Zoom lens and imaging device

Abstract

To provide a zoom lens which is compactly configured and yet has a high zoom ratio and offers good optical performance, and to provide an image capturing device having the same.SOLUTION: A zoom lens is provided, comprising a first lens group having positive refractive power, a second lens group having negative refractive power, an intermediate group comprising one or more lens groups, and a final lens group, arranged in order from the object side. The intermediate group has positive refractive power as a whole over an entire zoom range. A distance between the first lens group and the second lens group, a distance between the second lens group and the intermediate group, and a distance between the intermediate group and the final lens group change while zooming. The zoom lens satisfies predefined conditional expressions.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technology disclosed herein relates to a zoom lens and an imaging device. [Background technology]

[0002] Conventionally, the zoom lens described in Patent Document 1 below is known as a zoom lens that can be used in imaging devices such as digital cameras. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-086305 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] There is a demand for zoom lenses that are compact in size, yet possess a high magnification ratio and maintain good optical performance. These demands are increasing year by year.

[0005] The present disclosure aims to provide a zoom lens that is compact in size, yet has a high magnification ratio and maintains good optical performance, and an imaging device equipped with this zoom lens. [Means for solving the problem]

[0006] A zoom lens according to one aspect of this disclosure comprises, 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, an intermediate group including one or more lens groups, and a final lens group, wherein the intermediate group has positive refractive power as a whole throughout the entire range of magnification, and when magnification is changed, the distance between the first lens group and the second lens group changes, the distance between the second lens group and the intermediate group changes, the distance between the intermediate group and the final lens group changes, and if the intermediate group includes multiple lens groups, when magnification is changed, the distance between all adjacent lens groups within the intermediate group changes, and when the focal length of the entire system when focused on an object at infinity at the wide-angle end is fw, and when the focal length of the entire system when focused on an object at infinity at the telephoto end is ft, 6 <ft / fw<30 (1) The condition (1) expressed by is satisfied.

[0007] The zoom lens of the above embodiment preferably satisfies the following condition (1-1). 7.5 <ft / fw<20 (1-1)

[0008] If the Abbe number of the lens closest to the object in the first lens group is denoted by νd1 with respect to the d line, then the zoom lens in the above configuration is: 29.6 < νd1 < 50 (2) It is preferable that the condition (2) expressed by is satisfied.

[0009] If the Abbe number relative to the d line of the second lens from the object side in the first lens group is νd2, and the Abbe number relative to the d line of the third lens from the object side in the first lens group is νd3, then the zoom lens in the above configuration is: 68 < (νd² + νd³) / 2 < 98 (3) It is preferable that the condition expressed in equation (3) is satisfied.

[0010] The final lens group may be configured to have negative refractive power.

[0011] The first lens group may be configured to consist of a negative lens, a positive lens, and another positive lens, in that order from the object side to the image side.

[0012] The zoom lens according to the above aspect preferably includes a focus group that moves along the optical axis during focusing. The focus group preferably has a negative refractive power. The focus group preferably includes a positive lens and a negative lens. The focus group may be configured to be composed of a cemented lens in which a positive lens and a negative lens are cemented to each other. The fourth lens group from the object side of the zoom lens may be configured to be a focus group that moves along the optical axis during focusing.

[0013] The intermediate group preferably includes a lens group having at least one positive refractive power. The intermediate group may be configured to include the lens group having the most positive refractive power on the object side. The intermediate group may be configured to include, in order from the object side to the image side, a lens group having a positive refractive power and a lens group having a negative refractive power.

[0014] During zooming, all the lens groups may be configured to move.

[0015] The zoom lens according to the above aspect may be configured to be composed of five lens groups as a whole. Or, the zoom lens according to the above aspect may be configured to be composed of six lens groups as a whole.

[0016] The most object-side lens group of the intermediate group may be configured to include, in order from the object side to the image side, a positive lens, a positive lens, and a negative lens. The most object-side lens group of the intermediate group may be configured to include, in order from the image side to the object side, a positive lens, a positive lens, and a negative lens.

[0017] The second lens group may be configured to be composed of, in order from the object side to the image side, a negative lens, a negative lens, a positive lens, and a negative lens.

[0018] When the F-number in the state of focusing on an infinite object at the telephoto end is FNot, the zoom lens according to the above aspect satisfies 45 < FNot × (ft / fw) < 130 (4) It is preferable that the condition expressed in equation (4) is satisfied.

[0019] When the zoom lens is in focus on an object at infinity at the wide-angle end, and TLw is the sum of the distance along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the final lens group, and the back focus of the entire system in air equivalent distance, then the zoom lens of the above configuration is: 4.5 <TLw / fw<9.5 (5) It is preferable that the condition (5) expressed by is satisfied.

[0020] When the zoom lens is in focus on an object at infinity at the telephoto end, and TLt is the sum of the distance along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the final lens group, and the back focus of the entire system in air equivalent distance, then the zoom lens of the above configuration is: 0.5 <TLt / ft<1.3 (6) It is preferable that the condition expressed in equation (6) is satisfied.

[0021] When the zoom lens is in focus on an object at infinity at the telephoto end, if TLt is the sum of the distance along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the final lens group, and the back focus of the entire system in air equivalent distance, and ωt is the maximum half-angle of view when the zoom lens is in focus on an object at infinity at the telephoto end, then the zoom lens of the above configuration is: 10 <TLt / (ft×tanωt)<18 (7) It is preferable that the condition (7) expressed by is satisfied.

[0022] When the back focus of the entire system in air equivalent distance when focused on an object at infinity at the wide-angle end is Bfw, and the maximum half-angle of view when focused on an object at infinity at the wide-angle end is ωw, then the zoom lens of the above configuration is: 0.5 <Bfw / (fw×tanωw)<1.1 (8) It is preferable that the conditional expression (8) represented by is satisfied.

[0023] When the zoom lens of the above configuration is in focus on an object at infinity at the wide-angle end, if Denw is the distance along the optical axis from the lens surface closest to the object in the first lens group to the position of the paraxial entrance pupil, then the zoom lens of the above configuration is: 1.1 <Denw / fw<1.9 (9) It is preferable that the condition expressed in equation (9) is satisfied.

[0024] Let the fourth lens group from the object side of the zoom lens be the fourth lens group. When the fourth lens group moves during at least one of magnification and focusing, and DG4 is the distance along the optical axis from the lens surface closest to the object of the fourth lens group to the lens surface closest to the image of the fourth lens group, and TLw is the sum of the distance along the optical axis from the lens surface closest to the object of the first lens group to the lens surface closest to the image of the final lens group, when the lens is focused on an object at infinity at the wide-angle end, and the back focus of the entire system in air equivalent distance, then the zoom lens in the above configuration is: 0.009 <DG4 / TLw<0.12 (10) It is preferable that the conditional expression (10) represented by is satisfied.

[0025] In a configuration in which the zoom lens of the above embodiment includes a focus group that moves along the optical axis when focusing, if the average value of the specific gravity of all lenses in the focus group is Gfave, then the zoom lens of the above embodiment is 2.3 <Gfave<5.15 (11) It is preferable that the conditional expression (11) represented by is satisfied.

[0026] In a configuration in which the zoom lens of the above embodiment includes a focus group that moves along the optical axis when focusing, and the focus group includes at least one negative lens, if the specific gravity of the at least one negative lens of the focus group is Gfn, then the zoom lens of the above embodiment is 2.4 <Gfn<5.6 (12) It is preferable that the conditional expression (12) represented by is satisfied.

[0027] In the above configuration of the zoom lens, which includes an image stabilization group that moves in a direction intersecting the optical axis during image shake correction, if the average value of the specific gravity of all lenses in the image stabilization group is GISave, then the zoom lens in the above configuration is: 2.5 <GISave<5.2 (13) It is preferable that the conditional expression (13) represented by is satisfied.

[0028] In a configuration where the zoom lens of the above embodiment includes an image stabilization group that moves in a direction intersecting the optical axis during image shake correction, and the image stabilization group includes at least one positive lens, if the specific gravity of the at least one positive lens of the image stabilization group is GISp, then the zoom lens of the above embodiment is 2.6 <GISp<5 (14) It is preferable that the conditional expression (14) represented by is satisfied.

[0029] Let M1 be the amount of movement of the first lens group when zooming from the wide-angle end to the telephoto end, with the sign of M1 being positive when moving from the object side to the image side and negative when moving from the image side to the object side, and let TLt be the sum of the distance on the optical axis from the lens surface closest to the object of the first lens group to the lens surface closest to the image of the final lens group, and the back focus of the entire system in air equivalent distance, when the zoom lens of the above configuration is in focus on an object at infinity at the telephoto end, then the zoom lens of the above configuration is: 0.25 <- M1 / TLt < 0.6 (15) It is preferable that the conditional expression (15) represented by is satisfied.

[0030] Let M2 be the amount of movement of the second lens group when changing magnification from the wide-angle end to the telephoto end, with the sign of M2 being positive when moving from the object side to the image side and negative when moving from the image side to the object side, and let TLt be the sum of the distance on the optical axis from the lens surface closest to the object of the first lens group to the lens surface closest to the image of the final lens group, and the back focus of the entire system in air equivalent distance, when the zoom lens of the above configuration is in focus on an object at infinity at the telephoto end, then the zoom lens of the above configuration is: 0.01 <- M2 / TLt < 0.2 (16) It is preferable that the conditional expression (16) represented by is satisfied.

[0031] Let the lens group closest to the object in the intermediate group be the third lens group, and let M3 be the amount of movement of the third lens group when zooming from the wide-angle end to the telephoto end, with the sign of M3 being positive when moving from the object side to the image side and negative when moving from the image side to the object side, and let TLt be the sum of the distance on the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the final lens group, and the back focus of the entire system in air equivalent distance, when in focus on an object at infinity at the telephoto end, then the zoom lens of the above configuration is: 0.08 <- M3 / TLt < 0.4 (17) It is preferable that the conditional expression (17) represented by is satisfied.

[0032] Let the fourth lens group from the object side of the zoom lens be the fourth lens group, and let M4 be the amount of movement of the fourth lens group when changing magnification from the wide-angle end to the telephoto end, with the sign of M4 being positive when moving from the object side to the image side and negative when moving from the image side to the object side, and let TLt be the sum of the distance on the optical axis from the lens surface closest to the object of the first lens group to the lens surface closest to the image of the last lens group, and the back focus of the entire system in air equivalent distance, when the zoom lens of the above configuration is in focus on an object at infinity at the telephoto end, then the zoom lens of the above configuration is: 0.15 <- M4 / TLt < 0.3 (18) It is preferable that the conditional expression (18) represented by is satisfied.

[0033] Let the fifth lens group from the object side of the zoom lens be the fifth lens group, and let M5 be the amount of movement of the fifth lens group when changing magnification from the wide-angle end to the telephoto end, with the sign of M5 being positive when moving from the object side to the image side and negative when moving from the image side to the object side, and let TLt be the sum of the distance on the optical axis from the lens surface closest to the object of the first lens group to the lens surface closest to the image of the last lens group, and the back focus of the entire system in air equivalent distance, when the zoom lens of the above configuration is in focus on an object at infinity at the telephoto end, then the zoom lens of the above configuration is: 0.11 < -M5 / TLt < 0.31 (19) It is preferable that the condition expressed in equation (19) is satisfied.

[0034] If the center thickness of the lens closest to the object in the first lens group is d1, and the effective diameter of the object-side surface of the lens closest to the object in the first lens group is ED1, then the zoom lens in the above configuration is: 0.022 <d1 / ED1<0.04 (20) It is preferable that the conditional expression (20) represented by is satisfied.

[0035] If d1 is the central thickness of the lens closest to the object in the first lens group, Denw is the distance along the optical axis from the lens surface closest to the object in the first lens group to the position of the paraxial entrance pupil when in focus on an object at infinity at the wide-angle end, and ωw is the maximum half-angle of view when in focus on an object at infinity at the wide-angle end, then the zoom lens of the above configuration is: 0.035 <d1 / (Denw×tanωw)<0.077 (21) It is preferable that the conditional expression (21) represented by is satisfied.

[0036] If the central thickness of the second lens from the object side in the first lens group is d2, the paraxial radius of curvature of the object-side surface of the second lens from the object side in the first lens group is R2f, and the paraxial radius of curvature of the image-side surface of the second lens from the object side in the first lens group is R2r, then the zoom lens in the above configuration is: 0.06 <d2×(1 / R2f-1 / R2r)<0.19 (22) It is preferable that the conditional expression (22) represented by is satisfied.

[0037] If the center thickness of the lens closest to the object in the first lens group is d1 and the focal length of the first lens group is f1, then the zoom lens in the above configuration is: 0.01 <d1 / f1<0.021 (23) It is preferable that the conditional expression (23) represented by is satisfied.

[0038] If d1 is the central thickness of the lens closest to the object in the first lens group, and DG1 is the distance along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the first lens group, then the zoom lens in the above configuration is: 0.06 <d1 / DG1<0.125 (24) It is preferable that the conditional expression (24) represented by is satisfied.

[0039] If the Abbe number of the second lens from the object side in the first lens group is νd2 with respect to the d line, then the zoom lens in the above embodiment is: 75 < νd2 < 120 (25) It is preferable that the conditional expression (25) represented by is satisfied.

[0040] If the Abbe number of the third lens from the object side in the first lens group is νd3, then the zoom lens in the above configuration is: 70 < νd3 < 110 (26) It is preferable that the conditional expression (26) represented by is satisfied.

[0041] If the partial dispersion ratio between the g-line and the F-line of the second lens from the object side in the first lens group is θgF2, then the zoom lens in the above embodiment is: 0.46 < θgF2 < 0.62 (27) It is preferable that the conditional expression (27) represented by is satisfied.

[0042] If the partial dispersion ratio between the g-line and the F-line of the third lens from the object side in the first lens group is θgF3, then the zoom lens in the above embodiment is: 0.46 < θgF3 < 0.62 (28) It is preferable that the conditional expression (28) represented by is satisfied.

[0044] In a configuration in which the zoom lens of the above embodiment includes a focus group that moves along the optical axis when focusing, if the paraxial radius of curvature of the lens surface on the object side of the focus group is RfF and the paraxial radius of curvature of the lens surface on the image side of the focus group is RfR, then the zoom lens of the above embodiment is 1.5 <RfF / RfR<6 (30) It is preferable that the conditional expression (30) represented by is satisfied.

[0045] In a configuration in which the zoom lens of the above embodiment includes a focus group that moves along the optical axis when focusing, if the focal length of the focus group is ffoc, the zoom lens of the above embodiment is -0.35 <ffoc / ft<-0.02 (31) It is preferable that the conditional expression (31) represented by is satisfied.

[0046] Zoom lens in the above configuration The statue In a configuration including an image stabilization group that moves in a direction intersecting the optical axis during image stabilization, if the focal length of the image stabilization group is fIS, then the zoom lens in the above configuration is: 0.01 < |fIS / ft| < 0.35 (32) It is preferable that the conditional expression (32) represented by is satisfied.

[0047] If the focal length of the second lens group is f2 and the focal length of the second lens from the object side in the second lens group is fL22, then the zoom lens in the above configuration is: 1.4 <fL22 / f2<7 (33) It is preferable that the conditional expression (33) represented by is satisfied.

[0048] In a configuration in which the zoom lens of the above embodiment includes a focus group that moves along the optical axis when focusing, if the lateral magnification of the focus group when focused on an object at infinity at the wide-angle end is βfw, and the combined lateral magnification of all lenses on the image side of the focus group when focused on an object at infinity at the wide-angle end is βfRw, then the zoom lens of the above embodiment is: -6<(1-βfw 2 )×βfRw 2 <-1 (34) It is preferable that the conditional expression (34) represented by is satisfied.

[0049] In a configuration in which the zoom lens of the above embodiment includes a focus group that moves along the optical axis when focusing, if the lateral magnification of the focus group when focused on an object at infinity at the telephoto end is βft, and the combined lateral magnification of all lenses on the image side of the focus group when focused on an object at infinity at the telephoto end is βfRt, then the zoom lens of the above embodiment is: -25<(1-βft 2 )×βfRt 2 <-6.3 (35) It is preferable that the conditional expression (35) represented by is satisfied.

[0050] In the above configuration of a zoom lens including an image stabilization group that moves in a direction intersecting the optical axis during image shake correction, if the lateral magnification of the image stabilization group when focused on an object at infinity at the wide-angle end is βISw, and the combined lateral magnification of all lenses on the image side of the image stabilization group when focused on an object at infinity at the wide-angle end is βISRw, then the above configuration of the zoom lens is: 0.75<|(1-βISw)×βISRw|<2.5 (36) It is preferable that the conditional expression (36) represented by is satisfied.

[0051] In a configuration of the zoom lens described above that includes an image stabilization group that moves in a direction intersecting the optical axis during image shake correction, if the lateral magnification of the image stabilization group when focused on an object at infinity at the telephoto end is βISt, and the combined lateral magnification of all lenses on the image side of the image stabilization group when focused on an object at infinity at the telephoto end is βISRt, then the zoom lens described above is: 1.7<|(1-βISt)×βISRt|<7 (37) It is preferable that the conditional expression (37) represented by is satisfied.

[0052] In a configuration of the zoom lens described above, which includes a focus group that moves along the optical axis when focusing, let βfw be the lateral magnification of the focus group when focused on an object at infinity at the wide-angle end, βfRw be the combined lateral magnification of all lenses on the image side of the focus group when focused on an object at infinity at the wide-angle end, ffoc be the focal length of the focus group, ffRw be the combined focal length of all lenses on the image side of the focus group when focused on an object at infinity at the wide-angle end, Dexw be the sum of the distance along the optical axis from the paraxial exit pupil position to the image-side lens surface of the final lens group and the back focus of the entire system in air equivalent distance when focused on an object at infinity at the wide-angle end, and ωw be the maximum half-angle of view when focused on an object at infinity at the wide-angle end, then γw = (1 - βfw2 )×βfRw 2 If we assume that BRw = {βfw / (ffoc×γw)-1 / (βfRw×ffRw)-(1 / Dexw)}, then the zoom lens of the above configuration is, 0 < |BRw × (fw × tanωw)| < 0.25 (38) It is preferable that the conditional expression (38) represented by is satisfied.

