Zoom lens and image capturing device

Abstract

To provide a zoom lens which offers a large image circle, a wide angle of view, a compact configuration, and good optical performance, and to provide an image capturing device equipped with the same.SOLUTION: A zoom lens is provided, comprising a first lens group with positive refractive power located on the most object side, an intermediate group comprising multiple lens groups, and a final lens group located on the most image side. All distances between adjacent lens groups change while zooming. The first lens group includes two negative lenses arranged successively in order from the most object side to the image side, where a negative lens of the two negative lenses on the object side is a meniscus lens having a convex surface on the object side. The zoom lens satisfies a conditional expression related to a focal length f1 of the first lens group and a focal length fw of the entire system at the wide-angle end as follows: 0.1<fw / f1<0.8.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] 2. Description of the Related Art Conventionally, a zoom lens that can be used in imaging devices such as broadcast cameras or cinema cameras is known, as disclosed in Patent Document 1 below. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-078849 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for zoom lenses that have a large image circle, a wide angle, are compact, and have good optical performance, and these demands are becoming higher every year.

[0005] The present disclosure provides a zoom lens that has a large image circle, a wide angle, is compact, and has good optical performance, and an imaging device that includes this zoom lens. [Means for solving the problem]

[0006] A first aspect of the present disclosure is a zoom lens comprising a first lens group having positive refractive power and arranged closest to the object side, an intermediate group including a plurality of lens groups, and a final lens group arranged closest to the image side, wherein all intervals between adjacent lens groups change during zooming, the first lens group includes two negative lenses arranged consecutively from closest to the object side to closest to the image side, and of the two negative lenses, the negative lens closest to the object side is a meniscus lens with a convex surface facing the object side, 0.1 <fw / f1<0.8 (1) Here, the focal length of the entire system when focused on an object at infinity at the wide-angle end is defined as fw, and the focal length of the first lens group is defined as f1.

[0007] A second aspect of the present disclosure provides the zoom lens of the first aspect, 0.1 <H1f / Hft<0.95 (2) Conditional expression (2) expressed as follows is satisfied. Here, H1f is the distance on the optical axis from the lens surface in the first lens group closest to the object to the object-side principal point of the first lens group when focused on an object at infinity. Hft is the distance on the optical axis from the lens surface in the first lens group closest to the object to the object-side principal point of the entire system when focused on an object at infinity at the telephoto end. The signs of H1f and Hft are negative for the object side and positive for the image side, with the lens surface in the first lens group closest to the object as the reference.

[0008] In a third aspect of the present disclosure, in the zoom lens of the first aspect, an L1n lens having negative refractive power is disposed adjacent to the image side of the L1p lens, which is the positive lens closest to the object among the positive lenses included in the first lens group.

[0009] A fourth aspect of the present disclosure provides the zoom lens of the first aspect, 0.28 <H1f / Hft<0.7 (2-1) The definitions of the symbols in conditional formula (2-1) are the same as those in conditional formula (2) of the second aspect.

[0010] A fifth aspect of the present disclosure is a zoom lens according to the first aspect, wherein, when the distance on the optical axis between the object-side principal point position of the first lens group and the image-side principal point position of the first lens group is defined as HD1, 1.4 <HD1 / f1<2.16 (3) Conditional expression (3) expressed as follows is satisfied.

[0011] A sixth aspect of the present disclosure is a zoom lens of the first aspect, wherein the first lens group is composed of, in order from the object side to the image side, a 1a subgroup, a 1b subgroup, and a 1c subgroup, and when focusing, the distance between the 1a subgroup and the 1b subgroup changes, and the distance between the 1b subgroup and the 1c subgroup changes.

[0012] A seventh aspect of the present disclosure is a zoom lens according to the sixth aspect, wherein, when the focal length of the 1b sub group is f1b, 0.3 <f1 / f1b<1 (4) Conditional expression (4) expressed as follows is satisfied.

[0013] An eighth aspect of the present disclosure is the zoom lens of the sixth aspect, wherein the lens closest to the image side in the 1a sub group is a negative lens.

[0014] A ninth aspect of the present disclosure is the zoom lens of the eighth aspect, wherein a positive lens is disposed adjacent to the object side of the negative lens closest to the image side in the 1a subgroup.

[0015] A tenth aspect of the present disclosure is the zoom lens of the sixth aspect, wherein the 1a sub group has negative refractive power.

[0016] An eleventh aspect of the present disclosure is the zoom lens of the sixth aspect, wherein the 1b sub-group has positive refractive power.

[0017] A twelfth aspect of the present disclosure is the zoom lens of the sixth aspect, wherein the 1c subgroup has positive refractive power.

[0018] A thirteenth aspect of the present disclosure is a zoom lens according to the sixth aspect, wherein, when focusing from an object at infinity to a closest object, the 1a subgroup and the 1c subgroup are fixed relative to the image plane, and the 1b subgroup moves toward the image side.

[0019] A fourteenth aspect of the present disclosure is the zoom lens of the first aspect, wherein the first lens group is fixed relative to the image plane during zooming.

[0020] A fifteenth aspect of the present disclosure is the zoom lens of the first aspect, wherein the final lens group is fixed relative to the image plane during zooming.

[0021] A sixteenth aspect of the present disclosure is the zoom lens of the first aspect, wherein the first lens group includes six or more lenses.

[0022] A seventeenth aspect of the present disclosure is the zoom lens of the first aspect, including an aperture stop that is fixed relative to the image plane during zooming.

[0023] An eighteenth aspect of the present disclosure is the zoom lens of the first aspect, 0.7 <H1r / f1<1.5 (5) Conditional expression (5) expressed as follows is satisfied. Here, H1r is the distance on the optical axis from the lens surface in the first lens group closest to the image to the image-side principal point of the first lens group when focused on an object at infinity. The sign of H1r is negative on the object side and positive on the image side, based on the lens surface in the first lens group closest to the image.

[0024] A nineteenth aspect of the present disclosure is the zoom lens of the first aspect, 0.7 <H1f / f1<2 (6) Conditional expression (6) expressed as follows is satisfied. Here, H1f is the distance on the optical axis from the lens surface in the first lens group closest to the object to the object-side principal point of the first lens group when focused on an object at infinity. The sign of H1f is negative on the object side and positive on the image side, based on the lens surface in the first lens group closest to the object.

[0025] A twentieth aspect of the present disclosure is a zoom lens according to the third aspect, wherein, when the refractive index of the L1p lens with respect to the d-line is N1p, 1.7 <N1p<2.1 (7) Conditional expression (7) expressed as follows is satisfied.

[0026] A twenty-first aspect of the present disclosure is a zoom lens according to the third aspect, wherein, when the Abbe number of the L1p lens based on the d-line is ν1p, 15<ν1p<30 (8) Conditional expression (8) expressed as follows is satisfied.

[0027] A twenty-second aspect of the present disclosure is a zoom lens according to the third aspect, wherein, when the refractive index of the L1n lens with respect to the d-line is N1n, 1.43 <N1n<1.85 (9) Conditional expression (9) expressed as follows is satisfied.

[0028] A twenty-third aspect of the present disclosure is a zoom lens according to the third aspect, wherein, when the Abbe number of the L1n lens based on the d-line is ν1n, 30<ν1n<60 (10) Condition (10) expressed by the following expression is satisfied.

[0029] A twenty-fourth aspect of the present disclosure is a zoom lens according to the third aspect, in which, when the average value of the Abbe numbers based on the d-line of all negative lenses located closer to the object side than the L1p lens is taken as ν1nave, 35<ν1nave<60 (11) Condition (11) expressed by the following expression is satisfied.

[0030] A twenty-fifth aspect of the present disclosure is a zoom lens according to the third aspect, in which, when the average value of the partial dispersion ratio between the g-line and the F-line of all negative lenses located closer to the object side than the L1p lens is θ1nave, 0.5<θ1nave<0.6 (12) Condition (12) expressed by the following expression is satisfied.

[0031] A 26th aspect of the present disclosure is a zoom lens according to the first aspect, wherein, when the zoom lens is focused on an object at infinity at the wide-angle end, the distance on the optical axis from the lens surface of the first lens group closest to the object to the paraxial entrance pupil position is Denw: 2 <Denw / fw<3.5 (13) Condition (13) expressed by the following expression is satisfied.

[0032] A 27th aspect of the present disclosure is a zoom lens according to the 6th aspect, wherein, when the focal length of the 1a sub group is f1a, -2 <f1 / f1a<0 (14) Condition (14) expressed by the following expression is satisfied.

[0033] A 28th aspect of the present disclosure is a zoom lens according to the 6th aspect, wherein, when the focal length of the 1c sub group is f1c, 0.3 <f1 / f1c<0.8 (15) Condition (15) expressed by the following expression is satisfied.

[0034] A 29th aspect of the present disclosure is a zoom lens according to the first aspect, wherein, when the paraxial radius of curvature of the image side surface of the lens closest to the object side in the first lens group is R2 and the paraxial radius of curvature of the object side surface of the second lens from the object side in the first lens group is R3, -3<(R2-R3) / (R2+R3)<0 (16) Condition (16) expressed by the following expression is satisfied.

[0035] In a 30th aspect of the present disclosure, in the zoom lens of the first aspect, when the longest air gap among the air gaps on the optical axis included in the final lens group is defined as the longest air gap at the wide-angle end while focusing on an object at infinity, an EX group is arranged to be insertable and removable, so that the EX group changes the focal length of the zoom lens while keeping the imaging position constant by being inserted into the optical path with the longest air gap.

[0036] A thirty-first aspect of the present disclosure is a zoom lens according to the thirtieth aspect, in which the maximum image height changes by inserting or removing the EX group.

[0037] A thirty-second aspect of the present disclosure is the zoom lens of the first aspect, 0.03 <d1R / IHw<0.097 (17) Conditional expression (17) expressed as follows is satisfied. Here, d1R is the distance on the optical axis from the lens surface in the first lens group closest to the image to the lens surface adjacent to the lens surface in the first lens group closest to the image when focused on an object at infinity at the wide-angle end. IHw is the maximum image height when focused on an object at infinity at the wide-angle end.

[0038] A thirty-third aspect of the present disclosure is an imaging device including the zoom lens of any one of the first to thirty-second aspects.

[0039] In this specification, the terms "consisting of" and "consisting of" are intended to mean that, in addition to the listed components, other components may also be included, such as lenses that have substantially no refractive power, optical elements other than lenses, such as apertures, filters, and cover glasses, and mechanical parts, such as lens flanges, lens barrels, image sensors, and image stabilization mechanisms.

[0040] In this specification, "a lens group having positive refractive power" and "the lens group has positive refractive power" mean that the lens group as a whole has positive refractive power. Similarly, "a lens group having negative refractive power" and "the lens group has negative refractive power" mean that the lens group as a whole has negative refractive power. "A lens having negative refractive power" and "a negative lens" are synonymous. In this specification, the "lens group" and "focusing group" are not limited to configurations consisting of multiple lenses, and may also be configurations consisting of only one lens.

[0041] A hybrid aspherical lens (a lens in which a lens (e.g., a spherical lens) and an aspherical film formed on that lens are integrally constructed, functioning as a single aspherical lens overall) is not considered a cemented lens, but is treated as a single lens. Unless otherwise specified, the radius of curvature, sign of refractive power, and surface shape of lenses including aspherical surfaces are those in the paraxial region. The sign of the radius of curvature of a surface with a convex shape facing the object side is positive, and the sign of the radius of curvature of a surface with a convex shape facing the image side is negative.

[0042] In this specification, "total system" refers to a zoom lens. "Back focus in air equivalent distance" is the air equivalent distance on the optical axis from the lens surface closest to the image side of the zoom lens to the image plane. 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 a geometric distance unless otherwise specified. Unless otherwise specified, the values ​​used in the conditional expressions are values ​​based on the d-line when focused on an object at infinity.

[0043] The terms "d-line," "C-line," "F-line," and "g-line" used in this specification are emission lines, and the wavelength of the d-line is treated as 587.56 nm (nanometers), the wavelength of the C-line as 656.27 nm (nanometers), the wavelength of the F-line as 486.13 nm (nanometers), and the wavelength of the g-line as 435.84 nm (nanometers). [Effects of the Invention]

[0044] According to the present disclosure, it is possible to provide a zoom lens that has a large image circle, a wide angle, is compact, and has good optical performance, and an imaging device that includes this zoom lens. [Brief explanation of the drawings]

