Zoom lens and imaging device

Abstract

To provide a zoom lens which exhibits a high zoom ratio and is yet compact and lightweight, and an imaging device equipped with this zoom lens.SOLUTION: The zoom lens comprises, in order from object side to image side: a first lens group having positive refractive power; a second lens group having negative refractive power; and a subsequent group having a plurality of lens groups. An aperture diaphragm is included at a position closer to the image side than the most image side lens surface of the second lens group, and the most image side lens group in the subsequent group includes at least one negative lens the object side lens surface of which is a concave in contact with air. At the time of zooming, the interval between the first and second lens groups changes, the interval between the second lens group and the subsequent group changes, and the interval of all of adjacent lens groups in the subsequent group changes. The zoom lens satisfies a predetermined conditional expression.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The technology of the present disclosure relates to a zoom lens and an imaging device.

Background Art

[0002] As a zoom lens applicable to imaging devices such as digital cameras and video cameras, for example, the lens system described in Patent Document 1 below is known.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, there has been a demand for a compact and lightweight zoom lens that achieves a high magnification ratio.

[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a compact and lightweight zoom lens that achieves a high magnification ratio, and an imaging device including this zoom lens.

Means for Solving the Problems

[0006] A first aspect of the present disclosure is a zoom lens, which comprises, in order from the object side to the image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a subsequent group having a plurality of lens groups. An aperture stop is included on the image side of the most image-side lens surface of the second lens group. The most image-side lens group within the subsequent group includes at least one negative lens whose object-side lens surface is a concave surface in contact with air. During zooming, the distance between the first lens group and the second lens group changes, the distance between the second lens group and the subsequent group changes, and the distances between all adjacent lens groups within the subsequent group change. During zooming, the lens intervals inside the first lens group, the second lens group, and the plurality of lens groups are invariant. In the wide-angle end in a state of focusing on an infinite object, the focal length of the entire system is fw, and the distance on the optical axis from the most object-side lens surface of the first lens group to the paraxial entrance pupil position is Denw. When the sign of Denw is positive if the paraxial entrance pupil position is on the image side of the most object-side lens surface of the first lens group, and negative if the paraxial entrance pupil position is on the object side of the most object-side lens surface of the first lens group, 0.7 < fw / Denw < 1.5 (1) The conditional expression (1) represented by the above is satisfied.

[0007] In the above first aspect, in the wide-angle end in a state of focusing on an infinite object, when the distance on the optical axis from the paraxial exit pupil position to the image plane is Dexw, and the sign of Dexw is positive if the paraxial exit pupil position is on the object side of the image plane, and negative if the paraxial exit pupil position is on the image side of the image plane, 0.25 < fw / Dexw < 1 (2) It is preferable to satisfy the conditional expression (2) represented by the above.

[0008] In the above first aspect, when the distance on the optical axis from the most object-side lens surface of the first lens group to the most image-side lens surface of the first lens group is D1, and the sum of the distance on the optical axis from the most object-side lens surface of the first lens group to the most image-side lens surface of the subsequent group and the back focus in terms of air equivalent distance in the telephoto end in a state of focusing on an infinite object is TLt, 0.01 < D1 / TLt < 0.1 (3) It is preferable to satisfy the conditional expression (3) represented by

[0009] In the above first aspect, when the focal length of the entire system at the telephoto end in the state of being focused on an infinitely distant object is ft, 4.9 < ft / fw < 12 (4) It is preferable to satisfy the conditional expression (4) represented by

[0010] In the above first aspect, the subsequent group includes at least one Lx lens whose image-side lens surface is a convex surface in contact with air, and among at least one optical system composed of from the lens surface adjacent to the image side of the aperture stop to the image-side lens surface of the Lx lens, when the aperture stop is taken as the object point in the state of being focused on an infinitely distant object, when the lateral magnification in the A optical system where the absolute value of the reciprocal of the lateral magnification at the wide-angle end is the smallest is βA, -0.5 < 1 / βA < 0.5 (5) It is preferable to satisfy the conditional expression (5) represented by

[0011] In the above first aspect, when the height from the optical axis of the marginal ray on the optical axis at the most image-side lens surface of the A optical system at the telephoto end in the state of being focused on an infinitely distant object is HAt, and the height from the optical axis of the marginal ray on the optical axis at the aperture stop at the telephoto end in the state of being focused on an infinitely distant object is HSt, 0.73 < HAt / HSt < 2.3 (6) It is preferable to satisfy the conditional expression (6) represented by

[0012] In the above first aspect, when the focal length of the entire system at the telephoto end in the state of being focused on an infinitely distant object is ft, and the combined focal length from the most object-side lens surface of the subsequent group to the most image-side lens surface of the A optical system at the telephoto end in the state of being focused on an infinitely distant object is fpAt, 3 < ft / fpAt < 15 (7) It is preferable to satisfy the conditional expression (7) represented by

[0013] In the first aspect described above, when the height from the optical axis of the marginal ray on the optical axis at the telephoto end in the state of being focused on an infinitely distant object to the most image-side lens surface of the A optical system is HAt, and the height from the optical axis of the chief ray of the maximum image height at the wide-angle end in the state of being focused on an infinitely distant object to the most image-side lens surface of the A optical system is HAw, 0.35 < HAt / HAw < 1.6 (8) It is preferable to satisfy the conditional expression (8) represented by

[0014] In the first aspect described above, it is preferable that the subsequent group includes a lens surface that is an image-side surface and is a concave surface in contact with air between the most image-side lens surface of the A optical system and the object-side surface included in the most image-side lens group within the subsequent group and is a concave surface in contact with air.

[0015] In the first aspect described above, when the distance on the optical axis from the aperture stop to the most image-side lens surface of the A optical system at the telephoto end in the state of being focused on an infinitely distant object is DSAt, and the sum of the distance on the optical axis from the aperture stop to the most image-side lens surface of the subsequent group and the back focus in terms of air equivalent distance at the telephoto end in the state of being focused on an infinitely distant object is DSLt, 0.1 < DSAt / DSLt < 0.54 (9) It is preferable to satisfy the conditional expression (9) represented by

[0016] In the first aspect described above, when the interval on the optical axis between the most image-side lens surface of the A optical system and the lens surface adjacent to the image side of the lens surface at the telephoto end in the state of being focused on an infinitely distant object is dA, and the maximum image height at the telephoto end is Yt, 0.015 < dA / Yt < 0.35 (10) It is preferable to satisfy the conditional expression (10) represented by

[0017] In the above first aspect, when the distance on the optical axis from the lens surface closest to the object side of the first lens group to the lens surface closest to the image side of the subsequent group at the telephoto end in the state of being focused on an infinitely distant object, and the back focus in terms of air equivalent distance are defined as TLt, and the focal length of the entire system at the telephoto end in the state of being focused on an infinitely distant object is defined as ft, 0.65 < TLt / ft < 1.5 (11) it is preferable to satisfy the conditional expression (11) represented by this.

[0018] In the above first aspect, it is preferable that the first lens group includes, in order from the object side to the image side, a negative lens and a positive lens continuously.

[0019] In the above first aspect, when the back focus of the air equivalent distance at the wide-angle end in the state of being focused on an infinitely distant object is defined as BFw, and the maximum image height at the wide-angle end is defined as Yw, 0.38 < BFw / Yw < 1.5 (12) it is preferable to satisfy the conditional expression (12) represented by this.

[0020] In the above first aspect, when the Abbe number of the lens closest to the object side of the first lens group based on the d line is defined as ν1, 10 < ν1 < 50 (13) it is preferable to satisfy the conditional expression (13) represented by this.

[0021] In the above first aspect, when the refractive index of the lens closest to the object side of the first lens group with respect to the d line is defined as N1, 1.7 < N1 < 2.3 (14) it is preferable to satisfy the conditional expression (14) represented by this.

[0022] In the above first aspect, when the refractive index of the negative lens closest to the object side among the negative lenses included in the second lens group with respect to the d line is defined as N2n, 1.6 < N2n < 2.2 (15) it is preferable to satisfy the conditional expression (15) represented by this.

[0023] In the first aspect, when the refractive index of the positive lens with the strongest refractive power among the positive lenses included in the second lens group with respect to the d-line is N2p, 1.65 < N2p < 2 (16) It is preferable to satisfy the conditional expression (16) represented by

[0024] In the first aspect, when the Abbe number based on the d-line of the negative lens closest to the image side among the negative lenses included in the subsequent group is νnL, 27 < νnL < 102 (17) It is preferable to satisfy the conditional expression (17) represented by

[0025] In the first aspect, it is preferable that the subsequent group includes at least one lens group having a positive refractive power.

[0026] In the first aspect, in the state of focusing on an infinite object, at the telephoto end, the sum of the distance on the optical axis from the lens surface closest to the object side of the first lens group to the lens surface closest to the image side of the subsequent group and the back focus in terms of air equivalent distance is TLt. In the state of focusing on an infinite object, for the lens group with the positive refractive power included in the subsequent group and closest to the object side, the difference in the position in the optical axis direction between the wide-angle end and the telephoto end is Mp. The sign of Mp is positive if the lens group closest to the object side moves from the object side to the image side when zooming from the wide-angle end to the telephoto end, and negative if it moves from the image side to the object side. -0.45 < Mp / TLt < -0.06 (18) It is preferable to satisfy the conditional expression (18) represented by

[0027] In the first aspect, when the focal length of the lens group closest to the object side among the lens groups with positive refractive power included in the subsequent group in the state of focusing on an infinite object is fp and the focal length of the second lens group is f2, -4.3 < fp / f2 < -1.1 (19) It is preferable to satisfy the conditional expression (19) represented by

[0028] In the first aspect described above, when the distance on the optical axis from the lens surface closest to the image side of the first lens group at the telephoto end in the state of being focused on an infinitely distant object to the lens surface closest to the object side of the lens group having a positive refractive power included in the subsequent group is D1pt, and the sum of the distance on the optical axis from the lens surface closest to the object side of the first lens group to the lens surface closest to the image side of the subsequent group and the back focus in terms of the air equivalent distance is TLt, 0.2 < D1pt / TLt < 0.5 (20) It is preferable to satisfy the conditional expression (20) represented by this.

