5648 80.48 2 29.270 18.31 54.30 3* 280.173 2.00 1.83481 42.7 0.5648 53.75 4 155.870 5.45 52.52 5 -375.961 1.80 1.83481 42.7 0.5648 51.60 6 225.928 0.15 50.99 7 84.818 3.18 1.92286 18.9 0.6495 50.77 8 163.735 1.67 50.35 9 105.795 7.28 1.60300 65.4 0.5401 50.50 10* -150.548 4.41 50.53 11 -4717.965 4.81 1.43387 95.1 0.5373 51.08 12 -94.980 0.30 51.23 13 -88.919 1.70 1.80000 29.8 0.6017 51.23 14 -232.086 0.18 52.15 15 175.795 1.70 1.91650 31.6 0.5911 53.05 16 49.947 16.88 1.43875 94.7 0.5340 52.95 17 -59.093 0.40 54.17 18 96.943 9.06 1.43387 95.1 0.5373 57.99 19 -139.950 0.40 58.13 20 226.739 8.09 1.76385 48.5 0.5589 57.84 21 -96.159 (variable) 57.58 22 116.531 0.70 2.00100 29.1 0.5997 16.83 23 15.705 2.44 15.03 24 -221.676 0.70 1.43875 94.7 0.5340 14.83 25 29.388 2.33 14.89 26 -297.693 5.26 1.85478 24.8 0.6122 15.36 27 -11.681 0.70 1.88300 40.8 0.5667 15.85 28 79.733 0.21 16.87 29 28.756 2.74 1.64769 33.8 0.5938 17.66 30 3447.924 (variable) 17.82 31 -33.370 0.80 1.72916 54.7 0.5444 18.16 32 67.737 2.57 1.84666 23.8 0.6205 19.12 33 -860.675 (variable) 19.68 34(Aperture) ∞ 1.20 26.42 35* 93.760 4.97 1.59522 67.7 0.5442 27.65 36 -80.813 0.20 28.34 37 405.249 5.77 1.53172 48.8 0.5631 28.65 38 -31.138 1.00 1.88300 40.8 0.5667 28.83 39 -50.564 (variable) 29.46 40 67.650 4.97 1.63980 34.5 0.5922 27.49 41 -56.802 2.51 27.38 42 -125.211 0.90 1.88300 40.8 0.5667 25.84 43 27.932 4.22 1.48749 70.2 0.5300 25.25 44 363.120 0.20 25.41 45 59.287 8.08 1.43875 94.7 0.5340 25.68 46 -20.425 0.90 2.00100 29.1 0.5997 25.68 47 -45.910 0.13 27.14 48 72.344 5.70 1.48749 70.2 0.5300 28.02 49 -35.435 3.31 28.06 50 ∞ 33.00 1.60859 46.4 0.5664 40.00 51 ∞ 13.20 1.51680 64.2 0.5347 40.00 52 ∞ (variable) 40.00 Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 2.84749e-06 A 6=-4.72980e-08 A 8=-3.14612e-11 A10= 9.09207e-14 A12= 1.11026e-16 A14= 1.64083e-20 A16= 3.93184e-25 A 3= 4.11397e-05 A 5= 3.88082e-07 A 7= 2.10099e-09 A 9=-1.07103e-12 A11=-3.93486e-15 A13=-1.84824e-18 A15=-8.23382e-23 3rd page K = 0.00000e+00 A 4=-5.14521e-07 A 6=-6.20253e-08 A 8=-7.56683e-10 A10=-3.25392e-13 A12= 1.57466e-15 A14=-6.47873e-19 A16=-2.07821e-22 A 3=-2.71914e-05 A 5= 2.02826e-07 A 7= 9.51601e-09 A 9= 3.14741e-11 A11=-3.27113e-14 A13=-1.73567e-17 A15= 2.23429e-20 Side 10 K = 0.00000e+00 A 4= 2.75132e-06 A 6= 2.08109e-08 A 8= 2.91496e-10 A10= 2.00838e-13 A12=-7.68144e-16 A14= 1.11564e-18 A16= 2.19134e-22 A 3=-1.01147e-05 A 5=-7.53981e-08 A 7=-3.16716e-09 A 9=-1.46328e-11 A11= 1.68471e-14 A13=-5.56537e-18 A15=-2.76125e-20 Page 35 K = 7.99321e+00 A 4=-3.72150e-06 A 6= 1.86956e-09 A 8=-4.16672e-12 Various data Zoom ratio 15.31 Wide Angle Mid-Telephoto Focal length 4.26 15.50 65.24 F-number 1.86 1.86 3.04 Half angle of view (°) 52.24 19.53 4.82 Image height 5.50 5.50 5.50 Lens total length 296.35 296.35 296.35 BF 40.83 40.83 40.83 d21 0.47 34.24 47.41 d30 27.65 4.81 3.25 d33 16.80 19.50 2.10 d39 61.12 47.49 53.27 d52 8.30 8.30 8.30 Lens Group Data Group starting plane focal length 1 1 27.06 2 22 -15.68 3 31 -52.42 4 34 48.77 5 40 51.72 [Numerical example 4] Unit: mm Surface Data Surface number rd Nd νd