[0045] [Figure 1] 1A and 1B are diagrams showing a cross-sectional view of the configuration of a zoom lens according to an embodiment and a movement locus thereof, which corresponds to the zoom lens of Example 1. [Figure 2] FIG. 2 is a cross-sectional view of the configuration of the first lens group of the zoom lens of FIG. 1, and is also a diagram for explaining symbols in conditional expressions. [Figure 3] FIG. 2 is a cross-sectional view of the configuration of the zoom lens in FIG. 1 in the telephoto end state, and is also a diagram for explaining the symbols in the conditional expressions. [Figure 4] FIG. 2 is a diagram showing insertion and removal of the EX group in the wide-angle end state of the zoom lens of FIG. 1, and is also a diagram for explaining the symbols in the conditional expressions. [Figure 5] FIG. 10 is a diagram for explaining an effective radius. [Figure 6] FIG. 1 is a cross-sectional view of the configuration of a zoom lens according to Example 1-1. [Figure 7] 3A to 3C are diagrams showing various aberrations of the zoom lens of Example 1. [Figure 8] 1A to 1C are diagrams showing various aberrations of the zoom lens of Example 1-1. [Figure 9] 10A and 10B are diagrams illustrating a cross-sectional view of the configuration of a zoom lens according to a second embodiment and a movement locus thereof. [Figure 10] 10A to 10C are diagrams showing various aberrations of the zoom lens of Example 2. [Figure 11]FIG. 10 is a cross-sectional view of the configuration of the zoom lens of Example 2-1 in the wide-angle end state. [Figure 12] 2A to 2C are diagrams showing various aberrations of the zoom lens of Example 2-1. [Figure 13] 10A and 10B are diagrams showing a cross-sectional view of the configuration of a zoom lens according to a third embodiment and a movement locus thereof; [Figure 14] 10A to 10C are diagrams illustrating various aberrations of the zoom lens according to the third embodiment. [Figure 15] FIG. 10 is a cross-sectional view of the configuration of the zoom lens of Example 3-1 in the wide-angle end state. [Figure 16] 3A to 3C are diagrams showing various aberrations of the zoom lens of Example 3-1. [Figure 17] 10A and 10B are diagrams showing a cross-sectional view of the configuration of a zoom lens according to a fourth embodiment and a movement locus thereof; [Figure 18] 10A to 10C are diagrams illustrating various aberrations of the zoom lens according to the fourth embodiment. [Figure 19] FIG. 4 is a cross-sectional view of the configuration of the zoom lens of Example 4-1 in the wide-angle end state. [Figure 20] 4A to 4C are diagrams showing various aberrations of the zoom lens of Example 4-1. [Figure 21] 10A and 10B are diagrams showing a cross-sectional view of the configuration of a zoom lens according to a fifth embodiment and a movement locus thereof. [Figure 22] 10A to 10C are diagrams showing various aberrations of the zoom lens of Example 5. [Figure 23] FIG. 5 is a cross-sectional view of the configuration of the zoom lens of Example 5-1 in the wide-angle end state. [Figure 24] 5A to 5C are diagrams showing various aberrations of the zoom lens of Example 5-1. [Figure 25] 13A and 13B are diagrams showing a cross-sectional view of the configuration of a zoom lens according to a sixth embodiment and a movement locus thereof. [Figure 26] 13A to 13C are diagrams illustrating various aberrations of the zoom lens of Example 6. [Figure 27] FIG. 6 is a cross-sectional view of the configuration of the zoom lens of Example 6-1 in the wide-angle end state. [Figure 28] 6A to 6C are diagrams showing various aberrations of the zoom lens of Example 6-1. [Figure 29] 13A and 13B are diagrams showing a cross-sectional view of the configuration of a zoom lens according to a seventh embodiment and a movement locus thereof. [Figure 30]10A to 10C are diagrams showing various aberrations of the zoom lens of Example 7. [Figure 31] FIG. 7 is a cross-sectional view of the configuration of the zoom lens of Example 7-1 in the wide-angle end state. [Figure 32] 7A to 7C are diagrams showing various aberrations of the zoom lens of Example 7-1. [Figure 33] 13A and 13B are diagrams showing a cross-sectional view of the configuration of a zoom lens according to an eighth embodiment and a movement locus thereof. [Figure 34] 13A to 13C are diagrams showing various aberrations of the zoom lens of Example 8. [Figure 35] FIG. 8 is a cross-sectional view of the configuration of the zoom lens of Example 8-1 in the wide-angle end state. [Figure 36] 8A to 8C are diagrams showing various aberrations of the zoom lens of Example 8-1. [Figure 37] 13A and 13B are diagrams showing a cross-sectional view of the configuration of a zoom lens according to a ninth embodiment and a movement locus thereof. [Figure 38] 13A to 13C are diagrams showing various aberrations of the zoom lens of Example 9. [Figure 39] FIG. 10 is a cross-sectional view of the configuration of the zoom lens of Example 9-1 in the wide-angle end state. [Figure 40] 9A to 9C are diagrams showing various aberrations of the zoom lens of Example 9-1. [Figure 41] 13A and 13B are diagrams showing a cross-sectional view of the configuration of a zoom lens according to a tenth embodiment and a movement locus thereof. [Figure 42] 13A to 13C are diagrams showing various aberrations of the zoom lens of Example 10. [Figure 43] FIG. 10 is a cross-sectional view of the configuration of the zoom lens of Example 10-1 in the wide-angle end state. [Figure 44] 10A to 10C are diagrams showing various aberrations of the zoom lens of Example 10-1. [Figure 45] 1 is a schematic configuration diagram of an imaging device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0046] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0047] FIG. 1 shows a cross-sectional view of the configuration of a zoom lens according to an embodiment of the present disclosure, as well as a movement trajectory of a light beam. FIG. 1 illustrates a state in which the lens is focused on an object at infinity, with the left side being the object side and the right side being the image side. In FIG. 1, the upper row labeled "Wide" illustrates the wide-angle end state, and the lower row labeled "Tele" illustrates the telephoto end state. In FIG. 1, the light beams are shown as an on-axis light beam and a light beam with a maximum half angle of view ωw at the wide-angle end, and an on-axis light beam and a light beam with a maximum half angle of view ωt at the telephoto end. The example shown in FIG. 1 corresponds to the zoom lens of Example 1, which will be described later.

[0048] FIG. 1 shows an example in which a parallel-plate optical member PP is arranged between the zoom lens and the image plane Sim, assuming that the zoom lens is applied to an imaging device. The optical member PP is a member that is assumed to include various filters and / or cover glass. The various filters include a low-pass filter, an infrared cut filter, and / or a filter that cuts off specific wavelength ranges. The optical member PP is a member that does not have refractive power. It is also possible to configure an imaging device without the optical member PP.

[0049] The zoom lens of the present disclosure includes a first lens group G1 having positive refractive power and positioned closest to the object, a middle group GM including multiple lens groups, and a final lens group GE positioned closest to the image. When zooming, the spacing between all adjacent lens groups changes. The first lens group G1 includes two negative lenses arranged consecutively from the object side to the image side. Of the two negative lenses in the first lens group G1, the object-side negative lens is a negative meniscus lens with its convex surface facing the object side. This configuration allows for a wide image circle while maintaining a large zoom ratio, and is advantageous for achieving compactness while ensuring a wide angle of view.

[0050] The intermediate group GM may be configured to include at least one of a negative group UN, an N lens group GN, and a P lens group GP, as described below.

[0051] The negative group UN is located adjacent to the image side of the first lens group G1, and is composed of two or less lens groups that have negative refractive power as a whole. The placement of such a negative group UN is advantageous for increasing the zoom ratio.

[0052] The N lens group GN is a lens group with negative refractive power that is located closer to the image side than the negative group UN. This N lens group GN is advantageous for achieving a wide angle while also reducing the size.

[0053] The P lens group GP is a lens group with positive refractive power that is located closer to the image than the negative lens group UN and closer to the object than the final lens group GE. This P lens group GP is advantageous in suppressing aberration fluctuations during magnification changes.

[0054] As an example, the intermediate group GM in FIG. 1 is made up of, in order from the object side to the image side, a negative group UN, an N lens group GN, and a P lens group GP.

[0055] In the example of Figure 1, during magnification variation, the first lens group G1 and the final lens group GE are fixed relative to the image plane Sim, while the negative lens group UN, the N lens group GN, and the P lens group GP move along the optical axis Z while changing the spacing between adjacent lens groups. In Figure 1, the solid arrows between the upper and lower rows indicate the approximate movement trajectories of each lens group that move during magnification variation from the wide-angle end to the telephoto end.

[0056] In this specification, a lens group is defined as a group whose distance from adjacent groups in the optical axis direction changes during magnification. The distance between adjacent lenses within a lens group does not change during magnification. In this specification, the "first lens group G1," the "lens groups" included in the intermediate group GM, the "N lens group GN," the "P lens group GP," and the "final lens group GE" are components of a zoom lens, each containing at least one lens and separated by an air gap that changes during magnification. During magnification, each lens group is moved or fixed individually, and the distance between lenses within each lens group does not change. The "lens group" may also include components other than lenses without refractive power, such as an aperture stop St.

[0057] In the zoom lens of the present disclosure, it is preferable that the first lens group G1 is fixed relative to the image plane Sim during zooming, which can prevent the center of gravity from shifting during zooming.

[0058] It is preferable that the first lens group G1 includes six or more lenses. This is advantageous for suppressing aberrations. To better suppress aberrations, it is preferable that the first lens group G1 includes eight or more lenses. For example, configuring the first lens group G1 to consist of nine lenses is advantageous for better suppression of aberrations.

[0059] It is preferable to dispose a negative lens adjacent to the image side of the positive lens included in the first lens group G1 that is closest to the object. In this case, the refractive power of the negative lens on the image side in the first lens group G1 can be suppressed, which is advantageous for weight reduction and for correcting axial chromatic aberration at the telephoto end.

[0060] Hereinafter, of the positive lenses included in the first lens group G1, the positive lens closest to the object side will be referred to as the L1p lens, and the negative lens arranged adjacent to the L1p lens on the image side will be referred to as the L1n lens. Figure 2 shows the first lens group G1 of the zoom lens in Figure 1. The first lens group G1 in Figure 2 is composed of, in order from the object side to the image side, lenses L11 to L19. In the example in Figure 2, lens L13 corresponds to the L1p lens, and lens L14 corresponds to the L1n lens.

[0061] It is preferable that the image-side surface of the L1n lens has a concave shape, which is advantageous for suppressing fluctuations in astigmatism during focusing.

[0062] The first lens group G1 may be configured to include, in order from the object side to the image side, a 1a sub-group G1a, a 1b sub-group G1b, and a 1c sub-group G1c, and may be configured so that the distance between the 1a sub-group G1a and the 1b sub-group G1b changes during focusing, and the distance between the 1b sub-group G1b and the 1c sub-group G1c changes during focusing. This configuration is advantageous for suppressing aberration fluctuations during focusing while simplifying the drive mechanism.

[0063] As an example, in the example of Figure 2, the 1a subgroup G1a consists of lenses L11 to L14, in order from the object side to the image side, the 1b subgroup G1b consists of lens L15, and the 1c subgroup G1c consists of lenses L16 to L19, in order from the object side to the image side.

[0064] When focusing from an object at infinity to a nearest object, the 1a sub-group G1a and the 1c sub-group G1c may be fixed relative to the image plane Sim, and the 1b sub-group G1b may be configured to move toward the image side. In this case, the amount of movement of the 1b sub-group G1b during focusing can be reduced.

[0065] In what follows, the group that moves along the optical axis Z during focusing will be referred to as the focusing group. Focusing is achieved by movement of the focusing group. In the example of Figure 1, the focusing group is made up of the 1b subgroup G1b. In Figure 1, an arrow indicating the direction of movement during focusing from an object at infinity to the closest object is shown below the focusing group in the lower diagram. The focusing group functions over the entire magnification range, including the wide-angle end, but to avoid cluttering the diagram, the above arrow is only shown in the lower diagram.

[0066] It is preferable that the 1a sub-group G1a has negative refractive power. This is advantageous for widening the angle of view. It is preferable that the 1b sub-group G1b has positive refractive power. This can reduce the amount of movement of the groups that move during focusing. It is preferable that the 1c sub-group G1c has positive refractive power. This is advantageous for suppressing spherical aberration.

[0067] The 1a subgroup G1a may be configured to include the L1p lens, which is advantageous for suppressing chromatic aberration of magnification.

[0068] The 1a sub-group G1a may be configured to include only one positive lens. This is advantageous for reducing the weight of the 1a sub-group G1a. When the 1a sub-group G1a includes only one positive lens, the positive lens may be an L1p lens.

[0069] The lens closest to the image side in the 1a subgroup G1a is a negative lens, and this negative lens may be configured to be an L1n lens. In this case, the refractive power of the negative lens on the image side in the first lens group G1 can be suppressed, which is advantageous for weight reduction, correction of axial chromatic aberration at the telephoto end, and suppression of aberration fluctuations during focusing.

[0070] When the lens closest to the image side of the 1a sub-group G1a is a negative lens, it is preferable to arrange a positive lens adjacent to the negative lens on the object side. More specifically, it is preferable that the 1a sub-group G1a includes, in order from the lens closest to the image side to the lens closest to the object side, an L1n lens and an L1p lens. This is advantageous for suppressing fluctuations in chromatic aberration during focusing.

[0071] It is preferable that the 1a subgroup G1a has at least one aspherical lens surface, which is advantageous for suppressing distortion.

[0072] It is preferable that the 1b sub-group G1b includes a positive lens, which is advantageous for suppressing fluctuations in spherical aberration during focusing.

[0073] The 1b sub-group G1b may be configured to consist of only one positive lens, which is advantageous for reducing the weight of the focusing group.

[0074] It is preferable that the positive lens included in the 1b subgroup G1b has at least one aspherical lens surface, which is advantageous for suppressing fluctuations in field curvature during focusing.

[0075] It is preferable that the 1c sub-group G1c includes three or more positive lenses, which is advantageous for suppressing longitudinal chromatic aberration.

[0076] It is preferable that the 1c sub-group G1c has at least one aspherical lens surface, which is advantageous for suppressing spherical aberration.

[0077] When varying the magnification, it is preferable that the final lens group GE is fixed relative to the image plane Sim, which makes it easier to suppress fluctuations in the F-number when varying the magnification.

[0078] It is preferable that the lens closest to the image side in the final lens group GE is a positive lens, which makes it easier to obtain a lens system with a smaller F-number.

[0079] The zoom lens of the present disclosure preferably includes an aperture stop St that is fixed relative to the image plane Sim during zooming. This simplifies the mechanical structure, which is advantageous for reducing weight. In the example of Figure 1, the aperture stop St is located closest to the object side of the final lens group GE.

[0080] Next, preferred and possible configurations for the conditional expressions of the zoom lens of the present disclosure will be described. In the following description of the conditional expressions, the same symbols will be used for elements with the same definitions, and some redundant explanations of the symbols will be omitted. Also, in the following, to avoid redundant explanations, the "zoom lens of the present disclosure" will also be referred to simply as the "zoom lens."

[0081] It is preferable that the zoom lens satisfy the following conditional expression (1). Here, fw is the focal length of the entire system when focused on an object at infinity at the wide-angle end. f1 is the focal length of the first lens group G1. By ensuring that the corresponding value of conditional expression (1) is not below the lower limit, the refractive power of the first lens group G1 can be strengthened, which is advantageous for shortening the overall length of the lens system. By ensuring that the corresponding value of conditional expression (1) is not above the upper limit, the refractive power of the first lens group G1 does not become too strong, which is advantageous for achieving a wider angle of view while suppressing aberrations. 0.1 <fw / f1<0.8 (1)

[0082] To obtain better characteristics, the lower limit of conditional expression (1) should preferably be set to 0.15, more preferably to 0.2, even more preferably to 0.23, and even more preferably to 0.25. To obtain better characteristics, the upper limit of conditional expression (1) should preferably be set to 0.5, more preferably to 0.45, even more preferably to 0.42, and even more preferably to 0.4.