[0053] In a configuration of the zoom lens described above, which includes a focus group that moves along the optical axis when focusing, let βft be the lateral magnification of the focus group when focused on an object at infinity at the telephoto end, βfRt be the combined lateral magnification of all lenses on the image side of the focus group when focused on an object at infinity at the telephoto end, ffoc be the focal length of the focus group, ffRt be the combined focal length of all lenses on the image side of the focus group when focused on an object at infinity at the telephoto end, Dext be the sum of the distance along the optical axis from the paraxial exit pupil position to the image-side lens surface of the final lens group and the back focus of the entire system in air equivalent distance when focused on an object at infinity at the telephoto end, and ωt be the maximum half-angle of view when focused on an object at infinity at the telephoto end, then γt = (1 - βft 2 )×βfRt 2 If we assume that BRt = {βft / (ffoc×γt)-1 / (βfRt×ffRt)-(1 / Dext)}, then the zoom lens of the above configuration is, 0 < |BRt × (ft × tanωt)| < 0.034 (39) It is preferable that the conditional expression (39) represented by is satisfied.

[0054] When the focal length of the first lens group is f1 and the focal length of the second lens group is f2, the zoom lens in the above configuration is: -10 <f1 / f2<-5.6 (40) It is preferable that the conditional expression (40) represented by is satisfied.

[0055] If the focal length of the second lens group is f2 and the focal length of the lens group closest to the object in the intermediate group is f3, then the zoom lens in the above configuration is: -0.9 <f2 / f3<-0.54 (41) It is preferable that the conditional expression (41) represented by is satisfied.

[0056] The lens group closest to the object in the intermediate group preferably includes five or more lenses.

[0057] In the configuration of the zoom lens described above, which includes a focus group that moves along the optical axis when focusing, it is preferable that the number of lenses included in the focus group is two or less.

[0058] The lens system may be configured such that, when changing magnification from the wide-angle end to the telephoto end, only five of the movement trajectories of each lens group are different from one another.

[0059] The zoom lens of the above embodiment may be configured to include multiple lens groups that move along the same trajectory when changing magnification from the wide-angle end to the telephoto end. In that case, the zoom lens of the above embodiment may include a focus group that moves along the optical axis when focusing, and the focus group may be configured to be positioned between multiple lens groups that move along the same trajectory.

[0060] When zooming from the wide-angle end to the telephoto end, the fourth lens group from the object side of the zoom lens and the final lens group may be configured to move along the same trajectory.

[0061] If the fourth lens group from the object side of the zoom lens is designated as the fourth lens group, and the amount of movement of the fourth lens group during magnification from the wide-angle end to the telephoto end is M4, and the amount of movement of the final lens group during magnification from the wide-angle end to the telephoto end is ME, and the signs of M4 and ME are positive when moving from the object side to the image side and negative when moving from the image side to the object side, then the zoom lens in the above configuration is: 0.9 <M4 / ME<1.1 (42) It is preferable that the conditional expression (42) represented by is satisfied.

[0062] When the focal length of the intermediate group is fMw when the lens is in focus on an object at infinity at the wide-angle end, the zoom lens of the above configuration is: 0.54 <fw / fMw<0.95 (43) It is preferable that the conditional expression (43) represented by is satisfied.

[0063] When the focal length of the intermediate group is fMt when the lens is in focus on an object at infinity at the telephoto end, the zoom lens of the above configuration is: 5.1 <ft / fMt<20 (44) It is preferable that the conditional expression (44) represented by is satisfied.

[0064] In a configuration in which the zoom lens of the above embodiment includes a focus group that moves along the optical axis when focusing, the amount of movement of the lens group adjacent to the object side of the focus group when changing magnification from the wide-angle end to the telephoto end is MfF, and the amount of movement of the lens group adjacent to the image side of the focus group when changing magnification from the wide-angle end to the telephoto end is MfR, and the signs of MfF and MfR are positive when moving from the object side to the image side and negative when moving from the image side to the object side, then the zoom lens of the above embodiment is, 0.9 <MfF / MfR<1.1 (45) It is preferable that the conditional expression (45) represented by is satisfied.

[0065] The zoom lens in the above embodiment may be configured to include eight or more aspherical lens surfaces.

[0066] The lens closest to the image in the second lens group may be configured to include an aspherical surface. The lens closest to the object in the second lens group may also be configured to include an aspherical surface.

[0067] The lens closest to the image in the lens group closest to the object within the intermediate group may be configured to include an aspherical surface.

[0068] The object-side surface of the image-side lens in the second lens group may be configured to have an aspherical shape such that the refractive power at the position of the maximum effective diameter is weaker than the refractive power near the optical axis.

[0069] The image-side surface of the lens closest to the object in the second lens group may be configured to have an aspherical shape, where the refractive power at the position of the maximum effective diameter is stronger than the refractive power near the optical axis.

[0070] The object-side surface of the image-side lens in the object-side lens group of the intermediate group may be configured to have an aspherical shape in which the refractive power at the position of the maximum effective diameter is weaker than the refractive power near the optical axis.

[0071] The image-side surface of the lens closest to the object in the intermediate lens group may be configured to have an aspherical shape such that the refractive power at the position of the maximum effective diameter is weaker than the refractive power near the optical axis.

[0072] If the paraxial radius of curvature of the object-side surface of the image-side lens in the second lens group is Rc2ef, and the radius of curvature of the object-side surface of the image-side lens in the second lens group at the position of the maximum effective diameter is Ry2ef, then the zoom lens in the above configuration is: 0.1 <Rc2ef / Ry2ef<0.999 (46) It is preferable that the conditional expression (46) represented by is satisfied.

[0073] If the paraxial radius of curvature of the image-side surface of the lens closest to the object in the second lens group is Rc21r, and the radius of curvature at the position of the maximum effective diameter of the image-side surface of the lens closest to the object in the second lens group is Ry21r, then the zoom lens in the above configuration is: 1.001 <Rc21r / Ry21r<4.5 (47) It is preferable that the conditional expression (47) represented by is satisfied.

[0074] If Rc3ef is the paraxial radius of curvature of the object-side surface of the image-side lens in the object-side lens group of the intermediate group, and Ry3ef is the radius of curvature of the object-side surface of the image-side lens in the object-side lens group of the intermediate group at the position of the maximum effective diameter, then the zoom lens of the above configuration is: 0.1 <Rc3ef / Ry3ef<0.999 (48) It is preferable that the conditional expression (48) represented by is satisfied.

[0075] If the paraxial radius of curvature of the image-side surface of the lens closest to the object in the intermediate lens group is Rc31r, and the radius of curvature of the image-side surface of the lens closest to the object in the intermediate lens group at the position of the maximum effective diameter is Ry31r, then the zoom lens of the above configuration is: 0 <Rc31r / Ry31r<0.999 (49) It is preferable that the conditional expression (49) represented by is satisfied.

[0076] If the paraxial radius of curvature of the object-side surface of the image-side lens of the second lens group is Rc2ef, the paraxial radius of curvature of the image-side surface of the image-side lens of the second lens group is Rc2er, the radius of curvature of the object-side surface of the image-side lens of the second lens group at the position of the maximum effective diameter is Ry2ef, and the radius of curvature of the image-side surface of the image-side lens of the second lens group at the position of the maximum effective diameter is Ry2er, then the zoom lens of the above configuration is: 1.05<(1 / Rc2ef-1 / Rc2er) / (1 / Ry2ef-1 / Ry2er)<5 (50) It is preferable that the conditional expression (50) represented by is satisfied.

[0077] If the paraxial radius of curvature of the object-side surface of the lens closest to the object in the second lens group is Rc21f, the paraxial radius of curvature of the image-side surface of the lens closest to the object in the second lens group is Rc21r, the radius of curvature at the position of the maximum effective diameter of the object-side surface of the lens closest to the object in the second lens group is Ry21f, and the radius of curvature at the position of the maximum effective diameter of the image-side surface of the lens closest to the object in the second lens group is Ry21r, then the zoom lens in the above configuration is: 0.4<(1 / Rc21f-1 / Rc21r) / (1 / Ry21f-1 / Ry21r)<0.99 (51) It is preferable that the conditional expression (51) represented by is satisfied.

[0078] If the paraxial radius of curvature of the object-side surface of the image-side lens in the object-side lens group of the intermediate group is Rc3ef, the paraxial radius of curvature of the image-side surface of the image-side lens in the object-side lens group of the intermediate group is Rc3er, the radius of curvature of the object-side surface of the image-side lens in the object-side lens group of the intermediate group at the position of the maximum effective diameter is Ry3ef, and the radius of curvature of the image-side surface of the image-side lens in the object-side lens group of the intermediate group at the position of the maximum effective diameter is Ry3er, then the zoom lens of the above configuration is: 1.01<(1 / Rc3ef-1 / Rc3er) / (1 / Ry3ef-1 / Ry3er)<2 (52) It is preferable that the conditional expression (52) represented by is satisfied.

[0079] If the paraxial radius of curvature of the object-side surface of the lens closest to the object in the intermediate lens group is Rc31f, the paraxial radius of curvature of the image-side surface of the lens closest to the object in the intermediate lens group is Rc31r, the radius of curvature at the position of the maximum effective diameter of the object-side surface of the lens closest to the object in the intermediate lens group is Ry31f, and the radius of curvature at the position of the maximum effective diameter of the image-side surface of the lens closest to the object in the intermediate lens group is Ry31r, then the zoom lens of the above configuration is: 1.1<(1 / Rc31f-1 / Rc31r) / (1 / Ry31f-1 / Ry31r)<3 (53) It is preferable that the conditional expression (53) represented by is satisfied.

[0080] An imaging device according to another aspect of the present disclosure comprises a zoom lens according to the above aspect of the present disclosure.

[0081] Furthermore, the terms "~consisting of" and "~consisting of" in this specification are intended to include, in addition to the listed components, lenses that substantially have no refractive power, optical elements other than lenses such as apertures, filters, and cover glass, and mechanical parts such as lens flanges, lens barrels, image sensors, and image stabilization mechanisms.

[0082] In this specification, "a group having positive refractive power" and "a group having positive refractive power" mean that the group as a whole has positive refractive power. Similarly, "a group having negative refractive power" and "a group having negative refractive power" mean that the group as a whole has negative refractive power. "A lens having positive refractive power" and "a positive lens" are synonymous. "A lens having negative refractive power" and "a negative lens" are synonymous. In this specification, "the first lens group," "the second lens group," "the intermediate group," "the lens group," "the final lens group," "the focusing group," and "the image stabilization group" are not limited to configurations consisting of multiple lenses, but may also consist of only one lens.

[0083] A composite aspherical lens (a lens in which a spherical lens and an aspherical film formed on that spherical lens are integrally constructed and function as a single aspherical lens as a whole) is not considered a cemented lens and is treated as a single lens. Unless otherwise specified, the sign of the refractive force and the surface shape for lenses including aspherical surfaces shall be those of the paraxial region. The sign of the radius of curvature shall be positive for the radius of curvature of a surface with a convex shape facing the object, and negative for the radius of curvature of a surface with a convex shape facing the image.

[0084] In this specification, "entire system" refers to a zoom lens. The "focal length" used in the conditional equations is the paraxial focal length. Unless otherwise specified, the "distance on the optical axis" used in the conditional equations is a geometric distance. Unless otherwise specified, the values ​​used in the conditional equations are those with the d line as the reference when the lens is in focus on an object at infinity.

[0085] The terms "d-line," "C-line," "F-line," and "g-line" used herein are emission lines. The wavelength of the d-line is treated as 587.56 nm (nanometers), the wavelength of the C-line as 656.27 nm (nanometers), the wavelength of the F-line as 486.13 nm (nanometers), and the wavelength of the g-line as 435.84 nm (nanometers). [Effects of the Invention]

[0086] According to this disclosure, it is possible to provide a zoom lens that is compact in size, yet has a high magnification ratio and maintains good optical performance, and an imaging device equipped with this zoom lens. [Brief explanation of the drawing]

[0087] [Figure 1] This figure corresponds to the zoom lens of Example 1 and shows a cross-sectional view and movement trajectory of the configuration of a zoom lens according to one embodiment. [Figure 2] This figure shows the configuration and light beam of the zoom lens at each magnification state. [Figure 3] This is a diagram to explain the effective diameter. [Figure 4] This is a diagram to explain aspherical shapes. [Figure 5] These are aberration diagrams of the zoom lens of Example 1. [Figure 6] This figure shows a cross-sectional view and movement trajectory of the zoom lens configuration in Example 2. [Figure 7] These are aberration diagrams for the zoom lens of Example 2. [Figure 8] This figure shows a cross-sectional view and movement trajectory of the zoom lens configuration in Example 3. [Figure 9] This figure shows the configuration and light beam of the zoom lens of Example 3 in each magnification state. [Figure 10] These are aberration diagrams for the zoom lens of Example 3. [Figure 11] This figure shows a cross-sectional view and movement trajectory of the zoom lens configuration in Example 4. [Figure 12] These are aberration diagrams for the zoom lens of Example 4. [Figure 13] This figure shows a cross-sectional view and movement trajectory of the zoom lens configuration of Example 5. [Figure 14] These are aberration diagrams for the zoom lens of Example 5. [Figure 15] This figure shows a cross-sectional view and movement trajectory of the zoom lens configuration of Example 6. [Figure 16] These are aberration diagrams for the zoom lens of Example 6. [Figure 17] This figure shows a cross-sectional view and movement trajectory of the zoom lens configuration of Example 7. [Figure 18] These are aberration diagrams for the zoom lens of Example 7. [Figure 19] This figure shows a cross-sectional view and movement trajectory of the zoom lens configuration of Example 8. [Figure 20] This figure shows the configuration and light beam of the zoom lens of Example 8 in each magnification state. [Figure 21] These are aberration diagrams for the zoom lens of Example 8. [Figure 22] This is a front perspective view of an imaging device according to one embodiment. [Figure 23] This is a perspective view of the rear side of an imaging device according to one embodiment. [Modes for carrying out the invention]

[0088] Embodiments of this disclosure will be described below with reference to the drawings.

[0089] Figure 1 shows a cross-sectional view and movement trajectory of the configuration of a zoom lens at the wide-angle end according to one embodiment of the present disclosure. Figure 2 shows cross-sectional views and light beams of the configuration of the zoom lens in Figure 1 at each state. In Figure 2, the upper section labeled "WIDE" shows the wide-angle end state, and the lower section labeled "TELE" shows the telephoto end state. In Figure 2, the light beams are shown as the axial light beam wa and the light beam wb of the maximum half-angle ωw at the wide-angle end state, and the axial light beam ta and the light beam tb of the maximum half-angle ωt at the telephoto end state. The examples shown in Figures 1 and 2 correspond to the zoom lens of Embodiment 1 described later. Figures 1 and 2 show the state when focused on an object at infinity, with the left side being the object side and the right side being the image side. The zoom lens according to one embodiment of the present disclosure will be described below, mainly with reference to Figure 1.

[0090] Figure 1 shows an example where a parallel plate-shaped optical element PP is placed between the zoom lens and the image plane Sim, assuming that a zoom lens is applied to the imaging device. The optical element PP is a component that is intended to be various filters and / or cover glass. The various filters include low-pass filters, infrared cut filters, and / or filters that cut out a specific wavelength range. The optical element PP is a component that does not have refractive power. It is also possible to configure the imaging device without the optical element PP.

[0091] The zoom lens of this disclosure comprises, in order from the object side to the image side along the optical axis Z, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an intermediate group GM including one or more lens groups, and a final lens group GE. When the magnification is changed, the distance between the first lens group G1 and the second lens group G2 changes, the distance between the second lens group G2 and the intermediate group GM changes, and the distance between the intermediate group GM and the final lens group GE changes. Furthermore, if the intermediate group GM includes multiple lens groups, the distance between all adjacent lens groups within the intermediate group GM changes when the magnification is changed. The above configuration is advantageous for achieving a high magnification ratio. The intermediate group GM has a positive refractive power as a whole throughout the entire magnification range. Setting the refractive power of the intermediate group GM in this way is advantageous for shortening the overall length of the lens system.

[0092] In this specification, "first lens group G1," "second lens group G2," the "lens group" included in the intermediate group GM, and the "final lens group GE" are components of a zoom lens, each containing at least one lens, separated by the air gap that changes during magnification. During magnification, each lens group is moved or fixed, and the inter-lens spacing within each lens group does not change. In other words, in this specification, a group in which the spacing between adjacent groups changes during magnification, but the total spacing between adjacent lenses within itself does not change, is considered a single lens group.

[0093] As an example, the zoom lens in Figure 1 consists of the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5, in order from the object side to the image side. In the example in Figure 1, the intermediate group GM consists of the third lens group G3 and the fourth lens group G4, and the final lens group GE consists of the fifth lens group G5. Configuring the zoom lens to consist of five lens groups in total in this way is advantageous in shortening the overall length of the lens system while simplifying the magnification mechanism.

[0094] As an example, each lens group in Figure 1 is composed of the lenses described below. The first lens group G1 consists of three lenses, L11 to L13, arranged from the object side to the image side. The second lens group G2 consists of four lenses, L21 to L24, arranged from the object side to the image side. The third lens group G3 consists of an aperture diaphragm St and seven lenses, L31 to L37, arranged from the object side to the image side. The fourth lens group G4 consists of two lenses, L41 to L42, arranged from the object side to the image side. The fifth lens group G5 consists of two lenses, L51 to L52, arranged from the object side to the image side. The aperture diaphragm St in Figure 1 does not represent shape or size, but rather its position in the optical axis direction.