[0029] In the first aspect described above, the subsequent group includes at least one Lx lens whose lens surface on the image side is a convex surface in contact with air, and among at least one optical system composed of the lens surface on the image side adjacent to the aperture stop to the lens surface on the image side of the Lx lens, when the aperture stop is the object point in the state of being focused on an infinitely distant object, Wide-angle end the optical system in which the absolute value of the reciprocal of the lateral magnification at is the minimum is defined as the A optical system, and when the combined focal length at the wide-angle end in the state of being focused on an infinitely distant object from the lens surface adjacent to the image side of the lens surface on the image side of the A optical system to the lens surface on the image side of the subsequent group is fBw, -1.6 < fw / fBw < -0.25 (21) It is preferable to satisfy the conditional expression (21) represented by this.

[0030] In the first aspect described above, when the maximum half field angle at the wide-angle end in the state of being focused on an infinitely distant object is ωw and the maximum image height at the wide-angle end is Yw, 0.97 < fw×tanωw / Yw < 1.3 (22) It is preferable to satisfy the conditional expression (22) represented by this.

[0031] In the first aspect described above, it is preferable that the subsequent group includes a focus group that moves along the optical axis during focusing.

[0032] In the first aspect described above, it is preferable that the focus group consists of two or fewer lenses.

[0033] In the first aspect described above, the focus group preferably has a negative refractive power.

[0034] In the first aspect described above, when the focal length of the first lens group is f1 and the focal length of the second lens group is f2, -0.3 < f2 / f1 < -0.05 (23) It is preferable to satisfy the conditional expression (23) represented by.

[0035] A second aspect of the present disclosure is an imaging device including the zoom lens according to the first aspect.

[0036] In addition, the "consisting of" and "comprising" in this specification are intended to mean that, in addition to the listed components, lenses having substantially no refractive power, optical elements other than lenses such as diaphragms, filters, and cover glasses, and mechanical parts such as lens flanges, lens barrels, imaging elements, and shake correction mechanisms may be included.

[0037] The "group having a positive refractive power" in this specification means having a positive refractive power as a whole group. The "group having a negative refractive power" means having a negative refractive power as a whole group. "Lens having a positive refractive power" and "positive lens" are synonymous. "Lens having a negative refractive power" and "negative lens" are synonymous.

[0038] In addition, the "first lens group", "second lens group", and "plurality of lens groups" in this specification each refer to a part of the zoom lens that includes at least one lens separated by an air interval that changes during zooming. During zooming, it is moved or fixed in units of lens groups, and the mutual interval of the lenses within one lens group does not change. That is, in this specification, a group in which the interval with an adjacent group changes during zooming and the total interval of adjacent lenses within itself does not change is regarded as one lens group. The "~ lens group" is not limited to a configuration consisting of a plurality of lenses, and may also be a configuration consisting of only one lens.

[0039] "Single lens" means a single lens that is not joined. However, a compound aspherical lens (a lens in which a spherical lens and an aspherical film formed on the spherical lens are integrally configured and function as a single aspherical lens as a whole) is not regarded as a joined lens and is treated as a single lens. Regarding a lens including an aspherical surface, the sign of the refractive power and the surface shape are considered in the paraxial region unless otherwise specified.

[0040] In this specification, "entire system" means a zoom lens. The "focal length" used in the conditional expressions is the paraxial focal length. The "distance on the optical axis" used in the conditional expressions is considered as the geometric length rather than the air-equivalent length unless otherwise specified. The "back focus at the air-equivalent distance" is the air-equivalent distance on the optical axis from the most image-side lens surface of the zoom lens to the image-side focal position of the zoom lens.

[0041] The values used in the conditional expressions are the values based on the d-line when focused on an infinite object. The "d-line", "C-line" and "F-line" described in this specification are emission lines. In this specification, the wavelength of the d-line is treated as 587.56 nm (nanometers), the wavelength of the C-line is 656.27 nm (nanometers), and the wavelength of the F-line is 486.13 nm (nanometers).

Effects of the Invention

[0042] According to the present disclosure, it is possible to provide a small and lightweight zoom lens while achieving a high magnification ratio, and an imaging device including this zoom lens.

Brief Description of the Drawings

[0043]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Embodiments for Carrying Out the Invention

[0044] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing the configuration of a zoom lens and a movement locus according to an embodiment of the present disclosure. In FIG. 1, the upper part marked with "WIDE" shows the wide-angle end state, and the lower part marked with "TELE" shows the telephoto end state. FIG. 2 is a cross-sectional view showing the configuration and light beam in each variable magnification state of the zoom lens of FIG. 1. In FIG. 2, the uppermost part marked with "WIDE" shows the wide-angle end state, the middle part marked with "MIDDLE" shows the intermediate focal length state, and the lower part marked with "TELE" shows the telephoto end state. Further, in FIG. 2, as the light beams, the on-axis light beam wa and the light beam wb of the maximum angle of view in the wide-angle end state, the on-axis light beam ma and the light beam mb of the maximum angle of view in the intermediate focal length state, and the on-axis light beam ta and the light beam tb of the maximum angle of view in the telephoto end state are shown. FIGS. 1 and 2 show a state of focusing on an infinite object, with the left side being the object side and the right side being the image side. The examples shown in FIGS. 1 and 2 correspond to the zoom lens of Example 1 described later.

[0045] The zoom lens according to this embodiment includes, 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, and a subsequent group Gr having a plurality of lens groups. In FIG. 1, as an example, the subsequent group Gr includes a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group G6 having a negative refractive power.

[0046] In the example shown in FIG. 1, the first lens group G1 consists of three lenses L11 to L13 in order from the object side to the image side. The second lens group G2 consists of four lenses L21 to L24 in order from the object side to the image side. The third lens group G3 consists of an aperture stop St and six lenses L31 to L36 in order from the object side to the image side. The fourth lens group G4 consists of four lenses L41 to L44 in order from the object side to the image side. The fifth lens group G5 consists of two lenses L51 to L52 in order from the object side to the image side. The sixth lens group G6 consists of one lens L61.

[0047] The zoom lens according to this embodiment is configured to include an aperture stop St on the image side of the most image-side lens surface of the second lens group G2. Note that the aperture stop St in FIGS. 1 and 2 indicates the position in the optical axis direction, rather than the shape and size.

[0048] In the zoom lens according to this embodiment, during zooming, 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 subsequent group Gr changes, and the distances between all adjacent lens groups within the subsequent group Gr change. Also, during zooming, the lens intervals inside the plurality of lens groups included in the first lens group G1, the second lens group G2, and the subsequent group Gr are invariant. That is, in the zoom lens according to this embodiment, the distances between all adjacent lens groups change relative to each other, and the lens intervals inside each lens group are invariant. In FIG. 1, the schematic movement trajectories of 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 sixth lens group G6 during zooming from the wide-angle end to the telephoto end are indicated by arrows between the upper and lower parts.

[0049] As described above, the zoom lens includes, 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, and a subsequent group Gr having a plurality of lens groups. The aperture stop St is included on the image side of the most image-side lens surface of the second lens group G2. During zooming, the distances between all adjacent lens groups change relative to each other, and the lens intervals inside each lens group are invariant, which is advantageous for achieving a high zoom ratio.

[0050] The most image-side lens group within the subsequent group Gr includes at least one negative lens whose object-side lens surface is a concave surface in contact with air. By including at least one negative lens whose object-side lens surface is a concave surface in contact with air in the most image-side lens group within the subsequent group Gr, it is advantageous for shortening the overall length of the lens system. In FIG. 1, as an example, the sixth lens group G6, which is the most image-side lens group within the subsequent group Gr, has a concave surface on its object-side lens surface in contact with air and includes a lens L61 having a negative refractive power.

[0051] The first lens group G1 preferably includes, in order from the object side to the image side, a negative lens and a positive lens in succession. By adopting such a configuration, it is advantageous for suppressing magnification chromatic aberration on the wide-angle side and for suppressing axial chromatic aberration on the telephoto side. In FIG. 1, as an example, the first lens group G1 includes, in order from the object side to the image side, a lens L11 having a negative refractive power and a lens L12 having a positive refractive power.

[0052] The subsequent group Gr preferably includes at least one lens group having a positive refractive power. By including at least one lens group having a positive refractive power in the subsequent group Gr, it is advantageous for achieving a high magnification ratio. In FIG. 1, as an example, the subsequent group Gr includes two lens groups having positive refractive powers, namely, the third lens group G3 and the fourth lens group G4.

[0053] The subsequent group Gr preferably includes a focus group that moves along the optical axis Z during focusing. Here, the focus group is composed of at least one lens that moves during focusing. Focusing is achieved by the movement of the focus group. By including the focus group in the subsequent group Gr, it is advantageous for suppressing fluctuations in various aberrations generated during focusing. The rightward arrows marked below the lenses L51 to L52 in FIG. 1 indicate that the lenses L51 to L52 are a focus group that moves toward the image side during focusing from an infinite object to a close-distance object.