[0083] It is preferable that the zoom lens satisfy the following conditional expression (2): Here, H1f is the axial distance from the object-side lens surface of the first lens group G1 to the object-side principal point position PH1f of the first lens group G1 when focused on an object at infinity. Hft is the axial distance from the object-side lens surface of the first lens group G1 to the object-side principal point position PHft of the entire system when focused on an object at infinity at the telephoto end. The signs of H1f and Hft are negative for the object side and positive for the image side, based on the object-side lens surface of the first lens group G1. As an example, FIG. 2 shows the object-side principal point position PH1f of the first lens group G1 and the above-mentioned distance H1f. FIG. 3 also shows the telephoto end state of the zoom lens of FIG. 1, and as an example, FIG. 3 also shows the object-side principal point position PHft of the entire system and the above-mentioned distance Hft. By ensuring that the value corresponding to condition (2) does not fall below the lower limit, it is advantageous for suppressing aberrations related to off-axial rays. By ensuring that the value corresponding to condition (2) does not fall above the upper limit, it is advantageous for shortening the overall length of the lens system while maintaining the zoom ratio. 0.1 <H1f / Hft<0.95 (2)

[0084] To obtain better characteristics, the lower limit of conditional expression (2) is more preferably set to 0.28, even more preferably to 0.3, even more preferably to 0.33, and even more preferably to 0.37. To obtain better characteristics, the upper limit of conditional expression (2) is more preferably set to 0.7, even more preferably to 0.6, and even more preferably to 0.5. For example, it is more preferable that the zoom lens satisfy the following conditional expression (2-1): 0.28 <H1f / Hft<0.7 (2-1)

[0085] It is preferable that the zoom lens satisfy the following conditional expression (3). Here, HD1 is the distance on the optical axis between the object-side principal point position PH1f of the first lens group G1 and the image-side principal point position PH1r of the first lens group G1 when focused on an object at infinity. As an example, FIG. 2 shows the image-side principal point position PH1r of the first lens group G1 and the above-mentioned distance HD1. Ensuring that the corresponding value of conditional expression (3) is not equal to or less than the lower limit is advantageous for suppressing aberration fluctuations during magnification variation. Ensuring that the corresponding value of conditional expression (3) is not equal to or greater than the upper limit facilitates shortening the overall length of the first lens group G1, which is advantageous for weight reduction. 1.4 <HD1 / f1<2.16 (3)

[0086] To obtain better characteristics, the lower limit of conditional expression (3) should preferably be set to 1.5, and more preferably to 1.6.To obtain better characteristics, the upper limit of conditional expression (3) should preferably be set to 2.15, and even more preferably to 2.1, and even more preferably to 2.05.

[0087] It is preferable that the zoom lens satisfy the following conditional expression (5). Here, H1r is the distance on the optical axis from the lens surface of the first lens group G1 closest to the image to the image-side principal point position PH1r of the first lens group G1 when focused on an object at infinity. The sign of H1r is negative for the object side and positive for the image side, based on the lens surface of the first lens group G1 closest to the image. As an example, Figure 2 shows the above distance H1r. Ensuring that the value corresponding to conditional expression (5) is not equal to or less than the lower limit is advantageous for suppressing various aberrations related to axial rays. Ensuring that the value corresponding to conditional expression (5) is not equal to or greater than the upper limit is advantageous for achieving a high zoom ratio. 0.7 <H1r / f1<1.5 (5)

[0088] In order to obtain better characteristics, the lower limit of conditional expression (5) should preferably be set to 0.75, more preferably to 0.8, and even more preferably to 0.85.In order to obtain better characteristics, the upper limit of conditional expression (5) should preferably be set to 1.4, more preferably to 1.3, and even more preferably to 1.25.

[0089] It is preferable that the zoom lens satisfy the following conditional expression (6): By ensuring that the value corresponding to conditional expression (6) is not below the lower limit, it is advantageous for suppressing aberrations related to off-axial rays. By ensuring that the value corresponding to conditional expression (6) is not above the upper limit, it is advantageous for reducing the diameter of the first lens group G1 while maintaining a wide angle. 0.7 <H1f / f1<2 (6)

[0090] In order to obtain better characteristics, the lower limit of conditional expression (6) should preferably be set to 0.8, more preferably to 0.9, and even more preferably to 1. In order to obtain better characteristics, the upper limit of conditional expression (6) should preferably be set to 1.7, more preferably to 1.6, and even more preferably to 1.5.

[0091] If the refractive index of the L1p lens for the d-line is N1p, it is preferable that the zoom lens satisfy the following conditional expression (7): Ensuring that the corresponding value of conditional expression (7) is not equal to or less than the lower limit thereof is advantageous for suppressing fluctuations in spherical aberration during zooming. Ensuring that the corresponding value of conditional expression (7) is not equal to or greater than the upper limit thereof widens the range of selectable Abbe numbers, which is advantageous for correcting axial chromatic aberration at the telephoto end. 1.7 <N1p<2.1 (7)

[0092] In order to obtain better characteristics, the lower limit of conditional expression (7) should preferably be set to 1.75, and more preferably to 1.8.In order to obtain better characteristics, the upper limit of conditional expression (7) should preferably be set to 2.05, and even more preferably to 2.

[0093] When the Abbe number of the L1p lens based on the d-line is v1p, it is preferable that the zoom lens satisfy the following conditional expression (8). Ensuring that the corresponding value of conditional expression (8) is not equal to or smaller than the lower limit thereof is advantageous for suppressing lateral chromatic aberration at the wide-angle end. Ensuring that the corresponding value of conditional expression (8) is not equal to or larger than the upper limit thereof is advantageous for correcting axial chromatic aberration at the telephoto end. 15<ν1p<30 (8)

[0094] In order to obtain better characteristics, the lower limit of conditional expression (8) should preferably be set to 16, and more preferably to 17. In order to obtain better characteristics, the upper limit of conditional expression (8) should preferably be set to 28, and even more preferably to 25, and even more preferably to 24.

[0095] If the refractive index of the L1n lens for the d-line is N1n, it is preferable that the zoom lens satisfy the following conditional expression (9): Ensuring that the corresponding value of conditional expression (9) is not equal to or less than the lower limit thereof is advantageous for suppressing fluctuations in spherical aberration during zooming. Ensuring that the corresponding value of conditional expression (9) is not equal to or greater than the upper limit thereof widens the range of selectable Abbe numbers, which is advantageous for correcting axial chromatic aberration at the telephoto end. 1.43 <N1n<1.85 (9)

[0096] To obtain better characteristics, the lower limit of conditional expression (9) should preferably be set to 1.5, more preferably to 1.55, and even more preferably to 1.6. To obtain better characteristics, the upper limit of conditional expression (9) should preferably be set to 1.8.

[0097] If the Abbe number of the L1n lens based on the d-line is v1n, it is preferable that the zoom lens satisfy the following conditional expression (10): Ensuring that the corresponding value of conditional expression (10) is not equal to or smaller than the lower limit thereof is advantageous for suppressing lateral chromatic aberration at the wide-angle end. Ensuring that the corresponding value of conditional expression (10) is not equal to or larger than the upper limit thereof is advantageous for correcting axial chromatic aberration at the telephoto end. 30<ν1n<60 (10)

[0098] In order to obtain better characteristics, the lower limit of conditional expression (10) should preferably be set to 35, more preferably to 37, and even more preferably to 38. In order to obtain better characteristics, the upper limit of conditional expression (10) should preferably be set to 59, and even more preferably to 58.5.

[0099] If the average value of the Abbe numbers based on the d-line of all negative lenses located closer to the object side than the L1p lens is taken as ν1nave, it is preferable that the zoom lens satisfy the following conditional expression (11): Ensuring that the corresponding value of conditional expression (11) is not equal to or smaller than the lower limit thereof is advantageous for suppressing lateral chromatic aberration at the wide-angle end. Ensuring that the corresponding value of conditional expression (11) is not equal to or larger than the upper limit thereof is advantageous for correcting axial chromatic aberration at the telephoto end. 35<ν1nave<60 (11)

[0100] In order to obtain better characteristics, the lower limit of conditional expression (11) should preferably be set to 40, and more preferably to 40.4. In order to obtain better characteristics, the upper limit of conditional expression (11) should preferably be set to 59, and even more preferably to 58.1.

[0101] If the average value of the partial dispersion ratios between the g-line and the F-line of all negative lenses located closer to the object than the L1p lens is θ1nave, it is preferable that the zoom lens satisfy the following conditional expression (12). Ensuring that the corresponding value of conditional expression (12) is not below the lower limit thereof allows the selection of a material with a lower specific gravity, which is advantageous for weight reduction. Ensuring that the corresponding value of conditional expression (12) is not above the upper limit thereof is advantageous for suppressing second-order chromatic aberration of magnification. 0.5<θ1nave<0.6 (12)

[0102] In order to obtain better characteristics, the lower limit of conditional expression (12) should more preferably be set to 0.53, even more preferably to 0.54, and even more preferably to 0.55.

[0103] If the refractive indices of a lens for the g-line, F-line, and C-line are Ng, NF, and NC, respectively, and the partial dispersion ratio between the g-line and F-line of that lens is θg,F, then θg,F is defined by the following equation. θg,F=(Ng-NF) / (NF-NC)

[0104] It is preferable for the zoom lens to satisfy the following conditional expression (13): Here, Denw is the axial distance from the object-side lens surface of the first lens group G1 to the paraxial entrance pupil position Penw when focused on an object at infinity at the wide-angle end. FIG. 4 shows the wide-angle end state of the zoom lens of FIG. 1, and as an example, FIG. 4 also shows the paraxial entrance pupil position Penw and the distance Denw. By ensuring that the value corresponding to conditional expression (13) is not less than the lower limit, the axial distance from the object-side lens surface of the first lens group G1 to the paraxial entrance pupil position at the wide-angle end can be increased, which is advantageous for suppressing fluctuations in field curvature during zooming. By ensuring that the value corresponding to conditional expression (13) is not less than the upper limit, the axial distance from the object-side lens surface of the first lens group G1 to the paraxial entrance pupil position at the wide-angle end can be decreased, which is advantageous for widening the angle of view. 2 <Denw / fw<3.5 (13)

[0105] In order to obtain better characteristics, the lower limit of conditional expression (13) should preferably be set to 2.1, more preferably to 2.2, and even more preferably to 2.3. In order to obtain better characteristics, the upper limit of conditional expression (13) should preferably be set to 3.3, more preferably to 3.2, and even more preferably to 3.

[0106] It is preferable that the zoom lens satisfy the following conditional expression (16). Here, the paraxial radius of curvature of the image-side surface of the lens closest to the object in the first lens group G1 is R2. The paraxial radius of curvature of the object-side surface of the second lens from the object side in the first lens group G1 is R3. By ensuring that the corresponding value of conditional expression (16) is not below the lower limit, the refractive power of the air lens formed between the lens closest to the object side of the zoom lens and the second lens from the object side of the zoom lens can be shifted to negative refractive power, which is advantageous for suppressing distortion. By ensuring that the corresponding value of conditional expression (16) is not above the upper limit, the absolute value of the radius of curvature of the image-side surface of the lens closest to the object side of the zoom lens does not become too small, which is advantageous for suppressing ghosting. -3<(R2-R3) / (R2+R3)<0 (16)

[0107] In order to obtain better characteristics, the lower limit of conditional expression (16) should preferably be set to -2.5, more preferably to -2.7, and even more preferably to -2.8.In order to obtain better characteristics, the upper limit of conditional expression (16) should preferably be set to -0.5, and even more preferably to -1.

[0108] It is preferable that the zoom lens satisfy the following conditional expression (17). Here, d1R is the distance on the optical axis from the lens surface in the first lens group G1 closest to the image to the lens surface adjacent to the lens surface in the first lens group G1 closest to the image when the zoom lens is focused on an object at infinity at the wide-angle end. IHw is the maximum image height when the zoom lens is focused on an object at infinity at the wide-angle end. As an example, FIG. 4 shows the distance d1R, and FIG. 1 shows the maximum image height IHw. Ensuring that the value corresponding to conditional expression (17) is not equal to or less than the lower limit is advantageous for the arrangement of the drive mechanism. Ensuring that the value corresponding to conditional expression (17) is not equal to or greater than the upper limit is advantageous for achieving both compactness and a high zoom ratio. 0.03 <d1R / IHw<0.097 (17)

[0109] In order to obtain better characteristics, the lower limit of conditional expression (17) should preferably be set to 0.04, more preferably to 0.045, and even more preferably to 0.052.In order to obtain better characteristics, the upper limit of conditional expression (17) should preferably be set to 0.092, more preferably to 0.085, and even more preferably to 0.079.

[0110] It is preferable that the zoom lens satisfy the following conditional expression (18): By ensuring that the corresponding value of conditional expression (18) is not below its lower limit, the refractive power of the first lens group G1 can be strengthened, which is advantageous for shortening the overall length of the lens system. By ensuring that the corresponding value of conditional expression (18) is not above its upper limit, the entrance pupil can be positioned closer to the object, which is advantageous for reducing the diameter of the first lens group G1. 0.5 <Denw / f1<1.5 (18)

[0111] In order to obtain better characteristics, the lower limit of conditional expression (18) should preferably be set to 0.6, and more preferably to 0.7.In order to obtain better characteristics, the upper limit of conditional expression (18) should preferably be set to 1.4, and even more preferably to 1.3, and even more preferably to 1.2.

[0112] It is preferable that the zoom lens satisfy the following conditional expression (19). Here, Dent is the distance on the optical axis from the lens surface of the first lens group G1 closest to the object to the paraxial entrance pupil position Pent when focused on an object at infinity at the telephoto end. As an example, FIG. 3 shows the above-mentioned paraxial entrance pupil position Pent and the above-mentioned distance Dent. Ensuring that the corresponding value of conditional expression (19) is not equal to or less than the lower limit is advantageous for suppressing various aberrations associated with off-axial rays at the telephoto end. Ensuring that the corresponding value of conditional expression (19) is not equal to or greater than the upper limit is advantageous for suppressing various aberrations associated with on-axial rays at the telephoto end. 1 <Dent / f1<3 (19)

[0113] In order to obtain better characteristics, it is more preferable that the lower limit of conditional expression (19) be set to 1.3, even more preferable that it be set to 1.5, and even more preferable that it be set to 1.7.In order to obtain better characteristics, it is more preferable that the upper limit of conditional expression (19) be set to 2.5.

[0114] If the axial thickness of the first lens group G1 is DG1, it is preferable that the zoom lens satisfy the following conditional expression (20). As an example, the thickness DG1 is shown in FIG. 2. Ensuring that the value corresponding to conditional expression (20) is not below the lower limit value is advantageous for correcting various aberrations. Ensuring that the value corresponding to conditional expression (20) is not above the upper limit value is advantageous for compactness. 0.6 <HD1 / DG1<1.5 (20)

[0115] In order to obtain better characteristics, the lower limit of conditional expression (20) should preferably be set to 0.65, more preferably to 0.7, and even more preferably to 0.75.In order to obtain better characteristics, the upper limit of conditional expression (20) should preferably be set to 1.3, more preferably to 1.2, and even more preferably to 1.1.

[0116] It is preferable that the zoom lens satisfy the following conditional expression (21). Here, FNot is the F-number when focused on an object at infinity at the telephoto end. ωt is the maximum half angle of view when focused on an object at infinity at the telephoto end. ωt is expressed in degrees. An example of ωt is shown in FIG. 1. By ensuring that the value corresponding to conditional expression (21) is not less than the lower limit, the diameter of the lens barrel does not become too large, which is advantageous for achieving compactness and weight reduction. By ensuring that the value corresponding to conditional expression (21) is not more than the upper limit, it is advantageous for achieving a bright optical system by maintaining a relatively small F-number all the way to the telephoto end. twenty five <FNot×ωt<35 (21)

[0117] In order to obtain better characteristics, the lower limit of conditional expression (21) should preferably be set to 27, more preferably to 28, and even more preferably to 29. In order to obtain better characteristics, the upper limit of conditional expression (21) should preferably be set to 34, more preferably to 33, and even more preferably to 32.