[0095] In the example in Figure 1, during magnification, all lens groups move along the optical axis Z, changing the spacing between adjacent lens groups. The curved arrows below each of the five lens groups in Figure 1 show the approximate movement trajectory of each lens group during magnification from the wide-angle end to the telephoto end. Configuring all lens groups to move during magnification, as in the example in Figure 1, is advantageous for suppressing aberrations across the entire magnification range.

[0096] The first lens group G1 may be configured to consist of a negative lens, a positive lens, and another positive lens, in that order from the object side to the image side. In this case, the overall length of the lens system is shortened, which is advantageous in suppressing lateral chromatic aberration at the wide-angle end and axial chromatic aberration at the telephoto end.

[0097] The second lens group G2 may be configured to consist of a negative lens, a negative lens, a positive lens, and a negative lens, in that order from the object side to the image side. This configuration is advantageous for suppressing chromatic aberration at the wide-angle end.

[0098] The intermediate lens group GM preferably includes at least one lens group having positive refractive power. This is advantageous for shortening the overall length of the lens system. The intermediate lens group GM may also be configured to include the lens group having positive refractive power closest to the object. This is advantageous for shortening the overall length of the lens system. The intermediate lens group GM may also be configured to include a lens group having positive refractive power and a lens group having negative refractive power, in a continuous sequence from the object side to the image side. This is advantageous for suppressing field curvature.

[0099] The lens group closest to the object in the intermediate GM group may be configured to include a positive lens, a positive lens, and a negative lens in a continuous sequence from the object side to the image side. This configuration is advantageous for suppressing spherical aberration. A more preferred configuration is one in which the lens group closest to the object in the intermediate GM group includes a positive lens, a positive lens, and a negative lens in a continuous sequence from the object side to the image side.

[0100] The lens group closest to the object in the intermediate GM group may be configured to include a positive lens, a positive lens, and a negative lens in a continuous sequence from the image side to the object side. This configuration is advantageous for suppressing field curvature. A more preferred configuration is one in which the lens group closest to the object in the intermediate GM group includes a positive lens, a positive lens, and a negative lens in a continuous sequence from the image side to the object side.

[0101] The lens group closest to the object in the intermediate GM group may be configured to include five or more lenses. This configuration is advantageous in suppressing fluctuations in spherical aberration during magnification.

[0102] The final lens group GE may be configured to have negative refractive power. This configuration is advantageous for shortening the overall length of the lens system.

[0103] The zoom lens of this disclosure preferably includes a focus group that moves along the optical axis Z during focusing. In this specification, the group that moves along the optical axis Z during focusing is referred to as the focus group. Focusing is achieved by the movement of the focus group. In the example of Figure 1, the focus group consists of the fourth lens group G4. The parentheses and rightward arrow below the fourth lens group G4 in Figure 1 indicate that the fourth lens group G4 is a focus group that moves toward the image side when focusing from an object at infinity to the nearest object.

[0104] As shown in the example in Figure 1, configuring the zoom lens so that the fourth lens group from the object side is the focusing group is advantageous in suppressing changes in the angle of view during focusing.

[0105] The focusing group preferably has negative refractive power. In this case, the amount of movement of the focusing group during focusing can be suppressed, which is advantageous for making the entire system smaller and lighter. The focusing group preferably includes at least one negative lens. In this case, it is advantageous for suppressing fluctuations in chromatic aberration during focusing.

[0106] The focusing group preferably includes a positive lens and a negative lens. This configuration is advantageous in suppressing fluctuations in chromatic aberration during focusing. The focusing group may also be configured as a cemented lens in which the positive lens and the negative lens are joined together. This configuration is advantageous in suppressing fluctuations in chromatic aberration during focusing and is also advantageous in terms of miniaturization compared to the case in which the positive lens and the negative lens are not joined together.

[0107] The number of lenses included in the focusing group is preferably two or less. This is advantageous for reducing the weight of the focusing group.

[0108] The zoom lens of this disclosure preferably includes an image stabilization group that moves in a direction intersecting the optical axis Z during image shake correction. In this specification, the group that moves in a direction intersecting the optical axis Z during image shake correction is referred to as the image stabilization group. Image shake correction is performed by the movement of the image stabilization group. In the example of Figure 1, the image stabilization group consists of the second lens group G2. The parentheses and vertical double arrows below the second lens group G2 in Figure 1 indicate that the second lens group G2 is an image stabilization group.

[0109] The image stabilization group preferably includes at least one positive lens. This is advantageous in suppressing fluctuations in chromatic aberration during image blur correction.

[0110] Next, preferred and possible configurations of the conditional formulas for the zoom lens of this disclosure will be described. In the following description of the conditional formulas, the same symbols will be used for the same definitions to avoid redundant explanations, and some redundant explanations of symbols will be omitted. Also, in the following, to avoid redundant explanations, "the zoom lens of this disclosure" will also be simply referred to as "the zoom lens."

[0111] When the total focal length of the system when focused on an object at infinity at the wide-angle end is fw, and the total focal length of the system when focused on an object at infinity at the telephoto end is ft, it is preferable that the zoom lens satisfies the following condition (1). By ensuring that the corresponding value of condition (1) does not fall below the lower limit, an optical system with a higher magnification ratio can be provided. By ensuring that the corresponding value of condition (1) does not exceed the upper limit, the magnification ratio does not become too high, which is advantageous for miniaturization. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (1-1), and even more preferable that it satisfies the following condition (1-2). 6 <ft / fw<30 (1) 7.5 <ft / fw<20 (1-1) 9 <ft / fw<16.5 (1-2)

[0112] When νd1 is the Abbe number of the object-side lens in the first lens group G1 with respect to the d line, it is preferable that the zoom lens satisfies the following condition (2). By ensuring that the corresponding value in condition (2) does not fall below the lower limit, it is possible to suppress overcorrection of axial chromatic aberration at the telephoto end. By ensuring that the corresponding value in condition (2) does not exceed the upper limit, it is advantageous for correcting axial chromatic aberration at the telephoto end. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (2-1), and even more preferable that it satisfies the following condition (2-2). 29.6 < νd1 < 50 (2) 30.5 < νd1 < 46 (2-1) 31.6 < νd1 < 42.8 (2-2)

[0113] If the Abbe number of the second lens from the object side in the first lens group G1 is νd2 relative to the d line, and the Abbe number of the third lens from the object side in the first lens group G1 is νd3 relative to the d line, then it is preferable for the zoom lens to satisfy the following condition (3). By ensuring that the corresponding value in condition (3) does not fall below the lower limit, it is advantageous for correcting axial chromatic aberration at the telephoto end. By ensuring that the corresponding value in condition (3) does not exceed the upper limit, it is possible to suppress overcorrection of axial chromatic aberration at the telephoto end. To obtain even better characteristics, it is more preferable for the zoom lens to satisfy the following condition (3-1), and even more preferable for it to satisfy the following condition (3-2). 68 < (νd² + νd³) / 2 < 98 (3) 77.5 < (νd² + νd³) / 2 < 95 (3-1) 81.55 < (νd2 + νd3) / 2 < 93 (3-2)

[0114] When the F-number at the telephoto end, when focused on an object at infinity, is denoted as FNot, it is preferable that the zoom lens satisfies the following condition (4). If the aperture diameter of the aperture diaphragm St is variable, FNot shall be the value of the open F-number. Ensuring that the corresponding value in condition (4) does not fall below the lower limit is advantageous for achieving a high magnification ratio. Ensuring that the corresponding value in condition (4) does not exceed the upper limit is advantageous for reducing the F-number. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (4-1), and even more preferable that it satisfies the following condition (4-2). 45 <FNot×(ft / fw)<130 (4) 56 <FNot×(ft / fw)<120 (4-1) 58 <FNot×(ft / fw)<107 (4-2)

[0115] It is preferable that the zoom lens satisfies the following condition (5). Here, TLw is the sum of the distance along the optical axis from the lens surface closest to the object of the first lens group G1 to the lens surface closest to the image of the final lens group GE, when the lens is in focus on an object at infinity at the wide-angle end, and the back focus of the entire system in air equivalent distance. Note that "back focus of the entire system in air equivalent distance" is the distance along the optical axis from the lens surface closest to the image of the entire system to the image plane. Keeping the corresponding value of condition (5) above the lower limit is advantageous for suppressing various aberrations at the wide-angle end. Keeping the corresponding value of condition (5) above the upper limit is advantageous for shortening the overall length of the lens system at the wide-angle end. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (5-1), and even more preferable that it satisfies the following condition (5-2). 4.5 <TLw / fw<9.5 (5) 5.2 <TLw / fw<8.5 (5-1) 5.8 <TLw / fw<7.45 (5-2)

[0116] It is preferable that the zoom lens satisfies the following condition (6). Here, TLt is the sum of the distance along the optical axis from the lens surface closest to the object of the first lens group G1 to the lens surface closest to the image of the final lens group GE, when the lens is in focus on an object at infinity at the telephoto end, and the back focus of the entire system in air equivalent distance. Ensuring that the corresponding value of condition (6) does not fall below the lower limit is advantageous in suppressing various aberrations at the telephoto end. Ensuring that the corresponding value of condition (6) does not exceed the upper limit is advantageous in shortening the overall length of the lens system at the telephoto end. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (6-1), and even more preferable that it satisfies the following condition (6-2). 0.5 <TLt / ft<1.3 (6) 0.58 <TLt / ft<1.24 (6-1) 0.67 <TLt / ft<1.19 (6-2)

[0117] When the maximum half-angle of view at the telephoto end with an object at infinity is denoted as ωt, it is preferable for the zoom lens to satisfy the following condition (7). tan is the tangent value. As an example, Figure 2 shows the maximum half-angle of view ωt at the telephoto end with an object at infinity. By ensuring that the corresponding value in condition (7) does not fall below the lower limit, the axial light beam ta can be gently focused toward the image plane Sim at the telephoto end, which is advantageous in suppressing axial chromatic aberration that occurs when the light beam is focused. By ensuring that the corresponding value in condition (7) does not exceed the upper limit, it is advantageous in shortening the overall length of the lens system at the telephoto end. To obtain even better characteristics, it is more preferable for the zoom lens to satisfy the following condition (7-1), and even more preferable to satisfy the following condition (7-2). 10 <TLt / (ft×tanωt)<18 (7) 11.2 <TLt / (ft×tanωt)<16.9 (7-1) 12.1 <TLt / (ft×tanωt)<15.4 (7-2)

[0118] It is preferable for the zoom lens to satisfy the following condition (8). Here, Bfw is the back focus of the entire system in air equivalent distance when in focus on an object at infinity at the wide-angle end. Also, ωw is the maximum half-angle of view when in focus on an object at infinity at the wide-angle end. As an example, Figure 2 shows the maximum half-angle of view ωw when in focus on an object at infinity at the wide-angle end. Ensuring that the corresponding value of condition (8) does not fall below the lower limit is advantageous in securing peripheral illumination. Ensuring that the corresponding value of condition (8) does not exceed the upper limit is advantageous in shortening the overall length of the lens system at the wide-angle end. To obtain even better characteristics, it is more preferable for the zoom lens to satisfy the following condition (8-1), and even more preferable to satisfy the following condition (8-2). 0.5 <Bfw / (fw×tanωw)<1.1 (8) 0.56 <Bfw / (fw×tanωw)<0.95 (8-1) 0.63 <Bfw / (fw×tanωw)<0.8 (8-2)

[0119] When the zoom lens is focused on an object at infinity at the wide-angle end, and Denw is the distance along the optical axis from the lens surface closest to the object in the first lens group G1 to the paraxial entrance pupil position Penw, it is preferable that the zoom lens satisfies the following condition (9). As an example, Figure 2 shows the above distance Denw and the paraxial entrance pupil position Penw. By ensuring that the corresponding value of condition (9) does not fall below the lower limit, the on-axial light beam wa and the off-axis light beam passing through the first lens group G1 can be suitably separated, which is advantageous for correcting chromatic aberration. By ensuring that the corresponding value of condition (9) does not exceed the upper limit, the paraxial entrance pupil position Penw is located closer to the object, so the height of the off-axis rays passing through the first lens group G1 from the optical axis Z can be reduced. This is advantageous for making the first lens group G1 smaller and lighter. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (9-1), and even more preferable that it satisfies the following condition (9-2). 1.1 <Denw / fw<1.9 (9) 1.25 <Denw / fw<1.75 (9-1) 1.44 <Denw / fw<1.69 (9-2)

[0120] If the fourth lens group from the object side of the zoom lens is designated as the fourth lens group G4, the fourth lens group G4 may be configured to move during at least one of magnification and focusing. In this configuration, it is preferable that the zoom lens satisfies the following condition (10). Here, DG4 is the distance on the optical axis from the lens surface closest to the object in the fourth lens group G4 to the lens surface closest to the image in the fourth lens group G4. By ensuring that the corresponding value of condition (10) does not fall below the lower limit, it is advantageous to shorten the overall length of the lens system. By ensuring that the corresponding value of condition (10) does not exceed the upper limit, it is advantageous to lighten the fourth lens group G4, which is driven during at least one of magnification and focusing. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (10-1), and even more preferable that it satisfies the following condition (10-2). 0.009 <DG4 / TLw<0.12 (10) 0.015 <DG4 / TLw<0.05 (10-1) 0.02 <DG4 / TLw<0.028 (10-2)

[0121] When Gfave is the average value of the specific gravity of all lenses in the focusing group, it is preferable that the zoom lens satisfies the following condition (11). By ensuring that the corresponding value in condition (11) does not fall below the lower limit, readily available materials can be used for the focusing group, which is advantageous in realizing a focusing group with less aberration variation during focusing. By ensuring that the corresponding value in condition (11) does not exceed the upper limit, it is advantageous in reducing the weight of the focusing group. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (11-1), and even more preferable that it satisfies the following condition (11-2). 2.3 <Gfave<5.15 (11) 2.7 <Gfave<4.78 (11-1) 2.91 <Gfave<3.5 (11-2)

[0122] In a configuration in which the focusing group includes at least one negative lens, it is preferable that the zoom lens satisfies the following condition (12). Here, Gfn is the specific gravity of at least one negative lens in the focusing group. By ensuring that the corresponding value of condition (12) does not fall below the lower limit, readily available materials can be used for the focusing group, which is advantageous in realizing a focusing group with less aberration variation during focusing. By ensuring that the corresponding value of condition (12) does not exceed the upper limit, it is advantageous in reducing the weight of the focusing group. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (12-1), and even more preferable that it satisfies the following condition (12-2). 2.4 <Gfn<5.6 (12) 2.8 <Gfn<5 (12-1) 3.1 <Gfn<3.6 (12-2)

[0123] When the average specific gravity of all lenses in the image stabilization group is taken as GISave, it is preferable that the zoom lens satisfies the following condition (13). By ensuring that the corresponding value in condition (13) does not fall below the lower limit, readily available materials can be used in the image stabilization group, which is advantageous in realizing an image stabilization group with less aberration variation during image blur correction. By ensuring that the corresponding value in condition (13) does not exceed the upper limit, it is advantageous in reducing the weight of the image stabilization group. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (13-1), and even more preferable that it satisfies the following condition (13-2). 2.5 <GISave<5.2 (13) 3 <GISave<4.5 (13-1) 3.5 <GISave<4 (13-2)

[0124] In a configuration where the image stabilization group includes at least one positive lens, it is preferable that the zoom lens satisfies the following condition (14). Here, the specific gravity of at least one positive lens in the image stabilization group is defined as GISp. By ensuring that the corresponding value in condition (14) does not fall below the lower limit, readily available materials can be used for the image stabilization group, which is advantageous in realizing an image stabilization group with less aberration variation during image shake correction. By ensuring that the corresponding value in condition (14) does not exceed the upper limit, it is advantageous in reducing the weight of the image stabilization group. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (14-1), and even more preferable that it satisfies the following condition (14-2). 2.6 <GISp<5 (14) 2.8 <GISp<4.6 (14-1) 2.95 <GISp<3.7 (14-2)

[0125] When the amount of movement of the first lens group G1 during magnification from the wide-angle end to the telephoto end is denoted as M1, it is preferable for the zoom lens to satisfy the following condition (15). Here, the sign of M1 is positive when moving from the object side to the image side, and negative when moving from the image side to the object side. As an example, Figure 2 shows the amount of movement M1 of the first lens group G1 described above. By ensuring that the corresponding value of condition (15) does not fall below the lower limit, it is advantageous to achieve a high magnification ratio. By ensuring that the corresponding value of condition (15) does not exceed the upper limit, fluctuations in the center of gravity position during magnification can be suppressed. To obtain even better characteristics, it is more preferable for the zoom lens to satisfy the following condition (15-1), and even more preferable to satisfy the following condition (15-2). 0.25 <- M1 / TLt < 0.6 (15) 0.31 <- M1 / TLt < 0.53 (15-1) 0.36 < -M1 / TLt < 0.46 (15-2)

[0126] When the amount of movement of the second lens group G2 during magnification from the wide-angle end to the telephoto end is denoted as M2, it is preferable for the zoom lens to satisfy the following condition (16). Here, the sign of M2 is positive when moving from the object side to the image side, and negative when moving from the image side to the object side. Ensuring that the corresponding value of condition (16) does not fall below the lower limit is advantageous for achieving a high magnification ratio. Ensuring that the corresponding value of condition (16) does not exceed the upper limit is advantageous for suppressing fluctuations in distortion aberration during magnification. To obtain even better characteristics, it is more preferable for the zoom lens to satisfy the following condition (16-1), and even more preferable for it to satisfy the following condition (16-2). 0.01 <- M2 / TLt < 0.2 (16) 0.02 < -M2 / TLt < 0.15 (16-1) 0.036 <- M2 / TLt < 0.109 (16-2)