[0054] The focus group preferably consists of two or fewer lenses. By having the focus group composed of two or fewer lenses, it is advantageous for reducing the weight of the focus group. Also, the focus group preferably has a negative refractive power. By having the focus group have a negative refractive power, it is advantageous for reducing the movement amount of the focus group during focusing.

[0055] For the zoom lens according to this embodiment, when the focal length of the entire system at the wide-angle end in the state of focusing on an infinitely distant object is fw, and the distance on the optical axis Z from the lens surface closest to the object side of the first lens group to the paraxial entrance pupil position Penw at the wide-angle end in the state of focusing on an infinitely distant object is Denw, it is preferable to satisfy the following conditional expression (1). Here, the sign of Denw is positive if the paraxial entrance pupil position Penw is on the image side with respect to the lens surface closest to the object side of the first lens group, and negative if the paraxial entrance pupil position Penw is on the object side with respect to the lens surface closest to the object side of the first lens group. FIG. 3 is a cross-sectional view showing the configuration and light beam corresponding to the wide-angle end state of the zoom lens of FIGS. 1 and 2, and shows the paraxial entrance pupil position Penw and the distance Denw as an example.

[0056] By ensuring that the corresponding value of the conditional expression (1) does not fall below the lower limit, the distance Denw does not become too large, and the paraxial entrance pupil position Penw can be brought closer to the object side. As a result, the height from the optical axis Z when the off-axis ray passes through the first lens group G1 can be reduced, and the increase in the diameter of the first lens group G1 can be suppressed, which is advantageous for miniaturization and weight reduction of the first lens group G1. By ensuring that the corresponding value of the conditional expression (1) does not exceed the upper limit, the rays at each image height in the first lens group G1 are appropriately separated, which is advantageous for correcting the longitudinal chromatic aberration. In order to obtain better characteristics, it is more preferable to satisfy the following conditional expression (1-1), and it is even more preferable to satisfy the following conditional expression (1-2). 0.7 < fw / Denw < 1.5 (1) 0.83 < fw / Denw < 1.35 (1-1) 0.94 < fw / Denw < 1.22 (1-2)

[0057] For the zoom lens according to this embodiment, when the focal length of the entire system at the wide-angle end in a state of focusing on an infinite object is fw, and the distance on the optical axis Z from the paraxial exit pupil position Pexw to the image plane Sim at the wide-angle end in a state of focusing on an infinite object is Dexw, it is preferable to satisfy the following conditional expression (2). Here, the sign of Dexw is positive if the paraxial exit pupil position Pexw is on the object side with respect to the image plane Sim, and negative if the paraxial exit pupil position Pexw is on the image side with respect to the image plane Sim. FIG. 3 shows an example of the paraxial exit pupil position Pexw and the distance Dexw. By preventing the corresponding value of the conditional expression (2) from falling below the lower limit, the overall length of the lens system can be shortened, which is advantageous for miniaturization. By preventing the corresponding value of the conditional expression (2) from exceeding the upper limit, the incident angle of off-axis rays on the image plane Sim can be reduced, which is advantageous for ensuring the peripheral light quantity. To obtain better characteristics, it is more preferable to satisfy the following conditional expression (2-1), and it is even more preferable to satisfy the following conditional expression (2-2). 0.25 < fw / Dexw < 1 (2) 0.33 < fw / Dexw < 0.6 (2-1) 0.39 < fw / Dexw < 0.55 (2-2)

[0058] For the zoom lens according to this embodiment, when the distance on the optical axis Z from the most object-side lens surface of the first lens group G1 to the most image-side lens surface of the first lens group G1 is D1, and the sum of the distance on the optical axis Z from the most object-side lens surface of the first lens group G1 to the most image-side lens surface of the subsequent group Gr and the back focus in terms of air equivalent distance at the telephoto end in a state of focusing on an infinite object is TLt, it is preferable to satisfy the following conditional expression (3). The lower part of FIG. 1 shows an example of the distance D1 and the sum TLt. By preventing the corresponding value of the conditional expression (3) from falling below the lower limit, it is advantageous for suppressing axial chromatic aberration on the telephoto side. By preventing the corresponding value of the conditional expression (3) from exceeding the upper limit, the first lens group G1 can be lightened, which is advantageous for lightening the entire lens system. To obtain better characteristics, it is more preferable to satisfy the following conditional expression (3-1), and it is even more preferable to satisfy the following conditional expression (3-2). 0.01 < D1 / TLt < 0.1 (3) 0.015 < D1 / TLt < 0.07 (3-1) 0.02 < D1 / TLt < 0.053 (3-2)

[0059] For the zoom lens according to this embodiment, when the focal length of the entire system at the wide-angle end in the state of focusing on an infinite object is fw, and the focal length of the entire system at the telephoto end in the state of focusing on an infinite object is ft, it is preferable to satisfy the following conditional expression (4). By preventing the corresponding value of the conditional expression (4) from falling below the lower limit, it becomes advantageous to increase the magnification ratio. By preventing the corresponding value of the conditional expression (4) from exceeding the upper limit, the magnification ratio does not become too high, which is advantageous for miniaturizing the entire lens system. In order to obtain better characteristics, it is more preferable to satisfy the following conditional expression (4-1), and it is even more preferable to satisfy the following conditional expression (4-2). 4.9 < ft / fw < 12 (4) 5.7 < ft / fw < 10 (4-1) 6.2 < ft / fw < 7.5 (4-2)

[0060] The subsequent group Gr includes at least one Lx lens whose image-side lens surface is a convex surface in contact with air, and among at least one optical system composed of the lens surface adjacent to the image side of the aperture stop St to the image-side lens surface of the Lx lens, when the aperture stop St is regarded as an object point in the state of focusing on an infinite object, when the absolute value of the reciprocal of the lateral magnification at the wide-angle end in the A optical system where the lateral magnification is minimized is βA, it is preferable to satisfy the following conditional expression (5). That is, when the lateral magnification of each optical system composed of the lens surface adjacent to the image side of the aperture stop St to the image-side lens surface of each Lx lens is βx, the optical system where |1 / βx| is minimized is the "A optical system", and the lateral magnification βA of the A optical system preferably satisfies the conditional expression (5). Also, the image-side lens surface of the Lx lens in the A optical system (that is, the convex surface in contact with air) is hereinafter referred to as "Surface A".

[0061] For example, in the zoom lens shown in FIG. 1, the Lx lens, whose image-side lens surface included in the subsequent group Gr is a convex surface in contact with air, is composed of six lenses, namely, lenses L31, L35, L42, L43, L44, and L61. Among the six optical systems formed from the object-side lens surface of lens L31 adjacent to the image side of the aperture stop St to the image-side lens surface of each of the above Lx lenses, the optical system with the minimum |1 / βx| is the optical system formed from the object-side lens surface of lens L31 to the image-side lens surface of lens L44. In this case, the "A optical system" is the optical system formed from the object-side lens surface of lens L31 to the image-side lens surface of lens L44, and as shown in FIGS. 1 and 3, surface A is the image-side lens surface of lens L44.

[0062] By preventing the corresponding value of conditional expression (5) from falling below the lower limit, it is possible to suppress a decrease in the angle formed between the chief ray of the off-axis light beam passing through surface A and the optical axis Z, and it is possible to suppress overcorrection of the astigmatism occurring between surface A and the image plane Sim. By preventing the corresponding value of conditional expression (5) from exceeding the upper limit, it is possible to suppress an increase in the angle formed between the chief ray of the off-axis light beam passing through surface A and the optical axis Z, which is advantageous for correcting the astigmatism occurring between surface A and the image plane Sim. In order to obtain better characteristics, it is more preferable to satisfy the following conditional expression (5-1), and it is even more preferable to satisfy the following conditional expression (5-2). -0.5 < 1 / βA < 0.5 (5) -0.4 < 1 / βA < 0.36 (5-1) -0.35 < 1 / βA < 0.13 (5-2)

[0063] For the zoom lens according to this embodiment, when the height from the optical axis Z of the marginal ray on the axis at the telephoto end in the state of focusing on an infinite object at the most image-side lens surface of the A optical system (i.e., surface A) is denoted as HAt, and the height from the optical axis Z of the marginal ray on the axis at the aperture stop St at the telephoto end in the state of focusing on an infinite object is denoted as HSt, it is preferable to satisfy the following conditional expression (6). FIG. 4 is a partial cross-sectional view showing the configuration corresponding to the telephoto end state of the zoom lens in FIGS. 1 and 2 and the axial light beam ta, and shows the heights HAt and HSt as an example. By preventing the corresponding value of the conditional expression (6) from falling below the lower limit, it is advantageous for suppressing spherical aberration on the telephoto side. By preventing the corresponding value of the conditional expression (6) from exceeding the upper limit, an increase in the diameter of the subsequent group Gr can be suppressed, which is advantageous for weight reduction. In order to obtain better characteristics, it is more preferable to satisfy the following conditional expression (6-1), and it is even more preferable to satisfy the following conditional expression (6-2). 0.73 < HAt / HSt < 2.3 (6) 0.83 < HAt / HSt < 1.6 (6-1) 0.92 < HAt / HSt < 1.37 (6-2)