[0118] It is preferable that the zoom lens satisfy the following conditional expression (22): By ensuring that the corresponding value of conditional expression (22) is not equal to or less than the lower limit, the distance on the optical axis from the lens surface of the first lens group G1 closest to the object to the paraxial entrance pupil position on the wide-angle side can be made longer, which is advantageous for suppressing fluctuations in field curvature during magnification. By ensuring that the corresponding value of conditional expression (22) is not equal to or greater than the upper limit, the distance on the optical axis from the lens surface of the first lens group G1 closest to the object to the paraxial entrance pupil position on the wide-angle side can be made shorter, which is advantageous for widening the angle of view. 2 <Denw / IHw<3.5 (22)

[0119] In order to obtain better characteristics, it is more preferable that the lower limit of conditional expression (22) be set to 2.2, even more preferable that it be set to 2.3, and even more preferable that it be set to 2.4.In order to obtain even better characteristics, it is more preferable that the upper limit of conditional expression (22) be set to 3.4.

[0120] It is preferable that the zoom lens satisfy the following conditional expression (23). Here, Bfw is the back focal length in air equivalent distance when focused on an object at infinity at the wide-angle end. Ensuring that the value corresponding to conditional expression (23) is not equal to or less than the lower limit thereof is advantageous for ensuring sufficient peripheral light intensity. Ensuring that the value corresponding to conditional expression (23) is not equal to or greater than the upper limit thereof is advantageous for shortening the overall length of the lens system. 2 <Bfw / IHw<3.5 (23)

[0121] In order to obtain better characteristics, it is more preferable that the lower limit of conditional expression (23) be set to 2.2, even more preferable that it be set to 2.3, and even more preferable that it be set to 2.4.In order to obtain even better characteristics, it is more preferable that the upper limit of conditional expression (23) be set to 3.4.

[0122] If the maximum half angle of view when focused on an object at infinity at the wide-angle end is ωw, it is preferable that the zoom lens satisfy the following conditional expression (24). ωw is expressed in degrees. An example of ωw is shown in FIG. 1. Ensuring that the value corresponding to conditional expression (24) is not equal to or smaller than the lower limit thereof is advantageous for achieving a wider angle of view. Ensuring that the value corresponding to conditional expression (24) is not equal to or larger than the upper limit thereof is advantageous for achieving compactness. 40<ωw<55 (24)

[0123] In order to obtain better characteristics, the lower limit of conditional expression (24) should preferably be set to 41, and more preferably to 42. In order to obtain better characteristics, the upper limit of conditional expression (24) should preferably be set to 54, and even more preferably to 53.

[0124] If the focal length of the entire system at the telephoto end when focused on an object at infinity is ft, it is preferable that the zoom lens satisfy the following conditional expression (25): Ensuring that the corresponding value of conditional expression (25) is not equal to or less than the lower limit thereof is advantageous for suppressing aberration fluctuations during zooming. Ensuring that the corresponding value of conditional expression (25) is not equal to or greater than the upper limit thereof is advantageous for achieving a high zoom ratio. 0.1 <fw / ft<0.3 (25)

[0125] In order to obtain better characteristics, the lower limit of conditional expression (25) should preferably be set to 0.11, more preferably to 0.12, and even more preferably to 0.13. In order to obtain better characteristics, the upper limit of conditional expression (25) should preferably be set to 0.25, more preferably to 0.23, and even more preferably to 0.21.

[0126] It is preferable that the zoom lens satisfy the following conditional expression (26). Here, Dexw is the distance on the optical axis from the paraxial exit pupil position Pexw to the image plane Sim when focused on an object at infinity at the wide-angle end. However, if an optical element without refractive power is disposed between the paraxial exit pupil position and the image plane Sim, Dexw is calculated for that optical element using the air-equivalent distance. As an example, FIG. 4 shows the paraxial exit pupil position Pexw and a schematic representation of the distance Dexw. In FIG. 4, a parallel-plate-like optical element without refractive power that should be calculated using the air-equivalent distance is indicated by a dashed line. By ensuring that the value corresponding to conditional expression (26) is not less than the lower limit, the overall length of the lens system can be shortened, which is advantageous for compactness. By ensuring that the value corresponding to conditional expression (26) is not less than the upper limit, the angle of incidence of the off-axial chief ray on the image plane Sim can be reduced, which is advantageous for ensuring peripheral illumination. 0.02 <IHw / Dexw<0.2 (26)

[0127] In order to obtain better characteristics, the lower limit of conditional expression (26) should preferably be set to 0.025, more preferably to 0.03, and even more preferably to 0.032. In order to obtain better characteristics, the upper limit of conditional expression (26) should preferably be set to 0.15, more preferably to 0.13, and even more preferably to 0.11.

[0128] It is preferable that the zoom lens satisfy the following conditional expression (31). Here, the central thickness of the lens closest to the object in the first lens group G1 is defined as tL1. The effective radius of the object-side surface of the lens closest to the object in the first lens group G1 is defined as ErL1. As an example, FIG. 2 shows the central thickness tL1 and the effective radius ErL1 described above. Ensuring that the value corresponding to conditional expression (31) is not equal to or smaller than the lower limit thereof is advantageous for improving the robustness of the lens closest to the object in the first lens group G1. Ensuring that the value corresponding to conditional expression (31) is not equal to or larger than the upper limit thereof is advantageous for reducing weight. 0.015 <tL1 / ErL1<0.1 (31)

[0129] In order to obtain better characteristics, the lower limit of conditional expression (31) should preferably be set to 0.02, more preferably to 0.025, and even more preferably to 0.03.In order to obtain better characteristics, the upper limit of conditional expression (31) should preferably be set to 0.09, and even more preferably to 0.08.

[0130] Here, the "effective radius" will be explained with reference to FIG. 5. FIG. 5 is an explanatory diagram. In FIG. 5, the left side is the object side and the right side is the image side. FIG. 5 shows an on-axis ray Xa and an off-axis ray Xb passing through the lens Lx. In the example of FIG. 5, the upper ray Xb1 of the off-axis ray Xb is the outermost ray. Here, "outside" refers to the radially outward direction centered on the optical axis Z, i.e., the side away from the optical axis Z. The position of the intersection of this outermost ray and the lens surface is the position Px of the maximum effective diameter. The distance from the position Px of the maximum effective diameter to the optical axis Z is the effective radius Er of the object-side surface of the lens Lx. Note that in the example of FIG. 5, the upper ray of the off-axis ray Xb is the outermost ray, but which ray is the outermost ray varies depending on the lens system.

[0131] In a configuration in which the first lens group G1 is composed of the above-mentioned 1a sub-group G1a, 1b sub-group G1b, and 1c sub-group G1c, and the distance between the 1a sub-group G1a and the 1b sub-group G1b changes during focusing, and the distance between the 1b sub-group G1b and the 1c sub-group G1c changes, it is preferable that the zoom lens satisfy at least one of the following conditional expressions (4), (14), (15), (28), (29), and (30).

[0132] In the following conditional expression (4), the focal length of the 1b subgroup G1b is set to f1b. By ensuring that the corresponding value of conditional expression (4) is not below the lower limit, the amount of movement of the group that moves during focusing can be reduced, which is advantageous for size reduction. By ensuring that the corresponding value of conditional expression (4) is not above the upper limit, which is advantageous for suppressing fluctuations in spherical aberration during focusing. 0.3 <f1 / f1b<1 (4)

[0133] In order to obtain better characteristics, the lower limit of conditional expression (4) should preferably be set to 0.35, and more preferably to 0.4. In order to obtain better characteristics, the upper limit of conditional expression (4) should preferably be set to 0.8, and even more preferably to 0.7, and even more preferably to 0.65.

[0134] In the following conditional expression (14), the focal length of the 1a sub-group G1a is set to f1a. By ensuring that the corresponding value of conditional expression (14) is not equal to or less than the lower limit, the degree of divergence of the on-axis light beam by the 1a sub-group G1a can be weakened, which is advantageous for reducing the diameter of the 1b sub-group G1b. By ensuring that the corresponding value of conditional expression (14) is not equal to or greater than the upper limit, the negative refractive power of the 1a sub-group G1a can be strengthened, and therefore, by strengthening the positive refractive power of the 1b sub-group G1b and the portion closer to the image than the 1b sub-group G1b, the amount of change in spacing during focusing can be reduced, which is advantageous for shortening the overall length of the lens system. -2 <f1 / f1a<0 (14)

[0135] In order to obtain better characteristics, the lower limit of conditional expression (14) should preferably be set to -1.8, and more preferably to -1.7.In order to obtain better characteristics, the upper limit of conditional expression (14) should preferably be set to -0.5, and even more preferably to -0.7, and even more preferably to -1.

[0136] In the following conditional expression (15), the focal length of the 1c subgroup G1c is set to f1c. Ensuring that the corresponding value of conditional expression (15) is not equal to or less than the lower limit thereof is advantageous for shortening the overall length of the first lens group G1. Ensuring that the corresponding value of conditional expression (15) is not equal to or greater than the upper limit thereof is advantageous for suppressing various aberrations at the telephoto end. 0.3 <f1 / f1c<0.8 (15)

[0137] In order to obtain better characteristics, the lower limit of conditional expression (15) should preferably be set to 0.4, more preferably to 0.5, and even more preferably to 0.55.In order to obtain better characteristics, the upper limit of conditional expression (15) should preferably be set to 0.75, and even more preferably to 0.7.

[0138] In the following conditional expression (28), the thickness on the optical axis of the 1a subgroup G1a is defined as D1a. As an example, the thickness D1a is shown in FIG. 2. Ensuring that the value corresponding to conditional expression (28) is not equal to or smaller than the lower limit thereof is advantageous for suppressing aberration fluctuations when focusing on the axial light beam at the telephoto end. Ensuring that the value corresponding to conditional expression (28) is not equal to or larger than the upper limit thereof is advantageous for weight reduction. 0.2 <D1a / DG1<0.7 (28)

[0139] In order to obtain better characteristics, the lower limit of conditional expression (28) should preferably be set to 0.3, more preferably to 0.35, and even more preferably to 0.4. In order to obtain better characteristics, the upper limit of conditional expression (28) should preferably be set to 0.65, more preferably to 0.6, and even more preferably to 0.55.

[0140] In the following conditional expression (29), the thickness on the optical axis of the 1b subgroup G1b is defined as D1b. As an example, the thickness D1b is shown in FIG. 2. Ensuring that the value corresponding to conditional expression (29) is not equal to or smaller than the lower limit is advantageous for suppressing fluctuations in spherical aberration during focusing. Ensuring that the value corresponding to conditional expression (29) is not equal to or larger than the upper limit is advantageous for reducing weight. 0.05 <D1b / DG1<0.2 (29)

[0141] In order to obtain better characteristics, the lower limit of conditional expression (29) should preferably be set to 0.06, more preferably to 0.07, and even more preferably to 0.09.In order to obtain better characteristics, the upper limit of conditional expression (29) should preferably be set to 0.15, more preferably to 0.13, and even more preferably to 0.12.

[0142] In the following conditional expression (30), the thickness on the optical axis of the 1c subgroup G1c is defined as D1c. As an example, the thickness D1c is shown in FIG. 2. Ensuring that the value corresponding to conditional expression (30) is not equal to or smaller than the lower limit is advantageous for suppressing fluctuations in spherical aberration during focusing. Ensuring that the value corresponding to conditional expression (30) is not equal to or larger than the upper limit is advantageous for reducing weight. 0.2 <D1c / DG1<0.7 (30)

[0143] In order to obtain even better characteristics, it is more preferable that the lower limit of conditional expression (30) be set to 0.3.In order to obtain even better characteristics, it is more preferable that the upper limit of conditional expression (30) be set to 0.6, even more preferably to 0.5, and even more preferably to 0.4.

[0144] In a zoom lens configuration including the above-described N lens group GN, it is preferable that the zoom lens satisfy the following conditional expression (36). Here, the focal length of the N lens group GN is taken as fN. By ensuring that the corresponding value of conditional expression (36) is not below the lower limit, the refractive power of the first lens group G1 can be suppressed, which is advantageous for suppressing aberration fluctuations during zooming. By ensuring that the corresponding value of conditional expression (36) is not above the upper limit, the refractive power of the N lens group GN can be suppressed, which is advantageous for suppressing aberration fluctuations during zooming. -2.3 <fN / f1<-0.6 (36)

[0145] In order to obtain better characteristics, the lower limit of conditional expression (36) should preferably be set to -2.1, more preferably to -1.95, and even more preferably to -1.84.In order to obtain better characteristics, the upper limit of conditional expression (36) should preferably be set to -0.8, more preferably to -1, and even more preferably to -1.13.

[0146] In a zoom lens configuration including the negative group UN, it is preferable that the zoom lens satisfy the following conditional expression (37). Here, fUN is the focal length of the negative group UN when focused on an object at infinity at the wide-angle end. By ensuring that the corresponding value of conditional expression (37) is not below the lower limit, the refractive power of the negative group UN can be strengthened, thereby reducing the amount of movement of the negative group UN during zooming, which is advantageous for shortening the overall length of the lens system. By ensuring that the corresponding value of conditional expression (37) is not above the upper limit, the refractive power of the first lens group G1 can be strengthened, which is advantageous for reducing the diameter and weight of the negative group UN. -1 <fUN / f1<-0.2 (37)

[0147] In order to obtain better characteristics, the lower limit of conditional expression (37) should preferably be set to -0.9, more preferably to -0.75, and even more preferably to -0.65.In order to obtain better characteristics, the upper limit of conditional expression (37) should preferably be set to -0.3, more preferably to -0.35, and even more preferably to -0.44.

[0148] In a zoom lens configuration including the negative unit UN, it is preferable that the zoom lens satisfy the following conditional expression (38): By ensuring that the corresponding value of conditional expression (38) is not below the lower limit, the refractive power of the negative unit UN does not become too strong, which is advantageous for suppressing aberration fluctuations during zooming. By ensuring that the corresponding value of conditional expression (38) is not above the upper limit, the refractive power of the negative unit UN does not become too weak, which is advantageous for size reduction. -1 <fw / fUN<-0.25 (38)

[0149] In order to obtain better characteristics, the lower limit of conditional expression (38) should preferably be set to -0.9, more preferably to -0.8, and even more preferably to -0.7.In order to obtain better characteristics, the upper limit of conditional expression (38) should preferably be set to -0.35, more preferably to -0.45, and even more preferably to -0.52.