θgf Effective diameter 1* 1361.505 2.50 1.83481 42.7 0.5648 80.99 2 30.245 19.94 55.71 3* -1073.774 2.00 1.83481 42.7 0.5648 55.26 4 258.752 5.65 54.39 5 -164.106 1.80 1.83481 42.7 0.5648 53.94 6 565.661 0.15 54.09 7 84.640 3.77 1.92286 18.9 0.6495 54.83 8 182.609 1.67 54.64 9 121.869 8.31 1.60300 65.4 0.5401 55.14 10* -142.323 4.41 55.15 11 -629.558 3.97 1.43387 95.1 0.5373 54.06 12 -102.125 0.30 53.96 13 -95.126 1.70 1.80000 29.8 0.6017 53.96 14 -434.163 0.18 54.21 15 118.492 1.70 1.91650 31.6 0.5911 54.20 16 48.477 15.67 1.43875 94.7 0.5340 52.95 17 -72.906 0.40 53.46 18 103.192 9.06 1.43387 95.1 0.5373 56.65 19 -117.455 0.40 56.80 20 120.711 7.42 1.76385 48.5 0.5589 56.18 21 -172.654 (variable) 55.71 22 110.466 0.70 2.00100 29.1 0.5997 23.54 23 18.982 3.99 20.83 24 -119.654 0.70 1.43875 94.7 0.5340 20.65 25 39.064 2.33 20.05 26 187.319 6.14 1.85478 24.8 0.6122 19.90 27 -15.240 0.70 1.88300 40.8 0.5667 19.64 28 66.966 0.21 19.20 29 30.296 2.56 1.64769 33.8 0.5938 19.30 30 111.479 (variable) 19.01 31 -31.724 0.80 1.72916 54.7 0.5444 18.81 32 43.602 2.57 1.84666 23.8 0.6205 20.02 33 517.969 (variable) 20.47 34(Aperture) ∞ 1.20 26.90 35* 66.519 7.25 1.49700 81.5 0.5375 28.37 36 -35.333 0.20 29.23 37 23.911 7.30 1.56732 42.8 0.5731 29.31 38 -503.867 1.00 1.88300 40.8 0.5667 28.21 39 29.910 (variable) 26.41 40 74.744 4.57 1.63980 34.5 0.5922 28.50 41 -63.142 4.77 28.32 42 294.521 0.90 1.88300 40.8 0.5667 25.94 43 29.281 3.84 1.48749 70.2 0.5300 25.26 44 200.109 0.20 25.26 45 44.869 8.24 1.43875 94.7 0.5340 25.37 46 -21.687 0.90 2.00100 29.1 0.5997 25.05 47 -75.189 0.13 26.15 48 78.189 5.78 1.48749 70.2 0.5300 26.73 49 -33.733 3.30 26.81 50 ∞ 33.00 1.60859 46.4 0.5664 40.00 51 ∞ 13.20 1.51680 64.2 0.5347 40.00 52 ∞ (variable) 40.00 Image plane ∞ Aspheric Data Front page K = 0.00000e+00 A 4= 3.83738e-06 A 6=-5.32871e-08 A 8= 1.14634e-10 A10= 6.58885e-13 A12= 8.87995e-17 A14=-8.25113e-20 A16=-3.48384e-24 A 3= 1.67014e-05 A 5= 3.06218e-07 A 7= 2.01696e-09 A 9=-1.47909e-11 A11=-1.43567e-14 A13= 3.05264e-18 A15= 8.53350e-22 3rd page K = 0.00000e+00 A 4=-2.38676e-06 A 6=-1.30610e-07 A 8=-7.86972e-10 A10= 5.61841e-12 A12=-2.85199e-16 A14=-1.89121e-17 A16=-2.29860e-21 A 3=-1.07217e-05 A 5= 6.04553e-07 A 7= 1.60769e-08 A 9=-2.81412e-11 A11=-2.53262e-13 A13= 4.61780e-16 A15= 3.34122e-19 Side 10 K = 0.00000e+00 A 4= 3.02986e-07 A 6=-3.43320e-08 A 8=-3.08699e-12 A10= 5.14179e-13 A12=-8.76808e-18 A14= 1.34224e-18 A16= 2.54380e-22 A 3=-3.20215e-06 A 5= 2.46718e-07 A 7= 2.32830e-09 A 9=-9.44921e-12 A11=-6.86418e-15 A13=-2.05722e-17 A15=-3.09662e-20 Page 35 K = 8.36579e+00 A 4=-1.23239e-05 A 6= 2.64928e-09 A 8=-2.13225e-11 Various data Zoom ratio 15.31 Wide Angle Mid-Telephoto Focal length 4.26 15.50 65.28 F-number 1.87 1.87 3.05 Half angle of view (°) 52.22 19.54 4.82 Image height 5.50 5.50 5.50 Lens total length 296.34 296.34 296.34 BF 39.11 39.11 39.11 d21 0.47 35.08 50.95 d30 39.93 8.36 4.29 d33 14.40 17.40 2.09 d39 44.46 38.42 41.94 d52 6.60 6.60 6.60 Zoom lens group data Group starting plane focal length 1 1 29.49 2 22 -18.38 3 31 -45.54 4 34 46.09 5 40 47.33