[0064] For the zoom lens according to this embodiment, when the focal length of the entire system at the telephoto end in the state of focusing on an infinite object is denoted as ft, and the combined focal length from the most object-side lens surface of the subsequent group Gr to the most image-side lens surface of the A optical system (i.e., surface A) at the telephoto end in the state of focusing on an infinite object is denoted as fpAt, it is preferable to satisfy the following conditional expression (7). By preventing the corresponding value of the conditional expression (7) from falling below the lower limit, it is advantageous for ensuring the peripheral light quantity. By preventing the corresponding value of the conditional expression (7) from exceeding the upper limit, it is advantageous for suppressing spherical aberration on the telephoto side. In order to obtain better characteristics, it is more preferable to satisfy the following conditional expression (7-1), and it is even more preferable to satisfy the following conditional expression (7-2). 3 < ft / fpAt < 15 (7) 4.5 < ft / fpAt < 12 (7-1) 5.7 < ft / fpAt < 9 (7-2)

[0065] For the zoom lens according to this embodiment, when the height from the optical axis Z of the marginal ray on the optical axis at the telephoto end in the state of focusing on an infinite object at the most image-side lens surface of the A optical system (i.e., surface A) is defined as HAt, and the height from the optical axis Z of the chief ray of the maximum image height at the wide-angle end in the state of focusing on an infinite object at the most image-side lens surface of the A optical system (i.e., surface A) is defined as HAw, it is preferable to satisfy the following conditional expression (8). FIG. 3 shows an example of the height HAw. By preventing the corresponding value of the conditional expression (8) from falling below the lower limit, it is advantageous for suppressing the astigmatism on the wide-angle side. By preventing the corresponding value of the conditional expression (8) from exceeding the upper limit, it is advantageous for suppressing the fluctuation of the field curvature during zooming. In order to obtain better characteristics, it is more preferable to satisfy the following conditional expression (8-1), and it is even more preferable to satisfy the following conditional expression (8-2). 0.35 < HAt / HAw < 1.6 (8) 0.65 < HAt / HAw < 1.4 (8-1) 0.83 < HAt / HAw < 1.25 (8-2)

[0066] It is preferable that the subsequent group Gr includes a lens surface that is an image-side surface and is a concave surface in contact with air between the most image-side lens surface of the A optical system (i.e., surface A) and the object-side surface of the lens surface that is a concave surface in contact with air and is included in the most image-side lens group within the subsequent group Gr. By adopting such a configuration, it is advantageous for suppressing the astigmatism on the wide-angle side while maintaining the miniaturization of the entire lens system. In the example of FIG. 1, between the image-side surface of the lens L44, which is the most image-side lens surface of the A optical system (i.e., surface A), and the object-side surface of the lens L61, which is an object-side surface of the most image-side sixth lens group G6 within the subsequent group Gr and is a concave surface in contact with air, it includes the image-side surface of the lens L52, which is an image-side surface and is a concave surface in contact with air.

[0067] For the zoom lens according to this embodiment, when the distance on the optical axis Z from the aperture stop St to the most image-side lens surface of the A optical system (i.e., surface A of A) at the telephoto end in the state of focusing on an infinite object is defined as DSAt, and the sum of the distance on the optical axis Z from the aperture stop St to the most image-side lens surface of the subsequent group Gr and the back focus in terms of the air equivalent distance at the telephoto end in the state of focusing on an infinite object is defined as DSLt, it is preferable to satisfy the following conditional expression (9). In the lower part of FIG. 1, as an example, the distances DSAt and the sum DSLt are shown. By preventing the corresponding value of the conditional expression (9) from falling below the lower limit, the refraction of the off-axis light rays from surface A of A toward the image plane Sim can be made gentle, which is advantageous for suppressing the occurrence of various off-axis aberrations. By preventing the corresponding value of the conditional expression (9) from exceeding the upper limit, the light beam diameter on the image side of the aperture stop St can be reduced, which is advantageous for reducing the size of the subsequent group Gr. To obtain better characteristics, it is more preferable to satisfy the following conditional expression (9-1), and it is even more preferable to satisfy the following conditional expression (9-2). 0.1 < DSAt / DSLt < 0.54 (9) 0.15 < DSAt / DSLt < 0.4 (9-1) 0.18 < DSAt / DSLt < 0.32 (9-2)

[0068] For the zoom lens according to this embodiment, when the interval on the optical axis Z between the most image-side lens surface of the A optical system (i.e., surface A of A) and the lens surface adjacent to the image side of the said lens surface (i.e., surface A of A) at the telephoto end in the state of focusing on an infinite object is defined as dA, and the maximum image height at the telephoto end is defined as Yt, it is preferable to satisfy the following conditional expression (10). In the lower part of FIG. 1, as an example, the interval dA is shown, and in the lower part of FIG. 2, as an example, the maximum image height Yt is shown. By preventing the corresponding value of the conditional expression (10) from falling below the lower limit, it is advantageous for reducing the size of the entire lens system. By preventing the corresponding value of the conditional expression (10) from exceeding the upper limit, it is advantageous for suppressing spherical aberration on the telephoto side. To obtain better characteristics, it is more preferable to satisfy the following conditional expression (10-1), and it is even more preferable to satisfy the following conditional expression (10-2). 0.015 < dA / Yt < 0.35 (10) 0.025 < dA / Yt < 0.2 (10 - 1) 0.037 < dA / Yt < 0.11 (10 - 2)

[0069] For the zoom lens according to this embodiment, when the distance on the optical axis Z from the most object-side lens surface of the first lens group G1 to the most image-side lens surface of the subsequent group Gr at the telephoto end in the state of being focused on an infinite object and the back focus in terms of air equivalent distance are summed as TLt, and the focal length of the entire system at the telephoto end in the state of being focused on an infinite object is ft, it is preferable to satisfy the following conditional expression (11). By preventing the corresponding value of the conditional expression (11) from falling below the lower limit, it is advantageous for suppressing axial chromatic aberration on the telephoto side. By preventing the corresponding value of the conditional expression (11) from exceeding the upper limit, it is advantageous for shortening the overall length of the lens system and for miniaturization. In order to obtain better characteristics, it is more preferable to satisfy the following conditional expression (11 - 1), and it is even more preferable to satisfy the following conditional expression (11 - 2). 0.65 < TLt / ft < 1.5 (11) 0.8 < TLt / ft < 1.4 (11 - 1) 0.95 < TLt / ft < 1.27 (11 - 2)

[0070] For the zoom lens according to this embodiment, when the back focus in terms of air equivalent distance at the wide-angle end in the state of being focused on an infinite object is BFw and the maximum image height at the wide-angle end is Yw, it is preferable to satisfy the following conditional expression (12). By preventing the corresponding value of the conditional expression (12) from falling below the lower limit, it is advantageous for ensuring the peripheral light quantity. By preventing the corresponding value of the conditional expression (12) from exceeding the upper limit, it is advantageous for shortening the overall length of the lens system and for miniaturization. In order to obtain better characteristics, it is more preferable to satisfy the following conditional expression (12 - 1), and it is even more preferable to satisfy the following conditional expression (12 - 2). 0.38 < BFw / Yw < 1.5 (12) 0.45 < BFw / Yw < 1.2 (12 - 1) 0.59 < BFw / Yw < 0.98 (12 - 2)

[0071] When the Abbe number based on the d-line of the lens on the object side of the first lens group G1 is ν1, it is preferable to satisfy the following conditional expression (13). By preventing the corresponding value of the conditional expression (13) from falling below the lower limit, it is possible to suppress overcorrection of axial chromatic aberration. By preventing the corresponding value of the conditional expression (13) from exceeding the upper limit, it is advantageous for correcting axial chromatic aberration. In order to obtain better characteristics, it is more preferable to satisfy the following conditional expression (13-1), and it is even more preferable to satisfy the following conditional expression (13-2). In the example of FIG. 1, the lens L11 satisfies the conditional expression (13). 10 < ν1 < 50 (13) 12 < ν1 < 40 (13-1) 14 < ν1 < 27.3 (13-2)

[0072] When the refractive index with respect to the d-line of the lens on the object side of the first lens group G1 is N1, it is preferable to satisfy the following conditional expression (14). By preventing the corresponding value of the conditional expression (14) from falling below the lower limit, it is advantageous for suppressing spherical aberration. By preventing the corresponding value of the conditional expression (14) from exceeding the upper limit, the availability of the lens material is enhanced, and a more easily manufacturable material can be used. In order to obtain better characteristics, it is more preferable to satisfy the following conditional expression (14-1), and it is even more preferable to satisfy the following conditional expression (14-2). In the example of FIG. 1, the lens L11 satisfies the conditional expression (14). 1.7 < N1 < 2.3 (14) 1.84 < N1 < 2.22 (14-1) 1.88 < N1 < 2.16 (14-2)

[0073] Among the negative lenses included in the second lens group G2, when the refractive index with respect to the d-line of the negative lens closest to the object side is N2n, it is preferable to satisfy the following conditional expression (15). By ensuring that the corresponding value of the conditional expression (15) does not fall below the lower limit, it is possible to secure the refractive power without excessively reducing the absolute value of the curvature radius of the negative lens. Therefore, it is possible to prevent the thickening of the negative lens in the optical axis direction, which is advantageous for weight reduction. By ensuring that the corresponding value of the conditional expression (15) does not exceed the upper limit, the availability of the lens material is improved, and a more manufacturable material can be used. To obtain better characteristics, it is more preferable to satisfy the following conditional expression (15-1), and even more preferable to satisfy the following conditional expression (15-2). In the example of FIG. 1, the lens L21 satisfies the conditional expression (15). 1.6 < N2n < 2.2 (15) 1.65 < N2n < 2.11 (15-1) 1.7 < N2n < 2.05 (15-2)