[0150] When the focal length of the final lens group GE is fE, it is preferable that the zoom lens satisfy the following conditional expression (39): Ensuring that the corresponding value of conditional expression (39) is not equal to or smaller than the lower limit thereof is advantageous for size reduction. Ensuring that the corresponding value of conditional expression (39) is not equal to or larger than the upper limit thereof is advantageous for suppressing various aberrations. 0.03 <fw / fE<0.75 (39)

[0151] In order to obtain better characteristics, the lower limit of conditional expression (39) should preferably be set to 0.07, more preferably to 0.1, and even more preferably to 0.14.In order to obtain better characteristics, the upper limit of conditional expression (39) should preferably be set to 0.63, more preferably to 0.5, and even more preferably to 0.42.

[0152] In a zoom lens configuration including the P lens group GP, it is preferable that the zoom lens satisfy the following conditional expression (40). Here, the focal length of the P lens group GP is fP. Ensuring that the value corresponding to conditional expression (40) is not below the lower limit is advantageous for achieving a high zoom ratio. Ensuring that the value corresponding to conditional expression (40) is not above the upper limit is advantageous for suppressing aberration fluctuations during zooming. 0.1 <fw / fP<0.6 (40)

[0153] In order to obtain better characteristics, the lower limit of conditional expression (40) should preferably be set to 0.15, more preferably to 0.2, and even more preferably to 0.25.In order to obtain better characteristics, the upper limit of conditional expression (40) should preferably be set to 0.5, more preferably to 0.42, and even more preferably to 0.35.

[0154] The zoom lens of the present disclosure may be configured to include an EX group EX that changes the focal length of the zoom lens by being inserted or removed from the optical path. In this specification, the longest air gap on the optical axis among the air gaps included in the final lens group GE when focused on an object at infinity at the wide-angle end is referred to as the maximum air gap DAmax. The EX group EX may be configured to be inserted or removed from the optical path at this maximum air gap DAmax, thereby changing the focal length of the zoom lens while maintaining a constant imaging position. In this case, a zoom lens with a variable focal length can be obtained.

[0155] As an example, the above-mentioned maximum air distance DAmax and the EX group EX are shown in Figure 4. In the example of Figure 4, the maximum air distance DAmax is formed between the fourth and fifth lenses from the object side in the final lens group GE. The EX group EX in Figure 4 is made up of seven lenses.

[0156] FIG. 6 shows a cross-sectional view of the configuration and light beams of a zoom lens when the EX group EX of FIG. 4 is inserted into the zoom lens of FIG. 1 as Example 1-1. The final lens group GEE of FIG. 6 is configured such that the EX group EX is inserted inside the final lens group GE of FIG. 1, which is what distinguishes the example of FIG. 6 from the example of FIG. 1. The other lens groups and group configurations of the example of FIG. 6 are the same as those of the example of FIG. 1. FIG. 6 shows a state in which focus is on an object at infinity, with the left side being the object side and the right side being the image side. In FIG. 6, the upper row labeled "Wide" shows the wide-angle end state, and the lower row labeled "Tele" shows the telephoto end state. In FIG. 6, the axial light beam and the light beam at the maximum half angle of view ωEXw at the wide-angle end, as well as the axial light beam and the light beam at the maximum half angle of view ωEXt at the telephoto end, are shown.

[0157] When a zoom lens includes the above-described EX group EX, it may be configured so that the maximum image height changes when the EX group EX is inserted or removed. For example, in the wide-angle end state, the maximum image height IHEw in the example shown in Figure 6 is enlarged compared to the maximum image height IHw in the example shown in Figure 1 where the EX group EX is not inserted. By configuring it in this way, it is possible to obtain a zoom lens that has a wider image circle while maintaining the angle of view.

[0158] It is preferable that the zoom lens satisfy the following conditional expression (27). Here, when focused on an object at infinity at the wide-angle end, the composite lateral magnification of all lenses located to the image side of the longest air distance DAmax is defined as βAmaxR. Ensuring that the corresponding value of conditional expression (27) is not equal to or less than the lower limit thereof is advantageous for reducing the diameter of the lens group consisting of all lenses located to the image side of the longest air distance DAmax. Ensuring that the corresponding value of conditional expression (27) is not equal to or greater than the upper limit thereof is advantageous for suppressing aberration fluctuations when the longest air distance DAmax changes due to an error. 0.1<βAmaxR<0.3 (27)

[0159] In order to obtain better characteristics, the lower limit of conditional expression (27) should preferably be set to 0.13, more preferably to 0.15, and even more preferably to 0.17.In order to obtain better characteristics, the upper limit of conditional expression (27) should preferably be set to 0.27, more preferably to 0.25, and even more preferably to 0.23.

[0160] It is preferable that the zoom lens satisfy the following conditional expression (32). Here, ft is the focal length of the zoom lens when the EX group EX is not inserted and the zoom lens is focused on an object at infinity at the telephoto end. ωt is the maximum half angle of view when the EX group EX is not inserted and the zoom lens is focused on an object at infinity at the telephoto end. fEXt is the focal length of the zoom lens when the EX group EX is inserted and the zoom lens is focused on an object at infinity at the telephoto end. ωEXt is the maximum half angle of view when the EX group EX is inserted and the zoom lens is focused on an object at infinity at the telephoto end. tan is the tangent. Ensuring that the corresponding value of conditional expression (32) is not equal to or less than the lower limit is advantageous in simultaneously suppressing various aberrations when the EX group EX is not inserted and various aberrations when the EX group EX is inserted. Ensuring that the corresponding value of conditional expression (32) is not equal to or greater than the upper limit makes it easier to obtain the desired image size when the EX group EX is inserted. 0.3<(ft×tanωt) / (fEXt×tanωEXt)<0.9 (32)

[0161] In order to obtain better characteristics, the lower limit of conditional expression (32) should preferably be set to 0.5, more preferably to 0.6, and even more preferably to 0.65.In order to obtain better characteristics, the upper limit of conditional expression (32) should preferably be set to 0.85, more preferably to 0.8, and even more preferably to 0.75.

[0162] It is preferable that the zoom lens satisfy the following conditional expression (33). Here, TLw is the sum of the axial distance from the lens surface of the first lens group G1 closest to the object to the lens surface of the final lens group GE closest to the image, and the back focus in terms of air equivalent distance, when focused on an object at infinity at the wide-angle end. DEX is the axial thickness of the EX group EX. As an example, Figure 6 shows the above thickness DEX. Ensuring that the corresponding value of conditional expression (33) is not equal to or less than the lower limit is advantageous for suppressing aberrations that occur in the EX group EX. Ensuring that the corresponding value of conditional expression (33) is not equal to or greater than the upper limit is advantageous for reducing the weight of the EX group EX. 0.07 <DEX / TLw<0.15 (33)

[0163] In order to obtain better characteristics, the lower limit of conditional expression (33) should preferably be set to 0.075, more preferably to 0.08, and even more preferably to 0.085.In order to obtain better characteristics, the upper limit of conditional expression (33) should preferably be set to 0.13, more preferably to 0.12, and even more preferably to 0.11.

[0164] It is preferable that the zoom lens satisfy the following conditional expression (34). Here, the focal length of the lens component closest to the image in the EX group EX is defined as fLEXe. Note that one lens component means one single lens or one cemented lens. A single lens is one lens that is not cemented. By ensuring that the value corresponding to conditional expression (34) is not equal to or smaller than the lower limit, it is possible to prevent over-correction of distortion occurring in the EX group EX. By ensuring that the value corresponding to conditional expression (34) is not equal to or larger than the upper limit, it is advantageous for correcting distortion occurring in the EX group EX. -1.5 <Bfw / fLEXe<-0.9 (34)

[0165] In order to obtain even better characteristics, the lower limit of conditional expression (34) should preferably be set to -1.45. In order to obtain even better characteristics, the upper limit of conditional expression (34) should preferably be set to -0.92, more preferably to -0.93, and even more preferably to -0.94.

[0166] It is preferable that the zoom lens satisfy the following conditional expression (35). Here, the refractive index at the d-line of the lens in the EX group EX closest to the object is set to NEX1. Ensuring that the corresponding value of conditional expression (35) is not below the lower limit value helps to suppress spherical aberration that occurs in the EX group EX. Ensuring that the corresponding value of conditional expression (35) is not above the upper limit value helps to suppress axial chromatic aberration that occurs in the EX group EX. 1.43 <NEX1<1.8 (35)

[0167] In order to obtain better characteristics, the lower limit of conditional expression (35) should preferably be set to 1.47, and more preferably to 1.5.In order to obtain better characteristics, the upper limit of conditional expression (35) should preferably be set to 1.76, and even more preferably to 1.73, and even more preferably to 1.7.

[0168] Note that the example shown in FIG. 1 is just one example, and various modifications are possible without departing from the spirit and scope of the technology of the present disclosure. For example, the lens groups constituting the intermediate group GM may be different from those in the example of FIG. 1. The number of lens groups included in the intermediate group GM and the number of lens groups included in the negative group UN may be different from those in the example of FIG. 1. The numbers of lenses included in the first lens group G1, negative group UN, N lens group GN, P lens group GP, final lens group GE, and focusing group may be different from those in the example of FIG. 1. The positions of the focusing group, aperture stop St, and lens groups that move during magnification may be configured differently from those in the example of FIG. 1.

[0169] The above-described preferred and possible configurations can be arbitrarily combined within a range that does not cause a contradiction, and it is preferable that they be selectively adopted as appropriate according to the required specifications.

[0170] As an example, a preferred embodiment of the present disclosure is a zoom lens comprising a first lens group G1 having positive refractive power and positioned closest to the object, an intermediate group GM including a plurality of lens groups, and a final lens group GE positioned closest to the image, wherein all of the intervals between adjacent lens groups change during magnification variation, the first lens group G1 includes two negative lenses arranged consecutively from closest to the object side to the image side, and of the two negative lenses, the negative lens closest to the object side is a negative meniscus lens with its convex surface facing the object side, and wherein the above conditional formula (1) is satisfied.

[0171] Next, examples of the zoom lens of the present disclosure will be described with reference to the drawings. Note that the reference symbols assigned to each group in the cross-sectional views of each example are used independently for each example to avoid cluttering the explanation and drawings due to an increase in the number of digits in the reference symbols. Therefore, even if common reference symbols are assigned in drawings of different examples, this does not necessarily mean that the configuration is the same.

[0172] [Example 1] The configuration and movement locus of the zoom lens of Example 1 are shown in Figure 1, and since the illustration method and configuration are as described above, some overlapping explanations will be omitted here. The zoom lens of Example 1 consists, in order from the object side to the image side, of a first lens group G1 having positive refractive power, an intermediate group GM, and a final lens group GE having positive refractive power. The intermediate group GM consists, in order from the object side to the image side, of a negative group UN, an N lens group GN having negative refractive power, and a P lens group GP having positive refractive power. The negative group UN consists of a single lens group having negative refractive power.

[0173] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the final lens group GE are fixed with respect to the image plane Sim, and the negative lens group UN, the N lens group GN, and the P lens group GP move along the optical axis Z while changing the spacing between themselves and the adjacent lens groups.

[0174] The first lens group G1 consists, in order from the object side to the image side, of a 1a sub-group G1a having negative refractive power, a 1b sub-group G1b having positive refractive power, and a 1c sub-group G1c having positive refractive power. The focusing group consists of the 1b sub-group G1b. The 1b sub-group G1b consists of a single lens element, the fifth from the object side. When focusing from an object at infinity to the closest object, the 1a sub-group G1a and the 1c sub-group G1c are fixed with respect to the image plane Sim, and the 1b sub-group G1b moves toward the image side.

[0175] For the zoom lens of Example 1, basic lens data is shown in Tables 1A and 1B, specifications and variable surface spacing are shown in Table 2, and aspherical coefficients are shown in Table 3. The basic lens data tables are divided into two tables to avoid making one table too long.

[0176] The table of basic lens data is written as follows. The "Sn" column shows the surface number, with the surface closest to the object being surface 1 and the numbers increasing by one as you move towards the image side. The "R" column shows the radius of curvature of each surface. The "D" column shows the surface spacing on the optical axis between each surface and its adjacent surface on the image side. The "Nd" column shows the refractive index for the d-line of each component element. The "νd" column shows the Abbe number of each component element based on the d-line. The "θg,F" column shows the partial dispersion ratio between the g-line and F-line of each component element.

[0177] In the table of basic lens data, the sign of the radius of curvature of a surface with a convex shape facing the object side is positive, and the sign of the radius of curvature of a surface with a convex shape facing the image side is negative. Table 1 also shows the aperture stop St and optical element PP. The column for the surface number corresponding to the aperture stop St is filled in with the surface number and the phrase (St). The value in the bottom column of the D column in the table is the distance between the surface closest to the image side in the table and the image plane Sim. The symbol DD[ ] is used to indicate the variable surface distance when varying magnification, and the object-side surface number of this distance is entered in the [ ] in the D column.

[0178] Table 2 shows the zoom ratio Zr, focal length f, maximum F-number FNo., maximum full angle of view 2ω, and variable surface spacing based on the d-line. The zoom ratio is synonymous with the zoom magnification. The [°] in the 2ω column indicates that the unit is degrees. In Table 2, the "Wide," "Middle," and "Tele" columns show the values ​​for the wide-angle end, mid-focal length state, and telephoto end state, respectively.

[0179] In the basic lens data, the surface numbers of aspherical surfaces are marked with an *, and the value of the paraxial radius of curvature is listed in the column for the radius of curvature of the aspherical surface. In Table 3, the Sn row shows the surface numbers of aspherical surfaces, and the KA and Am rows show the numerical values ​​of the aspherical coefficients for each aspherical surface. Note that m in Am is an integer of 3 or more, and varies depending on the surface. For example, for the first surface of Example 1, m = 4, 6, 8, 10, 12, 14, 16, 18, 20. The numerical values ​​of the aspherical coefficients in Table 3, "E±n" (n: integer), are expressed as "×10 ±n KA and Am are aspherical coefficients in the aspherical formula given below. Zd=C×h 2 / {1+(1-KA×C 2 ×h 2 ) 1 / 2}+ΣAm×h m however, Zd: Aspheric depth (length of the perpendicular line drawn from a point on the aspheric surface at height h to a plane perpendicular to the optical axis Z where the vertex of the aspheric surface is in contact) h: Height (distance from optical axis Z to lens surface) C: Reciprocal of paraxial curvature radius KA, Am: aspherical coefficients In the aspherical formula, Σ means the summation over m.

[0180] In the data in each table, degrees are used as the unit of angle and millimeters as the unit of length, but since the optical system can be used with proportional magnification or reduction, other appropriate units can also be used. Also, in each table below, values ​​are listed rounded to a predetermined number of decimal places.