[0127] If the lens group closest to the object in the intermediate group GM is designated as the third lens group G3, and the amount of movement of the third lens group G3 during magnification from the wide-angle end to the telephoto end is M3, then it is preferable for the zoom lens to satisfy the following condition (17). Here, the sign of M3 is positive when moving from the object side to the image side, and negative when moving from the image side to the object side. Ensuring that the corresponding value of condition (17) does not fall below the lower limit is advantageous for achieving a high magnification ratio. Ensuring that the corresponding value of condition (17) does not exceed the upper limit is advantageous for suppressing fluctuations in spherical aberration during magnification. To obtain even better characteristics, it is more preferable for the zoom lens to satisfy the following condition (17-1), and even more preferable for it to satisfy the following condition (17-2). 0.08 <- M3 / TLt < 0.4 (17) 0.13 <- M3 / TLt < 0.35 (17-1) 0.17 <- M3 / TLt < 0.23 (17-2)

[0128] If the fourth lens group from the object side of a zoom lens is designated as the fourth lens group G4, and the amount of movement of the fourth lens group G4 during magnification from the wide-angle end to the telephoto end is M4, then it is preferable that the zoom lens satisfies the following condition (18). Here, the sign of M4 is positive when moving from the object side to the image side, and negative when moving from the image side to the object side. Ensuring that the corresponding value of condition (18) does not fall below the lower limit is advantageous for achieving a high magnification ratio. Ensuring that the corresponding value of condition (18) does not exceed the upper limit is advantageous for suppressing fluctuations in field curvature during magnification. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (18-1), and even more preferable that it satisfies the following condition (18-2). 0.15 <- M4 / TLt < 0.3 (18) 0.166 <- M4 / TLt < 0.25 (18-1) 0.18 <- M4 / TLt < 0.222 (18-2)

[0129] If the fifth lens group from the object side of a zoom lens is designated as the fifth lens group G5, and the amount of movement of the fifth lens group G5 during magnification from the wide-angle end to the telephoto end is M5, then it is preferable that the zoom lens satisfies the following condition (19). Here, the sign of M5 is positive when moving from the object side to the image side, and negative when moving from the image side to the object side. Ensuring that the corresponding value of condition (19) does not fall below the lower limit is advantageous for achieving a high magnification ratio. Ensuring that the corresponding value of condition (19) does not exceed the upper limit is advantageous for suppressing fluctuations in field curvature during magnification. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (19-1), and even more preferable that it satisfies the following condition (19-2). 0.11 < -M5 / TLt < 0.31 (19) 0.13 <- M5 / TLt < 0.27 (19-1) 0.16 <- M5 / TLt < 0.24 (19-2)

[0130] When the center thickness of the lens closest to the object in the first lens group G1 is d1, and the effective diameter of the object-side surface of the lens closest to the object in the first lens group G1 is ED1, it is preferable that the zoom lens satisfies the following condition (20). By ensuring that the corresponding value of condition (20) does not fall below the lower limit, it is advantageous to ensure the strength of the lens closest to the object in the first lens group G1. By ensuring that the corresponding value of condition (20) does not exceed the upper limit, it is advantageous to reduce the weight of the first lens group G1. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (20-1), and even more preferable that it satisfies the following condition (20-2). 0.022 <d1 / ED1<0.04 (20) 0.025 <d1 / ED1<0.035 (20-1) 0.027 <d1 / ED1<0.032 (20-2)

[0131] In this specification, the "effective diameter" of a lens surface is defined as twice the distance from the point of intersection between the outermost ray passing through the lens surface and the lens surface, and the optical axis Z, among the light rays that enter the lens surface from the object side and are emitted towards the image side. Here, "outer" refers to the radially outer side with respect to the optical axis Z, that is, the side away from the optical axis Z. Furthermore, the "outermost ray passing through the lens surface" is determined by considering the entire range of magnification.

[0132] Figure 3 shows an example of the effective diameter ED for illustrative purposes. In Figure 3, the left side is the object side and the right side is the image side. Figure 3 shows the on-axis light beam Xa and off-axis light beam Xb passing through lens Lx. In the example in Figure 3, the ray Xb1, which is the upper ray of the off-axis light beam Xb, is the outermost ray. Therefore, in the example in Figure 3, the effective diameter ED of the object-side surface of lens Lx is twice the distance from the intersection point of the object-side surface of lens Lx and the ray Xb1 to the optical axis Z. Also, the position of the intersection point of the outermost ray and the lens surface is the position Px of the maximum effective diameter. Note that in the example in Figure 3, the upper ray of the off-axis light beam Xb is the outermost ray, but which ray is the outermost ray will vary depending on the optical system.

[0133] It is preferable that the zoom lens satisfies the following condition (21). Ensuring that the corresponding value in condition (21) does not fall below the lower limit is advantageous in securing the strength of the lens closest to the object in the first lens group G1. Ensuring that the corresponding value in condition (21) does not exceed the upper limit is advantageous in reducing the weight of the first lens group G1. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (21-1), and even more preferable that it satisfies the following condition (21-2). 0.035 <d1 / (Denw×tanωw)<0.077 (21) 0.045 <d1 / (Denw×tanωw)<0.07 (21-1) 0.055 <d1 / (Denw×tanωw)<0.067 (21-2)

[0134] It is preferable that the zoom lens satisfies the following condition (22). Here, d2 is the center thickness of the second lens from the object side in the first lens group G1. Also, R2f is the paraxial radius of curvature of the object-side surface of the second lens from the object side in the first lens group G1, and R2r is the paraxial radius of curvature of the image-side surface of the second lens from the object side in the first lens group G1. Ensuring that the corresponding value in condition (22) does not fall below the lower limit is advantageous in ensuring the strength of the second lens from the object side in the first lens group G1. Ensuring that the corresponding value in condition (22) does not exceed the upper limit is advantageous in reducing the weight of the first lens group G1. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (22-1), and even more preferable that it satisfies the following condition (22-2). 0.06 <d2×(1 / R2f-1 / R2r)<0.19 (22) 0.085 <d2×(1 / R2f-1 / R2r)<0.175 (22-1) 0.091 <d2×(1 / R2f-1 / R2r)<0.143 (22-2)

[0135] When the focal length of the first lens group G1 is f1, it is preferable that the zoom lens satisfies the following condition (23). Ensuring that the corresponding value in condition (23) does not fall below the lower limit is advantageous in ensuring the strength of the lens closest to the object in the first lens group G1. Ensuring that the corresponding value in condition (23) does not exceed the upper limit is advantageous in reducing the weight of the first lens group G1. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (23-1), and even more preferable that it satisfies the following condition (23-2). 0.01 <d1 / f1<0.021 (23) 0.013 <d1 / f1<0.019 (23-1) 0.014 <d1 / f1<0.016 (23-2)

[0136] When DG1 is the distance along the optical axis from the lens surface closest to the object in the first lens group G1 to the lens surface closest to the image in the first lens group G1, it is preferable that the zoom lens satisfies the following condition (24). Ensuring that the corresponding value of condition (24) does not fall below the lower limit is advantageous in ensuring the strength of the lens closest to the object in the first lens group G1. Ensuring that the corresponding value of condition (24) does not exceed the upper limit is advantageous in reducing the weight of the first lens group G1. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (24-1), and even more preferable that it satisfies the following condition (24-2). 0.06 <d1 / DG1<0.125 (24) 0.08 <d1 / DG1<0.12 (24-1) 0.098 <d1 / DG1<0.115 (24-2)

[0137] When νd2 is the Abbe number of the second lens from the object side in the first lens group G1 with respect to the d line, it is preferable that the zoom lens satisfies the following condition (25). By ensuring that the corresponding value of condition (25) does not fall below the lower limit, it is advantageous to suppress axial chromatic aberration at the telephoto end. By ensuring that the corresponding value of condition (25) does not exceed the upper limit, it is possible to suppress overcorrection of axial chromatic aberration at the telephoto end. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (25-1), and even more preferable that it satisfies the following condition (25-2). 75 < νd2 < 120 (25) 81.55 < νd2 < 110 (25-1) 85 < νd2 < 105.9 (25-2)

[0138] When the Abbe number of the third lens from the object side of the first lens group G1 is νd3, based on the d line, it is preferable that the zoom lens satisfies the following condition (26). By ensuring that the corresponding value of condition (26) does not fall below the lower limit, it is advantageous to suppress axial chromatic aberration at the telephoto end. By ensuring that the corresponding value of condition (26) does not exceed the upper limit, it is possible to suppress overcorrection of axial chromatic aberration at the telephoto end. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (26-1), and even more preferable that it satisfies the following condition (26-2). 70 < νd3 < 110 (26) 75 < νd3 < 105 (26-1) 81.55 < νd3 < 100 (26-2)

[0139] When θgF2 is the partial dispersion ratio between the g-line and the F-line of the second lens from the object side in the first lens group G1, it is preferable that the zoom lens satisfies the following condition (27). By ensuring that the corresponding value of condition (27) does not fall below the lower limit, it is advantageous to suppress second-order axial chromatic aberration at the telephoto end. By ensuring that the corresponding value of condition (27) does not exceed the upper limit, it is possible to suppress overcorrection of second-order axial chromatic aberration at the telephoto end. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (27-1), and even more preferable that it satisfies the following condition (27-2). 0.46 < θgF2 < 0.62 (27) 0.48 < θgF2 < 0.57 (27-1) 0.52 < θgF2 < 0.55 (27-2)

[0140] Furthermore, if the refractive indices of a lens for the g-line, F-line, and C-line are Ng, NF, and NC, respectively, and the partial dispersion ratio between the g-line and F-line of that lens is θgF, then θgF is defined by the following formula. θgF = (Ng - NF) / (NF - NC)

[0141] When θgF3 is the partial dispersion ratio between the g-line and the F-line of the third lens from the object side in the first lens group G1, it is preferable that the zoom lens satisfies the following condition (28). By ensuring that the corresponding value of condition (28) does not fall below the lower limit, it is advantageous to suppress second-order axial chromatic aberration at the telephoto end. By ensuring that the corresponding value of condition (28) does not exceed the upper limit, it is possible to suppress overcorrection of second-order axial chromatic aberration at the telephoto end. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (28-1), and even more preferable that it satisfies the following condition (28-2). 0.46 < θgF3 < 0.62 (28) 0.48 < θgF3 < 0.57 (28-1) 0.52 < θgF3 < 0.55 (28-2)

[0143] When the paraxial radius of curvature of the lens surface closest to the object in the focusing group is RfF, and the paraxial radius of curvature of the lens surface closest to the image in the focusing group is RfR, it is preferable that the zoom lens satisfies the following condition (30). By ensuring that the corresponding value in condition (30) does not fall below the lower limit, the refractive power of the focusing group can be secured, which is advantageous in suppressing the amount of movement of the focusing group when focusing. By ensuring that the corresponding value in condition (30) does not exceed the upper limit, it is advantageous in suppressing fluctuations in astigmatism when focusing. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (30-1), and even more preferable that it satisfies the following condition (30-2). 1.5 <RfF / RfR<6 (30) 1.8 <RfF / RfR<5 (30-1) 2.09 <RfF / RfR<4.02 (30-2)

[0144] When the focal length of the focusing group is ffoc, it is preferable that the zoom lens satisfies the following condition (31). By ensuring that the corresponding value of condition (31) does not fall below the lower limit, the refractive power of the focusing group can be secured, which is advantageous in suppressing the amount of movement of the focusing group when focusing. By ensuring that the corresponding value of condition (31) does not exceed the upper limit, it is advantageous in suppressing fluctuations of various aberrations when focusing. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (31-1), and even more preferable that it satisfies the following condition (31-2). -0.35 <ffoc / ft<-0.02 (31) -0.28 <ffoc / ft<-0.05 (31-1) -0.2 <ffoc / ft<-0.08 (31-2)

[0145] When the focal length of the image stabilization group is fIS, it is preferable that the zoom lens satisfies the following condition (32). Ensuring that the corresponding value in condition (32) does not fall below the lower limit is advantageous in suppressing fluctuations of various aberrations during image shake correction. Ensuring that the corresponding value in condition (32) does not exceed the upper limit ensures the refractive power of the image stabilization group, which is advantageous in suppressing the amount of movement of the image stabilization group during image shake correction. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (32-1), and even more preferable that it satisfies the following condition (32-2). 0.01 < |fIS / ft| < 0.35 (32) 0.03 < |fIS / ft| < 0.28 (32-1) 0.05 < |fIS / ft| < 0.23 (32-2)

[0146] When the focal length of the second lens group G2 is f2 and the focal length of the second lens from the object side in the second lens group G2 is fL22, it is preferable that the zoom lens satisfies the following condition (33). By ensuring that the corresponding value of condition (33) does not fall below the lower limit, it is advantageous to suppress chromatic aberration. By ensuring that the corresponding value of condition (33) does not exceed the upper limit, it is advantageous to suppress distortion. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (33-1), and even more preferable that it satisfies the following condition (33-2). 1.4 <fL22 / f2<7 (33) 3 <fL22 / f2<6 (33-1) 4 <fL22 / f2<5.6 (33-2)

[0147] The zoom lens preferably satisfies the following conditional expression (34). Here, the lateral magnification of the focus group in a state of being focused on an infinite object at the wide-angle end is defined as βfw. Also, the combined lateral magnification of all lenses on the image side of the focus group in a state of being focused on an infinite object at the wide-angle end is defined as βfRw. By ensuring that the corresponding value of conditional expression (34) does not fall below the lower limit, it is advantageous for suppressing fluctuations in various aberrations during focusing at the wide-angle end. By ensuring that the corresponding value of conditional expression (34) does not exceed the upper limit, the movement amount of the focus group during focusing at the wide-angle end can be suppressed, which is advantageous for shortening the overall length of the lens system. To obtain better characteristics, it is more preferable for the zoom lens to satisfy the following conditional expression (34-1), and even more preferable to satisfy the following conditional expression (34-2). -6 < (1 - βfw 2 ) × βfRw 2 < -1 (34) -5.5 < (1 - βfw 2 ) × βfRw 2 < -1.5 (34-1) -4.7 < (1 - βfw 2 ) × βfRw 2 < -2.2 (34-2)

[0148] The zoom lens preferably satisfies the following conditional expression (35). Here, the lateral magnification of the focus group in a state of being focused on an infinite object at the telephoto end is defined as βft. Also, the combined lateral magnification of all lenses on the image side of the focus group in a state of being focused on an infinite object at the telephoto end is defined as βfRt. By ensuring that the corresponding value of conditional expression (35) does not fall below the lower limit, it is advantageous for suppressing fluctuations in various aberrations during focusing at the telephoto end. By ensuring that the corresponding value of conditional expression (35) does not exceed the upper limit, the movement amount of the focus group during focusing at the telephoto end can be suppressed, which is advantageous for shortening the overall length of the lens system. To obtain better characteristics, it is more preferable for the zoom lens to satisfy the following conditional expression (35-1), and even more preferable to satisfy the following conditional expression (35-2). -25 < (1 - βft 2 ) × βfRt 2<-6.3 (35) -22<(1-βft 2 )×βfRt 2 <-7.5 (35-1) -19.3<(1-βft 2 )×βfRt 2 <-8.3 (35-2)

[0149] It is preferable that the zoom lens satisfies the following condition (36). Here, βISw is the lateral magnification of the image stabilization group when focused on an object at infinity at the wide-angle end. Also, βISRw is the combined lateral magnification of all lenses on the image side of the image stabilization group when focused on an object at infinity at the wide-angle end. By ensuring that the corresponding value of condition (36) does not fall below the lower limit, the amount of movement of the image stabilization group during image shake correction at the wide-angle end can be suppressed, which is advantageous for miniaturization in the radial direction. By ensuring that the corresponding value of condition (36) does not exceed the upper limit, it is advantageous for suppressing fluctuations in various aberrations during image shake correction at the wide-angle end. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (36-1), and even more preferable that it satisfies the following condition (36-2). 0.75<|(1-βISw)×βISRw|<2.5 (36) 0.9<|(1-βISw)×βISRw|<2.1 (36-1) 1.05<|(1-βISw)×βISRw|<1.64 (36-2)

[0150] It is preferable that the zoom lens satisfies the following condition (37). Here, βISt is the lateral magnification of the image stabilization group when in focus on an object at infinity at the telephoto end. Also, βISRt is the combined lateral magnification of all lenses on the image side of the image stabilization group when in focus on an object at infinity at the telephoto end. By ensuring that the corresponding value of condition (37) does not fall below the lower limit, the amount of movement of the image stabilization group during image shake correction at the telephoto end can be suppressed, which is advantageous for miniaturization in the radial direction. By ensuring that the corresponding value of condition (37) does not exceed the upper limit, it is advantageous for suppressing fluctuations in various aberrations during image shake correction at the telephoto end. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (37-1), and even more preferable that it satisfies the following condition (37-2). 1.7<|(1-βISt)×βISRt|<7 (37) 2<|(1-βISt)×βISRt|<6 (37-1) 2.3<|(1-βISt)×βISRt|<5.5 (37-2)