[0074] Among the positive lenses included in the second lens group G2, when the refractive index with respect to the d-line of the positive lens with the strongest refractive power is N2p, it is preferable to satisfy the following conditional expression (16). By ensuring that the corresponding value of the conditional expression (16) does not fall below the lower limit, it is advantageous for suppressing spherical aberration. By ensuring that the corresponding value of the conditional expression (16) does not exceed the upper limit, the availability of the lens material is improved, and a more manufacturable material can be used. To obtain better characteristics, it is more preferable to satisfy the following conditional expression (16-1), and even more preferable to satisfy the following conditional expression (16-2). In the example of FIG. 1, the lens L23 satisfies the conditional expression (16). 1.65 < N2p < 2 (16) 1.71 < N2p < 1.93 (16-1) 1.77 < N2p < 1.9 (16-2)

[0075] When the Abbe number of the most image-side negative lens among the negative lenses included in the subsequent group Gr is defined as νnL based on the d-line, it is preferable to satisfy the following conditional expression (17). By preventing the corresponding value of the conditional expression (17) from falling below the lower limit, it is advantageous for suppressing magnification chromatic aberration. By preventing the corresponding value of the conditional expression (17) from exceeding the upper limit, it is possible to suppress the overcorrection of magnification chromatic aberration. To obtain better characteristics, it is more preferable to satisfy the following conditional expression (17-1), and it is even more preferable to satisfy the following conditional expression (17-2). In the example of FIG. 1, the lens L61 satisfies the conditional expression (17). 27 < νnL < 102 (17) 50 < νnL < 96 (17-1) 70 < νnL < 88 (17-2)

[0076] For the zoom lens according to this embodiment, the sum of the distance on the optical axis Z from the lens surface closest to the object side of the first lens group G1 to the lens surface closest to the image side of the subsequent group Gr at the telephoto end in the state of focusing on an infinite object and the back focus in terms of air equivalent distance is defined as TLt. In the state of focusing on an infinite object, when the difference in the direction of the optical axis Z between the position at the wide-angle end and the position at the telephoto end of the lens group having a positive refractive power among the lens groups included in the subsequent group Gr and closest to the object side is defined as Mp, it is preferable to satisfy the following conditional expression (18). Here, the sign of Mp is positive if the lens group closest to the object side moves from the object side to the image side, and negative if it moves from the image side to the object side when zooming from the wide-angle end to the telephoto end. By ensuring that the corresponding value of the conditional expression (18) does not fall below the lower limit, the absolute value of Mp does not become too large, so that the amount of movement during zooming of the lens group closest to the object side among the lens groups having a positive refractive power included in the subsequent group Gr can be suppressed from becoming large, which is advantageous for miniaturization. By ensuring that the corresponding value of the conditional expression (18) does not exceed the upper limit, the absolute value of Mp does not become too small, which is advantageous for achieving a high zoom ratio. To obtain better characteristics, it is more preferable to satisfy the following conditional expression (18-1), and even more preferable to satisfy the following conditional expression (18-2). In the example of FIG. 1, for the third lens group G3, which is the lens group closest to the object side among the lens groups having a positive refractive power included in the subsequent group Gr, when the difference in the direction of the optical axis Z between the position at the wide-angle end and the position at the telephoto end is defined as Mp, the conditional expression (18) is satisfied. -0.45 < Mp / TLt < -0.06 (18) -0.39 < Mp / TLt < -0.12 (18-1) -0.33 < Mp / TLt < -0.15 (18-2)

[0077] For the zoom lens according to this embodiment, when the focal length of the lens group closest to the object side among the lens groups having positive refractive power included in the subsequent group Gr in a state of being focused on an infinite object is set as fp, and the focal length of the second lens group G2 is set as f2, it is preferable to satisfy the following conditional expression (19). By preventing the corresponding value of the conditional expression (19) from falling below the lower limit, the absolute value of f2 does not become too small, which is advantageous for suppressing fluctuations in various aberrations generated during zooming. By preventing the corresponding value of the conditional expression (19) from exceeding the upper limit, the absolute value of f2 does not become too large, which is advantageous for shortening the second lens group G2 and for miniaturization. In order to obtain better characteristics, it is more preferable to satisfy the following conditional expression (19-1), and it is even more preferable to satisfy the following conditional expression (19-2). In the example of FIG. 1, when the focal length of the third lens group G3, which is the lens group closest to the object side among the lens groups having positive refractive power included in the subsequent group Gr, is set as fp, the conditional expression (19) is satisfied. -4.3 < fp / f2 < -1.1 (19) -3.9 < fp / f2 < -1.5 (19-1) -3.4 < fp / f2 < -1.95 (19-2)

[0078] The zoom lens according to this embodiment has, at the telephoto end in a state of being focused on an infinite object, the distance on the optical axis Z from the most image-side lens surface of the first lens group G1 to the most object-side lens surface of the lens group having a positive refractive power among the lens groups included in the subsequent group Gr defined as D1pt, and when the sum of the distance on the optical axis Z from the most object-side lens surface of the first lens group G1 to the most image-side lens surface of the subsequent group Gr and the back focus in terms of air equivalent distance is defined as TLt, it is preferable to satisfy the following conditional expression (20). In the lower part of FIG. 1, the distance D1pt and the sum TLt are shown as an example. By preventing the corresponding value of the conditional expression (20) from falling below the lower limit, it is advantageous for shortening the overall length of the lens system. By preventing the corresponding value of the conditional expression (20) from exceeding the upper limit, it is advantageous for suppressing spherical aberration on the telephoto side. In order to obtain better characteristics, it is more preferable to satisfy the following conditional expression (20-1), and it is even more preferable to satisfy the following conditional expression (20-2). 0.2 < D1pt / TLt < 0.5 (20) 0.25 < D1pt / TLt < 0.42 (20-1) 0.29 < D1pt / TLt < 0.39 (20-2)

[0079] As described above, when the subsequent group Gr includes at least one Lx lens having a convex surface with the image-side lens surface in contact with air, among at least one optical system composed of the lens surface adjacent to the image side of the aperture stop St to the image-side lens surface of the Lx lens, the optical system in which the absolute value of the reciprocal of the lateral magnification at the wide-angle end with the aperture stop St as the object point in the state of being focused on an infinite object is minimized is defined as the A optical system. For the zoom lens according to the present embodiment, at the wide-angle end in the state of being focused on an infinite object, with the focal length of the entire system being fw, from the lens surface adjacent to the image side of the most image-side lens surface (i.e., surface A of the A surface) of the A optical system to the most image-side lens surface of the subsequent group Gr, when the combined focal length at the wide-angle end in the state of being focused on an infinite object is defined as fBw, it is preferable to satisfy the following conditional expression (21). By preventing the corresponding value of the conditional expression (21) from falling below the lower limit, it is advantageous for suppressing the aberration on the wide-angle side. By preventing the corresponding value of the conditional expression (21) from exceeding the upper limit, the negative refractive power from the lens surface adjacent to the image side of the A surface A to the most image-side lens surface of the subsequent group Gr can be increased, so the light beam diameter from the most object-side lens surface of the subsequent group Gr to the A surface A can be reduced, which is advantageous for miniaturization. To obtain better characteristics, it is more preferable to satisfy the following conditional expression (21-1), and it is even more preferable to satisfy the following conditional expression (21-2). -1.6 < fw / fBw < -0.25 (21) -1.3 < fw / fBw < -0.37 ( 21-1 ) -1.1 < fw / fBw < -0.69 ( 21-2 )

[0080] For the zoom lens according to this embodiment, when the focal length of the entire system at the wide-angle end in the state of focusing on an infinite object is fw, the maximum half field angle at the wide-angle end in the state of focusing on an infinite object is ωw, and the maximum image height at the wide-angle end is Yw, it is preferable to satisfy the following conditional expression (22). By preventing the corresponding value of the conditional expression (22) from falling below the lower limit, on the wide-angle side, the height of the off-axis ray passing through the lens closest to the object side of the first lens group G1 from the optical axis Z can be reduced, which is advantageous for reducing the diameter. By preventing the corresponding value of the conditional expression (22) from exceeding the upper limit, it is advantageous for suppressing various aberrations of off-axis rays on the wide-angle side. In order to obtain better characteristics, it is more preferable to satisfy the following conditional expression (22-1), and it is even more preferable to satisfy the following conditional expression (22-2). 0.97 < fw × tan ωw / Yw < 1.3 (22) 1 < fw × tan ωw / Yw < 1.19 (22-1) 1.02 < fw × tan ωw / Yw < 1.11 (22-2)

[0081] For the zoom lens according to this embodiment, 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 to satisfy the following conditional expression (23). By preventing the corresponding value of the conditional expression (23) from falling below the lower limit, it is advantageous for achieving a high magnification ratio. By preventing the corresponding value of the conditional expression (23) from exceeding the upper limit, it is advantageous for suppressing fluctuations in various aberrations that occur during zooming. In order to obtain better characteristics, it is more preferable to satisfy the following conditional expression (23-1), and it is even more preferable to satisfy the following conditional expression (23-2). -0.3 < f2 / f1 < -0.05 (23) -0.23 < f2 / f1 < -0.1 (23-1) -0.19 < f2 / f1 < -0.14 (23-2)

[0082] The preferred configurations and possible configurations described above, including those related to conditional expressions, can be combined arbitrarily, and it is preferable to selectively adopt them as appropriate according to the required specifications. Note that the conditional expressions that the zoom lens of the present disclosure preferably satisfies are not limited to the conditional expressions described in the form of equations, but include all conditional expressions obtained by arbitrarily combining the lower limit and the upper limit from among the conditional expressions described as preferable, more preferable, and even more preferable. Also, 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 lenses constituting each lens group may be different from that in the example of FIG. 1.

