Zoom lens, image capturing device having the same, and image capturing system

Abstract

To provide a zoom lens which achieves both reduction of size and weight and higher image quality while having a high zoom ratio and a large aperture ratio, and enables a high-speed zoom operation.SOLUTION: A zoom lens L0 consists of a first lens group L1 having positive refractive power, a second lens group L2 having negative refractive power, a third lens group L3 having positive refractive power, and a succeeding group LR. The first lens group is fixed with respect to an image plane when zooming from a wide-angle end to a telephoto end. The first lens group includes a single lens L11 having negative refractive power arranged on the most object side and multiple lenses having positive refractive power arranged on an image side of the single lens. An air lens is formed by an air gap between the single lens and a lens arranged next to the single lens on the image side. A curvature radius r111 of an object-side lens surface of the single lens, a curvature radius r112 of an image-side lens surface of the single lens, a focal length f1 of the first lens group, and a focal length f2 of the second lens group satisfy predetermined conditional expressions.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a zoom lens, which is suitable for optical devices such as digital still cameras, digital video cameras, surveillance cameras, and vehicle-mounted cameras. [Background technology]

[0002] There is a demand for a zoom lens system that is compact and lightweight, has excellent correction for chromatic aberration and other aberrations, and has high optical performance. There is also a demand for a zoom lens system that has a short focal length at the wide-angle end, a large zoom ratio, a small F-number, a large aperture ratio, and is easy to manufacture. There is also a demand for a zoom lens system that allows for high-speed zoom operation.

[0003] Patent Document 1 proposes a zoom lens that includes, arranged in order from the object side to the image side, a first lens group with positive refractive power that is fixed with respect to the image plane, a second lens group with negative refractive power, a third lens group with positive refractive power, and a rear group that includes multiple lens groups. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-134807 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the zoom lens described in Patent Document 1 tends to have a large lens diameter due to its small F-number, and the large front lens diameter results in an increase in size and weight. Also, if the refractive power of the second lens group is increased in order to reduce the front lens diameter, it becomes difficult to achieve high image quality.

[0006] The present invention provides a zoom lens that has a high zoom ratio and a large aperture ratio, yet is compact and lightweight, and provides high image quality, and is capable of high-speed zoom operation. [Means for solving the problem]

[0007] According to one aspect of the present invention, a zoom lens includes, in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a subsequent group consisting of multiple lens groups, and the spacing between adjacent lens groups changes during zooming from the wide-angle end to the telephoto end. The first lens group is fixed with respect to an image plane during zooming from the wide-angle end to the telephoto end, and includes a single lens having negative refractive power arranged closest to the object side, and multiple lenses having positive refractive power arranged on the image side of the single lens. An air lens is formed between the single lens and a lens arranged adjacent to the single lens on the image side by an air gap. When the radius of curvature of the object-side lens surface of the single lens is r111, the radius of curvature of the image-side lens surface of the single lens is r112, the focal length of the first lens group is f1, and the focal length of the second lens group is f2, -0.7<(r112+r111) / (r112-r111)<0.4 1.0 <f1 / (-f2)<4.2 The present invention is characterized in that the following conditional expression is satisfied:

[0008] Other objects and features of the present invention will be described in the following embodiments. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a zoom lens that has a high zoom ratio and a large aperture ratio, yet is compact and lightweight, and provides high image quality, and is capable of high-speed zoom operation. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view of a zoom lens according to a first embodiment. [Figure 2] 1A and 1B are aberration diagrams of the zoom lens of Example 1 at the wide-angle end and the telephoto end, respectively. [Figure 3] FIG. 10 is a cross-sectional view of a zoom lens according to a second embodiment. [Figure 4] 1A and 1B are aberration diagrams of the zoom lens of Example 2 at the wide-angle end and the telephoto end, respectively. [Figure 5] FIG. 10 is a cross-sectional view of a zoom lens according to a third embodiment. [Figure 6] 10A and 10B are aberration diagrams of the zoom lens of Example 3 at the wide-angle end and the telephoto end, respectively. [Figure 7] FIG. 10 is a cross-sectional view of a zoom lens according to a fourth embodiment. [Figure 8] 10A and 10B are aberration diagrams of the zoom lens of Example 4 at the wide-angle end and the telephoto end, respectively. [Figure 9] FIG. 10 is a cross-sectional view of a zoom lens according to a fifth embodiment. [Figure 10] 10A and 10B are aberration diagrams of the zoom lens of Example 5 at the wide-angle end and the telephoto end, respectively. [Figure 11] FIG. 10 is a cross-sectional view of a zoom lens according to a sixth embodiment. [Figure 12] 10A and 10B are aberration diagrams of the zoom lens of Example 6 at the wide-angle end and the telephoto end, respectively. [Figure 13] FIG. 10 is a cross-sectional view of a zoom lens according to a seventh embodiment. [Figure 14] 11A and 11B are aberration diagrams of the zoom lens of Example 7 at the wide-angle end and the telephoto end, respectively. [Figure 15] FIG. 1 is a schematic diagram of an imaging device. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a zoom lens, an imaging device having the same, and an imaging system according to the present invention will be described with reference to the accompanying drawings.

[0012] 1, 3, 5, 7, 9, 11, and 13 are cross-sectional views of the zoom lens L0 of Examples 1 to 7 when focused on infinity at the wide-angle end. The zoom lens L0 of each Example is a zoom lens used in imaging devices such as digital still cameras, digital video cameras, surveillance cameras, and vehicle-mounted cameras.

[0013] In each lens cross-sectional view, the left side is the object side (front) and the right side is the image side (rear). The zoom lens L0 of each embodiment is configured with multiple lens groups. In this specification, a lens group refers to a group of lenses that move or remain stationary as a unit during zooming. That is, in the zoom lens L0 of each embodiment, the spacing between adjacent lens groups changes during zooming from the wide-angle end to the telephoto end. Note that a lens group may be configured with a single lens, or may be configured with multiple lenses. The lens group may also include an aperture stop.

[0014] In each lens cross-sectional view, Li denotes the i-th (i is a natural number) lens group counted from the object side in the zoom lens L0, and LR denotes a subsequent group made up of multiple lens groups.

[0015] Additionally, SP denotes an aperture stop. IP denotes an image plane, on which the imaging surface of a solid-state imaging element (photoelectric conversion element) such as a CCD sensor or CMOS sensor is placed when the zoom lens L0 of each embodiment is used as the imaging optical system of a digital still camera or video camera. When the zoom lens L0 of each embodiment is used as the imaging optical system of a silver halide film camera, a photosensitive surface equivalent to the film surface is placed on the image plane IP.

[0016] The arrow in the optical axis direction indicates the direction of movement of the focus lens group when focusing from infinity to a close distance. The solid arrows below each lens group indicate the movement locus of that lens group when zooming from the wide-angle end to the telephoto end while focusing on an object at infinity. The dotted arrow below a specific lens group indicates the movement locus of that specific lens group when zooming from the wide-angle end to the telephoto end while focusing on a close object.

[0017] In the following embodiments, the wide-angle end and the telephoto end refer to zoom positions when the lens group is positioned at both ends of the range in which it can be mechanically moved on the optical axis.

[0018] 2, 4, 6, 8, 10, 12, and 14 are aberration diagrams of the zoom lens L0 of Examples 1 to 7 when focused at infinity. (A) is an aberration diagram at the wide-angle end, and (B) is an aberration diagram at the telephoto end.