[0069] [Table 1]

[0070] 9 shows a digital still camera as an imaging device using the zoom lens of each of the above-mentioned embodiments as an imaging optical system. Reference numeral 20 denotes a camera body, and 21 denotes an imaging optical system constituted by any of the zoom lenses of embodiments 1 to 4. Reference numeral 22 denotes a solid-state imaging element such as a CCD sensor or a CMOS sensor that is built into the camera body 20 and captures an optical image (subject image) formed by the imaging optical system 21. Reference numeral 23 denotes a recording unit that records image data generated by processing an imaging signal from the imaging element 22, and 24 denotes a rear display that displays the image data.

[0071] By using the zoom lens of each embodiment, a camera that is small in size and has high optical performance can be obtained.

[0072] The camera may be a single-lens reflex camera having a quick-turn mirror, or a mirrorless camera having no quick-turn mirror.

[0073] The above embodiment includes the following configurations.

[0074] (Configuration 1) A zoom lens having lens groups arranged in order from the object side, the lens groups being a first lens group having positive refractive power that does not move for zooming, a plurality of movable groups that each move for zooming, and a rear lens group having positive refractive power that does not move for zooming, in which the spacing between adjacent lens groups changes during zooming, the movable group includes, in order from the object side to the image side, a first negative lens group, a second negative lens group, and a positive lens group; the positive lens group includes an aperture stop, one or more positive lenses, and one or more negative lenses, and has at least one lens surface that is an aspheric surface; the average partial dispersion ratios for the g-line and the F-line and the average Abbe numbers based on the d-line of the one or more positive lenses included in the positive lens group are respectively θgFap and νdap, the average partial dispersion ratios for the g-line and the F-line and the average Abbe numbers based on the d-line of the one or more negative lenses included in the positive lens group are respectively θgFan and νdan, the distance on the optical axis at the wide-angle end from the aperture stop to the lens surface in the rear lens group closest to the image side is dPw, and the distance on the optical axis from the lens surface in the positive lens group closest to the image side to the lens surface in the rear lens group closest to the object side is dIE. -2.0×10 -3 ≦(θgFap-θgFan) / (νdap-νdan)<0 0.15≦dIE / dPw≦0.80 A zoom lens characterized by satisfying the following conditions. (Configuration 2) When the lateral magnification of the positive lens group is βR, -0.2≦β5R≦0.5 2. The zoom lens according to claim 1, wherein the following condition is satisfied: (Configuration 3) Let dG1 be 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, and dz be 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 rear lens group closest to the image side, 0.3≦dG1 / dz≦0.5 3. The zoom lens according to configuration 1 or 2, which satisfies the following conditions: (Configuration 4) Let dGP1z be the distance between the most object side position and the most image side position of the positive lens group during zooming between the wide-angle end and the telephoto end, and dGN1z be the distance between the most object side position and the most image side position of the first negative lens group during zooming between the wide-angle end and the telephoto end, and let the distance be a positive distance when the lens group is located closer to the image side at the telephoto end than at the wide-angle end, 0.02≦dGP1z / dGN1z≦0.40 4. The zoom lens according to any one of configurations 1 to 3, which satisfies the following condition: (Configuration 5) The average value of the refractive index at the d-line of the one or more positive lenses included in the positive lens group is Ndap is the average value of the refractive index at the d line of the one or more negative lenses included in the positive lens, and Ndan is 0.1≦Ndan-Ndap≦0.5 5. The zoom lens according to any one of configurations 1 to 4, which satisfies the following condition: (Configuration 6) When the average value of the partial dispersion ratios for the g-line and the F-line of one or more positive lenses included in the rear lens group is θgFbp, and the average value of the partial dispersion ratios for the g-line and the F-line of one or more negative lenses included in the rear lens group is θgFbn, -0.07 ≤ θgFbp - θgFbn ≤ -0.02 6. The zoom lens according to any one of configurations 1 to 5, which satisfies the following condition: (Configuration 7) 7. The zoom lens according to any one of configurations 1 to 6, wherein the positive lens group has the aperture stop closest to the object side. (Configuration 8) When zooming from the wide-angle end to the telephoto end, the first negative lens unit moves toward the image side, the second negative lens unit moves to be located closer to the image side at the telephoto end than at the wide-angle end, 8. The zoom lens according to any one of configurations 1 to 7, wherein the positive lens group moves toward the image side and the object side. (Configuration 9) The zoom lens according to any one of configurations 1 to 8, wherein the first lens group has, as lens groups whose spacing changes during focusing, a negative lens group that does not move for focusing, a positive lens group that moves for focusing, and a positive lens group that does not move for focusing, arranged in this order from the object side to the image side. (Configuration 10) The zoom lens according to any one of configurations 1 to 9, and an image sensor for capturing an image of a subject through the zoom lens.