[0151] Zoom lenses preferably satisfy the following condition (38). Here, the symbols are defined as follows: βfw is the lateral magnification of the focus group when in focus on an object at infinity at the wide-angle end. βfRw is the combined lateral magnification of all lenses on the image side of the focus group when in focus on an object at infinity at the wide-angle end. ffoc is the focal length of the focus group. ffRw is the combined focal length of all lenses on the image side of the focus group when in focus on an object at infinity at the wide-angle end. Dexw is the sum of the distance along the optical axis from the paraxial exit pupil position Pexw to the image-side lens surface of the final lens group GE when in focus on an object at infinity at the wide-angle end, and the back focus of the entire system in air equivalent distance. As an example, Figure 2 shows the paraxial exit pupil position Pexw when in focus on an object at infinity at the wide-angle end. Using the above symbols, γw and BRw are defined as follows. γw=(1-βfw 2 )×βfRw 2 BRw={βfw / (ffoc×γw)-1 / (βfRw×ffRw)-(1 / Dexw)} By ensuring that the corresponding value in conditional equation (38) does not fall below the lower limit, it is advantageous to shorten the overall length of the lens system. By ensuring that the corresponding value in conditional equation (38) does not exceed the upper limit, it is advantageous to suppress the angle of view fluctuation when focusing at the wide-angle end. To obtain even better characteristics, it is more preferable for the zoom lens to satisfy the following conditional equation (38-1), and even more preferable to satisfy the following conditional equation (38-2). 0 < |BRw × (fw × tanωw)| < 0.25 (38) 0 < |BRw × (fw × tanωw)| < 0.15 (38-1) 0 < |BRw × (fw × tanωw)| < 0.0755 (38-2)

[0152] Zoom lenses preferably satisfy the following condition (39). Here, the symbols are defined as follows: βft is the lateral magnification of the focus group when in focus on an object at infinity at the telephoto end. βfRt is the combined lateral magnification of all lenses on the image side of the focus group when in focus on an object at infinity at the telephoto end. ffoc is the focal length of the focus group. ffRt is the combined focal length of all lenses on the image side of the focus group when in focus on an object at infinity at the telephoto end. Dext is the sum of the distance along the optical axis from the paraxial exit pupil position Pext to the image-side lens surface of the final lens group GE when in focus on an object at infinity at the telephoto end, and the back focus of the entire system in air equivalent distance. As an example, Figure 2 shows the paraxial exit pupil position Pext when in focus on an object at infinity at the telephoto end. Using the above symbols, γt and BRt are defined as follows. γt=(1-βft 2 )×βfRt 2 BRt={βft / (ffoc×γt)-1 / (βfRt×ffRt)-(1 / Dext)} By ensuring that the corresponding value in conditional equation (39) does not fall below the lower limit, it is advantageous to shorten the overall length of the lens system. By ensuring that the corresponding value in conditional equation (39) does not exceed the upper limit, it is advantageous to suppress the change in the angle of view when focusing at the telephoto end. To obtain even better characteristics, it is more preferable for the zoom lens to satisfy the following conditional equation (39-1), and even more preferable to satisfy the following conditional equation (39-2). 0 < |BRt × (ft × tanωt)| < 0.034 (39) 0 < |BRt × (ft × tanωt)| < 0.015 (39-1) 0 < |BRt × (ft × tanωt)| < 0.0085 (39-2)

[0153] When the focal length of the first lens group G1 is f1 and the focal length of the second lens group G2 is f2, it is preferable that the zoom lens satisfies the following condition (40). Ensuring that the corresponding value of condition (40) does not fall below the lower limit is advantageous for suppressing spherical aberration at the telephoto end. Ensuring that the corresponding value of condition (40) does not exceed the upper limit is advantageous for achieving a high magnification ratio. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (40-1), and even more preferable that it satisfies the following condition (40-2). -10 <f1 / f2<-5.6 (40) -9 <f1 / f2<-6.1 (40-1) -8.4 <f1 / f2<-6.5 (40-2)

[0154] When the focal length of the lens group closest to the object in the intermediate GM group is set to f3, it is preferable that the zoom lens satisfies the following condition (41). Ensuring that the corresponding value of condition (41) does not fall below the lower limit is advantageous in suppressing fluctuations in spherical aberration during magnification. Ensuring that the corresponding value of condition (41) does not exceed the upper limit is advantageous in suppressing fluctuations in distortion during magnification. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (41-1), and even more preferable that it satisfies the following condition (41-2). -0.9 <f2 / f3<-0.54 (41) -0.8 <f2 / f3<-0.6 (41-1) -0.77 <f2 / f3<-0.64 (41-2)

[0155] If the fourth lens group from the object side of a zoom lens is designated as the fourth lens group G4, it is preferable that the zoom lens satisfies the following condition (42). Here, the amount of movement of the fourth lens group G4 during magnification from the wide-angle end to the telephoto end is denoted as M4. The amount of movement of the final lens group GE during magnification from the wide-angle end to the telephoto end is denoted as ME. Furthermore, the signs of M4 and ME are positive when moving from the object side to the image side, and negative when moving from the image side to the object side. By ensuring that the corresponding value of condition (42) does not fall below the lower limit, it is possible to suppress the narrowing of the spacing between groups during magnification, which is advantageous for simplifying the drive mechanism. By ensuring that the corresponding value of condition (42) does not exceed the upper limit, it is possible to suppress the widening of the spacing between groups during magnification, which is advantageous for simplifying the drive mechanism. To obtain better characteristics, it is more preferable for the zoom lens to satisfy the following condition (42-1), and even more preferable for it to satisfy the following condition (42-2). 0.9 <M4 / ME<1.1 (42) 0.99 <M4 / ME<1.01 (42-1) 0.9999 <M4 / ME<1.0001 (42-2)

[0156] When the focal length of the intermediate group GM is fMw when in focus on an object at infinity at the wide-angle end, it is preferable that the zoom lens satisfies the following condition (43). Ensuring that the corresponding value of condition (43) does not fall below the lower limit is advantageous for shortening the overall length of the lens system. Ensuring that the corresponding value of condition (43) does not exceed the upper limit is advantageous for suppressing spherical aberration at the wide-angle end. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (43-1), and even more preferable that it satisfies the following condition (43-2). 0.54 <fw / fMw<0.95 (43) 0.6 <fw / fMw<0.87 (43-1) 0.64 <fw / fMw<0.75 (43-2)

[0157] When the focal length of the intermediate group GM is fMt when the lens is in focus on an object at infinity at the telephoto end, it is preferable that the zoom lens satisfies the following condition (44). Ensuring that the corresponding value of condition (44) does not fall below the lower limit is advantageous for shortening the overall length of the lens system. Ensuring that the corresponding value of condition (44) does not exceed the upper limit is advantageous for suppressing spherical aberration at the telephoto end. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (44-1), and even more preferable that it satisfies the following condition (44-2). 5.1 <ft / fMt<20 (44) 6.3 <ft / fMt<15 (44-1) 7.3 <ft / fMt<12.2 (44-2)

[0158] It is preferable that the zoom lens satisfies the following condition (45). Here, MfF is the amount of movement of the lens group adjacent to the object side of the focus group when zooming from the wide-angle end to the telephoto end. Also, MfR is the amount of movement of the lens group adjacent to the image side of the focus group when zooming from the wide-angle end to the telephoto end. The signs of MfF and MfR are positive when moving from the object side to the image side, and negative when moving from the image side to the object side. By ensuring that the corresponding value of condition (45) does not fall below the lower limit, it is possible to suppress the narrowing of the spacing between groups when zooming, which is advantageous for simplifying the drive mechanism. By ensuring that the corresponding value of condition (45) does not exceed the upper limit, it is possible to suppress the widening of the spacing between groups when zooming, which is advantageous for simplifying the drive mechanism. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (45-1), and even more preferable that it satisfies the following condition (45-2). 0.9 <MfF / MfR<1.1 (45) 0.99 <MfF / MfR<1.01 (45-1) 0.9999 <MfF / MfR<1.0001 (45-2)

[0159] The lens group may be configured such that only five of the movement trajectories of each lens group that move during magnification from the wide-angle end to the telephoto end are different from each other. In other words, the lens group may be configured so that there are five types of movement trajectories for each lens group that move during magnification. For example, as in the embodiment described later, if there are multiple lens groups that move along the same movement trajectory during magnification from the wide-angle end to the telephoto end, the movement trajectory of those multiple lens groups is counted as one type. In the technology of this disclosure, if the movement trajectories are different in a part of the magnification range of the entire magnification range, they are considered to be different movement trajectories when magnifying from the wide-angle end to the telephoto end, even if the movement trajectories are the same in other parts of the magnification range. Furthermore, the above-mentioned "movement trajectory" naturally refers to the lens group that moves during magnification, and does not refer to the lens group that is fixed during magnification.

[0160] A zoom lens may be configured to include multiple lens groups that move along the same trajectory when changing magnification from the wide-angle end to the telephoto end. In this case, the lens groups moving along the same trajectory can be driven by a single cam, thus simplifying the lens group drive mechanism. Note that the above phrase, "same trajectory when changing magnification from the wide-angle end to the telephoto end," means that the same trajectory is used throughout the entire range of magnification from the wide-angle end to the telephoto end.

[0161] For example, when zooming from the wide-angle end to the telephoto end, the fourth lens group from the object side of the zoom lens and the final lens group GE may be configured to move along the same trajectory. In this case, the lens groups moving along the same trajectory can be driven by a single cam, thus simplifying the lens group drive mechanism, and the following effects can also be obtained. Here, the third and fourth lens groups from the object side of the zoom lens are designated as the third lens group G3 and the fourth lens group G4, respectively. As shown in Figure 2, in the third lens group G3, the axial light beam and peripheral light beam are close together near the optical axis, while in the final lens group GE, the axial light beam and peripheral light beam are separated. By changing the distance between the third lens group G3 and the fourth lens group G4, and making the trajectory of the final lens group GE the same as the trajectory of the fourth lens group G4, the lens group drive mechanism can be simplified while maintaining a good balance between spherical aberration and field curvature during zooming. When a zoom lens satisfies the above condition (42), it is preferable that the fourth lens group G4 and the final lens group GE move along the same trajectory when the zoom is changed from the wide-angle end to the telephoto end.

[0162] If a zoom lens includes multiple lens groups that move along the same trajectory when changing magnification from the wide-angle end to the telephoto end, the focus group may be configured to be positioned between the multiple lens groups that move along the same trajectory. In this case, the multiple lens groups and the focus group that move along the same trajectory can be driven by a single cam, and the mechanism that drives when focusing can also be used to drive when changing magnification, thus simplifying the drive mechanism. When the zoom lens satisfies the above condition (45), it is preferable to configure the focus group to be positioned between the multiple lens groups that move along the same trajectory.

[0163] A zoom lens may be configured to include eight or more aspherical lens surfaces. This configuration is advantageous for suppressing various aberrations.

[0164] The image-side lens of the second lens group G2 may be configured to include an aspherical element. This configuration is advantageous for suppressing astigmatism. The object-side lens of the second lens group G2 may also be configured to include an aspherical element. This configuration is advantageous for suppressing distortion.

[0165] The lens closest to the image in the lens group closest to the object in the intermediate GM group may be configured to include an aspherical element. This configuration is advantageous in suppressing field curvature. The lens closest to the object in the lens group closest to the object in the intermediate GM group may be configured to include an aspherical element. This configuration is advantageous in suppressing spherical aberration.

[0166] The object-side surface of the image-side lens in the second lens group G2 may be configured to have an aspherical shape, where the refractive power at the position of maximum effective diameter is weaker than the refractive power near the optical axis. This configuration is advantageous for suppressing astigmatism. This aspherical shape will be explained below with reference to Figure 4.

[0167] The relative strength of refractive power at two different points on the same plane of an aspherical lens can be determined, for example, from the relative magnitudes of the absolute values ​​of the radii of curvature at each point. As an example, Figure 4 shows a cross-sectional view of an aspherical surface Sa on the object-side surface of the lens, where the refractive power at the position Px of maximum effective diameter is weaker than the refractive power near the optical axis. In Figure 4, the normal to the aspherical surface Sa at the position Px of maximum effective diameter is shown by a dashed line, and the intersection of this normal and the optical axis Z is defined as point P1. The absolute value of the radius of curvature of the aspherical surface Sa at the position Px of maximum effective diameter is |P1-Px|, which is the length of the line segment connecting the position Px of maximum effective diameter and point P1. On the other hand, the radius of curvature of the aspherical surface Sa near the optical axis is the so-called paraxial radius of curvature. In Figure 4, a portion of the paraxial sphere Sp of the aspherical surface Sa is shown by a dotted line. The paraxial sphere Sp is a sphere with radius |Rp| that passes through the intersection of the aspherical surface Sa and the optical axis Z, and is centered at point P2 on the optical axis. The absolute value of the radius of curvature of the aspherical surface Sa near the optical axis is equal to the radius |Rp| of this paraxial sphere Sp. In the example in Figure 4, "the refractive power at the position of maximum effective diameter Px is weaker than the refractive power near the optical axis" means that |P1-Px| is longer than |Rp|.

[0168] A similar approach can be taken for configurations where the relationship between the strengths of refractive powers is reversed compared to the example in Figure 4. That is, if |P1-Px| and |Rp| are defined in the same way as above, then "the refractive power at the position Px, where the effective diameter is greatest, is stronger than the refractive power near the optical axis" means that |P1-Px| is shorter than |Rp|.

[0169] The image-side surface of the lens closest to the object in the second lens group G2 may be configured to have an aspherical shape, where the refractive power at the position of the maximum effective diameter is stronger than the refractive power near the optical axis. This configuration is advantageous for suppressing distortion aberration.

[0170] The object-side surface of the image-side lens in the object-side lens group of the intermediate GM group may be configured to have an aspherical shape in which the refractive power at the position of the maximum effective diameter is weaker than the refractive power near the optical axis. This configuration is advantageous in suppressing field curvature.

[0171] The image-side surface of the lens closest to the object in the lens group closest to the object in the intermediate GM group may be configured to have an aspherical shape in which the refractive power at the position of the maximum effective diameter is weaker than the refractive power near the optical axis. This configuration is advantageous for suppressing spherical aberration.

[0172] It is preferable that the zoom lens satisfies the following condition (46). Here, Rc2ef is the paraxial radius of curvature of the object-side surface of the image-side lens of the second lens group G2. Ry2ef is the radius of curvature of the object-side surface of the image-side lens of the second lens group G2 at the position of the maximum effective diameter. By ensuring that the corresponding value of condition (46) does not fall below the lower limit, it is possible to suppress excessive correction of astigmatism. By ensuring that the corresponding value of condition (46) does not exceed the upper limit, it is advantageous for suppressing astigmatism. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (46-1), and even more preferable that it satisfies the following condition (46-2). 0.1 <Rc2ef / Ry2ef<0.999 (46) 0.45 <Rc2ef / Ry2ef<0.95 (46-1) 0.66 <Rc2ef / Ry2ef<0.8 (46-2)

[0173] It is preferable that the zoom lens satisfies the following condition (47). Here, the paraxial radius of curvature of the image-side surface of the lens closest to the object in the second lens group G2 is Rc21r. The radius of curvature at the position of the maximum effective diameter of the image-side surface of the lens closest to the object in the second lens group G2 is Ry21r. By ensuring that the corresponding value of condition (47) does not fall below the lower limit, it is advantageous to suppress distortion aberration. By ensuring that the corresponding value of condition (47) does not exceed the upper limit, it is possible to suppress overcorrection of distortion aberration. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (47-1), and even more preferable that it satisfies the following condition (47-2). 1.001 <Rc21r / Ry21r<4.5 (47) 1.05 <Rc21r / Ry21r<2.5 (47-1) 1.07 <Rc21r / Ry21r<1.27 (47-2)

[0174] It is preferable that the zoom lens satisfies the following condition (48). Here, Rc3ef is defined as the paraxial radius of curvature of the object-side surface of the image-side lens in the object-side lens group of the intermediate GM. Ry3ef is defined as the radius of curvature of the object-side surface of the image-side lens in the object-side lens group of the intermediate GM at the position of the maximum effective diameter. By ensuring that the corresponding value of condition (48) does not fall below the lower limit, it is possible to suppress excessive correction of field curvature. By ensuring that the corresponding value of condition (48) does not exceed the upper limit, it is advantageous to suppress field curvature. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (48-1), and even more preferable that it satisfies the following condition (48-2). 0.1 <Rc3ef / Ry3ef<0.999 (48) 0.5 <Rc3ef / Ry3ef<0.95 (48-1) 0.77 <Rc3ef / Ry3ef<0.85 (48-2)

[0175] It is preferable that the zoom lens satisfies the following condition (49). Here, the paraxial radius of curvature of the image-side surface of the lens closest to the object in the lens group closest to the object in the intermediate GM group is defined as Rc31r. The radius of curvature of the image-side surface of the lens closest to the object in the lens group closest to the object in the intermediate GM group at the position of the maximum effective diameter is defined as Ry31r. By ensuring that the corresponding value of condition (49) does not fall below the lower limit, it is possible to suppress excessive correction of spherical aberration. By ensuring that the corresponding value of condition (49) does not exceed the upper limit, it is advantageous for suppressing spherical aberration. To obtain even better characteristics, it is more preferable that the zoom lens satisfies the following condition (49-1), and even more preferable that it satisfies the following condition (49-2). 0 <Rc31r / Ry31r<0.999 (49) 0.08 <Rc31r / Ry31r<0.92 (49-1) 0.4 <Rc31r / Ry31r<0.87 (49-2)

[0176] It is preferable that the zoom lens satisfies the following condition (50). Here, the paraxial radius of curvature of the object-side surface of the lens closest to the image in the second lens group G2 is Rc2ef. The paraxial radius of curvature of the image-side surface of the lens closest to the image in the second lens group G2 is Rc2er. The radius of curvature of the object-side surface of the lens closest to the image in the second lens group G2 at the position of the maximum effective diameter is Ry2ef. The radius of curvature of the image-side surface of the lens closest to the image in the second lens group G2 at the position of the maximum effective diameter is Ry2er. By ensuring that the corresponding value of condition (50) does not fall below the lower limit, it is possible to suppress excessive correction of astigmatism. By ensuring that the corresponding value of condition (50) does not exceed the upper limit, it is advantageous for suppressing astigmatism. To obtain better characteristics, it is more preferable that the zoom lens satisfies the following condition (50-1), and even more preferable that it satisfies the following condition (50-2). 1.05<(1 / Rc2ef-1 / Rc2er) / (1 / Ry2ef-1 / Ry2er)<5 (50) 1.2<(1 / Rc2ef-1 / Rc2er) / (1 / Ry2ef-1 / Ry2er)<3.5 (50-1) 1.4<(1 / Rc2ef-1 / Rc2er) / (1 / Ry2ef-1 / Ry2er)<2 (50-2)