[0019] In the spherical aberration diagram, Fno is the F-number, and shows the amount of spherical aberration for the d-line (wavelength 587.56 nm) and g-line (wavelength 435.84 nm). In the astigmatism diagram, ΔS shows the amount of astigmatism on the sagittal image plane for the d-line, and ΔM shows the amount of astigmatism on the meridional image plane for the d-line. In the distortion diagram, the amount of distortion for the d-line is shown. In the chromatic aberration diagram, the amount of chromatic aberration for the g-line is shown. ω is the imaging half angle of view (°) (angle of view in paraxial calculations).

[0020] Next, the characteristic configuration of the zoom lens L0 of each embodiment will be described.

[0021] In order to reduce the diameter of the front lens element, it is important to appropriately set the configuration of the first lens unit L1 and the power distribution of each lens unit. In particular, the diameter of the front lens element can be effectively reduced by increasing the refractive power of the negative lens positioned on the object side. However, if the refractive power of the negative lens positioned on the object side becomes too strong, it becomes difficult to correct distortion. Therefore, in order to obtain a zoom lens L0 that is compact, lightweight, and provides high image quality while having a high zoom ratio and a large aperture ratio, and that is capable of high-speed zoom operation, it is important to appropriately set the arrangement of the lenses and lens units that make up the zoom lens L0.

[0022] The zoom lens L0 according to each embodiment comprises, arranged in order from the object side to the image side, a first lens unit L1 with positive refractive power, a second lens unit L2 with negative refractive power, a third lens unit L3 with positive refractive power, and a trailing lens unit LR composed of multiple lens units. In the zoom lens L0 of each embodiment, the spacing between adjacent lens units changes during zooming from the wide-angle end to the telephoto end. The first lens unit L1 is fixed with respect to the image plane IP during zooming from the wide-angle end to the telephoto end.

[0023] Zoom lenses with high zoom ratios and large aperture ratios tend to have large front lens diameters and therefore large masses. For this reason, keeping the first lens unit L1 fixed during zooming makes it easier to achieve high-speed zoom operations.

[0024] The rear group LR is made up of multiple lens groups, and the spacing between adjacent lens groups changes during zooming. By changing the spacing between adjacent lens groups in the lens groups that make up the rear group LR, it becomes easier to suppress aberration fluctuations during zooming, and high image quality can be achieved.

[0025] In the zoom lens L0 according to each embodiment, the first lens group L1 includes a single lens L11 with negative refractive power arranged closest to the object, and a plurality of lenses with positive refractive power arranged on the image side of the single lens L11. An air lens is formed between the single lens L11 and the lens arranged adjacent to the single lens L11 on the image side, by an air gap. This makes it easy to reduce the diameter of the front lens.

[0026] Furthermore, the zoom lens L0 according to each embodiment satisfies the following conditional expressions (1) and (2).

[0027] -0.7<(r112+r111) / (r112-r111)<0.4 ···(1) 1.0 <f1 / (-f2)<4.2 ···(2) Here, r111 is the radius of curvature of the object-side lens surface of the single lens L11, and r112 is the radius of curvature of the image-side lens surface of the single lens L11, f1 is the focal length of the first lens group L1, and f2 is the focal length of the second lens group L2.

[0028] Conditional expression (1) defines the shape of the single lens L11. If the upper limit of conditional expression (1) is exceeded, it becomes difficult to correct distortion at the wide-angle end. If the lower limit of conditional expression (1) is not met, it becomes difficult to reduce the diameter of the front lens element.

[0029] Conditional expression (2) defines the ratio of the focal length of the first lens unit L1 to the focal length of the second lens unit L2. If the upper limit of conditional expression (2) is exceeded, it becomes difficult to correct various aberrations that occur in the second lens unit L2, and it becomes particularly difficult to correct distortion at the wide-angle end and spherical aberration at the telephoto end. If the lower limit of conditional expression (2) is not met, it becomes difficult to reduce the diameter of the front lens element.

[0030] Furthermore, it is more preferable that the numerical ranges of the conditional expressions (1) and (2) be within the ranges of the following conditional expressions (1) and (2).

[0031] -0.68<(r112+r111) / (r112-r111)<0.20 ···(1a) 2.00 <f1 / (-f2)<4.09 ···(2a) It is more preferable that the numerical ranges of the conditional expressions (1) and (2) satisfy the ranges of the following conditional expressions (1b) and (2b).

[0032] -0.67<(r112+r111) / (r112-r111)<0.10 ···(1b) 2.50 <f1 / (-f2)<4.03 ···(2b) Next, a description will be given of configurations that are preferably satisfied in the zoom lens L0 according to each embodiment.

[0033] In the zoom lens L0 according to each embodiment, the first lens group L1 preferably includes three or more lenses with positive refractive power that are arranged on the image side of the single lens L11. By including three or more lenses with positive refractive power in the first lens group L1, it becomes easy to shorten the overall length of the zoom lens L0, and the zoom lens L0 can be made more compact.

[0034] In the zoom lens L0 according to each embodiment, it is preferable that the rear group LR consists of three or more lens groups, which makes it easier to correct aberrations during zooming and enables high image quality to be achieved.

[0035] In the zoom lens L0 according to each embodiment, it is preferable that the rear group LR includes a plurality of lens groups that move during zooming from the wide-angle end to the telephoto end. Having at least two or more lens groups included in the rear group LR move during zooming facilitates achieving a high zoom ratio. It is even more preferable that at least two or more lens groups included in the rear group LR move toward the object side during zooming from the wide-angle end to the telephoto end.

[0036] In the zoom lens L0 according to each embodiment, it is preferable that all lenses included in the first lens group L1 are fixed during focusing. Also, in the zoom lens L0 according to each embodiment, it is preferable that the subsequent lens group LR include a lens group that moves during focusing. By keeping the first lens group L1, which has a large lens diameter and a large mass, fixed during focusing and performing focusing using some of the lens groups included in the subsequent lens group LR, which has a relatively small lens diameter, it is easy to simplify the focus drive mechanism and achieve size reduction.

[0037] In the zoom lens L0 according to each embodiment, the second lens unit L2 preferably includes three or more lenses with negative refractive power. By including three or more lenses with negative refractive power in the second lens unit L2, distortion aberration, particularly at the wide-angle end, can be easily corrected, and high image quality can be achieved.

[0038] In the zoom lens L0 according to each embodiment, the third lens unit L3 preferably includes a plurality of lenses with positive refractive power. By including two or more lenses with positive refractive power in the third lens unit L3, it becomes easier to correct spherical aberration, particularly at the telephoto end, and high image quality can be achieved.

[0039] In the zoom lens L0 according to each embodiment, the third lens unit L3 preferably includes one or more lenses with negative refractive power. By including one or more lenses with negative refractive power in the third lens unit L3, it becomes easier to correct longitudinal chromatic aberration, particularly at the telephoto end, and high image quality can be achieved.

[0040] Next, conditions that the zoom lens L0 of each embodiment should preferably satisfy will be described.

[0041] It is preferable that the zoom lens L0 according to each embodiment satisfies one or more of the following conditional expressions (3) to (12).

[0042] 0.6 <f11 / f1<1.4 ···(3) 0.10 <T1 / f1<0.65 ···(4) 0.5<-f2 / fw<1.5 (5) 1 <f3 / fw<10 ···(6) 0.2 <BFw / fw<1.2 ···(7) 0.9 <D12t / fw<2.5 ···(8) 0.9 <f21 / f2<1.8 ···(9) -2.0<β2t<-0.3 (10) 0.02 <T11 / fw<0.20 ···(11) 0.03 <D112 / fw<0.30 ···(12) Here, f11 is the focal length of the single lens L11. f1 is the focal length of the first lens group L1. T1 is the axial distance from the lens surface of the first lens group L1 closest to the object to the lens surface of the first lens group L1 closest to the image. f2 is the focal length of the second lens group L2. fw is the focal length of the zoom lens at the wide-angle end when focusing on infinity. f3 is the focal length of the third lens group L3. BFw is the back focal length of the zoom lens L0 at the wide-angle end when focusing on infinity. The back focal length is the air-equivalent value of the axial distance from the final lens surface (the surface closest to the image) to the image plane IP. D12t is the axial distance from the lens surface of the first lens group L1 closest to the image to the lens surface of the second lens group L2 closest to the object at the telephoto end. f21 is the focal length of the lens in the second lens group L2 located closest to the object. β2t is the lateral magnification of the second lens group L2 at the telephoto end. T11 is the distance on the optical axis from the object-side lens surface of the single lens L11 to the image-side lens surface of the single lens L11. D112 is the distance on the optical axis from the image-side lens surface of the single lens L11 to the object-side lens surface of the lens located adjacent to the image side of the single lens L11.