[0075] The embodiments described above are merely representative examples, and various modifications and alterations are possible for each embodiment when implementing the present invention. [Explanation of symbols]

[0076] G1, L1 First lens group L2 Second lens group L3: Third lens group L4 4th lens group L5 Fifth lens group GE rear lens group GZ moving group GN1, GN2 negative lens group GP1 positive lens group

Claims

1. A zoom lens having lens groups arranged in order from the object side, the lens groups being a first lens group having positive refractive power that does not move for zooming, a plurality of movable groups that each move for zooming, and a rear lens group having positive refractive power that does not move for zooming, in which the spacing between adjacent lens groups changes during zooming, the movable group includes a first negative lens group, a second negative lens group, and a positive lens group, arranged in this order from the object side to the image side; the positive lens group includes an aperture stop, one or more positive lenses, and one or more negative lenses; the average partial dispersion ratios for the g-line and the F-line and the average Abbe numbers based on the d-line of the one or more positive lenses included in the positive lens group are respectively θgFap and νdap, the average partial dispersion ratios for the g-line and the F-line and the average Abbe numbers based on the d-line of the one or more negative lenses included in the positive lens group are respectively θgFan and νdan, the distance on the optical axis at the wide-angle end from the aperture stop to the lens surface in the rear lens group closest to the image side is dPw, and the distance on the optical axis from the lens surface in the positive lens group closest to the image side to the lens surface in the rear lens group closest to the object side is dIE. -2.0×10 －３ ≦(θgFap-θgFan) / (νdap-νdan)<0 0.15≦dIE / dPw≦0.80 A zoom lens characterized by satisfying the following conditions.

2. When the lateral magnification of the positive lens group is βR, −0.2≦β5R≦0.5 2. The zoom lens according to claim 1, which satisfies the following condition:

3. Let dG1 be 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, and dz be 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 rear lens group closest to the image side, 0.3≦dG1 / dz≦0.5 2. The zoom lens according to claim 1, which satisfies the following condition:

4. Let dGP1z be the distance between the most object side position and the most image side position of the positive lens group during zooming between the wide-angle end and the telephoto end, and dGN1z be the distance between the most object side position and the most image side position of the first negative lens group during zooming between the wide-angle end and the telephoto end, and let the distance be a positive distance when the lens group is located closer to the image side at the telephoto end than at the wide-angle end, 0.02≦dGP1z / dGN1z≦0.40 2. The zoom lens according to claim 1, which satisfies the following condition:

5. The average value of the refractive index at the d-line of the one or more positive lenses included in the positive lens group is Ndap is the average value of the refractive index at the d line of the one or more negative lenses included in the positive lens, Ndan is 0.1≦Ndan−Ndap≦0.5 2. The zoom lens according to claim 1, which satisfies the following condition:

6. When the average value of the partial dispersion ratios for the g-line and the F-line of one or more positive lenses included in the rear lens group is θgFbp, and the average value of the partial dispersion ratios for the g-line and the F-line of one or more negative lenses included in the rear lens group is θgFbn, −0.07≦θgFbp−θgFbn≦−0.02 2. The zoom lens according to claim 1, which satisfies the following condition:

7. 2. The zoom lens according to claim 1, wherein the positive lens group has the aperture stop closest to the object side.

8. When zooming from the wide-angle end to the telephoto end, the first negative lens unit moves toward the image side, the second negative lens unit moves to be located closer to the image side at the telephoto end than at the wide-angle end, 2. The zoom lens according to claim 1, wherein the positive lens group moves toward the image side and the object side.

9. 2. The zoom lens according to claim 1, wherein the first lens group includes, as lens groups whose spacing changes during focusing, a negative lens group that does not move for focusing, a positive lens group that moves for focusing, and a positive lens group that does not move for focusing, arranged in this order from the object side to the image side.

10. A zoom lens according to any one of claims 1 to 9; and an image sensor for capturing an image of a subject through the zoom lens.

Images