[0181] [Table 1A]

[0182] [Table 1B]

[0183] [Table 2]

[0184] [Table 3]

[0185] FIG. 7 shows aberration diagrams of the zoom lens of Example 1 when focused on an object at infinity. From left to right, FIG. 7 shows spherical aberration, astigmatism, distortion, and lateral chromatic aberration. In FIG. 7, the upper row labeled "Wide" shows aberrations at the wide-angle end, the middle row labeled "Middle" shows aberrations at the intermediate focal length, and the lower row labeled "Tele" shows aberrations at the telephoto end. In the spherical aberration diagram, aberrations at the d-line, C-line, and F-line are shown by solid lines, long-dashed lines, and short-dashed lines, respectively. In the astigmatism diagram, aberrations at the d-line in the sagittal direction are shown by solid lines, and aberrations at the d-line in the tangential direction are shown by short-dashed lines. In the distortion diagram, aberrations at the d-line are shown by solid lines. In the lateral chromatic aberration diagram, aberrations at the C-line and F-line are shown by long-dashed lines and short-dashed lines, respectively. In the spherical aberration diagram, the maximum F-number is shown after FNo.=. In the other aberration diagrams, the maximum half angle of view is shown after ω=.

[0186] The symbols, meanings, notation methods, and illustration methods of each data item related to the above-mentioned Example 1 are basically the same in the following Examples unless otherwise specified, and therefore, redundant explanations will be omitted below.

[0187] [Example 1-1] Example 1-1 is an example in which an EX group EX is inserted into the zoom lens of Example 1. The configuration of the zoom lens of Example 1-1 and a cross-sectional view of the light beam are shown in FIG. 6. The zoom lens of Example 1-1 has a final lens group GEE in which an EX group EX is inserted inside the final lens group GE of Example 1, instead of the final lens group GE of Example 1. The configuration of the other lens groups and groups in Example 1-1 are the same as those of the zoom lens of Example 1.

[0188] For the zoom lens of Example 1-1, basic lens data is shown in Tables 4A and 4B, specifications and variable surface spacings are shown in Table 5, aspherical coefficients are shown in Table 6, and aberration diagrams are shown in FIG.

[0189] [Table 4A]

[0190] [Table 4B]

[0191] [Table 5]

[0192] [Table 6]

[0193] [Example 2] The configuration and movement trajectory of the zoom lens of Example 2 are shown in Figure 9. The zoom lens of Example 2 consists, in order from the object side to the image side, of a first lens group G1 having positive refractive power, an intermediate group GM, and a final lens group GE having positive refractive power. The intermediate group GM consists, in order from the object side to the image side, of a negative group UN, an N lens group GN having negative refractive power, and a P lens group GP having positive refractive power. The negative group UN consists of a single lens group having negative refractive power.

[0194] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the final lens group GE are fixed with respect to the image plane Sim, and the negative lens group UN, the N lens group GN, and the P lens group GP move along the optical axis Z while changing the spacing between themselves and the adjacent lens groups.

[0195] The first lens group G1 consists, in order from the object side to the image side, of a 1a sub-group G1a having negative refractive power, a 1b sub-group G1b having positive refractive power, and a 1c sub-group G1c having positive refractive power. The focusing group consists of the 1b sub-group G1b. The 1b sub-group G1b consists of a single lens element and is the fourth lens element from the object side. When focusing from an object at infinity to the closest object, the 1a sub-group G1a and the 1c sub-group G1c are fixed with respect to the image plane Sim, and the 1b sub-group G1b moves toward the image side.

[0196] For the zoom lens of Example 2, basic lens data is shown in Tables 7A and 7B, specifications and variable surface spacing is shown in Table 8, aspherical coefficients are shown in Table 9, and aberration diagrams are shown in FIG.

[0197] [Table 7A]

[0198] [Table 7B]

[0199] [Table 8]

[0200] [Table 9]

[0201] [Example 2-1] Example 2-1 is an example in which an EX group EX is inserted into the zoom lens of Example 2. A cross-sectional view of the configuration and light beam of the zoom lens of Example 2-1 in the wide-angle end state is shown in FIG. 11. The zoom lens of Example 2-1 has a final lens group GEE in which an EX group EX is inserted inside the final lens group GE of Example 2, instead of the final lens group GE of Example 2. The configuration of the other lens groups and groups in Example 2-1 are the same as those of the zoom lens of Example 2.

[0202] For the zoom lens of Example 2-1, basic lens data is shown in Tables 10A and 10B, specifications and variable surface spacing is shown in Table 11, aspherical coefficients are shown in Table 12, and aberration diagrams are shown in FIG.

[0203] [Table 10A]

[0204] [Table 10B]

[0205] [Table 11]

[0206] [Table 12]

[0207] [Example 3] The configuration and movement trajectory of the zoom lens of Example 3 are shown in Figure 13. The zoom lens of Example 3 consists, in order from the object side to the image side, of a first lens group G1 having positive refractive power, an intermediate group GM, and a final lens group GE having positive refractive power. The intermediate group GM consists, in order from the object side to the image side, of a negative group UN, an N lens group GN having negative refractive power, and a P lens group GP having positive refractive power. The negative group UN consists of a single lens group having negative refractive power.

[0208] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the final lens group GE are fixed with respect to the image plane Sim, and the negative lens group UN, the N lens group GN, and the P lens group GP move along the optical axis Z while changing the spacing between themselves and the adjacent lens groups.

[0209] The first lens group G1 consists, in order from the object side to the image side, of a 1a sub-group G1a having negative refractive power, a 1b sub-group G1b having positive refractive power, and a 1c sub-group G1c having positive refractive power. The focusing group consists of the 1b sub-group G1b. The 1b sub-group G1b consists of a single lens element, the fifth from the object side. When focusing from an object at infinity to the closest object, the 1a sub-group G1a and the 1c sub-group G1c are fixed with respect to the image plane Sim, and the 1b sub-group G1b moves toward the image side.

[0210] For the zoom lens of Example 3, basic lens data is shown in Tables 13A and 13B, specifications and variable surface spacing is shown in Table 14, aspherical coefficients are shown in Table 15, and aberration diagrams are shown in FIG.

[0211] [Table 13A]

[0212] [Table 13B]

[0213] [Table 14]

[0214] [Table 15]

[0215] [Example 3-1] Example 3-1 is an example in which an EX group EX is inserted into the zoom lens of Example 3. A cross-sectional view of the configuration and light beam of the zoom lens of Example 3-1 in the wide-angle end state is shown in FIG. 15. The zoom lens of Example 3-1 has a final lens group GEE in which an EX group EX is inserted inside the final lens group GE of Example 3, instead of the final lens group GE of Example 3. The configuration of the other lens groups and groups in Example 3-1 are the same as those of the zoom lens of Example 3.

[0216] For the zoom lens of Example 3-1, basic lens data is shown in Tables 16A and 16B, specifications and variable surface spacing is shown in Table 17, aspherical coefficients are shown in Table 18, and aberration diagrams are shown in FIG.

[0217] [Table 16A]

[0218] [Table 16B]

[0219] [Table 17]

[0220] [Table 18]

[0221] [Example 4] The configuration and movement locus of the zoom lens of Example 4 are shown in Figure 17. The zoom lens of Example 4 consists, in order from the object side to the image side, of a first lens group G1 having positive refractive power, an intermediate group GM, and a final lens group GE having positive refractive power. The intermediate group GM consists, in order from the object side to the image side, of a negative group UN, an N lens group GN having negative refractive power, and a P lens group GP having positive refractive power. The negative group UN consists of a single lens group having negative refractive power.

[0222] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the final lens group GE are fixed with respect to the image plane Sim, and the negative lens group UN, the N lens group GN, and the P lens group GP move along the optical axis Z while changing the spacing between themselves and the adjacent lens groups.

[0223] The first lens group G1 consists, in order from the object side to the image side, of a 1a sub-group G1a having negative refractive power, a 1b sub-group G1b having positive refractive power, and a 1c sub-group G1c having positive refractive power. The focusing group consists of the 1b sub-group G1b. The 1b sub-group G1b consists of a single lens element and is the fourth lens element from the object side. When focusing from an object at infinity to the closest object, the 1a sub-group G1a and the 1c sub-group G1c are fixed with respect to the image plane Sim, and the 1b sub-group G1b moves toward the image side.

[0224] For the zoom lens of Example 4, basic lens data is shown in Tables 19A and 19B, specifications and variable surface spacing is shown in Table 20, aspherical coefficients are shown in Table 21, and aberration diagrams are shown in FIG.

[0225] [Table 19A]

[0226] [Table 19B]

[0227] [Table 20]

[0228] [Table 21]

[0229] [Example 4-1] Example 4-1 is an example in which an EX group EX is inserted into the zoom lens of Example 4. A cross-sectional view of the configuration and light beam of the zoom lens of Example 4-1 in the wide-angle end state is shown in FIG. 19. The zoom lens of Example 4-1 has a final lens group GEE in which an EX group EX is inserted inside the final lens group GE of Example 4, instead of the final lens group GE of Example 4. The configuration of the other lens groups and groups in Example 4-1 are the same as those of the zoom lens of Example 4.

[0230] For the zoom lens of Example 4-1, basic lens data is shown in Tables 22A and 22B, specifications and variable surface spacing is shown in Table 23, aspherical coefficients are shown in Table 24, and aberration diagrams are shown in FIG.

[0231] [Table 22A]

[0232] [Table 22B]

[0233] [Table 23]

[0234] [Table 24]

[0235] [Example 5] The configuration and movement locus of the zoom lens of Example 5 are shown in Figure 21. The zoom lens of Example 5 consists of, in order from the object side to the image side, a first lens group G1 having positive refractive power, an intermediate group GM, and a final lens group GE having positive refractive power. The intermediate group GM consists, in order from the object side to the image side, of a negative group UN, an N lens group GN having negative refractive power, and a P lens group GP having positive refractive power. The negative group UN consists of a single lens group having negative refractive power.

[0236] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the final lens group GE are fixed with respect to the image plane Sim, and the negative lens group UN, the N lens group GN, and the P lens group GP move along the optical axis Z while changing the spacing between themselves and the adjacent lens groups.

[0237] The first lens group G1 consists, in order from the object side to the image side, of a 1a sub-group G1a having negative refractive power, a 1b sub-group G1b having positive refractive power, and a 1c sub-group G1c having positive refractive power. The focusing group consists of the 1b sub-group G1b. The 1b sub-group G1b consists of a single lens element, the fifth from the object side. When focusing from an object at infinity to the closest object, the 1a sub-group G1a and the 1c sub-group G1c are fixed with respect to the image plane Sim, and the 1b sub-group G1b moves toward the image side.

[0238] For the zoom lens of Example 5, basic lens data is shown in Tables 25A and 25B, specifications and variable surface spacing are shown in Table 26, aspherical coefficients are shown in Table 27, and aberration diagrams are shown in FIG.

[0239] [Table 25A]

[0240] [Table 25B]

[0241] [Table 26]

[0242] [Table 27]

[0243] [Example 5-1] Example 5-1 is an example in which an EX group EX is inserted into the zoom lens of Example 5. A cross-sectional view of the configuration and light beam of the zoom lens of Example 5-1 in the wide-angle end state is shown in FIG. 23. The zoom lens of Example 5-1 has a final lens group GEE in which an EX group EX is inserted inside the final lens group GE of Example 5, instead of the final lens group GE of Example 5. The configuration of the other lens groups and groups in Example 5-1 are the same as those of the zoom lens of Example 5.

[0244] For the zoom lens of Example 5-1, basic lens data is shown in Tables 28A and 28B, specifications and variable surface spacing is shown in Table 29, aspherical coefficients are shown in Table 30, and aberration diagrams are shown in FIG.

[0245] [Table 28A]

[0246] [Table 28B]

[0247] [Table 29]

[0248] [Table 30]

[0249] [Example 6] The configuration and movement locus of the zoom lens of Example 6 are shown in Figure 25. The zoom lens of Example 6 consists, in order from the object side to the image side, of a first lens group G1 having positive refractive power, an intermediate group GM, and a final lens group GE having positive refractive power. The intermediate group GM consists, in order from the object side to the image side, of a negative group UN, an N lens group GN having negative refractive power, and a P lens group GP having positive refractive power. The negative group UN consists of a single lens group having negative refractive power.

[0250] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the final lens group GE are fixed with respect to the image plane Sim, and the negative lens group UN, the N lens group GN, and the P lens group GP move along the optical axis Z while changing the spacing between themselves and the adjacent lens groups.

[0251] The first lens group G1 consists, in order from the object side to the image side, of a 1a sub-group G1a having negative refractive power, a 1b sub-group G1b having positive refractive power, and a 1c sub-group G1c having positive refractive power. The focusing group consists of the 1b sub-group G1b. The 1b sub-group G1b consists of a single lens element, the fifth from the object side. When focusing from an object at infinity to the closest object, the 1a sub-group G1a and the 1c sub-group G1c are fixed with respect to the image plane Sim, and the 1b sub-group G1b moves toward the image side.

[0252] For the zoom lens of Example 6, basic lens data is shown in Tables 31A and 31B, specifications and variable surface spacing is shown in Table 32, aspherical coefficients are shown in Table 33, and aberration diagrams are shown in FIG.

[0253] [Table 31A]

[0254] [Table 31B]

[0255] [Table 32]

[0256] [Table 33]

[0257] [Example 6-1] Example 6-1 is an example in which an EX group EX is inserted into the zoom lens of Example 6. A cross-sectional view of the configuration and light beam of the zoom lens of Example 6-1 in the wide-angle end state is shown in FIG. 27. The zoom lens of Example 6-1 has a final lens group GEE in which an EX group EX is inserted inside the final lens group GE of Example 6, instead of the final lens group GE of Example 6. The configuration of the other lens groups and groups in Example 6-1 are the same as those of the zoom lens of Example 6.

[0258] For the zoom lens of Example 6-1, basic lens data is shown in Tables 34A and 34B, specifications and variable surface spacing is shown in Table 35, aspherical coefficients are shown in Table 36, and aberration diagrams are shown in FIG.

[0259] [Table 34A]

[0260] [Table 34B]

[0261] [Table 35]

[0262] [Table 36]

[0263] [Example 7] The configuration and movement locus of the zoom lens of Example 7 are shown in Figure 29. The zoom lens of Example 7 consists of, in order from the object side to the image side, a first lens group G1 having positive refractive power, an intermediate group GM, and a final lens group GE having positive refractive power. The intermediate group GM consists, in order from the object side to the image side, of a negative group UN and an N lens group GN having negative refractive power. The negative group UN consists of a single lens group having negative refractive power.

[0264] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the final lens group GE are fixed relative to the image plane Sim, and the negative lens group UN and the N lens group GN move along the optical axis Z while changing the spacing between themselves and the adjacent lens groups.