[0043] Conditional expression (3) defines the ratio between the focal length of the single lens L11 and the focal length of the first lens group L1. Exceeding the upper limit of conditional expression (3) is undesirable because it makes it difficult to correct distortion at the wide-angle end. Falling below the lower limit of conditional expression (3) is undesirable because it makes it difficult to reduce the diameter of the front lens element.

[0044] Conditional expression (4) defines the ratio between the thickness and focal length of the first lens unit L1. Exceeding the upper limit of conditional expression (4) is undesirable because it makes it difficult to reduce the diameter of the front lens element. Falling below the lower limit of conditional expression (4) is undesirable because it reduces the degree of freedom in aberration correction, making it difficult to correct various aberrations, particularly spherical aberration and coma at the telephoto end.

[0045] Conditional expression (5) defines the ratio between the focal length of the second lens unit L2 and the focal length of the zoom lens L0 at the wide-angle end. Exceeding the upper limit of conditional expression (5) is undesirable because it makes it difficult to correct distortion at the wide-angle end. Falling below the lower limit of conditional expression (5) is undesirable because it makes it difficult to reduce the diameter of the front lens element.

[0046] Conditional expression (6) defines the ratio of the focal length of the third lens group L3 to the focal length of the zoom lens L0 at the wide-angle end. Exceeding the upper limit of conditional expression (6) is undesirable because it makes it difficult to correct spherical aberration at the telephoto end. Falling below the lower limit of conditional expression (6) is undesirable because it increases the overall lens length and makes the zoom lens L0 larger.

[0047] Conditional expression (7) defines the ratio of the back focus at the wide-angle end to the focal length of the zoom lens L0. Here, the back focus is the distance on the optical axis from the vertex of the image-side surface of the optical element having power located closest to the image side to the image plane IP when focusing at infinity. Exceeding the upper limit of conditional expression (7) is undesirable because it increases the overall lens length and makes the zoom lens L0 larger. Falling below the lower limit of conditional expression (7) is undesirable because it increases the rear lens diameter and increases the lens weight of the zoom lens L0.

[0048] Conditional expression (8) defines the ratio of the distance between the first lens group L1 and the second lens group L2 at the telephoto end to the focal length of the zoom lens at the wide-angle end. Exceeding the upper limit of conditional expression (8) is undesirable because the overall lens length increases and the zoom lens L0 becomes large. Falling below the lower limit of conditional expression (8) is undesirable because it becomes difficult to achieve a high zoom ratio.

[0049] Conditional expression (9) defines the ratio between the focal length of the lens in the second lens group L2 that is closest to the object and the focal length of the second lens group L2. Exceeding the upper limit of conditional expression (9) is undesirable because it makes it difficult to correct distortion at the wide-angle end. Falling below the lower limit of conditional expression (9) is undesirable because it makes it difficult to reduce the diameter of the front lens element.

[0050] Conditional expression (10) defines the lateral imaging magnification of the second lens unit L2 at the telephoto end. Exceeding the upper limit of conditional expression (10) is undesirable because it becomes difficult to correct spherical aberration at the telephoto end. Falling below the lower limit of conditional expression (10) is undesirable because it becomes difficult to achieve a high zoom ratio.

[0051] Conditional expression (11) defines the relationship between the thickness of the single lens L11 and the focal length of the zoom lens L0 at the wide-angle end. Exceeding the upper limit of conditional expression (11) is undesirable because it makes it difficult to reduce the diameter of the front lens. Falling below the lower limit of conditional expression (11) is undesirable because it makes processing difficult and makes it difficult to achieve high image quality.

[0052] Conditional expression (12) defines the relationship between the distance from the vertex of the lens surface on the image side of the single lens L11 to the vertex of the surface on the object side of the lens arranged adjacent to the image side of the single lens L11, and the focal length of the zoom lens L0 at the wide-angle end. Exceeding the upper limit of conditional expression (12) is undesirable because it makes it difficult to reduce the diameter of the front lens. Falling below the lower limit of conditional expression (12) is undesirable because it makes it difficult to correct coma aberration at the telephoto end.

[0053] It is more preferable that the numerical ranges of the conditional expressions (3) to (12) be within the ranges of the following conditional expressions (3a) to (12a).

[0054] 0.69 <f11 / f1<1.21 ···(3a) 0.17 <T1 / f1<0.50 ···(4a) 0.75<-f2 / fw<1.37 (5a) 1.64 <f3 / fw<8.09 ···(6a) 0.33 <BFw / fw<1.04 ···(7a) 1.06 <D12t / fw<2.10 ···(8a) 1.07 <f21 / f2<1.60 ···(9a) -1.50<β2t<-0.49 (10a) 0.04 <T11 / fw<0.15 ···(11a) 0.05 <D112 / fw<0.24 ···(12a) It is more preferable that the numerical ranges of the conditional expressions (3) to (12) be the numerical ranges of the following conditional expressions (3b) to (12b).

[0055] 0.74 <f11 / f1<1.12 ···(3b) 0.21 <T1 / f1<0.43 ···(4b) 0.87<-f2 / fw<1.31 (5b) 1.96 <f3 / fw<7.14 ···(6b) 0.40 <BFw / fw<0.96 ···(7b) 1.14 <D12t / fw<1.90 ···(8b) 1.15 <f21 / f2<1.50 ···(9b) -1.25<β2t<-0.58 (10b) 0.05 <T11 / fw<0.12 ···(11b) 0.06 <D112 / fw<0.21 ···(12b) Next, the zoom lens L0 of each embodiment will be described in detail.

[0056] The zoom lens L0 of Example 1 comprises, arranged in order from the object side to the image side, a first lens unit L1 with positive refractive power, a second lens unit L2 with negative refractive power, a third lens unit L3 with positive refractive power, and a rear lens unit LR. The rear lens unit LR comprises, arranged in order from the object side to the image side, a fourth lens unit L4 with positive refractive power, a fifth lens unit L5 with negative refractive power, a sixth lens unit L6 with positive refractive power, and a seventh lens unit L7 with negative refractive power. The first lens unit L1 is fixed relative to the image plane IP during zooming. Each lens unit moves along a different path during zooming, changing the spacing between adjacent lens units. The third lens unit L3 has an aperture stop SP. During focusing from infinity to a close distance, the fifth lens unit L5 moves toward the image side, and the sixth lens unit L6 moves toward the image side.

[0057] The zoom lens L0 of Example 2 comprises, arranged in order from the object side to the image side, a first lens unit L1 with positive refractive power, a second lens unit L2 with negative refractive power, a third lens unit L3 with positive refractive power, and a rear lens unit LR. The rear lens unit LR comprises, arranged in order from the object side to the image side, a fourth lens unit L4 with positive refractive power, a fifth lens unit L5 with negative refractive power, a sixth lens unit L6 with negative refractive power, a seventh lens unit L7 with positive refractive power, and an eighth lens unit L8 with negative refractive power. The first lens unit L1 is fixed relative to the image plane IP during zooming. Each lens unit moves along a different path during zooming, changing the spacing between adjacent lens units. The third lens unit L3 has an aperture stop SP. During focusing from infinity to a close distance, the fifth lens unit L5 moves toward the object side, and the sixth lens unit L6 moves toward the image side.