[0083] As an example, a preferred aspect of the present disclosure includes, 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, and a subsequent group Gr having a plurality of lens groups, and includes an aperture stop St on the image side of the most image-side lens surface of the second lens group G2. The most image-side lens group within the subsequent group Gr includes at least one negative lens whose lens surface on the object side is a concave surface in contact with air. During zooming, 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 subsequent group Gr changes, and all the distances between adjacent lens groups within the subsequent group Gr change. During zooming, the lens intervals inside the first lens group G1, the second lens group G2, and the plurality of lens groups are invariant, and it is a zoom lens that satisfies the above conditional expression (1).

[0084] Next, an embodiment of the zoom lens of the present 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 in order to avoid complication of the description and the drawings due to an increase in the number of digits of the reference numerals. Therefore, even if the same reference numeral is attached in the drawings of different embodiments, it is not necessarily a common configuration. In addition, the following Examples 2 to 4 are examples of the present disclosure, and Examples 1, 5 to 8 are reference examples of the present disclosure.

[0085] [Embodiment 1] The configuration and movement locus of the zoom lens of Example 1 are shown in Fig. 1. Since the illustration method and configuration are as described above, redundant explanations are partially omitted here. For the zoom lens of Example 1, the basic lens data is shown in Table 1, the specifications and variable surface intervals are shown in Table 2, and the aspherical coefficients are shown in Table 3.

[0086] Table 1 is described as follows. In the column of Sn, the surface numbers are shown when the surface closest to the object side is taken as the first surface and the numbers are incremented one by one toward the image side. In the column of R, the radius of curvature of each surface is shown. In the column of D, the axial surface interval between each surface and the surface adjacent to it on the image side is shown. In the column of Nd, the refractive index of each component with respect to the d-line is shown. In the column of νd, the Abbe number of each component based on the d-line is shown. Table 1 also shows the aperture stop St. In the column of the surface number corresponding to the aperture stop St, the surface number and the phrase "(St)" are described. Also, in the column of the surface number corresponding to the above-mentioned surface A, the surface number and the phrase "(A)" are described. In Table 1, the sign of the radius of curvature of the surface with a convex surface facing the object side is positive, and the sign of the radius of curvature of the surface with a convex surface facing the image side is negative. In Table 1, for the variable surface interval during zooming, the symbol DD[ ] is used, and the surface number on the object side of this interval is attached in [ ] and described in the column of D.

[0087] Table 2 shows the zoom ratio Zr, the focal length f of the entire system, the back focus BF, the F-number FNo., the maximum full field angle 2ω, and the variable surface interval during zooming. The [°] in the column of 2ω indicates that the unit is degrees. The values shown in Table 2 are the values based on the d-line in the state of focusing on an infinite object. In Table 2, the values in the wide-angle end state, the intermediate focal length state, and the telephoto end state are shown in the columns denoted as WIDE, MIDDLE, and TELE, respectively.

[0088] In Table 1, an asterisk is attached to the surface number of the aspherical surface, and the paraxial radius of curvature value is described in the column of the radius of curvature of the aspherical surface. In Table 3, in the row of Sn, the surface numbers of the aspherical surfaces are shown, and in the rows of KA and Am (m is an integer of 3 or more), the aspherical coefficient values for each aspherical surface are shown. The "E±n" (n is an integer) of the aspherical coefficient values in Table 3 is "×10 ±nIt means "」". KA and Am are aspherical coefficients in the aspherical formula represented by the following formula. Zd = C × h 2 / {1+(1 - KA × C 2 × h 2 ) 1 / 2}+ ΣAm × h m However, Zd: Aspherical depth (the length of the perpendicular dropped from a point on the aspherical surface at height h to the plane perpendicular to the optical axis where the aspherical vertex touches) h: Height (the distance from the optical axis to the lens surface) C: Reciprocal of the paraxial radius of curvature KA, Am: Aspherical coefficients where Σ in the aspherical formula means the sum with respect to m.

[0089] In the data of each table, degrees are used as the unit of angle and mm (millimeter) is 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 following tables, the values are rounded to a predetermined number of digits.

[0090]

Table 1

[0091]

Table 2

[0092]

Table 3

[0093] Fig. 5 shows aberration diagrams of the zoom lens according to Example 1 in a state focused on an infinite object. In Fig. 5, spherical aberration, astigmatism, distortion, and chromatic aberration of magnification are shown in order from the left. In Fig. 5, the aberrations in the wide-angle end state are shown in the upper row labeled "WIDE", the aberrations in the intermediate focal length state are shown in the middle row labeled "MIDDLE", 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, and F-line are shown by solid line, long dashed line, and short dashed 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 chromatic aberration of magnification diagram, the aberrations for the C-line and F-line are shown by a long dashed line and a short dashed line, respectively. In the spherical aberration diagram, the value of the F-number is shown after "FNo.=", and in the other aberration diagrams, the value of the semi-field angle is shown after "ω=".

[0094] The symbols, meanings, description methods, and illustration methods of the respective data regarding Example 1 above are the same in the following examples unless otherwise specified, so duplicate explanations are omitted below.

[0095] [Example 2] Fig. 6 is a diagram showing a cross-sectional view and a movement locus of the configuration at the wide-angle end in a state where the zoom lens according to Example 2 is focused on an infinite object. Note that in Fig. 6 compared with Fig. 1, the illustration of the configuration at the telephoto end is omitted, and this is the same in the cross-sectional views of the following Examples 3 to 8. The zoom lens according to Example 2 includes, 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, and a subsequent group Gr. The subsequent group Gr includes, in order from the object side to the image side, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a negative refractive power.

[0096] The first lens group G1 consists of three lenses, L11 to L13, in order from the object side to the image side. The second lens group G2 consists of four lenses, L21 to L24, in order from the object side to the image side. The third lens group G3 consists of, in order from the object side to the image side, an aperture stop St and five lenses, L31 to L35. The fourth lens group G4 consists of six lenses, L41 to L46, in order from the object side to the image side. The fifth lens group G5 consists of a single lens, L51. The focus group consists of two lenses, L45 to L46.

[0097] For the zoom lens of Example 2, the basic lens data is shown in Table 4, the specifications and variable surface intervals are shown in Table 5, the aspherical coefficients are shown in Table 6, and each aberration diagram is shown in FIG. 7.

[0098] [Table 4]

[0099] [Table 5]

[0100] [Table 6]

[0101] [Example 3] FIG. 8 is a diagram showing a cross-sectional view of the configuration and the movement locus at the wide-angle end in a state where the zoom lens of Example 3 is focused on an infinite object. The zoom lens of Example 3 consists of, 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, and a subsequent group Gr. The subsequent group Gr consists of, in order from the object side to the image side, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a negative refractive power.

[0102] The first lens group G1 consists of three lenses L11 to L13 in order from the object side to the image side. The second lens group G2 consists of four lenses L21 to L24 in order from the object side to the image side. The third lens group G3 consists of an aperture stop St and five lenses L31 to L35 in order from the object side to the image side. The fourth lens group G4 consists of six lenses L41 to L46 in order from the object side to the image side. The fifth lens group G5 consists of a single lens L51. The focus group consists of two lenses L45 to L46.

[0103] For the zoom lens of Example 3, the basic lens data is shown in Table 7, the specifications and variable surface intervals are shown in Table 8, the aspherical coefficients are shown in Table 9, and each aberration diagram is shown in Figure 9.

[0104] [Table 7]

[0105] [Table 8]

[0106] [Table 9]

[0107] [Example 4] Figure 10 is a diagram showing a cross-sectional view of the configuration and a movement locus at the wide-angle end in a state where the zoom lens of Example 4 is focused on an infinite object. The zoom lens of Example 4 consists of a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a subsequent group Gr, in order from the object side to the image side. The subsequent group Gr consists of a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a negative refractive power, in order from the object side to the image side.

[0108] The first lens group G1 consists of three lenses L11 to L13 in order from the object side to the image side. The second lens group G2 consists of four lenses L21 to L24 in order from the object side to the image side. The third lens group G3 consists of an aperture stop St and five lenses L31 to L35 in order from the object side to the image side. The fourth lens group G4 consists of four lenses L41 to L44 in order from the object side to the image side. The fifth lens group G5 consists of three lenses L51 to L53 in order from the object side to the image side. The focus group consists of two lenses L51 to L52.

[0109] Regarding the zoom lens of Example 4, the basic lens data is shown in Table 10, the specifications and variable surface intervals are shown in Table 11, the aspherical coefficients are shown in Table 12, and each aberration diagram is shown in Figure 11.

[0110]

Table 10

[0111]

Table 11

[0112]

Table 12

[0113] [Example 5] Figure 12 is a diagram showing a cross-sectional view of the configuration and a movement locus at the wide-angle end in a state where the zoom lens of Example 5 is focused on an infinite object. The zoom lens of Example 5 consists of a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a subsequent group Gr, in order from the object side to the image side. The subsequent group Gr consists of a third lens group G3 having a positive refractive power and a fourth lens group G4 having a positive refractive power, in order from the object side to the image side.

[0114] The first lens group G1 consists of three lenses L11 to L13 in order from the object side to the image side. The second lens group G2 consists of four lenses L21 to L24 in order from the object side to the image side. The third lens group G3 consists of, in order from the object side to the image side, an aperture stop St and five lenses L31 to L35. The fourth lens group G4 consists of six lenses L41 to L46 in order from the object side to the image side. The focus group consists of two lenses L44 to L45.