[0265] The first lens group G1 consists, in order from the object side to the image side, of a 1a sub-group G1a having negative refractive power, a 1b sub-group G1b having positive refractive power, and a 1c sub-group G1c having positive refractive power. The focusing group consists of the 1b sub-group G1b. The 1b sub-group G1b consists of a single lens element, the fifth from the object side. When focusing from an object at infinity to the closest object, the 1a sub-group G1a and the 1c sub-group G1c are fixed with respect to the image plane Sim, and the 1b sub-group G1b moves toward the image side.

[0266] For the zoom lens of Example 7, basic lens data is shown in Tables 37A and 37B, specifications and variable surface spacing is shown in Table 38, aspherical coefficients are shown in Table 39, and various aberration diagrams are shown in FIG.

[0267] [Table 37A]

[0268] [Table 37B]

[0269] [Table 38]

[0270] [Table 39]

[0271] [Example 7-1] Example 7-1 is an example in which an extra lens group EX is inserted into the zoom lens of Example 7. A cross-sectional view of the configuration and light beam of the zoom lens of Example 7-1 in the wide-angle end state is shown in FIG. 31. The zoom lens of Example 7-1 has a final lens group GEE in which an extra lens group EX is inserted inside the final lens group GE of Example 7, instead of the final lens group GE of Example 7. The configuration of the other lens groups and groups in Example 7-1 are the same as those of the zoom lens of Example 7.

[0272] For the zoom lens of Example 7-1, basic lens data is shown in Tables 40A and 40B, specifications and variable surface spacing is shown in Table 41, aspherical coefficients are shown in Table 42, and aberration diagrams are shown in FIG.

[0273] [Table 40A]

[0274] [Table 40B]

[0275] [Table 41]

[0276] [Table 42]

[0277] [Example 8] The configuration and movement locus of the zoom lens of Example 8 are shown in Figure 33. The zoom lens of Example 8 consists, in order from the object side to the image side, of a first lens group G1 having positive refractive power, an intermediate group GM, and a final lens group GE having positive refractive power. The intermediate group GM consists, in order from the object side to the image side, of a negative lens group UN having negative refractive power as a whole, an N lens group GN having negative refractive power, and a P lens group GP having positive refractive power. The negative lens group UN consists, in order from the object side to the image side, of a second lens group G2 having positive refractive power and a third lens group G3 having negative refractive power.

[0278] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the final lens group GE are fixed relative to the image plane Sim, and the second lens group G2, the third lens group G3, the N lens group GN, and the P lens group GP move along the optical axis Z while changing the spacing between themselves and the adjacent lens groups.

[0279] The first lens group G1 consists, in order from the object side to the image side, of a 1a sub-group G1a having negative refractive power, a 1b sub-group G1b having positive refractive power, and a 1c sub-group G1c having positive refractive power. The focusing group consists of the 1b sub-group G1b. The 1b sub-group G1b consists of a single lens element, the fifth from the object side. When focusing from an object at infinity to the closest object, the 1a sub-group G1a and the 1c sub-group G1c are fixed with respect to the image plane Sim, and the 1b sub-group G1b moves toward the image side.

[0280] For the zoom lens of Example 8, basic lens data is shown in Tables 43A and 43B, specifications and variable surface spacing are shown in Table 44, aspherical coefficients are shown in Table 45, and various aberration diagrams are shown in FIG.

[0281] [Table 43A]

[0282] [Table 43B]

[0283] [Table 44]

[0284] [Table 45]

[0285] [Example 8-1] Example 8-1 is an example in which an EX group EX is inserted into the zoom lens of Example 8. A cross-sectional view of the configuration and light beam of the zoom lens of Example 8-1 in the wide-angle end state is shown in FIG. 35. The zoom lens of Example 8-1 has a final lens group GEE in which an EX group EX is inserted inside the final lens group GE of Example 8, instead of the final lens group GE of Example 8. The configuration of the other lens groups and groups in Example 8-1 are the same as those of the zoom lens of Example 8.

[0286] For the zoom lens of Example 8-1, basic lens data is shown in Tables 46A and 46B, specifications and variable surface spacing is shown in Table 47, aspherical coefficients are shown in Table 48, and aberration diagrams are shown in FIG.

[0287] [Table 46A]

[0288] [Table 46B]

[0289] [Table 47]

[0290] [Table 48]

[0291] [Example 9] The configuration and movement locus of the zoom lens of Example 9 are shown in Figure 37. The zoom lens of Example 9 consists, in order from the object side to the image side, of a first lens group G1 having positive refractive power, an intermediate group GM, and a final lens group GE having positive refractive power. The intermediate group GM consists, in order from the object side to the image side, of a negative group UN, an N lens group GN having negative refractive power, and a P lens group GP having positive refractive power. The negative group UN consists of a single lens group having negative refractive power.

[0292] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the final lens group GE are fixed with respect to the image plane Sim, and the negative lens group UN, the N lens group GN, and the P lens group GP move along the optical axis Z while changing the spacing between themselves and the adjacent lens groups.

[0293] The first lens group G1 consists, in order from the object side to the image side, of a 1a sub-group G1a having negative refractive power, a 1b sub-group G1b having positive refractive power, and a 1c sub-group G1c having positive refractive power. The focusing group consists of the 1b sub-group G1b. The 1b sub-group G1b consists of a single lens element, the fifth from the object side. When focusing from an object at infinity to the closest object, the 1a sub-group G1a and the 1c sub-group G1c are fixed with respect to the image plane Sim, and the 1b sub-group G1b moves toward the image side.

[0294] For the zoom lens of Example 9, basic lens data is shown in Tables 49A and 49B, specifications and variable surface spacing are shown in Table 50, aspherical coefficients are shown in Table 51, and aberration diagrams are shown in FIG.

[0295] [Table 49A]

[0296] [Table 49B]

[0297] [Table 50]

[0298] [Table 51]

[0299] [Example 9-1] Example 9-1 is an example in which an EX group EX is inserted into the zoom lens of Example 9. A cross-sectional view of the configuration and light beam of the zoom lens of Example 9-1 in the wide-angle end state is shown in FIG. 39. The zoom lens of Example 9-1 has a final lens group GEE in which an EX group EX is inserted inside the final lens group GE of Example 9, instead of the final lens group GE of Example 9. The configuration of the other lens groups and groups in Example 9-1 are the same as those of the zoom lens of Example 9.

[0300] For the zoom lens of Example 9-1, basic lens data is shown in Tables 52A and 52B, specifications and variable surface spacing is shown in Table 53, aspherical coefficients are shown in Table 54, and aberration diagrams are shown in FIG.

[0301] [Table 52A]

[0302] [Table 52B]

[0303] [Table 53]

[0304] [Table 54]

[0305] [Example 10] The configuration and movement locus of the zoom lens of Example 10 are shown in Figure 41. The zoom lens of Example 10 consists, in order from the object side to the image side, of a first lens group G1 having positive refractive power, an intermediate group GM, and a final lens group GE having positive refractive power. The intermediate group GM consists, in order from the object side to the image side, of a negative lens group UN having negative refractive power as a whole, an N lens group GN having negative refractive power, and a P lens group GP having positive refractive power. The negative lens group UN consists, in order from the object side to the image side, of a second lens group G2 having negative refractive power and a third lens group G3 having negative refractive power.

[0306] When changing magnification from the wide-angle end to the telephoto end, the first lens group G1 and the final lens group GE are fixed relative to the image plane Sim, and the second lens group G2, the third lens group G3, the N lens group GN, and the P lens group GP move along the optical axis Z while changing the spacing between themselves and the adjacent lens groups.

[0307] The first lens group G1 consists, in order from the object side to the image side, of a 1a sub-group G1a having negative refractive power, a 1b sub-group G1b having positive refractive power, and a 1c sub-group G1c having positive refractive power. The focusing group consists of the 1b sub-group G1b. The 1b sub-group G1b consists of a single lens element, the fifth from the object side. When focusing from an object at infinity to the closest object, the 1a sub-group G1a and the 1c sub-group G1c are fixed with respect to the image plane Sim, and the 1b sub-group G1b moves toward the image side.

[0308] For the zoom lens of Example 10, basic lens data is shown in Tables 55A and 55B, specifications and variable surface spacing are shown in Table 56, aspherical coefficients are shown in Table 57, and aberration diagrams are shown in FIG.

[0309] [Table 55A]

[0310] [Table 55B]

[0311] [Table 56]

[0312] [Table 57]

[0313] [Example 10-1] Example 10-1 is an example in which an EX group EX is inserted into the zoom lens of Example 10. A cross-sectional view of the configuration and light beam of the zoom lens of Example 10-1 in the wide-angle end state is shown in FIG. 43. The zoom lens of Example 10-1 has a final lens group GEE in which an EX group EX is inserted inside the final lens group GE of Example 10, instead of the final lens group GE of Example 10. The configuration of the other lens groups and groups in Example 10-1 are the same as those of the zoom lens of Example 10.

[0314] For the zoom lens of Example 10-1, basic lens data is shown in Tables 58A and 58B, specifications and variable surface spacing is shown in Table 59, aspherical coefficients are shown in Table 60, and various aberration diagrams are shown in FIG.

[0315] [Table 58A]

[0316] [Table 58B]

[0317] [Table 59]

[0318] [Table 60]

[0319] Tables 61 and 62 show the corresponding values ​​of conditional formulas (1) to (31) and (36) to (40), as well as the corresponding values ​​of IHw and ErL1, for the zoom lenses of Examples 1 to 10. The corresponding values ​​of conditional formulas (1) to (31) and (36) to (40) are values ​​when EX group EX is not inserted. Tables 63 and 64 show the corresponding values ​​of conditional formulas (32) to (35) for the zoom lenses of Examples 1-1 to 10-1. The corresponding values ​​of the Examples shown in Tables 61 to 64 may be used as the upper or lower limits of the conditional formulas to set preferred ranges for the conditional formulas.

[0320] [Table 61]

[0321] [Table 62]

[0322] [Table 63]

[0323] [Table 64]

[0324] The zoom lenses of Examples 1 to 10 are compact, yet have a large image circle and a maximum image height of 14.5 or more when focused on an object at infinity at the wide-angle end. Furthermore, the zoom lenses of Examples 1 to 10 are wide-angle lenses, with a maximum half angle of view of 40 degrees or more when focused on an object at infinity at the wide-angle end, and maintain high optical performance with various aberrations well corrected.

[0325] Next, an imaging device according to an embodiment of the present disclosure will be described. Fig. 45 shows a schematic configuration diagram of an imaging device 100 according to an embodiment of the present disclosure. The imaging device 100 is configured to include a zoom lens 1 according to an embodiment of the present disclosure. Examples of the imaging device 100 include a cinema camera, a broadcast camera, a surveillance camera, a digital camera, and a video camera.

[0326] The imaging device 100 includes a zoom lens 1, a filter 2 arranged on the image side of the zoom lens 1, and an image sensor 3 arranged on the image side of the filter 2. The zoom lens 1 in Figure 45 is shown conceptually. The zoom lens 1 includes an EX group EX that is inserted into or removed from the optical path to change the focal length of the zoom lens while keeping the imaging position constant.

[0327] The image sensor 3 converts the optical image formed by the zoom lens 1 into an electrical signal, and may be, for example, a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). The image sensor 3 is disposed so that its imaging plane coincides with the image plane of the zoom lens 1. Although only one image sensor 3 is shown in FIG. 45, the imaging device 100 may also be a so-called three-chip imaging device equipped with three image sensors.

[0328] The imaging device 100 also includes a signal processing unit 4, a magnification control unit 5, and a focus control unit 6. The signal processing unit 4 performs arithmetic processing on the output signal from the imaging element 3. The magnification control unit 5 controls the magnification of the zoom lens 1. The focus control unit 6 controls the focusing of the zoom lens 1.

[0329] Although the technology of the present disclosure has been described above using embodiments and examples, the technology of the present disclosure is not limited to the above embodiments and examples and can be modified in various ways. For example, the radius of curvature, surface spacing, refractive index, Abbe number, aspherical coefficient, etc. of each lens are not limited to the values ​​shown in the above examples and can take other values.