[0058] The zoom lens L0 of Example 3 comprises, arranged in order from the object side to the image side, a first lens unit L1 with positive refractive power, a second lens unit L2 with negative refractive power, a third lens unit L3 with positive refractive power, and a rear lens unit LR. The rear lens unit LR comprises, arranged in order from the object side to the image side, a fourth lens unit L4 with positive refractive power, a fifth lens unit L5 with positive refractive power, a sixth lens unit L6 with negative refractive power, and a seventh lens unit L7 with negative refractive power. The first lens unit L1 is fixed relative to the image plane IP during zooming. Each lens unit moves along a different path during zooming, changing the spacing between adjacent lens units. The third lens unit L3 has an aperture stop SP. During focusing from infinity to a close distance, the fifth lens unit L5 moves toward the object side, and the sixth lens unit L6 moves toward the object side.

[0059] The zoom lens L0 of Example 4 comprises, arranged in order from the object side to the image side, a first lens unit L1 with positive refractive power, a second lens unit L2 with negative refractive power, a third lens unit L3 with positive refractive power, and a rear lens unit LR. The rear lens unit LR comprises, arranged in order from the object side to the image side, a fourth lens unit L4 with positive refractive power, a fifth lens unit L5 with negative refractive power, a sixth lens unit L6 with positive refractive power, and a seventh lens unit L7 with negative refractive power. The first lens unit L1 is fixed relative to the image plane IP during zooming. Each lens unit moves along a different path during zooming, changing the spacing between adjacent lens units. The third lens unit L3 has an aperture stop SP. During focusing from infinity to a close distance, the fifth lens unit L5 moves toward the image side, and the sixth lens unit L6 moves toward the image side.

[0060] The zoom lens L0 of Example 5 comprises, arranged in order from the object side to the image side, a first lens unit L1 with positive refractive power, a second lens unit L2 with negative refractive power, a third lens unit L3 with positive refractive power, and a rear lens unit LR. The rear lens unit LR comprises, arranged in order from the object side to the image side, a fourth lens unit L4 with positive refractive power, a fifth lens unit L5 with negative refractive power, and a sixth lens unit L6 with positive refractive power. The first lens unit L1, the third lens unit L3, and the sixth lens unit L6 are fixed relative to the image plane IP during zooming. Each lens unit moves along a different path during zooming, changing the spacing between adjacent lens units. The third lens unit L3 has an aperture stop SP. When focusing from infinity to a close distance, the fifth lens unit L5 moves toward the image side.

[0061] The zoom lens L0 of Example 6 comprises, arranged in order from the object side to the image side, a first lens unit L1 with positive refractive power, a second lens unit L2 with negative refractive power, a third lens unit L3 with positive refractive power, and a rear lens unit LR. The rear lens unit LR comprises, arranged in order from the object side to the image side, a fourth lens unit L4 with positive refractive power, a fifth lens unit L5 with negative refractive power, a sixth lens unit L6 with positive refractive power, and a seventh lens unit L7 with negative refractive power. The first lens unit L1 is fixed relative to the image plane IP during zooming. Each lens unit moves along a different path during zooming, changing the spacing between adjacent lens units. The third lens unit L3 has an aperture stop SP. During focusing from infinity to a close distance, the fifth lens unit L5 moves toward the image side, and the sixth lens unit L6 moves toward the image side.

[0062] The zoom lens L0 of Example 7 comprises, arranged in order from the object side to the image side, a first lens unit L1 with positive refractive power, a second lens unit L2 with negative refractive power, a third lens unit L3 with positive refractive power, and a rear lens unit LR. The rear lens unit LR comprises, arranged in order from the object side to the image side, a fourth lens unit L4 with negative refractive power, a fifth lens unit L5 with positive refractive power, a sixth lens unit L6 with negative refractive power, a seventh lens unit L7 with positive refractive power, and an eighth lens unit L8 with negative refractive power. The first lens unit L1 is fixed relative to the image plane IP during zooming. Each lens unit moves along a different path during zooming, changing the spacing between adjacent lens units. The third lens unit L3 has an aperture stop SP. During focusing from infinity to a close distance, the sixth lens unit L6 moves toward the image side, and the seventh lens unit L7 moves toward the image side.

[0063] In the zoom lens L0 of Examples 1 to 7, all surfaces having refractive power are made up of refractive surfaces, which makes it possible to easily obtain optical performance equal to or better than that of surfaces having refractive power made up of diffractive optical elements or reflective surfaces, with less manufacturing difficulty than when the surfaces are made up of diffractive optical elements or reflective surfaces.

[0064] In the zoom lens L0 of Examples 1 to 7, image blur correction may be performed by moving a portion of the zoom lens L0 in a direction including a component perpendicular to the optical axis. By making the portion to be moved during image blur correction a lens group with a relatively small diameter located on the image side, the actuator for driving the zoom lens L0 can be made compact, and the lens device including the zoom lens L0 can be made smaller. For example, image blur correction may be performed by moving all or a portion of the third lens group L3 in a direction including a component perpendicular to the optical axis.

[0065] Numerical Examples 1 to 7 corresponding to Examples 1 to 7, respectively, are shown below.

[0066] In the surface data of each numerical example, r represents the radius of curvature of each optical surface, and d (mm) represents the axial spacing (distance on the optical axis) between the mth surface and the (m+1)th surface. Here, m is the surface number counted from the light incident side. Also, nd represents the refractive index of each optical element with respect to the d-line, and vd represents the Abbe number of the optical element with respect to the d-line. Note that the Abbe number vd of a material with respect to the d-line is given by vd=(Nd-1) / (NF-NC), where Nd, NF, and NC are the refractive indices at the Fraunhofer d-line (587.6 nm), F-line (486.1 nm), and C-line (656.3 nm). It is expressed as:

[0067] In each numerical example, d, focal length (mm), F-number, and half angle of view (°) are all values ​​when the zoom lens L0 of each example is focused on an object at infinity. "Back focus BF" is the distance on the optical axis from the final lens surface (the lens surface closest to the image) of the zoom lens L0 to the paraxial image plane, expressed as an air-equivalent length. "Total lens length" is the distance on the optical axis from the forefront lens surface (the lens surface closest to the object) of the zoom lens L0 to the final lens surface plus the back focus. "Lens group" is not limited to cases where it is composed of multiple lenses, but also includes cases where it is composed of a single lens.

[0068] If the optical surface is aspherical, an asterisk (*) is added to the right of the surface number. The aspherical shape is expressed as follows: X is the displacement from the vertex of the surface in the optical axis direction, h is the height from the optical axis in the direction perpendicular to the optical axis, R is the paraxial radius of curvature, k is the conic constant, and A4, A6, A8, A10, and A12 are the aspherical coefficients of each order. x=(h 2 / R) / [1+{1-(1+k)(h / R) 2} 1 / 2 ]+A4×h 4 +A6×h 6 +A8×h 8 +A10×h 10 +A12×h 12 In addition, "e±XX" in each aspherical coefficient is "×10± XX " means.