[0115] For the zoom lens of Example 5, the basic lens data is shown in Table 13, the specifications and variable surface intervals are shown in Table 14, the aspherical coefficients are shown in Table 15, and each aberration diagram is shown in FIG. 13.

[0116] [Table 13]

[0117] [Table 14]

[0118] [Table 15]

[0119] [Example 6] FIG. 14 is a diagram showing a cross-sectional view of the configuration and a movement locus at the wide-angle end in a state where the zoom lens of Example 6 is focused on an infinite object. The zoom lens of Example 6 consists of, 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, and a subsequent group Gr. The subsequent group Gr consists of, in order from the object side to the image side, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group G6 having a negative refractive power.

[0120] The first lens group G1 consists of two lenses, lenses L11 to L12, in order from the object side to the image side. The second lens group G2 consists of four lenses, lenses L21 to L24, in order from the object side to the image side. The third lens group G3 consists of, in order from the object side to the image side, an aperture stop St and four lenses, lenses L31 to L34. The fourth lens group G4 consists of three lenses, lenses L41 to L43, in order from the object side to the image side. The fifth lens group G5 consists of a single lens, lens L51. The sixth lens group G6 consists of two lenses, lenses L61 to L62, in order from the object side to the image side. The focus group consists of a single lens, lens L51.

[0121] For the zoom lens of Example 6, the basic lens data is shown in Table 16, the specifications and variable surface intervals are shown in Table 17, the aspherical coefficients are shown in Table 18, and each aberration diagram is shown in FIG. 15.

[0122] [Table 16]

[0123] [Table 17]

[0124] [Table 18]

[0125] [Example 7] FIG. 16 is a diagram showing a cross-sectional view of the configuration and a movement locus at the wide-angle end in a state where the zoom lens of Example 7 is focused on an infinite object. The zoom lens of Example 7 consists of, 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, and a subsequent group Gr. The subsequent group Gr consists of, in order from the object side to the image side, a third lens group G3 having a positive refractive power and a fourth lens group G4 having a positive refractive power.

[0126] The first lens group G1 consists of three lenses, lenses L11 to L13, in order from the object side to the image side. The second lens group G2 consists of four lenses, lenses L21 to L24, in order from the object side to the image side. The third lens group G3 consists of, in order from the object side to the image side, the aperture stop St and six lenses, lenses L31 to L36. The fourth lens group G4 consists of seven lenses, lenses L41 to L47, in order from the object side to the image side. The focus group consists of a single lens, lens L44. Unlike that of the first embodiment, the focus group of the seventh embodiment moves toward the object side when focusing from an infinite object to a closest object.

[0127] Regarding the zoom lens of the seventh embodiment, the basic lens data is shown in Table 19, the specifications and variable surface intervals are shown in Table 20, the aspherical coefficients are shown in Table 21, and each aberration diagram is shown in FIG. 17.

[0128] [Table 19]

[0129] [Table 20]

[0130] [Table 21]

[0131] [Embodiment 8] FIG. 18 is a cross-sectional view and a movement locus diagram showing the configuration at the wide-angle end in a state where the zoom lens of the eighth embodiment is focused on an infinite object. The zoom lens of the eighth embodiment includes, 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, and a subsequent group Gr. The subsequent group Gr includes, in order from the object side to the image side, a third lens group G3 having a positive refractive power and a fourth lens group G4 having a positive refractive power.

[0132] The first lens group G1 consists of three lenses, namely lenses L11 to L13, in order from the object side to the image side. The second lens group G2 consists of four lenses, namely lenses L21 to L24, in order from the object side to the image side. The third lens group G3 consists of, in order from the object side to the image side, an aperture stop St and five lenses, namely lenses L31 to L35. The fourth lens group G4 consists of six lenses, namely lenses L41 to L46, in order from the object side to the image side. The focus group consists of two lenses, namely lenses L44 to L45.

[0133] Regarding the zoom lens of Example 8, the basic lens data is shown in Table 22, the specifications and variable surface intervals are shown in Table 23, the aspherical coefficients are shown in Table 24, and each aberration diagram is shown in FIG. 19.

[0134]

Table 22

[0135]

Table 23

[0136]

Table 24

[0137] Tables 25 and 26 show the corresponding values of the conditional expressions (1) to (23) of the zoom lenses of Examples 1 to 8.

[0138]

Table 25

[0139]

Table 26

[0140] As can be seen from the data described above, the zoom lenses of Examples 1 to 8 have a zoom ratio of 5.5 times or more and achieve a high zoom ratio, while being configured to be small and lightweight.

[0141] Next, an imaging device according to an embodiment of the present disclosure will be described. FIGS. 20 and 21 show external views of a camera 30 which is an imaging device according to an embodiment of the present disclosure. FIG. 20 shows a perspective view of the camera 30 as seen from the front side, and FIG. 21 shows a perspective view of the camera 30 as seen from the back side. The camera 30 is a so-called mirrorless type digital camera, and an interchangeable lens 20 can be detachably attached thereto. The interchangeable lens 20 includes a zoom lens 1 according to an embodiment of the present disclosure housed in a lens barrel.

[0142] The camera 30 includes a camera body 31, and a shutter button 32 and a power button 33 are provided on the upper surface of the camera body 31. Further, an operation unit 34, an operation unit 35, and a display unit 36 are provided on the back surface of the camera body 31. The display unit 36 can display an image that has been captured and an image within the angle of view before being captured.

[0143] A photographing aperture through which light from a photographing object is incident is provided at the center of the front surface of the camera body 31, and a mount 37 is provided at a position corresponding to the photographing aperture. The interchangeable lens 20 is attached to the camera body 31 via the mount 37.

[0144] Inside the camera body 31, an imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) that outputs an imaging signal corresponding to a subject image formed by the interchangeable lens 20, a signal processing circuit that processes the imaging signal output from the imaging element to generate an image, and a recording medium for recording the generated image are provided. In the camera 30, it is possible to capture a still image or a moving image by pressing the shutter button 32, and the image data obtained by this capture is recorded on the above recording medium.

[0145] The above has described the technology of the present disclosure with reference to embodiments and examples. However, the technology of the present disclosure is not limited to the above embodiments and examples, and various modifications are possible. For example, the radius of curvature, surface interval, refractive index, Abbe number, aspherical coefficient, etc. of each lens are not limited to the values shown in the above numerical examples, and other values can be taken.

[0146] Also, the imaging device according to the embodiment of the present disclosure is not limited to the above example, and can be in various forms, such as cameras other than the mirrorless type, film cameras, video cameras, etc.

Explanation of Reference Numerals

[0147] 1 Zoom lens 20 Interchangeable lens 30 Camera 31 Camera body 32 Shutter button 33 Power button 34, 35 Operation unit 36 Display unit 37 Mount A A plane dA Interval D1, D1pt, Denw, Dexw, DSAt, DSLt Distance G1 First lens group G2 Second lens group G3 Third lens group G4 Fourth lens group G5 Fifth lens group G6 Sixth lens group Gr Subsequent group HAt, HAw, HSt Height L11~L62 Lenses ma, ta, wa On-axis light beam mb, tb, wb Light beam of maximum picture angle Penw Paraxial incident pupil position Pexw Paraxial exit pupil position Sim Image plane St Aperture stop 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 subsequent group at the telephoto end in the state of focusing on an infinitely distant object and the back focus in terms of air-equivalent distance Yt, Yw Maximum image height Z Optical axis ωw Maximum semi-field angle

Claims

1. It consists of a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a subsequent group having a plurality of lens groups, in order from the object side to the image side. An aperture stop is included on the image side of the most image-side lens surface of the second lens group. The most image-side lens group within the subsequent group includes at least one negative lens whose object-side lens surface is a concave surface in contact with air. During zooming, the distance between the first lens group and the second lens group changes, the distance between the second lens group and the subsequent group changes, and all the distances between adjacent lens groups within the subsequent group change. During zooming, the lens intervals inside the first lens group, the second lens group, and the plurality of lens groups are invariant. The second lens group consists of, in order from the object side to the image side, a negative meniscus lens with a convex surface facing the object side, a negative lens, a positive lens, and a negative meniscus lens with a convex surface facing the image side. The subsequent group includes two or three cemented lenses in which a positive lens and a negative lens are cemented together. The most object-side lens group within the subsequent group has a positive refractive power and includes, in order from the most object side to the image side, a single lens with a positive refractive power and a single lens with a positive refractive power, and includes a biconcave single lens on the most image side. The most image-side lens group within the subsequent group has a negative refractive power. Let the focal length of the entire system at the wide-angle end in the state of focusing on an infinite object be fw. Let the distance on the optical axis from the most object-side lens surface of the first lens group to the paraxial entrance pupil position at the wide-angle end in the state of focusing on an infinite object be Denw. The sign of Denw is positive if the paraxial entrance pupil position is on the image side of the most object-side lens surface of the first lens group, and negative if the paraxial entrance pupil position is on the object side of the most object-side lens surface of the first lens group. Let the focal length of the most object-side lens group having a positive refractive power among the lens groups having a positive refractive power included in the subsequent group in the state of focusing on an infinite object be fp. Let the focal length of the second lens group be f2. Let the focal length of the first lens group be f1. When 0.7 < fw / Denw < 1.5 (1) -2.338 ≤ fp / f2 < -1.5 (19 - 3) -0.3 < f2 / f1 ≤ -0.1539 (23 - 3) A zoom lens that satisfies the conditional expressions (1), (19 - 3), and (23 - 3) represented by the above.