[0177] It is preferable that the zoom lens satisfies the following condition (51). Here, the paraxial radius of curvature of the object-side surface of the lens closest to the object in the second lens group G2 is Rc21f. The paraxial radius of curvature of the image-side surface of the lens closest to the object in the second lens group G2 is Rc21r. The radius of curvature at the position of the maximum effective diameter of the object-side surface of the lens closest to the object in the second lens group G2 is Ry21f. The radius of curvature at the position of the maximum effective diameter of the image-side surface of the lens closest to the object in the second lens group G2 is Ry21r. By ensuring that the corresponding value of condition (51) does not fall below the lower limit, it is advantageous to suppress distortion aberration. By ensuring that the corresponding value of condition (51) does not exceed the upper limit, it is possible to suppress overcorrection of distortion aberration. To obtain better characteristics, it is more preferable that the zoom lens satisfies the following condition (51-1), and even more preferable that it satisfies the following condition (51-2). 0.4<(1 / Rc21f-1 / Rc21r) / (1 / Ry21f-1 / Ry21r)<0.99 (51) 0.65<(1 / Rc21f-1 / Rc21r) / (1 / Ry21f-1 / Ry21r)<0.97 (51-1) 0.75<(1 / Rc21f-1 / Rc21r) / (1 / Ry21f-1 / Ry21r)<0.95 (51-2)

[0178] It is preferable that the zoom lens satisfies the following condition (52). Here, Rc3ef is defined as the paraxial radius of curvature of the object-side surface of the image-side lens in the object-side lens group of the intermediate GM. Rc3er is defined as the paraxial radius of curvature of the image-side surface of the image-side lens in the object-side lens group of the intermediate GM. Ry3ef is defined as the radius of curvature of the object-side surface of the image-side lens in the object-side lens group of the intermediate GM at the position of the maximum effective diameter. Ry3er is defined as the radius of curvature of the image-side surface of the image-side lens in the object-side lens group of the intermediate GM at the position of the maximum effective diameter. By ensuring that the corresponding value in condition (52) does not fall below the lower limit, it is advantageous to suppress field curvature. By ensuring that the corresponding value in condition (52) does not exceed the upper limit, it is possible to suppress excessive correction of field curvature. To obtain better characteristics, it is more preferable that the zoom lens satisfies the following condition (52-1), and even more preferable that it satisfies the following condition (52-2). 1.01<(1 / Rc3ef-1 / Rc3er) / (1 / Ry3ef-1 / Ry3er)<2 (52) 1.02<(1 / Rc3ef-1 / Rc3er) / (1 / Ry3ef-1 / Ry3er)<1.5 (52-1) 1.03<(1 / Rc3ef-1 / Rc3er) / (1 / Ry3ef-1 / Ry3er)<1.1 (52-2)

[0179] The zoom lens preferably satisfies the following conditional expression (53). Here, the paraxial curvature radius of the object-side surface of the most object-side lens of the most object-side lens group of the intermediate group GM is denoted as Rc31f. The paraxial curvature radius of the image-side surface of the most object-side lens of the most object-side lens group of the intermediate group GM is denoted as Rc31r. The curvature radius at the position of the maximum effective diameter of the object-side surface of the most object-side lens of the most object-side lens group of the intermediate group GM is denoted as Ry31f. The curvature radius at the position of the maximum effective diameter of the image-side surface of the most object-side lens of the most object-side lens group of the intermediate group GM is denoted as Ry31r. By ensuring that the corresponding value of the conditional expression (53) does not fall below the lower limit, it is advantageous for suppressing spherical aberration. By ensuring that the corresponding value of the conditional expression (53) does not exceed the upper limit, it is possible to suppress the overcorrection of spherical aberration. To obtain better characteristics, it is more preferable for the zoom lens to satisfy the following conditional expression (53-1), and even more preferable to satisfy the following conditional expression (53-2). 1.1 < (1 / Rc31f - 1 / Rc31r) / (1 / Ry31f - 1 / Ry31r) < 3 (53) 1.2 < (1 / Rc31f - 1 / Rc31r) / (1 / Ry31f - 1 / Ry31r) < 2.3 (53-1) 1.26 < (1 / Rc31f - 1 / Rc31r) / (1 / Ry31f - 1 / Ry31r) < 1.64 (53-2)

[0180] Note that the example shown in FIG. 1 is just an example, and various modifications are possible within the scope not departing from the gist of the technology of the present disclosure. For example, the number of lens groups included in the intermediate group GM, the number of lens groups constituting the entire system, and the number of lenses included in each lens group may be different from those in the example of FIG. 1.

[0181] For example, the zoom lens may be configured to consist of six lens groups as a whole. In this case, it is advantageous for shortening the overall length of the lens system. Alternatively, the zoom lens may be configured to consist of seven lens groups as a whole. In this case, it is advantageous for the variation of various aberrations during zooming Suppression to be favorable.

[0182] The intermediate group GM may be configured to include two lens groups. For example, the intermediate group GM may be configured to include, in order from the object side to the image side, a lens group having a positive refractive power and a lens group having a negative refractive power.

[0183] The intermediate group GM may be configured to include three lens groups. For example, the intermediate group GM may be configured to include, in order from the object side to the image side, a lens group having a positive refractive power, a lens group having a positive refractive power, and a lens group having a negative refractive power. Alternatively, the intermediate group GM may be configured to include, in order from the object side to the image side, a lens group having a negative refractive power, a lens group having a positive refractive power, and a lens group having a negative refractive power.

[0184] The intermediate group GM may be configured to include four lens groups. For example, the intermediate group GM may be configured to include, in order from the object side to the image side, a lens group having a positive refractive power, a lens group having a positive refractive power, a lens group having a negative refractive power, and a lens group having a negative refractive power.

[0185] The intermediate group GM may be configured to include the aperture stop St. In this case, it is advantageous for miniaturization of the entire system. For example, the aperture stop St may be disposed on the most object side of the intermediate group GM.

[0186] The intermediate group GM may be configured such that the lens group on the most image side is the focus group. In this case, it is advantageous for suppressing the change in the angle of view during focusing.

[0187] When the zoom lens includes a plurality of focus groups, it is preferable that at least one of the plurality of focus groups has a preferable configuration and a possible configuration regarding the focus group described above.

[0188] The anti-vibration group may be configured to be included in the intermediate group GM. The anti-vibration group may be configured to be composed of a part of the lens groups included in the intermediate group GM.

[0189] The final lens group GE may be configured to have a positive refractive power. The final lens group GE may be configured to contain two or fewer lenses. This configuration is advantageous for miniaturization. The lens closest to the image in the zoom lens may be configured to be a positive lens. The second lens from the image side in the zoom lens may be configured to be a negative lens.

[0190] The preferred and possible configurations described above can be combined in any way and are preferably selected as appropriate according to the required specifications. The preferred conditional expressions that the zoom lens of this disclosure satisfies are not limited to those described in formula form, but include all conditional expressions obtained by arbitrarily combining lower and upper limits from the preferred, more preferred, and even more preferred conditional expressions.

[0191] As an example, a preferred embodiment of the zoom lens of the present disclosure comprises, in order from the object side to the image side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an intermediate group GM including one or more lens groups, and a final lens group GE, wherein the intermediate group GM has a positive refractive power as a whole throughout the entire range of magnification, and when magnification is changed, the distance between the first lens group G1 and the second lens group G2 changes, the distance between the second lens group G2 and the intermediate group GM changes, and the distance between the intermediate group GM and the final lens group GE changes, and if the intermediate group GM includes multiple lens groups, when magnification is changed, the distances between all adjacent lens groups within the intermediate group GM change, satisfying the above condition (1).

[0192] Next, embodiments of the zoom lens of this disclosure will be described with reference to the drawings. Note that the reference numerals attached to the lenses in the cross-sectional views of each embodiment are used independently for each embodiment to avoid complexity in the explanation and drawings due to the increasing number of digits in the reference numerals. Therefore, even if the same reference numerals are used in the drawings of different embodiments, they do not necessarily represent the same configuration. Furthermore, Examples 1 to 5 and 7 below are embodiments of the present disclosure, while Examples 6 and 8 are reference examples of the present disclosure.

[0193] [Example 1] The configuration and movement trajectory of the zoom lens of Example 1 are shown in Figure 1, and the method of illustration and configuration are as described above, so some redundant explanations will be omitted here. The zoom lens of Example 1 consists of, in order from the object side to the image side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having negative refractive power, and a fifth lens group G5 having negative refractive power. The intermediate group GM consists of the third lens group G3 and the fourth lens group G4. The final lens group GE consists of the fifth lens group G5. When changing magnification from the wide-angle end to the telephoto end, the above five lens groups move along the optical axis Z, changing the distance between adjacent lens groups on different movement trajectories. The focusing group consists of the fourth lens group G4. The image stabilization group consists of the second lens group G2.

[0194] For the zoom lens of Example 1, the basic lens data is shown in Table 1, the specifications and variable plane spacing are shown in Table 2, and the aspherical coefficient is shown in Table 3.

[0195] The basic lens data table is as follows: The Sn column shows the surface number, with the surface closest to the object being designated as the 1st surface and the number increasing by one as you move towards the image side. The R column shows the radius of curvature of each surface. The D column shows the interplanar spacing on the optical axis between each surface and the surface adjacent to it on the image side. The Nd column shows the refractive index of each component with respect to the d line. The νd column shows the Abbe number of each component with respect to the d line. The θgF column shows the partial dispersion ratio between the g line and the F line of each component. The ED column shows the effective diameter of each lens surface. SG column This shows the specific gravity of each component.

[0196] In the basic lens data table, the sign of the radius of curvature of a surface with a convex shape facing the object is positive, and the sign of the radius of curvature of a surface with a convex shape facing the image is negative. Table 1 also shows the aperture diaphragm St and optical component PP. In the column for the surface number of the surface corresponding to the aperture diaphragm St, the surface number and the phrase (St) are entered. The value in the bottom column of the surface spacing column in the table is the distance between the image-side surface in the table and the image plane Sim. For variable surface spacing, the symbol DD[ ] is used, and the object-side surface number for this spacing is placed inside the [ ] and entered in the surface spacing column.

[0197] Table 2 shows the magnification ratio Zr, focal length f, maximum aperture F-number FNo., maximum angle of view 2ω, and variable plane spacing relative to the d line. The magnification ratio is synonymous with zoom magnification. The [°] in the 2ω column indicates that the unit is degrees. In Table 2, the columns labeled "WIDE" show the values ​​at the wide-angle end, and the columns labeled "TELE" show the values ​​at the telephoto end.

[0198] In the basic lens data, the aspherical surface numbers are marked with an asterisk (*), and the column for the radius of curvature of the aspherical surface lists the value of the paraxial radius of curvature. In Table 3, the row labeled Sn shows the aspherical surface number, and the rows labeled KA and Am show the numerical value of the aspherical coefficient for each aspherical surface. Note that m in Am is an integer greater than or equal to 3 and varies depending on the surface. For example, in the 6th surface of Example 1, m = 3, 4, 5, 6, 7, 8, 9, 10. The numerical value of the aspherical coefficient in Table 3, "E±n" (n: integer), is "×10 ±n This means "[...]. KA and Am are the aspheric coefficients in the aspheric equation expressed by the following formula. Zd = C × h 2 / {1+(1-KA×C 2 ×h 2 ) 1 / 2}+ΣAm×h m however, Zd: Aspherical depth (length of the perpendicular line drawn from a point on the aspherical surface at height h to a plane perpendicular to the optical axis Z to which the aspherical surface tangent is located). h: Height (distance from the optical axis Z to the lens surface) C: Reciprocal of the radius of paraxial curvature KA, Am: Aspherical coefficients where the aspherical Σ means the sum with respect to m.

[0199] In the data of each table, degrees are used as the unit of angle and millimeters are used as the unit of length. However, since the optical system can be used even with proportional magnification or reduction, other appropriate units can also be used. Also, in each of the tables shown below, values rounded to a predetermined number of digits are described.

[0200]

Table 1

[0201]

Table 2

[0202]

Table 3

[0203] Fig. 5 shows aberration diagrams of the zoom lens of Example 1 in a state focused on an infinite object. In Fig. 5, from left to right, spherical aberration, astigmatism, distortion, and longitudinal chromatic aberration are shown. In Fig. 5, the aberrations in the wide-angle end state are shown in the upper row labeled "WIDE", and the aberrations in the telephoto end state are shown in the lower row labeled "TELE". In the spherical aberration diagram, the aberrations for the d-line, C-line, F-line, and g-line are shown by a solid line, a long dashed line, a short dashed line, and a one-dot chain line, respectively. In the astigmatism diagram, the aberration for the d-line in the sagittal direction is shown by a solid line, and the aberration for the d-line in the tangential direction is shown by a short dashed line. In the distortion diagram, the aberration for the d-line is shown by a solid line. In the longitudinal chromatic aberration diagram, the aberrations for the C-line, F-line, and g-line are shown by a long dashed line, a short dashed line, and a one-dot chain line, respectively. In the spherical aberration diagram, the value of the open F-number is shown after FNo. =. In the other aberration diagrams, the value of the maximum half field angle is shown after ω =.

[0204] The symbols, meanings, description methods, and illustration methods of the respective data regarding the above Example 1 are basically the same in the following examples as well, unless otherwise specified. Therefore, duplicate explanations are omitted below.

[0205] [Example 2] Figure 6 shows the configuration and movement trajectory of the zoom lens of Example 2. The zoom lens of Example 2 consists of, in order from the object side to the image side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with positive refractive power, a fourth lens group G4 with negative refractive power, and a fifth lens group G5 with negative refractive power. The intermediate group GM consists of the third lens group G3 and the fourth lens group G4. The final lens group GE consists of the fifth lens group G5. When changing magnification from the wide-angle end to the telephoto end, the above five lens groups move along the optical axis Z, changing the distance between adjacent lens groups on different movement trajectories.

[0206] The first lens group G1 consists of three lenses, L11 to L13, arranged from the object side to the image side. The second lens group G2 consists of four lenses, L21 to L24, arranged from the object side to the image side. The third lens group G3 consists of the aperture diaphragm St and eight lenses, L31 to L38, arranged from the object side to the image side. The fourth lens group G4 consists of two lenses, L41 to L42, arranged from the object side to the image side. The fifth lens group G5 consists of two lenses, L51 to L52, arranged from the object side to the image side. The focusing group is the fourth lens group G4. The image stabilization group consists of two lenses, L34 to L35.

[0207] For the zoom lens of Example 2, the basic lens data is shown in Table 4, the specifications and variable plane spacing in Table 5, the aspherical coefficient in Table 6, and the aberration diagrams in Figure 7.

[0208] [Table 4]

[0209] [Table 5]

[0210] [Table 6]

[0211] [Example 3] Figure 8 shows the configuration and movement trajectory of the zoom lens of Example 3, and Figure 9 shows the configuration and light beam in each magnification state. The zoom lens of Example 3 consists of, in order from the object side to the image side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with negative refractive power, and a sixth lens group G6 with negative refractive power. The intermediate group GM consists of the third lens group G3, the fourth lens group G4, and the fifth lens group G5. The final lens group GE consists of the sixth lens group G6. When changing magnification from the wide-angle end to the telephoto end, the fourth lens group G4 and the sixth lens group G6 move along the optical axis Z on the same trajectory, while the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 move along the optical axis Z on different trajectories, changing the distance between adjacent lens groups.

[0212] The first lens group G1 consists of three lenses, L11 to L13, arranged from the object side to the image side. The second lens group G2 consists of four lenses, L21 to L24, arranged from the object side to the image side. The third lens group G3 consists of five lenses, the aperture diaphragm St and L31 to L35, arranged from the object side to the image side. The fourth lens group G4 consists of three lenses, L41 to L43, arranged from the object side to the image side. The fifth lens group G5 consists of two lenses, L51 to L52, arranged from the object side to the image side. The sixth lens group G6 consists of two lenses, L61 to L62, arranged from the object side to the image side. The focusing group is the fifth lens group G5. The image stabilization group consists of two lenses, L34 to L35.

[0213] For the zoom lens of Example 3, the basic lens data is shown in Table 7, the specifications and variable plane spacing in Table 8, the aspherical coefficient in Table 9, and the aberration diagrams in Figure 10.

[0214] [Table 7]

[0215] [Table 8]

[0216] [Table 9]

[0217] [Example 4] Figure 11 shows the configuration and movement trajectory of the zoom lens of Example 4. The zoom lens of Example 4 consists of, in order from the object side to the image side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with negative refractive power, and a sixth lens group G6 with negative refractive power. The intermediate group GM consists of the third lens group G3, the fourth lens group G4, and the fifth lens group G5. The final lens group GE consists of the sixth lens group G6. When changing magnification from the wide-angle end to the telephoto end, the fourth lens group G4 and the sixth lens group G6 move along the optical axis Z on the same trajectory, while the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 move along the optical axis Z on different trajectories, changing the distance between adjacent lens groups.

[0218] The first lens group G1 consists of three lenses, L11 to L13, arranged from the object side to the image side. The second lens group G2 consists of four lenses, L21 to L24, arranged from the object side to the image side. The third lens group G3 consists of five lenses, the aperture diaphragm St and L31 to L35, arranged from the object side to the image side. The fourth lens group G4 consists of three lenses, L41 to L43, arranged from the object side to the image side. The fifth lens group G5 consists of two lenses, L51 to L52, arranged from the object side to the image side. The sixth lens group G6 consists of two lenses, L61 to L62, arranged from the object side to the image side. The focusing group is the fifth lens group G5. The image stabilization group consists of two lenses, L34 to L35.