[0069] [Numerical Example 1] Unit: mm Surface Data Surface number rd nd νd 1 -207.425 1.70 1.83481 42.7 2 95.825 4.21 3 393.916 2.00 1.72047 34.7 4 105.832 8.46 1.59522 67.7 5 -203.044 0.15 6 124.562 5.68 1.72916 54.7 7 -487.042 0.15 8 78.249 6.74 1.72916 54.7 9 -444.181 (variable) 10 8601.520 1.20 1.80400 46.5 11 28.416 5.54 12 -738.337 1.00 1.49700 81.5 13 63.533 3.06 14 -115.610 1.00 1.49700 81.5 15 35.816 3.84 1.90366 31.3 16 169.674 (variable) 17 (Aperture) ∞ 1.00 18 67.476 3.22 1.84666 23.8 19 -1153.421 0.60 20 55.893 1.20 2.00100 29.1 21 34.548 6.77 1.51742 52.4 22 -82.213 3.04 23* -43.690 0.05 1.59022 30.1 24 -46.141 1.20 1.72916 54.7 25 4358.607 (variable) 26 172.999 7.58 1.49700 81.5 27 -27.250 1.19 1.83400 37.2 28 231.097 0.15 29 48.103 7.69 1.48749 70.2 30 -81.882 0.15 31 42.435 9.37 1.43875 94.7 32 -82.878 0.15 33* 78.425 2.40 1.85400 40.4 34 37.200 9.41 1.61800 63.4 35 -70.814 (variable) 36 161.341 1.20 1.77250 49.6 37 28.989 (variable) 38* 48.348 3.91 1.58313 59.4 39 95.150 (variable) 40 224.141 7.07 1.80810 22.8 41 -35.894 1.50 1.49700 81.5 42 361.709 7.03 43 -34.951 1.50 1.92286 20.9 44 -125.011 (variable) Image plane ∞ Aspheric data Page 23 K = 0.00000e+00 A 4= 3.79285e-06 A 6=-1.22591e-10 A 8= 5.46760e-13 Page 33 K = 0.00000e+00 A 4=-7.34648e-06 A 6=-3.52185e-09 A 8= 3.20919e-13 Page 38 K = 0.00000e+00 A 4= 1.44392e-06 A 6= 4.53989e-09 A 8=-1.13675e-13 A10=-4.07591e-15 Various data Zoom ratio 4.12 Wide-angle Mid-range Telephoto Focal length 24.72 50.19 101.86 F-number 2.90 2.90 2.90 Half angle of view (°) 41.19 23.32 11.99 Lens total length 212.40 212.40 212.40 BF 11.98 26.45 21.74 d 9 0.80 16.04 34.02 d16 41.01 21.11 2.98 d25 19.68 9.87 0.79 d35 2.80 1.19 1.18 d37 7.64 6.92 6.23 d39 6.39 8.72 23.36 d44 11.98 26.45 21.74 Zoom lens group data Group starting plane focal length 1 1 83.05 2 10 -27.72 3 17 106.51 4 26 34.04 5 36 -45.93 6 38 163.53 7 40 -161.55 [Numerical Example 2] Unit: mm Surface Data Surface number rd nd νd 1 -208.117 2.00 2.00100 29.1 2 125.012 1.73 3 201.666 6.72 1.59522 67.7 4 -188.208 0.13 5 120.220 5.48 1.83481 42.7 6 -1189.696 0.15 7 69.551 5.71 1.83481 42.7 8 436.182 (variable) 9 214.024 1.20 1.90043 37.4 10 26.866 6.02 11 -282.246 1.20 1.59522 67.7 12 48.782 4.24 13 -64.715 1.20 1.49700 81.5 14 39.804 4.37 1.85025 30.1 15 -376.767 (variable) 16 (Aperture) ∞ 1.00 17 76.845 3.20 1.84666 23.8 18 -332.575 0.50 19 56.009 0.90 2.00100 29.1 20 34.921 6.63 1.51742 52.4 21 -82.324 3.17 22* -40.899 0.05 1.59022 30.1 23 -43.512 1.20 1.72916 54.7 24 -438.046 (variable) 25 107.656 9.03 1.49700 81.5 26 -23.891 1.19 1.95375 32.3 27 -1561.807 0.15 28 57.153 9.76 1.43875 94.7 29 -41.965 0.15 30* 84.677 7.95 1.80400 46.5 31* -52.890 (variable) 32 185.555 2.58 1.89286 20.4 33 -333.256 1.20 1.61800 63.4 34 46.156 (variable) 35 77.039 1.20 2.00100 29.1 36 30.744 (variable) 37* 37.408 4.07 1.58313 59.4 38* 53.618 0.13 39 47.870 1.39 2.00069 25.5 40 25.731 9.31 1.61800 63.4 41 176.934 (variable) 42 54.577 7.41 1.84666 23.8 43 -80.249 1.50 1.48749 70.2 44 42.160 7.49 45 -49.214 1.50 1.92286 20.9 46 -97.002 (variable) Image plane ∞ Aspheric data Page 22 K = 0.00000e+00 A 4= 4.39269e-06 A 6= 1.10097e-09 A 8= 6.31456e-13 Page 30 K = 0.00000e+00 A 4=-5.80494e-06 A 6=-2.08319e-09 A 8=-2.99833e-12 Page 31 K = 0.00000e+00 A 4= 1.13763e-06 A 6=-3.28114e-09 Page 37 K = 0.00000e+00 A 4= 2.38842e-06 A 6=-2.70374e-09 A 8=-1.84658e-11 A10= 2.89507e-14 Page 38 K = 0.00000e+00 A 4= 6.75134e-08 A 6=-3.59874e-09 A 8=-2.39776e-11 A10= 3.36099e-14 Various data Zoom ratio 4.13 Wide-angle Mid-range Telephoto Focal length 24.73 50.23 102.12 F-number 2.90 2.90 2.90 Half angle of view (°) 41.19 23.30 11.96 Lens total length 211.51 211.51 211.51 BF 11.80 26.61 26.29 d 8 0.80 15.28 30.36 d15 39.32 19.23 2.99 d24 19.57 9.93 0.78 d31 4.00 1.22 2.88 d34 4.47 7.50 6.25 d36 7.75 7.49 7.08 d41 1.00 1.44 12.05 d46 11.80 26.61 26.29 Zoom lens group data Group starting plane focal length 1 1 79.54 2 9 -24.54 3 16 97.60 4 25 34.35 5 32 -131.33 6 35 -51.78 7 37 123.01 8 42 770.84 [Numerical Example 3] Unit: mm Surface Data Surface number rd nd νd 1 -181.919 1.70 1.90043 37.4 2 111.072 3.71 3 364.499 5.59 1.59522 67.7 4 -177.536 0.14 5 154.743 4.78 1.75500 52.3 6 -870.763 0.15 7 84.502 7.28 1.75500 52.3 8 -367.735 (variable) 9 -2513.905 1.30 1.72916 54.7 10 27.941 6.20 11 -452.183 1.20 1.59522 67.7 12 68.302 2.86 13 -147.630 1.20 1.49700 81.5 14 37.027 4.02 1.90043 37.4 15 197.666 (variable) 16 (Aperture) ∞ 1.00 17 70.360 3.19 1.84666 23.8 18 -1084.899 0.60 19 62.970 1.20 2.05090 26.9 20 36.953 6.53 1.56732 42.8 21 -87.660 3.17 22* -43.587 0.05 1.59022 30.1 23 -46.864 1.40 1.77250 49.6 24 3434.700 (variable) 25 68.421 7.75 1.49700 81.5 26 -34.337 1.19 1.83400 37.2 27 94.819 0.15 28 45.071 5.49 1.49700 81.5 29 1775.190 0.15 30 38.956 9.94 1.49700 81.5 31 -94.914 2.39 32* 78.620 2.50 1.85400 40.4 33* 49.978 (variable) 34* 37.006 8.81 1.58313 59.4 35* -88.576 (variable) 36 123.459 1.20 2.00100 29.1 37 40.182 (variable) 38 73.297 8.72 1.84666 23.8 39 -41.340 1.40 1.60311 60.6 40 49.128 8.20 41 -33.125 1.40 1.92286 20.9 42 -59.144 (variable) Image plane ∞ Aspheric data Page 22 K = 0.00000e+00 A 4= 3.89058e-06 A 6= 6.70856e-10 A 8=-1.58188e-12 Page 32 K = 0.00000e+00 A 4= 4.26123e-06 A 6=-9.76054e-09 A 8=-4.97564e-12 Page 33 K = 0.00000e+00 A 4= 1.08509e-05 A 6=-5.04108e-09 A 8=-2.02185e-12 A10= 5.27144e-15 Page 34 K = 0.00000e+00 A 4=-1.80819e-06 A 6=-1.87700e-09 A 8= 3.87938e-13 Page 35 K = 0.00000e+00 A 4= 4.45032e-06 A 6=-4.27576e-09 A 8= 3.65399e-12 Various data Zoom ratio 4.12 Wide-angle Mid-range Telephoto Focal length 24.72 50.22 101.96 F-number 2.90 2.90 2.90 Half angle of view (°) 41.19 23.31 11.98 Lens total length 211.02 211.02 211.02 BF 11.85 26.68 22.74 d 8 0.80 16.99 35.41 d15 44.29 21.72 3.00 d24 20.71 11.73 0.78 d33 4.43 7.45 8.57 d35 2.11 1.69 3.52 d37 10.27 8.21 20.44 d42 11.85 26.68 22.74 Zoom lens group data Group starting plane focal length 1 1 94.31 2 9 -29.02 3 16 127.17 4 25 83.32 5 34 45.95 6 36 -59.94 7 38 -203.31 [Numerical Example 4] Unit: mm Surface Data Surface number rd nd νd 1 -266.746 1.60 1.90043 37.4 2 98.340 2.81 3 192.058 6.58 1.53775 74.7 4 -241.263 0.15 5 119.575 5.31 1.72916 54.7 6 -1682.093 0.15 7 76.157 6.72 1.72916 54.7 8 -880.300 (variable) 9 915.083 1.20 1.88300 40.8 10 29.841 5.73 11 -218.330 1.00 1.59522 67.7 12 63.389 3.69 13 -74.215 1.10 1.49700 81.5 14 41.057 4.98 1.77047 29.7 15 -204.631 (variable) 16 (Aperture) ∞ 1.00 17 78.578 3.15 1.84666 23.8 18 -594.031 0.60 19 59.615 1.20 2.00100 29.1 20 36.734 7.47 1.51742 52.4 21 -83.322 3.11 22* -44.261 0.05 1.59022 30.1 23 -47.091 1.20 1.77250 49.6 24 -640.625 (variable) 25 255.634 8.10 1.49700 81.5 26 -27.474 1.30 1.90043 37.4 27 -222.061 0.15 28 41.537 8.18 1.49700 81.5 29 -105.932 2.30 30 63.231 6.49 1.49700 81.5 31 -97.379 0.15 32* 85.354 2.40 1.85400 40.4 33 34.925 8.89 1.60311 60.6 34 -78.017 (variable) 35 157.315 1.20 1.72916 54.7 36 28.256 (variable) 37* 47.159 4.54 1.58313 59.4 38 160.935 (variable) 39 210.344 5.69 1.80518 25.4 40 -46.896 1.50 1.48749 70.2 41 59.110 9.57 42 -33.883 1.20 2.00069 25.5 43 -66.006 (variable) Image plane ∞ Aspheric data Page 22 K = 0.00000e+00 A 4= 3.72124e-06 A 6= 3.39835e-10 A 8= 6.96887e-13 Page 32 K = 0.00000e+00 A 4=-7.10364e-06 A 6=-3.27713e-09 A 8=-1.38031e-12 Page 37 K = 0.00000e+00 A 4= 1.68172e-06 A 6= 3.21879e-09 A 8= 5.86323e-12 A10=-1.26470e-14 Various data Zoom ratio 4.12 Wide-angle Mid-range Telephoto Focal length 24.78 50.31 102.06 F-number 2.90 2.90 2.90 Half angle of view (°) 41.12 23.27 11.97 Lens total length 211.98 211.98 211.98 BF 11.63 25.76 19.01 d 8 0.80 16.58 34.70 d15 42.76 21.90 2.98 d24 19.63 10.61 0.79 d34 2.50 1.78 1.10 d36 8.07 7.90 7.19 d38 6.12 7.00 25.75 d43 11.63 25.76 19.01 Zoom lens group data Group starting plane focal length 1 1 90.57 2 9 -27.00 3 16 119.23 4 25 35.02 5 35 -47.42 6 37 112.74 7 39 -90.78 [Numerical Example 5] Unit: mm Surface Data Surface number rd nd νd 1 -389.691 1.40 1.90366 31.3 2 82.287 1.23 3 110.994 6.05 1.65160 58.5 4 -281.308 0.15 5 85.673 4.31 1.65160 58.5 6 806.235 0.15 7 54.903 5.58 1.65160 58.5 8 785.992 (variable) 9 276.074 0.90 1.88300 40.8 10 20.141 4.07 11 -100.883 0.80 1.53775 74.7 12 49.869 3.05 13 -28.690 0.80 1.49700 81.5 14 73.099 3.05 15 69.513 2.56 1.78880 28.4 16 -73.855 (variable) 17 (Aperture) ∞ 1.00 18 66.752 2.49 1.84666 23.8 19 -170.746 0.60 20 52.894 1.00 1.90043 37.4 21 29.273 4.92 1.49700 81.5 22 -70.437 2.67 23* -36.877 0.05 1.59022 30.1 24 -37.750 0.80 2.00100 29.1 25 -159.049 (variable) 26 18.192 6.90 1.49700 81.5 27 -122.358 1.85 28* 34.893 2.00 1.85400 40.4 29 12.704 8.70 1.53775 74.7 30 -41.343 (variable) 31 201.365 0.80 1.69680 55.5 32 16.529 3.19 33* 33.474 0.05 1.59022 30.1 34 29.970 2.61 1.69895 30.1 35 91.279 (variable) 36 -7374.962 0.99 1.84666 23.8 37 18.843 8.00 1.95375 32.3 38 -532.203 (variable) Image plane ∞ Aspheric data Page 23 K = 0.00000e+00 A 4= 2.89420e-06 A 6=-1.34568e-08 A 8= 6.36985e-11 Page 28 K = 0.00000e+00 A 4=-2.64372e-05 A 6=-4.41245e-08 A 8=-1.20269e-10 Page 33 K = 0.00000e+00 A 4= 9.94261e-06 A 6= 5.34360e-08 A 8= 4.64696e-10 A10=-1.17368e-12 Various data Zoom ratio 3.77 Wide-angle Mid-range Telephoto Focal length 15.45 29.99 58.20 F-number 2.90 2.90 2.90 Half angle of view (°) 41.5 24.4 13.2 Lens total length 144.55 144.55 144.55 BF 13.62 13.62 13.62 d 8 0.80 12.60 26.36 d16 28.06 16.26 2.50 d25 14.40 3.69 0.79 d30 2.47 1.67 6.03 d35 2.46 13.97 12.50 d38 13.62 13.62 13.62 Zoom lens group data Group starting plane focal length 1 1 73.07 2 9 -18.38 3 17 95.63 4 26 25.34 5 31 -42.47 6 36 136.61 [Numerical Example 6] Unit: mm Surface Data Surface number rd nd νd 1 -145.889 1.50 1.80400 46.5 2 119.213 2.83 3 253.040 1.80 1.90043 37.4 4 99.211 10.81 1.59522 67.7 5 -178.530 0.15 6 173.080 5.74 1.72916 54.7 7 -394.348 2.00 2.00069 25.5 8 -422.661 0.15 9 95.066 7.91 1.72916 54.7 10 -254.672 (variable) 11 32331.499 1.20 1.80400 46.5 12 30.515 6.54 13 -299.616 1.00 1.53775 74.7 14 90.027 2.78 15 -141.186 1.00 1.43875 94.7 16 39.551 4.13 1.85025 30.1 17 177.556 (variable) 18 (Aperture) ∞ 1.00 19 68.706 3.23 1.84666 23.8 20 644.861 0.60 21 57.756 1.20 2.00100 29.1 22 35.487 8.08 1.51742 52.4 23 -76.532 3.14 24* -44.193 0.05 1.59022 30.1 25 -46.651 1.20 1.61800 63.4 26 629.006 (variable) 27 388.004 8.23 ​​1.49700 81.5 28 -28.092 1.19 1.83400 37.2 29 -820.088 0.15 30 47.740 7.55 1.49700 81.5 31 -108.833 0.15 32 44.919 10.21 1.43875 94.7 33 -90.770 0.16 34* 93.341 2.40 1.85400 40.4 35 38.885 9.13 1.61800 63.4 36 -68.796 (variable) 37 164.339 1.20 1.77250 49.6 38 28.327 (variable) 39* 41.956 3.18 1.58913 61.1 40 55.503 (variable) 41 162.671 7.26 1.80810 22.8 42 -34.956 1.50 1.49700 81.5 43 174.387 6.54 44 -35.777 1.50 1.92286 20.9 45 -106.777 (variable) Image plane ∞ Aspheric data Page 24 K = 0.00000e+00 A 4= 3.02503e-06 A 6= 3.04230e-10 A 8= 3.19935e-13 Page 34 K = 0.00000e+00 A 4=-7.45028e-06 A 6=-3.06797e-09 A 8= 1.75070e-12 Page 39 K = 0.00000e+00 A 4= 1.28377e-06 A 6= 3.88604e-09 A 8=-1.88119e-13 A10=-6.12251e-15 Various data Zoom ratio 4.71 Wide-angle Mid-range Telephoto Focal length 24.71 53.66 116.38 F-number 2.90 2.90 2.90 Half angle of view (°) 41.3 22.0 10.0 Lens total length 231.23 231.23 231.23 BF 11.38 27.62 23.01 d10 0.80 20.19 40.99 d17 50.25 24.76 2.98 d26 22.69 12.57 1.36 d36 2.84 1.19 1.19 d38 8.70 6.18 3.68 d40 6.18 10.33 29.64 d45 11.38 27.62 23.01 Zoom lens group data Group starting plane focal length 1 1 94.53 2 11 -30.84 3 18 115.09 4 27 34.67 5 37 -44.48 6 39 268.40 7 41 -230.97 [Numerical Example 7] Unit: mm Surface Data Surface number rd nd νd 1 -110.000 1.50 1.81600 46.6 2 110.000 3.07 3 493.334 1.80 1.80400 46.5 4 70.906 9.80 1.59522 67.7 5 -169.964 0.15 6 196.640 4.95 1.72916 54.7 7 -211.777 0.15 8 79.760 7.13 1.72916 54.7 9 -184.077 (variable) 10 354.643 1.20 1.88300 40.8 11 27.676 4.91 12 2967.414 1.00 1.53775 74.7 13 53.350 3.57 14 -80.750 1.00 1.43875 94.7 15 37.143 3.88 1.85025 30.1 16 344.923 (variable) 17 (Aperture) ∞ 1.00 18 72.562 2.66 1.84666 23.9 19 372.885 0.60 20 57.431 1.20 1.95375 32.3 21 35.760 7.09 1.51742 52.4 22 -85.235 (variable) 23* -43.596 0.05 1.59022 30.1 24 -46.839 1.20 1.61800 63.4 25 -190.441 (variable) 26 239.146 8.65 1.49700 81.5 27 -25.927 1.19 1.85150 40.8 28 -4745.541 0.15 29 49.220 8.85 1.49700 81.5 30 -81.928 0.15 31 43.459 9.11 1.43875 94.7 32 -90.430 1.06 33* 93.586 2.40 1.85400 40.4 34 39.080 9.51 1.61800 63.4 35 -59.538 (variable) 36 162.663 1.20 1.77250 49.6 37 26.850 (variable) 38* 44.357 3.99 1.58913 61.1 39 66.856 (variable) 40 243.719 8.35 1.80810 22.8 41 -33.555 1.50 1.49700 81.5 42 466.937 4.35 43 -38.492 1.50 1.92286 20.9 44 -130.591 (variable) Image plane ∞ Aspheric data Page 23 K = 0.00000e+00 A 4= 3.09065e-06 A 6= 8.97341e-10 A 8= 3.15334e-13 Page 33 K = 0.00000e+00 A 4=-8.20701e-06 A 6=-3.56263e-09 A 8= 1.99134e-12 Page 38 K = 0.00000e+00 A 4= 1.50567e-06 A 6= 6.57547e-09 A 8=-6.15310e-12 A10= 5.36338e-15 Various data Zoom ratio 3.67 Wide-angle Mid-range Telephoto Focal length 22.60 43.42 82.99 F-number 2.90 2.90 2.90 Half angle of view (°) 44.3 26.5 14.1 Lens total length 216.25 216.25 216.25 BF 11.83 26.43 22.33 d 9 0.80 14.07 30.07 d16 40.40 19.90 3.00 d22 3.25 5.48 5.28 d25 22.69 12.25 0.80 d35 2.50 1.19 2.40 d37 10.60 8.52 5.72 d39 4.31 8.53 26.79 d44 11.83 26.43 22.33 Zoom lens group data Group starting plane focal length 1 1 85.62 2 10 -27.33 3 17 51.61 4 23 -92.16 5 26 33.47 6 36 -41.79 7 38 209.93 8 40 -242.13 The various values ​​in each numerical example are summarized in Table 1 below.