2. Let the distance on the optical axis from the paraxial exit pupil position to the image plane at the wide-angle end in the state of focusing on an infinite object be Dexw. The sign of Dexw is positive if the paraxial exit pupil position is on the object side with respect to the image plane, and negative if the paraxial exit pupil position is on the image side with respect to the image plane. 0.25 < fw / Dexw < 1 (2) The zoom lens according to claim 1, which satisfies the conditional expression (2) represented by

3. Let D1 be the distance on the optical axis from the most object-side lens surface of the first lens group to the most image-side lens surface of the first lens group. When TLt is the sum of the distance on the optical axis from the most object-side lens surface of the first lens group to the most image-side lens surface of the subsequent group and the back focus in terms of air equivalent distance at the telephoto end in the state of focusing on an infinite object. 0.01 < D1 / TLt < 0.1 (3) The zoom lens according to claim 1 or claim 2, which satisfies the conditional expression (3) represented by

4. When ft is the focal length of the entire system at the telephoto end in the state of focusing on an infinite object. 4.9 < ft / fw < 12 (4) The zoom lens according to any one of claims 1 to 3, which satisfies the conditional expression (4) represented by

5. The subsequent group includes at least one Lx lens whose image-side lens surface is a convex surface in contact with air. Among at least one optical system constituted by the lens surface adjacent to the image side of the aperture stop to the image-side lens surface of the Lx lens, when the aperture stop is regarded as an object point in the state of focusing on an infinite object, let βA be the lateral magnification in the A optical system where the absolute value of the reciprocal of the lateral magnification at the wide-angle end is the minimum. -0.5 < 1 / βA < 0.5 (5) The zoom lens according to any one of claims 1 to 4, which satisfies the conditional expression (5) represented by

6. Let HAt be the height from the optical axis of the marginal ray on the axis at the most image-side lens surface of the A optical system at the telephoto end in the state of focusing on an infinite object. Let HSt be the height from the optical axis of the marginal ray on the axis at the aperture stop at the telephoto end in the state of focusing on an infinite object. 0.73 < HAt / HSt < 2.3 (6) The zoom lens according to claim 5, which satisfies the conditional expression (6) represented by

7. When ft is the focal length of the entire system at the telephoto end in the state of focusing on an infinite object. When fpAt is the combined focal length from the most object-side lens surface of the subsequent group to the most image-side lens surface of the A optical system at the telephoto end in the state of focusing on an infinite object. 3 < ft / fpAt < 15 (7) The zoom lens according to claim 5 or claim 6, which satisfies the conditional expression (7) represented by

8. When the height from the optical axis of the marginal ray on the optical axis at the telephoto end in the state of focusing on an infinite object on the most image-side lens surface of the A optical system is HA t, When the height from the optical axis of the principal ray of the maximum image height on the most image-side lens surface of the A optical system at the wide-angle end in the state of focusing on an infinite object is HA w, 0.35 < HA t / HA w < 1.6 (8) The zoom lens according to any one of claims 5 to 7, which satisfies the conditional expression (8) represented by

9. The subsequent group includes, between the most image-side lens surface of the A optical system and the object-side surface included in the most image-side lens group within the subsequent group, which is a concave lens surface in contact with air, a lens surface that is an image-side surface and is a concave lens surface in contact with air The zoom lens according to any one of claims 5 to 8.

10. When the distance on the optical axis from the aperture stop to the most image-side lens surface of the A optical system at the telephoto end in the state of focusing on an infinite object is DSA t, When the sum of the distance on the optical axis from the aperture stop to the most image-side lens surface of the subsequent group and the back focus in terms of air-equivalent distance at the telephoto end in the state of focusing on an infinite object is DSL t, 0.1 < DSA t / DSL t < 0.54 (9) The zoom lens according to any one of claims 5 to 9, which satisfies the conditional expression (9) represented by

11. When the interval on the optical axis between the most image-side lens surface of the A optical system and the lens surface adjacent to the image side of the lens surface at the telephoto end in the state of focusing on an infinite object is dA, When the maximum image height at the telephoto end is Yt, 0.015 < dA / Yt < 0.35 (10) The zoom lens according to any one of claims 5 to 10, which satisfies the conditional expression (10) represented by

12. When the sum of the distance on the optical axis from the most object-side lens surface of the first lens group to the most image-side lens surface of the subsequent group and the back focus in terms of air-equivalent distance at the telephoto end in the state of focusing on an infinite object is TL t, When the focal length of the entire system at the telephoto end in the state of focusing on an infinite object is ft, 0.65 < TL t / ft < 1.5 (11) The zoom lens according to any one of claims 1 to 11, which satisfies the conditional expression (11) represented by

13. The first lens group includes, in order from the object side to the image side, a negative lens and a positive lens, which are continuously arranged in sequence. The zoom lens according to any one of claims 1 to 12.

14. When the back focus of the air-equivalent distance at the wide-angle end in the state of focusing on an infinite object is BFW, and the maximum image height at the wide-angle end is YW, 0.38 < BFW / YW < 1.5 (12) The zoom lens according to any one of claims 1 to 13, which satisfies the conditional expression (12) represented by the above.

15. When the Abbe number of the lens on the most object side of the first lens group based on the d-line is ν1, 10 < ν1 < 50 (13) The zoom lens according to any one of claims 1 to 14, which satisfies the conditional expression (13) represented by the above.

16. When the refractive index of the lens on the most object side of the first lens group with respect to the d-line is N1, 1.7 < N1 < 2.3 (14) The zoom lens according to any one of claims 1 to 15, which satisfies the conditional expression (14) represented by the above.

17. When the refractive index of the most object-side negative lens among the negative lenses included in the second lens group with respect to the d-line is N2n, 1.6 < N2n < 2.2 (15) The zoom lens according to any one of claims 1 to 16, which satisfies the conditional expression (15) represented by the above.

18. When the refractive index of the most strongly refractive positive lens among the positive lenses included in the second lens group with respect to the d-line is N2p, 1.65 < N2p < 2 (16) The zoom lens according to any one of claims 1 to 17, which satisfies the conditional expression (16) represented by the above.

19. When the Abbe number of the most image-side negative lens among the negative lenses included in the subsequent group based on the d-line is νnL, 27 < νnL < 102 (17) The zoom lens according to any one of claims 1 to 18, which satisfies the conditional expression (17) represented by the above.

20. The subsequent group includes at least one lens group having a positive refractive power. The zoom lens according to any one of claims 1 to 19.

21. In the state of focusing on an infinite object at the telephoto end, the sum of the distance on the optical axis from the most object-side lens surface of the first lens group to the most image-side lens surface of the subsequent group and the back focus in terms of air-equivalent distance is TLt. In a state of being focused on an infinitely distant object, the difference in the optical axis direction between the position at the wide-angle end and the position at the telephoto end of the lens group having a positive refractive power and being the most object-side lens group among the lens groups included in the subsequent group is defined as Mp. When the sign of Mp is positive if the most object-side lens group moves from the object side toward the image side and negative if it moves from the image side toward the object side when zooming from the wide-angle end to the telephoto end. -0.45 < Mp / TLt < -0.06 (18) The zoom lens according to claim 20, which satisfies the conditional expression (18) represented by

22. In the telephoto end in a state of being focused on an infinitely distant object, the distance on the optical axis from the most image-side lens surface of the first lens group to the most object-side lens surface of the lens group having a positive refractive power and being the most object-side lens group among the lens groups included in the subsequent group is defined as D1pt. When the sum of the distance on the optical axis from the most object-side lens surface of the first lens group to the most image-side lens surface of the subsequent group and the back focus in terms of air equivalent distance is defined as TLt in the telephoto end in a state of being focused on an infinitely distant object. 0.2 < D1pt / TLt < 0.5 (20) The zoom lens according to claim 20 or claim 21, which satisfies the conditional expression (20) represented by

23. The subsequent group includes at least one Lx lens having a convex surface with an image-side lens surface in contact with air. Among at least one optical system constituted by the lens surface adjacent to the image side of the aperture stop to the image-side lens surface of the Lx lens, the optical system in which the absolute value of the reciprocal of the lateral magnification at the wide-angle end with the aperture stop as the object point in a state of being focused on an infinitely distant object is minimized is defined as the A optical system. When the combined focal length at the wide-angle end in a state of being focused on an infinitely distant object from the lens surface adjacent to the image side of the most image-side lens surface of the A optical system to the most image-side lens surface of the subsequent group is defined as fBw. -1.6 < fw / fBw < -0.25 (21) The zoom lens according to any one of claims 1 to 22, which satisfies the conditional expression (21) represented by

24. In the wide-angle end in a state of being focused on an infinitely distant object, the maximum semi-field angle is ωw. When the maximum image height at the wide-angle end is Yw. 0.97 < fw × tan ωw / Yw < 1.3 (22) The zoom lens according to any one of claims 1 to 23, which satisfies the conditional expression (22) represented by

25. The subsequent group includes a focus group that moves along the optical axis during focusing. The zoom lens according to any one of claims 1 to 24.

26. The focusing group consists of two or fewer lenses. The zoom lens according to claim 25.

27. The focusing group has a negative refractive power. The zoom lens according to claim 25 or claim 26.

28. −0.23 < f2 / f1 ≤ −0.1539 (23−4) The zoom lens according to any one of claims 1 to 27, which satisfies the conditional expression (23−4) represented by the above formula.

29. The subsequent group includes only two cemented lenses in which a positive lens and a negative lens are cemented together. The zoom lens according to any one of claims 1 to 28.

30. An imaging device including the zoom lens according to any one of claims 1 to 29.

Images