[0219] For the zoom lens of Example 4, the basic lens data is shown in Table 10, the specifications and variable plane spacing are shown in Table 11, the aspherical coefficient is shown in Table 12, and the aberration diagrams are shown in Figure 12.

[0220] [Table 10]

[0221] [Table 11]

[0222] [Table 12]

[0223] [Example 5] Figure 13 shows the configuration and movement trajectory of the zoom lens of Example 5. The zoom lens of Example 5 consists of, in order from the object side to the image side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with negative refractive power, and a sixth lens group G6 with negative refractive power. The intermediate group GM consists of the third lens group G3, the fourth lens group G4, and the fifth lens group G5. The final lens group GE consists of the sixth lens group G6. When changing magnification from the wide-angle end to the telephoto end, the fourth lens group G4 and the sixth lens group G6 move along the optical axis Z on the same trajectory, while the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 move along the optical axis Z on different trajectories, changing the distance between adjacent lens groups.

[0224] The first lens group G1 consists of three lenses, L11 to L13, arranged from the object side to the image side. The second lens group G2 consists of four lenses, L21 to L24, arranged from the object side to the image side. The third lens group G3 consists of the aperture diaphragm St and three lenses, L31 to L33, arranged from the object side to the image side. The fourth lens group G4 consists of four lenses, L41 to L44, arranged from the object side to the image side. The fifth lens group G5 consists of two lenses, L51 to L52, arranged from the object side to the image side. The sixth lens group G6 consists of two lenses, L61 to L62, arranged from the object side to the image side. The focusing group is the fifth lens group G5. The image stabilization group consists of two lenses, L41 to L42.

[0225] For the zoom lens of Example 5, the basic lens data is shown in Table 13, the specifications and variable plane spacing are shown in Table 14, the aspherical coefficient is shown in Table 15, and the aberration diagrams are shown in Figure 14.

[0226] [Table 13]

[0227] [Table 14]

[0228] [Table 15]

[0229] [Example 6] Figure 15 shows the configuration and movement trajectory of the zoom lens of Example 6. The zoom lens of Example 6 consists of, in order from the object side to the image side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with positive refractive power, a fourth lens group G4 with negative refractive power, and a fifth lens group G5 with positive refractive power. The intermediate group GM consists of the third lens group G3 and the fourth lens group G4. The final lens group GE consists of the fifth lens group G5. When changing magnification from the wide-angle end to the telephoto end, the above five lens groups move along the optical axis Z, changing the distance between adjacent lens groups on different movement trajectories.

[0230] The first lens group G1 consists of three lenses, L11 to L13, arranged from the object side to the image side. The second lens group G2 consists of four lenses, L21 to L24, arranged from the object side to the image side. The third lens group G3 consists of the aperture diaphragm St and eight lenses, L31 to L38, arranged from the object side to the image side. The fourth lens group G4 consists of two lenses, L41 to L42, arranged from the object side to the image side. The fifth lens group G5 consists of two lenses, L51 to L52, arranged from the object side to the image side. The focusing group is the fourth lens group G4. The image stabilization group consists of two lenses, L34 to L35.

[0231] For the zoom lens of Example 6, the basic lens data is shown in Table 16, the specifications and variable plane spacing are shown in Table 17, the aspherical coefficient is shown in Table 18, and the aberration diagrams are shown in Figure 16.

[0232] [Table 16]

[0233] [Table 17]

[0234] [Table 18]

[0235] [Example 7] Figure 17 shows the configuration and movement trajectory of the zoom lens of Example 7. The zoom lens of Example 7 consists of, in order from the object side to the image side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with negative refractive power, and a sixth lens group G6 with negative refractive power. The intermediate group GM consists of the third lens group G3, the fourth lens group G4, and the fifth lens group G5. The final lens group GE consists of the sixth lens group G6. When changing magnification from the wide-angle end to the telephoto end, the above six lens groups move along the optical axis Z, changing the distance between adjacent lens groups on different movement trajectories.

[0236] The first lens group G1 consists of three lenses, L11 to L13, arranged from the object side to the image side. The second lens group G2 consists of four lenses, L21 to L24, arranged from the object side to the image side. The third lens group G3 consists of five lenses, the aperture diaphragm St and L31 to L35, arranged from the object side to the image side. The fourth lens group G4 consists of three lenses, L41 to L43, arranged from the object side to the image side. The fifth lens group G5 consists of two lenses, L51 to L52, arranged from the object side to the image side. The sixth lens group G6 consists of two lenses, L61 to L62, arranged from the object side to the image side. The focusing group is the fifth lens group G5. The image stabilization group consists of two lenses, L34 to L35.

[0237] For the zoom lens of Example 7, the basic lens data is shown in Table 19, the specifications and variable plane spacing are shown in Table 20, the aspherical coefficient is shown in Table 21, and the aberration diagrams are shown in Figure 18.

[0238] [Table 19]

[0239] [Table 20]

[0240] [Table 21]

[0241] [Example 8] Figure 19 shows the configuration and movement trajectory of the zoom lens of Example 8, and Figure 20 shows the configuration and light beam in each magnification state. The zoom lens of Example 8 consists of, in order from the object side to the image side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with negative refractive power, a sixth lens group G6 with negative refractive power, and a seventh lens group G7 with positive refractive power. The intermediate group GM consists of the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6. The final lens group GE consists of the seventh lens group G7. When changing magnification from the wide-angle end to the telephoto end, the fourth lens group G4 and the sixth lens group G6 move along the optical axis Z on the same trajectory, while the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the seventh lens group G7 move along the optical axis Z on different trajectories, changing the distance between them and adjacent lens groups.

[0242] The first lens group G1 consists of three lenses, L11 to L13, arranged from the object side to the image side. The second lens group G2 consists of four lenses, L21 to L24, arranged from the object side to the image side. The third lens group G3 consists of the aperture diaphragm St and five lenses, L31 to L35, arranged from the object side to the image side. The fourth lens group G4 consists of three lenses, L41 to L43, arranged from the object side to the image side. The fifth lens group G5 consists of two lenses, L51 to L52, arranged from the object side to the image side. The sixth lens group G6 consists of one lens, L61. The seventh lens group G7 consists of one lens, L71. The focusing group is the fifth lens group G5. The image stabilization group consists of two lenses, L34 to L35.

[0243] For the zoom lens of Example 8, the basic lens data is shown in Table 22, the specifications and variable plane spacing are shown in Table 23, the aspherical coefficient is shown in Table 24, and the aberration diagrams are shown in Figure 21.

[0244] [Table 22]

[0245] [Table 23]

[0246] [Table 24]

[0247] Tables 25 to 28 show the conditional formula (1) for the zoom lenses in Examples 1 to 8. (28), and (30)~ The corresponding values ​​for (53) are shown. The corresponding values ​​for the examples shown in Tables 25 to 28 may be used as the upper or lower limit of the conditional expression to set a preferred range for the conditional expression.

[0248] [Table 25]

[0249] [Table 26]

[0250] [Table 27]

[0251] [Table 28]

[0252] The zoom lenses of Examples 1 to 8, while being compact in size, have a magnification ratio of 9x or more, achieving a high magnification ratio, and maintain high optical performance with various aberrations well corrected.

[0253] Next, an imaging device according to an embodiment of the present disclosure will be described. Figures 22 and 23 show external views of a camera 30, which is an imaging device according to one embodiment of the present disclosure. Figure 22 shows a perspective view of the camera 30 from the front, and Figure 23 shows a perspective view of the camera 30 from the rear. The camera 30 is a so-called mirrorless type digital camera, and an interchangeable lens 20 can be detachably attached. The interchangeable lens 20 is configured to include a zoom lens 1 according to one embodiment of the present disclosure, which is housed in the lens barrel.

[0254] The camera 30 comprises a camera body 31, the top of which is provided a shutter button 32 and a power button 33. The rear of the camera body 31 is provided with an operation unit 34, an operation unit 35, and a display unit 36. The display unit 36 ​​can display captured images and images within the field of view before capture.

[0255] A shooting aperture is provided in the center of the front of the camera body 31, into which light from the subject to be photographed enters. A mount 37 is provided at a position corresponding to the shooting aperture, and an interchangeable lens 20 is attached to the camera body 31 via the mount 37.

[0256] The camera body 31 contains an image sensor such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) that outputs an imaging signal corresponding to the subject image formed by the interchangeable lens 20, a signal processing circuit that processes the imaging signal output from the image sensor to generate an image, and a recording medium for recording the generated image. The camera 30 can take still images or videos by pressing the shutter button 32, and the image data obtained from this shooting is recorded on the recording medium.

[0257] Although the technology of this disclosure has been described above with reference to embodiments and examples, the technology of this disclosure is not limited to the above embodiments and examples, and various modifications are possible. For example, the radius of curvature, interplanar spacing, refractive index, Abbe number, and aspheric coefficient of each lens are not limited to the values ​​shown in each of the above embodiments, but can take other values.

[0258] Furthermore, the imaging device according to the embodiments of this disclosure is not limited to the above example, and can take various forms, such as cameras other than mirrorless cameras, film cameras, video cameras, and security cameras. [Explanation of Symbols]

[0259] 1 Zoom lens 20 interchangeable lenses 30 Cameras 31 Camera Body 32 Shutter button 33 Power button 34 Control section 35 Control section 36 Display section 37 Mount Denw distance ED Effective Diameter G1 First Lens Group G2 Second Lens Group G3 3rd lens group G4 4th lens group G5 5th lens group G6 6th lens group G7 7th lens group GE Final Lens Series GM intermediate group L11~L71 Lenses Lx lens M1 Travel amount P1 point P2 point |P1-Px| Length Penw Paraxial entrance pupil position Pext paraxial exit pupil position Pexw paraxial exit pupil position PP optical components Px Position of maximum effective diameter |Rp| Radius Sa aspherical surface Sim image plane Sp paraxial sphere St aperture diaphragm ta axial luminous flux tb Maximum half-angle luminous flux wa axial luminous flux WB (white balance) luminous flux at maximum half-angle Xa On-axis luminous flux Xb Off-axis luminous flux Xb1 ray Z optical axis ωt Maximum half-angle ωw Maximum half-angle

Claims

1. Starting from the object side and moving towards the image side, the lens consists of a first lens group with positive refractive power, a second lens group with negative refractive power, an intermediate group consisting of two or three lens groups, and a final lens group with negative refractive power. The aforementioned intermediate group has a positive refractive power as a whole across the entire range of magnification. During magnification, the distance between the first lens group and the second lens group changes, the distance between the second lens group and the intermediate group changes, the distance between the intermediate group and the final lens group changes, and the distance between all adjacent lens groups within the intermediate group changes. It includes a group of focusers that move along the optical axis when focusing, The aforementioned focus group has a negative refractive power, fw is the focal length of the entire system when in focus on an object at infinity at the wide-angle end. The focal length of the entire system when in focus on an object at infinity at the telephoto end is ft. The Abbe number of the second lens from the object side of the first lens group, with respect to the d line, is νd². The Abbe number of the third lens from the object side of the first lens group, with respect to the d line, is νd3. The center thickness of the lens closest to the object in the first lens group is d1. DG1 is the distance along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the first lens group. The Abbe number of the third lens from the object side of the first lens group, with respect to the d line, is νd3. The paraxial radius of curvature of the lens surface closest to the object in the aforementioned focus group is RfF. If RfR is the paraxial radius of curvature of the image-side lens surface of the aforementioned focus group, 6<ft / fw<30 (1) 81.55<(νd2+νd3) / 2<98 (3-3) 0.06<d1 / DG1<0.115 (24-3) 70<νd3<110 (26) 2.09<RfF / RfR<6 (30-3) A zoom lens that satisfies the following conditions: (1), (3-3), (24-3), (26), and (30-3).

2. If the Abbe number of the lens closest to the object in the first lens group is denoted by νd1, 29.6<νd1<50 (2) A zoom lens according to claim 1 that satisfies the conditional expression (2) represented by .

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

4. The zoom lens according to any one of claims 1 to 3, wherein the focus group includes a positive lens and a negative lens.

5. The zoom lens according to any one of claims 1 to 4, wherein the focus group comprises a cemented lens in which a positive lens and a negative lens are joined together.

6. The zoom lens according to any one of claims 1 to 5, wherein the fourth lens group from the object side of the zoom lens is a focus group that moves along the optical axis when focusing.

7. The zoom lens according to any one of claims 1 to 6, wherein the intermediate group includes at least one lens group having a positive refractive power.

8. The zoom lens according to any one of claims 1 to 7, wherein the intermediate group includes a lens group having the most positive refractive power on the object side.

9. The zoom lens according to any one of claims 1 to 8, wherein the intermediate group includes, in order from the object side to the image side, a group of lenses having positive refractive power and a group of lenses having negative refractive power.

10. A zoom lens according to any one of claims 1 to 9, wherein all lens groups move when the magnification is changed.

11. A zoom lens according to any one of claims 1 to 10, comprising five lens groups in total.

12. A zoom lens according to any one of claims 1 to 11, comprising six lens groups in total.

13. The zoom lens according to any one of claims 1 to 12, wherein the lens group closest to the object in the intermediate group includes, in order from the object side to the image side, a positive lens, a positive lens, and a negative lens.

14. The zoom lens according to any one of claims 1 to 13, wherein the lens group closest to the object in the intermediate group includes, in order from the image side to the object side, a positive lens, a positive lens, and a negative lens.

15. The zoom lens according to any one of claims 1 to 14, 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.

16. If FNot is the F-number when the lens is in focus on an object at infinity at the telephoto end, 45<FNot×(ft / fw)<130 (4) A zoom lens according to any one of claims 1 to 15 that satisfies the conditional expression (4) represented by .

17. When the lens is in focus on an object at infinity at the wide-angle end, the distance along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the final lens group, and the equivalent distance in air. If TLw is the sum of the back focus of the entire system, 4.5<TLw / fw<9.5 (5) A zoom lens according to any one of claims 1 to 16 that satisfies the conditional expression (5) represented by .

18. When the lens is in focus on an object at infinity at the telephoto end, if TLt is the sum of the distance along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the final lens group, and the back focus of the entire system in air equivalent distance, 0.5<TLt / ft<1.3 (6) A zoom lens according to any one of claims 1 to 17 that satisfies the conditional expression (6) represented by .

19. When the lens is in focus on an object at infinity at the telephoto end, the sum of the distance along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the final lens group, and the back focus of the entire system in air equivalent distance is TLt. If ωt is the maximum half-angle of view when in focus on an object at infinity at the telephoto end, 10<TLt / (ft×tanωt)<18 (7) A zoom lens according to any one of claims 1 to 18 that satisfies the conditional expression (7) represented by .

20. Bfw is the back focus of the entire system in terms of air-equivalent distance when focused on an object at infinity at the wide-angle end. If ωw is the maximum half-angle when in focus on an object at infinity at the wide-angle end, 0.5<Bfw / (fw×tanωw)<1.1 (8) A zoom lens according to any one of claims 1 to 19 that satisfies the conditional expression (8) represented by .

21. When the lens group is in focus on an object at infinity at the wide-angle end, Denw is defined as the distance along the optical axis from the lens surface closest to the object to the paraxial entrance pupil. 1.1<Denw / fw<1.9 (9) A zoom lens according to any one of claims 1 to 20 that satisfies the conditional expression (9) represented by .

22. The fourth lens group from the object side of the aforementioned zoom lens is designated as the fourth lens group. The fourth lens group moves during at least one of magnification and focusing. The distance along the optical axis from the lens surface closest to the object in the fourth lens group to the lens surface closest to the image in the fourth lens group is DG4. When the lens group is in focus on an object at infinity at the wide-angle end, if TLw is the sum of the distance along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the final lens group, and the back focus of the entire system in air equivalent distance, 0.009<DG4 / TLw<0.12 (10) A zoom lens according to any one of claims 1 to 21 that satisfies the conditional expression (10) represented by .

23. It includes a group of focusers that move along the optical axis when focusing, If Gfave is the average value of the specific gravity of all the lenses in the aforementioned focus group, 2.3<Gfave<5.15 (11) A zoom lens according to any one of claims 1 to 22 that satisfies the conditional expression (11) represented by .

24. The aforementioned focusing group includes at least one negative lens, When the specific gravity of at least one negative lens in the focus group is Gfn, 2.4<Gfn<5.6 (12) A zoom lens according to any one of claims 1 to 23 that satisfies the conditional expression (12) represented by .

25. It includes an anti-vibration group that moves in a direction intersecting the optical axis during image shake correction. If the average value of the specific gravity of all lenses in the aforementioned vibration isolation group is taken as GISave, 2.5<GISave<5.2 (13) A zoom lens according to any one of claims 1 to 24 that satisfies the conditional expression (13) represented by .

26. It includes an anti-vibration group that moves in a direction intersecting the optical axis during image shake correction. The vibration isolation group includes at least one positive lens, When the specific gravity of at least one positive lens in the vibration isolation group is GISp, 2.6<GISp<5 (14) A zoom lens according to any one of claims 1 to 25 that satisfies the conditional expression (14) represented by .

27. The amount of movement of the first lens group during magnification from the wide-angle end to the telephoto end is M1, The sign of M1 is positive when moving from the object side to the image side, and negative when moving from the image side to the object side. When the lens is in focus on an object at infinity at the telephoto end, if TLt is the sum of the distance along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the final lens group, and the back focus of the entire system in air equivalent distance, 0.25<-M1 / TLt<0.6 (15) A zoom lens according to any one of claims 1 to 26 that satisfies the conditional expression (15) represented by .