[0070] [Table 1]

[0071] [Imaging device] Next, an embodiment of a digital still camera (imaging device) using the zoom lens L0 of each embodiment as an imaging optical system will be described with reference to FIG. 15 . FIG. 15 is a diagram showing the configuration of an imaging device 10. The imaging device 10 includes a camera body 13, an imaging optical system (lens device) 11 including the zoom lens L0 of any of the above-described embodiments 1 to 7, and an imaging element (light receiving element) 12 that photoelectrically converts an image formed by the zoom lens L0. The imaging element 12 can be an imaging element such as a CCD sensor or a CMOS sensor. The lens device 11 and the camera body 13 may be configured as an integrated unit, or may be configured as detachable components. The camera body 13 may be a so-called single-lens reflex camera with a quick-turn mirror, or a so-called mirrorless camera without a quick-turn mirror. The imaging device 10 of this embodiment is small and lightweight, and can achieve high optical performance.

[0072] The imaging device 10 of this embodiment is not limited to the digital still camera shown in FIG. 15, but can be applied to various imaging devices such as broadcast cameras, cameras for silver halide film, and surveillance cameras.

[0073] [Imaging system] An imaging system (surveillance camera system) may be configured that includes the zoom lens of each embodiment and a control unit that controls the zoom lens. In this case, the control unit can control the zoom lens so that each lens group moves as described above during zooming, focusing, and image stabilization. In this case, the control unit does not need to be configured integrally with the zoom lens; the control unit may be configured separately from the zoom lens. For example, a control unit (control device) located far from the drive units that drive each lens of the zoom lens may include a transmission unit that sends control signals (commands) to control the zoom lens. Such a control unit allows the zoom lens to be remotely controlled.