[0330] The following additional notes are provided regarding the above embodiments and examples. [Appendix 1] The optical system comprises a first lens group having positive refractive power and disposed closest to the object, an intermediate group including a plurality of lens groups, and a final lens group disposed closest to the image, When changing magnification, the spacing between all adjacent lens groups changes, the first lens group includes two negative lenses arranged consecutively from the object side to the image side, Of the two negative lenses, the negative lens on the object side is a meniscus lens with its convex surface facing the object side, The focal length of the entire system when focused on an object at infinity at the wide-angle end is fw. If the focal length of the first lens group is f1, then 0.1 <fw / f1<0.8 (1) A zoom lens that satisfies conditional expression (1) expressed as follows: [Appendix 2] The distance on the optical axis from the lens surface of the first lens group closest to the object side to the object-side principal point position of the first lens group when focused on an object at infinity is defined as H1f, Hft is the distance on the optical axis from the lens surface of the first lens group closest to the object side to the object-side principal point position of the entire system when focused on an object at infinity at the telephoto end, The signs of H1f and Hft are as follows: when the object side is negative and the image side is positive, based on the lens surface of the first lens group closest to the object side, 0.1 <H1f / Hft<0.95 (2) The zoom lens according to claim 1, which satisfies conditional expression (2) expressed as follows: [Appendix 3] The zoom lens according to claim 1 or 2, wherein an L1n lens having negative refractive power is disposed adjacent to the image side of an L1p lens, which is the positive lens closest to the object among the positive lenses included in the first lens group. [Appendix 4] The distance on the optical axis from the lens surface of the first lens group closest to the object side to the object-side principal point position of the first lens group when focused on an object at infinity is defined as H1f, Hft is the distance on the optical axis from the lens surface of the first lens group closest to the object side to the object-side principal point position of the entire system when focused on an object at infinity at the telephoto end, The signs of H1f and Hft are as follows: when the object side is negative and the image side is positive, based on the lens surface of the first lens group closest to the object side, 0.28 <H1f / Hft<0.7 (2-1) The zoom lens according to any one of Supplementary Note 1 to Supplementary Note 3, which satisfies conditional expression (2-1) expressed by the following formula: [Appendix 5] When the focal point is focused on an object at infinity, the distance on the optical axis between the object-side principal point position of the first lens group and the image-side principal point position of the first lens group is defined as HD1, 1.4 <HD1 / f1<2.16 (3) 5. The zoom lens according to claim 1, which satisfies conditional expression (3) below. [Appendix 6] the first lens group is composed of, in order from the object side to the image side, a 1a sub-group, a 1b sub-group, and a 1c sub-group, 6. The zoom lens according to claim 1, wherein the distance between the 1a subgroup and the 1b subgroup changes and the distance between the 1b subgroup and the 1c subgroup changes during focusing. [Appendix 7] When the focal length of the 1b subgroup is f1b, 0.3 <f1 / f1b<1 (4) 7. The zoom lens according to claim 6, which satisfies conditional expression (4) expressed as follows: [Appendix 8] The zoom lens according to claim 6 or 7, wherein the lens closest to the image side in the 1a subgroup is a negative lens. [Appendix 9] 9. The zoom lens according to claim 8, wherein a positive lens is disposed adjacent to the object side of the negative lens that is closest to the image side in the 1a subgroup. [Appendix 10] 10. The zoom lens according to claim 6, wherein the 1a subgroup has negative refractive power. [Appendix 11] 11. The zoom lens according to claim 6, wherein the 1b subgroup has positive refractive power. [Appendix 12] 12. The zoom lens according to claim 6, wherein the 1c subgroup has positive refractive power. [Appendix 13] 13. The zoom lens according to claim 6, wherein, during focusing from an object at infinity to a closest object, the 1a sub group and the 1c sub group are fixed with respect to an image plane, and the 1b sub group moves toward the image side. [Appendix 14] 14. The zoom lens according to claim 1, wherein the first lens group is fixed relative to an image plane during zooming. [Appendix 15] 15. The zoom lens according to claim 1, wherein the final lens group is fixed relative to an image plane during zooming. [Appendix 16] 16. The zoom lens according to claim 1, wherein the first lens group includes six or more lenses. [Appendix 17] 17. The zoom lens according to any one of claims 1 to 16, including an aperture stop that is fixed relative to the image plane during zooming. [Appendix 18] H1r denotes the distance on the optical axis from the lens surface of the first lens group closest to the image side to the image side principal point position of the first lens group when focused on an object at infinity, The sign of H1r is, when the object side is negative and the image side is positive, based on the lens surface of the first lens group closest to the image side, 0.7 <H1r / f1<1.5 (5) 18. The zoom lens according to claim 1, which satisfies conditional expression (5) below. [Appendix 19] H1f is the distance on the optical axis from the lens surface of the first lens group closest to the object side to the object-side principal point position of the first lens group when focused on an object at infinity, The sign of H1f is as follows: when the object side is negative and the image side is positive, based on the lens surface of the first lens group closest to the object side: 0.7 <H1f / f1<2 (6) 19. The zoom lens according to any one of claims 1 to 18, which satisfies conditional expression (6) shown below. [Appendix 20] When the refractive index of the L1p lens with respect to the d line is N1p, 1.7 <N1p<2.1 (7) The zoom lens according to claim 3, which satisfies conditional expression (7) expressed as follows: [Appendix 21] When the Abbe number of the L1p lens based on the d line is ν1p, 15<ν1p<30 (8) The zoom lens according to claim 3 or 20, which satisfies conditional expression (8) shown below. [Appendix 22] When the refractive index of the L1n lens for the d line is N1n, 1.43 <N1n<1.85 (9) The zoom lens according to claim 3, which satisfies conditional expression (9) expressed as follows: [Appendix 23] When the Abbe number of the L1n lens based on the d line is ν1n, 30<ν1n<60 (10) The zoom lens according to claim 3 or 22, which satisfies conditional expression (10) shown below. [Appendix 24] When the average value of the Abbe numbers of all the negative lenses on the object side of the L1p lens based on the d-line is ν1nave, 35<ν1nave<60 (11) The zoom lens according to claim 3, which satisfies conditional expression (11) expressed as follows: [Appendix 25] When the average value of the partial dispersion ratio between the g-line and the F-line of all negative lenses on the object side of the L1p lens is θ1nave, 0.5<θ1nave<0.6 (12) The zoom lens according to claim 3, which satisfies conditional expression (12) expressed as follows: [Appendix 26] When the lens surface of the first lens group closest to the object side is focused on an object at infinity at the wide-angle end, the distance on the optical axis from the lens surface to the paraxial entrance pupil position is Denw. 2 <Denw / fw<3.5 (13) 26. The zoom lens according to claim 1, which satisfies conditional expression (13) below. [Appendix 27] When the focal length of the 1a subgroup is f1a, -2 <f1 / f1a<0 (14) 10. The zoom lens according to claim 6, which satisfies conditional expression (14) expressed as follows: [Appendix 28] When the focal length of the 1c subgroup is f1c, 0.3 <f1 / f1c<0.8 (15) 10. The zoom lens according to claim 6, which satisfies conditional expression (15) shown below. [Appendix 29] The paraxial radius of curvature of the image side surface of the lens closest to the object side in the first lens group is R2, If the paraxial radius of curvature of the object-side surface of the second lens from the object side in the first lens group is R3, -3<(R2-R3) / (R2+R3)<0 (16) 29. The zoom lens according to claim 1, which satisfies conditional expression (16) below. [Appendix 30] When the lens is focused on an object at infinity at the wide-angle end, the longest air gap on the optical axis included in the final lens group is defined as the longest air gap. 29. The zoom lens according to claim 1, wherein an EX group is removably arranged so that the EX group is inserted into the optical path with the longest air gap to change the focal length of the zoom lens while keeping the imaging position constant. [Appendix 31] 31. The zoom lens according to claim 30, wherein the maximum image height changes by inserting or extracting the EX group. [Appendix 32] When focused on an object at infinity at the wide-angle end, the distance on the optical axis from the lens surface of the first lens group closest to the image side to the lens surface adjacent to the lens surface of the first lens group closest to the image side is d1R, If the maximum image height when focused on an object at infinity at the wide-angle end is IHw, 0.03 <d1R / IHw<0.097 (17) 32. The zoom lens according to claim 1, which satisfies conditional expression (17) below. [Appendix 33] An imaging device comprising the zoom lens according to any one of Supplementary Note 1 to Supplementary Note 32. [Explanation of symbols]

[0331] 1 zoom lens 2. Filters 3. Image sensor 4. Signal Processing Section 5 Magnification control section 6 Focus control unit 100 Imaging device D1a thickness D1b thickness D1c Thickness d1R distance DAmax longest air gap Dent distance Denw Distance DEX Thickness Dexw Distance DG1 Thickness Er effective radius ErL1 effective radius EX EX group G1 First lens group G1a 1a subgroup G1b 1b subgroup G1c 1st subgroup G2 Second lens group G3 Third lens group GE final lens group GEE final lens group GM intermediate group GN N lens group GP P lens group H1f distance H1r distance HD1 interval Hft distance IHEw maximum image height IHw maximum image height L11~L19 lenses Lx Lens Pent paraxial entrance pupil position Penw Paraxial entrance pupil position Pexw paraxial exit pupil position PH1f Object side principal point position PH1r Image side principal point position PHft Object side principal point position PP optical components Px position Sim image plane St aperture stop tL1 Center thickness UN negative group Xa On-axis luminous flux Xb Off-axis luminous flux Xb1 ray Z optical axis ωEXt Maximum half angle of view ωEXw Maximum half angle of view ωt Maximum half angle of view ωw Maximum half angle of view

Claims

1. The optical system includes a first lens group having positive refractive power and arranged closest to the object, an intermediate lens group including a plurality of lens groups, and a final lens group arranged closest to the image, When changing magnification, the spacing between all adjacent lens groups changes, the first lens group includes two negative lenses successively arranged in order from the object side to the image side, Of the two negative lenses, the negative lens on the object side is a meniscus lens with a convex surface facing the object side, The focal length of the entire system when focused on an object at infinity at the wide-angle end is fw. When the focal length of the first lens group is f1, 0.1<fw / f1<0.8 (1) A zoom lens that satisfies conditional expression (1) expressed as follows:

2. H1f is the distance on the optical axis from the lens surface of the first lens group closest to the object side to the object-side principal point position of the first lens group when focused on an object at infinity, Hft is the distance on the optical axis from the lens surface of the first lens group closest to the object side to the object-side principal point position of the entire system when focused on an object at infinity at the telephoto end, The signs of H1f and Hft are as follows, where the object side is negative and the image side is positive, based on the lens surface of the first lens group closest to the object: 0.1<H1f / Hft<0.95 (2) 2. The zoom lens according to claim 1, which satisfies conditional expression (2) expressed as follows:

3. 2. The zoom lens according to claim 1, wherein an L1n lens having negative refractive power is disposed adjacent to an image side of an L1p lens which is the positive lens closest to the object side among the positive lenses included in the first lens group.

4. H1f is the distance on the optical axis from the lens surface of the first lens group closest to the object side to the object-side principal point position of the first lens group when focused on an object at infinity, Hft is the distance on the optical axis from the lens surface of the first lens group closest to the object side to the object-side principal point position of the entire system when focused on an object at infinity at the telephoto end, The signs of H1f and Hft are as follows, where the object side is negative and the image side is positive, based on the lens surface of the first lens group closest to the object: 0.28<H1f / Hft<0.7 (2-1) 2. The zoom lens according to claim 1, which satisfies conditional expression (2-1) expressed as follows:

5. When the distance on the optical axis between the object-side principal point position of the first lens group and the image-side principal point position of the first lens group in a state in which the lens is focused on an object at infinity is HD1, 1.4<HD1 / f1<2.16 (3) 2. The zoom lens according to claim 1, which satisfies conditional expression (3) expressed as follows:

6. the first lens group is composed of, in order from the object side to the image side, a 1a sub-group, a 1b sub-group, and a 1c sub-group, 2. The zoom lens according to claim 1, wherein, during focusing, the distance between the 1a-subgroup and the 1b-subgroup changes, and the distance between the 1b-subgroup and the 1c-subgroup changes.

7. When the focal length of the 1b subgroup is f1b, 0.3<f1 / f1b<1 (4) 7. The zoom lens according to claim 6, which satisfies conditional expression (4) expressed as follows:

8. 7. The zoom lens according to claim 6, wherein the lens element of the 1a subgroup closest to the image side is a negative lens element.

9. 9. The zoom lens according to claim 8, wherein a positive lens is disposed adjacent to the object side of the negative lens closest to the image side in the first subgroup.

10. 7. The zoom lens according to claim 6, wherein the first subgroup has negative refractive power.

11. 7. The zoom lens according to claim 6, wherein the 1b subgroup has positive refractive power.

12. 7. The zoom lens according to claim 6, wherein the 1c subgroup has positive refractive power.

13. 7. The zoom lens according to claim 6, wherein, during focusing from an object at infinity to a nearest object, the first-a sub-group and the first-c sub-group are fixed relative to an image plane, and the first-b sub-group moves toward the image side.

14. 2. The zoom lens according to claim 1, wherein the first lens group is fixed relative to the image plane during zooming.

15. 2. The zoom lens according to claim 1, wherein the final lens group is fixed relative to the image plane during zooming.

16. 2. The zoom lens according to claim 1, wherein the first lens group includes six or more lenses.

17. 2. The zoom lens of claim 1, including an aperture stop that is fixed relative to the image plane during zooming.

18. H1r denotes the distance on the optical axis from the lens surface of the first lens group closest to the image side to the image side principal point position of the first lens group when focused on an object at infinity, The sign of H1r is, when the object side is negative and the image side is positive, based on the lens surface of the first lens group closest to the image side, 0.7<H1r / f1<1.5 (5) 2. The zoom lens according to claim 1, which satisfies conditional expression (5) expressed as follows:

19. H1f is the distance on the optical axis from the lens surface of the first lens group closest to the object side to the object-side principal point position of the first lens group when focused on an object at infinity, The sign of H1f is, when the object side is negative and the image side is positive, based on the lens surface of the first lens group closest to the object side, 0.7<H1f / f1<2 (6) 2. The zoom lens according to claim 1, which satisfies conditional expression (6) expressed as follows:

20. When the refractive index of the L1p lens with respect to the d line is N1p, 1.7<N1p<2.1 (7) 4. The zoom lens according to claim 3, which satisfies conditional expression (7) expressed as follows:

21. When the Abbe number of the L1p lens based on the d line is ν1p, 15<ν1p<30 (8) 4. The zoom lens according to claim 3, which satisfies conditional expression (8) expressed as follows:

22. When the refractive index of the L1n lens with respect to the d line is N1n, 1.43<N1n<1.85 (9) 4. The zoom lens according to claim 3, which satisfies conditional expression (9) expressed as follows:

23. When the Abbe number of the L1n lens based on the d line is ν1n, 30<ν1n<60 (10) 4. The zoom lens according to claim 3, which satisfies conditional expression (10) expressed as follows:

24. When the average value of the Abbe numbers of all the negative lenses on the object side of the L1p lens based on the d-line is ν1nave, 35<ν1nave<60 (11) 4. The zoom lens according to claim 3, which satisfies conditional expression (11) expressed as follows:

25. When the average value of the partial dispersion ratio between the g-line and the F-line of all negative lenses closer to the object side than the L1p lens is θ1nave, 0.5<θ1nave<0.6 (12) 4. The zoom lens according to claim 3, which satisfies conditional expression (12) expressed as follows:

26. When the distance on the optical axis from the lens surface of the first lens group closest to the object to the paraxial entrance pupil position in a state in which the lens is focused on an object at infinity at the wide-angle end is Denw, 2<Denw / fw<3.5 (13) 2. The zoom lens according to claim 1, which satisfies conditional expression (13) expressed as follows:

27. When the focal length of the 1a subgroup is f1a, -2<f1 / f1a<0 (14) 7. The zoom lens according to claim 6, which satisfies conditional expression (14) expressed as follows:

28. When the focal length of the 1c subgroup is f1c, 0.3<f1 / f1c<0.8 (15) 7. The zoom lens according to claim 6, which satisfies conditional expression (15) expressed as follows:

29. The paraxial radius of curvature of the image side surface of the lens closest to the object side in the first lens group is R2, When the paraxial radius of curvature of the object-side surface of the second lens from the object side in the first lens group is R3, -3<(R2-R3) / (R2+R3)<0 (16) 2. The zoom lens according to claim 1, which satisfies conditional expression (16) expressed as follows:

30. When the lens is focused on an object at infinity at the wide-angle end, the longest air gap on the optical axis included in the final lens group is defined as the longest air gap.

2. The zoom lens according to claim 1, wherein an EX group is removably arranged so that the EX group is inserted into the optical path with the longest air gap to change the focal length of the zoom lens while keeping the image position constant.

31. 31. The zoom lens according to claim 30, wherein the maximum image height is changed by inserting or extracting the EX group.

32. When focused on an object at infinity at the wide-angle end, the distance on the optical axis from the lens surface of the first lens group closest to the image side to the lens surface adjacent to the lens surface of the first lens group closest to the image side is d1R; If the maximum image height when focused on an object at infinity at the wide-angle end is IHw, 0.03<d1R / IHw<0.097 (17) 2. The zoom lens according to claim 1, which satisfies conditional expression (17) expressed as follows:

33. An imaging device comprising the zoom lens according to any one of claims 1 to 32.

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