28. The amount of movement of the second lens group during magnification from the wide-angle end to the telephoto end is M2. The sign of M2 is positive when moving from the object side to the image side, and negative when moving from the image side to the object side. When the lens is in focus on an object at infinity at the telephoto end, if TLt is the sum of the distance along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the final lens group, and the back focus of the entire system in air equivalent distance, 0.01<-M2 / TLt<0.2 (16) A zoom lens according to any one of claims 1 to 27 that satisfies the conditional expression (16) represented by .

29. The lens group closest to the object in the aforementioned intermediate group is designated as the third lens group. The amount of movement of the third lens group during magnification from the wide-angle end to the telephoto end is M3, The sign of M3 is positive when moving from the object side to the image side, and negative when moving from the image side to the object side. When the lens is in focus on an object at infinity at the telephoto end, if TLt is the sum of the distance along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the final lens group, and the back focus of the entire system in air equivalent distance, 0.08<-M3 / TLt<0.4 (17) A zoom lens according to any one of claims 1 to 28 that satisfies the conditional expression (17) represented by .

30. The fourth lens group from the object side of the aforementioned zoom lens is designated as the fourth lens group. The amount of movement of the fourth lens group when changing magnification from the wide-angle end to the telephoto end is M4, The sign of M4 is positive when moving from the object side to the image side, and negative when moving from the image side to the object side. When the lens is in focus on an object at infinity at the telephoto end, if TLt is the sum of the distance along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the final lens group, and the back focus of the entire system in air equivalent distance, 0.15<-M4 / TLt<0.3 (18) A zoom lens according to any one of claims 1 to 29 that satisfies the conditional expression (18) represented by .

31. The fifth lens group from the object side of the aforementioned zoom lens is designated as the fifth lens group. The amount of movement of the fifth lens group when changing magnification from the wide-angle end to the telephoto end is M5, The sign of M5 is positive when moving from the object side to the image side, and negative when moving from the image side to the object side. When the lens is in focus on an object at infinity at the telephoto end, if TLt is the sum of the distance along the optical axis from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the final lens group, and the back focus of the entire system in air equivalent distance, 0.11<-M5 / TLt<0.31 (19) A zoom lens according to any one of claims 1 to 30 that satisfies the conditional expression (19) represented by .

32. When ED1 is defined as the effective diameter of the object-side surface of the lens closest to the object in the first lens group, 0.022<d1 / ED1<0.04 (20) A zoom lens according to any one of claims 1 to 31 that satisfies the conditional expression (20) represented by .

33. Denw is the distance along the optical axis from the lens surface closest to the object of the first lens group to the position of the paraxial entrance pupil when the lens is in focus on an object at infinity at the wide-angle end. If ωw is the maximum half-angle when in focus on an object at infinity at the wide-angle end, 0.035<d1 / (Denw×tanωw)<0.077 (21) A zoom lens according to any one of claims 1 to 32 that satisfies the conditional expression (21) represented by .

34. The center thickness of the second lens from the object side of the first lens group is d2. The paraxial radius of curvature of the object-side surface of the second lens from the object-side in the first lens group is R2f. If R2r is the paraxial radius of curvature of the image-side surface of the second lens from the object side in the first lens group, 0.06<d2×(1 / R2f-1 / R2r)<0.19 (22) A zoom lens according to any one of claims 1 to 33 that satisfies the conditional expression (22) represented by .

35. When the focal length of the first lens group is set to f1, 0.01<d1 / f1<0.021 (23) A zoom lens according to any one of claims 1 to 34 that satisfies the conditional expression (23) represented by .

36. 75<νd2<120 (25) A zoom lens according to any one of claims 1 to 35 that satisfies the conditional expression (25) represented by .

37. If the partial dispersion ratio between the g-line and the F-line of the second lens from the object side in the first lens group is θgF2, 0.46<θgF2<0.62 (27) A zoom lens according to any one of claims 1 to 36 that satisfies the conditional expression (27) represented by .

38. If the partial dispersion ratio between the g-line and the F-line of the third lens from the object side in the first lens group is θgF3, 0.46<θgF3<0.62 (28) A zoom lens according to any one of claims 1 to 37 that satisfies the conditional expression (28) represented by .

39. When the focal length of the aforementioned focus group is denoted as ffoc, -0.35<ffoc / ft<-0.02 (31) A zoom lens according to any one of claims 1 to 38 that satisfies the conditional expression (31) represented by .

40. It includes an anti-vibration group that moves in a direction intersecting the optical axis during image shake correction. When the focal length of the vibration isolation group is denoted as fIS, 0.01<|fIS / ft|<0.35 (32) A zoom lens according to any one of claims 1 to 39 that satisfies the conditional expression (32) represented by .

41. The focal length of the second lens group is f2, If the focal length of the second lens from the object side in the second lens group is fL22, 1.4<fL22 / f2<7 (33) A zoom lens according to any one of claims 1 to 40 that satisfies the conditional expression (33) represented by .

42. The horizontal magnification of the focus group when in focus on an object at infinity at the wide-angle end is βfw, When the combined lateral magnification of all lenses on the image side of the focus group is βfRw in a state where the focus is on an object at infinity at the wide-angle end, -6<(1-βfw ２ )×βfRw ２ <-1 (34) A zoom lens according to any one of claims 1 to 41 that satisfies the conditional expression (34) represented by .

43. The lateral magnification of the focus group when in focus on an object at infinity at the telephoto end is βft, When the combined lateral magnification of all lenses on the image side of the focus group is in focus on an object at infinity at the telephoto end, let βfRt be the result. -25<(1-βft ２ )×βfRt ２ <-6.3 (35) The zoom lens according to any one of claims 1 to 42 that satisfies the conditional expression (35) represented by Lens.

44. It includes an anti-vibration group that moves in a direction intersecting the optical axis during image shake correction. The horizontal magnification of the vibration damping group when in focus on an object at infinity at the wide-angle end is βISw, When the combined lateral magnification of all lenses on the image side of the image stabilization group is βISRw in a state where the object at infinity is in focus at the wide-angle end, 0.75<|(1-βISw)×βISRw|<2.5 (36) A zoom lens according to any one of claims 1 to 43 that satisfies the conditional expression (36) represented by .

45. It includes an anti-vibration group that moves in a direction intersecting the optical axis during image shake correction. The lateral magnification of the vibration damping group when focused on an object at infinity at the telephoto end is βIST. When the combined lateral magnification of all lenses on the image side of the image stabilization group is βISRt in a state where the object at infinity is in focus at the telephoto end, 1.7<|(1-βISt)×βISRt|<7 (37) A zoom lens according to any one of claims 1 to 44 that satisfies the conditional expression (37) represented by .

46. The horizontal magnification of the focus group when in focus on an object at infinity at the wide-angle end is βfw, When in focus on an object at infinity at the wide-angle end, the combined lateral magnification of all lenses on the image side of the focus group is βfRw. The focal length of the aforementioned focus group is ffoc, When in focus on an object at infinity at the wide-angle end, the combined focal length of all lenses on the image side of the focus group is ffRw. When in focus on an object at infinity at the wide-angle end, the sum of the distance along the optical axis from the paraxial exit pupil position to the image-side lens surface of the final lens group and the back focus of the entire system in air equivalent distance is dexw. Let ωw be the maximum half-angle of view when in focus on an object at infinity at the wide-angle end. γw=(1-β&w ２ )×βfRw ２ 、 If BRw = {βfw / (ffoc×γw) - 1 / (βfRw×ffRw) - (1 / Dexw)}, 0 < |BRw × (fw × tanωw)| < 0.25 (38) A zoom lens according to any one of claims 1 to 45 that satisfies the conditional expression (38) represented by .

47. The lateral magnification of the focus group when in focus on an object at infinity at the telephoto end is βft, When the focus is on an object at infinity at the telephoto end, the combined lateral magnification of all lenses on the image side of the focus group is βfRt. The focal length of the aforementioned focus group is ffoc, When the lens is in focus on an object at infinity at the telephoto end, the combined focal length of all lenses on the image side of the focus group is ffRt. When the telephoto end is focused on an object at infinity, the sum of the distance along the optical axis from the paraxial exit pupil position to the image-side lens surface of the final lens group and the back focus of the entire system in air equivalent distance is Dext. Let ωt be the maximum half-angle of view when the telephoto end is focused on an object at infinity. γt=(1-βft ２ )×βfRt ２ 、 If BRt = {βft / (ffoc×γt) - 1 / (βfRt×ffRt) - (1 / Dext)}, 0 < |BRt × (ft × tanωt)| < 0.034 (39) The zoom range according to any one of claims 1 to 46 that satisfies the conditional expression (39) represented by Lens.

48. The focal length of the first lens group is f1, When the focal length of the second lens group is set to f2, -10<f1 / f2<-5.6 (40) A zoom lens according to any one of claims 1 to 47 that satisfies the conditional expression (40) represented by .

49. The focal length of the second lens group is f2, If the focal length of the lens group closest to the object in the aforementioned intermediate group is set to f3, -0.9<f2 / f3<-0.54 (41) A zoom lens according to any one of claims 1 to 48 that satisfies the conditional expression (41) represented by .

50. The zoom lens according to any one of claims 1 to 49, wherein the lens group closest to the object in the intermediate group includes five or more lenses.

51. The zoom lens according to any one of claims 1 to 50, wherein the number of lenses included in the focus group is two or less.

52. The zoom lens according to any one of claims 1 to 51, wherein of the movement trajectories of each lens group that move when the zoom is changed from the wide-angle end to the telephoto end, there are only five movement trajectories that are different from each other.

53. A zoom lens according to any one of claims 1 to 52, comprising a plurality of lens groups that move along the same trajectory when changing magnification from the wide-angle end to the telephoto end.

54. The zoom lens according to claim 53, wherein the focus group is positioned between a plurality of lens groups that move along the same trajectory.

55. The zoom lens according to any one of claims 1 to 54, wherein when the zoom is changed from the wide-angle end to the telephoto end, the fourth lens group from the object side of the zoom lens and the final lens group move along the same trajectory.

56. The fourth lens group from the object side of the aforementioned zoom lens is designated as the fourth lens group. The amount of movement of the fourth lens group when changing magnification from the wide-angle end to the telephoto end is M4, ME is the amount of movement of the final lens group when changing magnification from the wide-angle end to the telephoto end. If the signs of M4 and ME are positive when moving from the object side to the image side, and negative when moving from the image side to the object side, 0.9<M4 / ME<1.1 (42) A zoom lens according to any one of claims 1 to 55 that satisfies the conditional expression (42) represented by .

57. When the focal length of the intermediate group is fMw in a state where it is in focus on an object at infinity at the wide-angle end, 0.54<fw / fMw<0.95 (43) A zoom lens according to any one of claims 1 to 56 that satisfies the conditional expression (43) represented by .

58. When the focal length of the intermediate group is fMt in the state where it is in focus on an object at infinity at the telephoto end, 5.1<ft / fMt<20 (44) A zoom lens according to any one of claims 1 to 57 that satisfies the conditional expression (44) represented by .

59. The amount of movement of the lens group adjacent to the object side of the focus group during magnification from the wide-angle end to the telephoto end is MfF. The amount of movement of the lens group adjacent to the image side of the focus group during magnification from the wide-angle end to the telephoto end is MfR. If the signs of MfF and MfR are positive when moving from the object side to the image side, and negative when moving from the image side to the object side, 0.9<MfF / MfR<1.1 (45) A zoom lens according to any one of claims 1 to 58 that satisfies the conditional expression (45) represented by .

60. A zoom lens according to any one of claims 1 to 59, comprising eight or more aspherical lens surfaces.

61. The zoom lens according to any one of claims 1 to 60, wherein the image-side lens of the second lens group includes an aspherical surface.

62. The zoom lens according to any one of claims 1 to 61, wherein the lens closest to the object in the second lens group is an aspherical lens.

63. The zoom lens according to any one of claims 1 to 62, wherein the lens on the image side of the lens group on the object side of the intermediate group includes an aspherical surface.

64. The zoom lens according to any one of claims 1 to 63, wherein the lens closest to the object in the lens group closest to the object of the intermediate group includes an aspherical lens.

65. The zoom lens according to any one of claims 1 to 64, wherein the object-side surface of the image-side lens of the second lens group has an aspherical shape in which the refractive power at the position of the maximum effective diameter is weaker than the refractive power near the optical axis.

66. The zoom lens according to any one of claims 1 to 65, wherein the image-side surface of the lens closest to the object in the second lens group has an aspherical shape in which the refractive power at the position of the maximum effective diameter is stronger than the refractive power near the optical axis.

67. The zoom lens according to any one of claims 1 to 66, wherein the object-side surface of the image-side lens of the object-side lens group of the intermediate group has an aspherical shape in which the refractive power at the position of the maximum effective diameter is weaker than the refractive power near the optical axis.

68. The zoom lens according to any one of claims 1 to 67, wherein the image-side surface of the lens closest to the object in the lens group closest to the object of the intermediate group has an aspherical shape in which the refractive power at the position of the maximum effective diameter is weaker than the refractive power near the optical axis.

69. The paraxial radius of curvature of the object-side surface of the image-side lens of the second lens group is Rc2ef. If Ry2ef is the radius of curvature at the position of the maximum effective diameter on the object-side surface of the image-side lens of the second lens group, 0.1<Rc2ef / Ry2ef<0.999 (46) The zoom lens according to any one of claims 1 to 68 that satisfies the conditional expression (46) represented by Lens.

70. The paraxial radius of curvature of the image-side surface of the lens closest to the object in the second lens group is Rc21r. If Ry21r is the radius of curvature at the position of the maximum effective diameter of the image-side surface of the lens closest to the object in the second lens group, 1.001<Rc21r / Ry21r<4.5 (47) A zoom lens according to any one of claims 1 to 69 that satisfies the conditional expression (47) represented by .

71. The paraxial radius of curvature of the object-side surface of the image-side lens of the object-side lens group of the aforementioned intermediate group is Rc3ef. If Ry3ef is the radius of curvature at the position of the maximum effective diameter of the object-side surface of the image-side lens of the object-side lens group of the aforementioned intermediate group, 0.1<Rc3ef / Ry3ef<0.999 (48) A zoom lens according to any one of claims 1 to 70 that satisfies the conditional expression (48) represented by .

72. The paraaxial radius of curvature of the image-side surface of the lens closest to the object in the lens group closest to the object in the aforementioned intermediate group is Rc31r. If Ry31r is the radius of curvature at the position of the maximum effective diameter of the image-side surface of the lens closest to the object in the intermediate lens group, 0<Rc31r / Ry31r<0.999 (49) A zoom lens according to any one of claims 1 to 71 that satisfies the conditional expression (49) represented by .

73. The paraxial radius of curvature of the object-side surface of the image-side lens of the second lens group is Rc2ef. The paraxial radius of curvature of the image-side surface of the lens closest to the image in the second lens group is Rc2er. The radius of curvature at the position of the maximum effective diameter of the object-side surface of the image-side lens of the second lens group is Ry2ef. If Ry²er is the radius of curvature at the position of the maximum effective diameter on the image-side surface of the lens closest to the image in the second lens group, 1.05<(1 / Rc2ef-1 / Rc2er) / (1 / Ry2ef-1 / Ry2er)<5 (50) A zoom lens according to any one of claims 1 to 72 that satisfies the conditional expression (50) represented by .

74. The paraxial radius of curvature of the object-side surface of the lens closest to the object in the second lens group is Rc21f. The paraxial radius of curvature of the image-side surface of the lens closest to the object in the second lens group is Rc21r. The radius of curvature at the position of the maximum effective diameter on the object-side surface of the lens closest to the object in the second lens group is Ry21f. If Ry21r is the radius of curvature at the position of the maximum effective diameter of the image-side surface of the lens closest to the object in the second lens group, 0.4<(1 / Rc21f-1 / Rc21r) / (1 / Ry21f-1 / Ry21r)<0.99 (51) A zoom lens according to any one of claims 1 to 73 that satisfies the conditional expression (51) represented by .

75. The paraxial radius of curvature of the object-side surface of the image-side lens of the object-side lens group of the aforementioned intermediate group is Rc3ef. The paraxial radius of curvature of the image-side surface of the image-side lens of the object-side lens group in the aforementioned intermediate group is R. c3er, The radius of curvature at the position of the maximum effective diameter of the object-side surface of the image-side lens of the object-side lens group of the aforementioned intermediate group is Ry3ef. If Ry3er is the radius of curvature at the position of the maximum effective diameter of the image-side surface of the image-side lens of the object-side lens group of the aforementioned intermediate group, 1.01<(1 / Rc3ef-1 / Rc3er) / (1 / Ry3ef-1 / Ry3er)<2 (52) A zoom lens according to any one of claims 1 to 74 that satisfies the conditional expression (52) represented by .

76. The paraxial curvature radius of the object-side surface of the object-side lens of the object-side lens group of the aforementioned intermediate group is Rc31f. The paraaxial radius of curvature of the image-side surface of the lens closest to the object in the lens group closest to the object in the aforementioned intermediate group is Rc31r. The radius of curvature at the position of the maximum effective diameter of the object-side surface of the object-side lens of the object-side lens group of the aforementioned intermediate group is Ry31f. If Ry31r is the radius of curvature at the position of the maximum effective diameter of the image-side surface of the lens closest to the object in the intermediate lens group, 1.1<(1 / Rc31f-1 / Rc31r) / (1 / Ry31f-1 / Ry31r)<3 (53) A zoom lens according to any one of claims 1 to 75 that satisfies the conditional expression (53) represented by .

77. 7.5<ft / fw<20 (1-1) A zoom lens according to any one of claims 1 to 76 that satisfies the conditional expression (1-1) represented by .

78. An imaging device comprising a zoom lens according to any one of claims 1 to 77.

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