[0074] Alternatively, the control unit may be provided with an operation unit such as a controller or buttons for remotely operating the zoom lens, so that the zoom lens can be controlled in response to user input to the operation unit. For example, the operation unit may be provided with a zoom-in button and a zoom-out button. The control unit may then send a signal to the drive unit of the zoom lens L0 so that the magnification of the zoom lens increases when the user presses the zoom-in button, and decreases when the user presses the zoom-out button.

[0075] The imaging system may also have a display unit such as a liquid crystal panel that displays information (movement state) related to the zoom of the zoom lens. Information related to the zoom of the zoom lens may be, for example, the zoom magnification (zoom state) or the movement amount (movement state) of each lens group. In this case, the user can remotely operate the zoom lens via the operation unit while viewing the information related to the zoom of the zoom lens displayed on the display unit. In this case, the display unit and operation unit may be integrated by using, for example, a touch panel.

[0076] The disclosure of each of the above embodiments includes the following configurations.

[0077] (Configuration 1) A zoom lens comprising, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a subsequent group made up of a plurality of lens groups, wherein the spacing between adjacent lens groups changes during zooming from the wide-angle end to the telephoto end, the first lens group is fixed with respect to an image plane during zooming from a wide-angle end to a telephoto end, the first lens group includes a single lens having negative refractive power arranged closest to the object, and a plurality of lenses having positive refractive power arranged on the image side of the single lens, an air lens is formed by an air gap between the single lens and a lens disposed adjacent to the single lens on the image side; When the radius of curvature of the object-side lens surface of the single lens is r111, the radius of curvature of the image-side lens surface of the single lens is r112, the focal length of the first lens group is f1, and the focal length of the second lens group is f2, -0.7<(r112+r111) / (r112-r111)<0.4 1.0 <f1 / (-f2)<4.2 A zoom lens characterized by satisfying the following conditional expressions: (Configuration 2) When the focal length of the zoom lens at the wide-angle end is fw, 0.5<-f2 / fw<1.5 2. The zoom lens according to claim 1, wherein the following condition is satisfied: (Configuration 3) When the focal length of the third lens group is f3 and the focal length of the zoom lens at the wide-angle end is fw, 1 <f3 / fw<10 3. The zoom lens according to configuration 1 or 2, wherein the following condition is satisfied: (Configuration 4) When the back focus of the zoom lens at the wide-angle end is BFw and the focal length of the zoom lens at the wide-angle end is fw, 0.2 <BFw / fw<1.2 4. The zoom lens according to any one of configurations 1 to 3, wherein the following condition is satisfied: (Configuration 5) When the distance on the optical axis from the lens surface of the first lens group closest to the image side to the lens surface of the second lens group closest to the object side at the telephoto end is D12t and the focal length of the zoom lens at the wide-angle end is fw, 0.9 <D12t / fw<2.5 5. A zoom lens according to any one of configurations 1 to 4, characterized in that the following conditional expression is satisfied: (Configuration 6) When the focal length of the lens located closest to the object in the second lens group is f12, 0.9 <f21 / f2<1.8 6. A zoom lens according to any one of configurations 1 to 5, characterized in that the following conditional expression is satisfied: (Configuration 7) When the lateral imaging magnification of the second lens group at the telephoto end is β2t, -2.0<β2t<-0.3 7. The zoom lens according to any one of configurations 1 to 6, wherein the following condition is satisfied: (Configuration 8) When the distance on the optical axis from the object-side lens surface of the single lens to the image-side lens surface of the single lens is T11 and the focal length of the zoom lens at the wide-angle end is fw, 0.02 <T11 / fw<0.20 8. The zoom lens according to any one of configurations 1 to 7, wherein the following condition is satisfied: (Configuration 9) When the distance on the optical axis from the image-side lens surface of the single lens to the object-side lens surface of the lens disposed adjacent to the image side of the single lens is D112, and the focal length of the zoom lens at the wide-angle end is fw, 0.03 <D112 / fw<0.30 9. A zoom lens according to any one of configurations 1 to 8, characterized in that the following conditional expression is satisfied: (Configuration 10) 10. A zoom lens according to any one of configurations 1 to 9, wherein the first lens group includes three or more lenses with positive refractive power arranged on the image side of the single lens. (Configuration 11) 11. A zoom lens according to any one of configurations 1 to 10, wherein the subsequent group is made up of three or more lens groups. (Configuration 12) 12. A zoom lens according to any one of configurations 1 to 11, wherein the subsequent group includes a plurality of lens groups that move during zooming from the wide-angle end to the telephoto end. (Configuration 13) 12. A zoom lens according to any one of configurations 1 to 11, wherein the subsequent group includes a plurality of lens groups that move toward the object side during zooming from the wide-angle end to the telephoto end. (Configuration 14) 14. A zoom lens according to any one of configurations 1 to 13, wherein all lenses included in the first lens group are fixed during focusing. (Configuration 15) 15. A zoom lens according to any one of configurations 1 to 14, wherein the subsequent group includes a lens group that moves during focusing. (Configuration 16) 16. The zoom lens according to any one of configurations 1 to 15, wherein the second lens group includes three or more lenses with negative refractive power. (Configuration 17) 17. A zoom lens according to any one of configurations 1 to 16, wherein the third lens group includes a plurality of lenses having positive refractive power. (Configuration 18) 18. A zoom lens according to any one of configurations 1 to 17, wherein the third lens group includes a lens with negative refractive power. (Configuration 19) When the focal length of the single lens is f11, 0.6 <f11 / f1<1.4 19. A zoom lens according to any one of configurations 1 to 18, wherein the following condition is satisfied: (Configuration 20) When the distance on the optical axis from the lens surface of the first lens group closest to the object side to the lens surface of the first lens group closest to the image side is T1, 0.1 <T1 / f1<0.65 20. A zoom lens according to any one of configurations 1 to 19, wherein the following condition is satisfied: (Configuration 21) An imaging device comprising the zoom lens according to any one of configurations 1 to 20, and an imaging element that receives an image formed by the zoom lens. (Configuration 22) 21. An imaging system comprising: a zoom lens according to any one of configurations 1 to 20; and a control unit that controls the zoom lens during zooming. (Configuration 23) 23. The imaging system according to claim 22, wherein the control unit is configured as a separate unit from the zoom lens and includes a transmission unit that transmits a control signal for controlling the zoom lens. (Configuration 24) 24. The imaging system according to configuration 22 or 23, wherein the control unit is configured as a separate unit from the zoom lens and has an operation unit for operating the zoom lens. (Configuration 25) 25. The imaging system according to any one of configurations 22 to 24, further comprising a display unit that displays information related to the zoom of the zoom lens.

[0078] Although the preferred embodiments and examples of the present invention have been described above, the present invention is not limited to these embodiments and examples, and various combinations, modifications, and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0079] L0 zoom lens L1 First lens group L2 Second lens group LR successor group L11 single lens

Claims

1. A zoom lens comprising, arranged in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a subsequent group made up of a plurality of lens groups, wherein the spacing between adjacent lens groups changes during zooming from the wide-angle end to the telephoto end, the first lens group is fixed with respect to an image plane during zooming from a wide-angle end to a telephoto end, the first lens group includes a single lens having negative refractive power arranged closest to the object, and a plurality of lenses having positive refractive power arranged on the image side of the single lens, an air lens is formed by an air gap between the single lens and a lens disposed adjacent to the single lens on the image side; When the radius of curvature of the object-side lens surface of the single lens is r111, the radius of curvature of the image-side lens surface of the single lens is r112, the focal length of the first lens group is f1, the focal length of the second lens group is f2, and the distance on the optical axis from the lens surface of the first lens group closest to the object side to the lens surface of the first lens group closest to the image side is T1, -0.7<(r112+r111) / (r112-r111)<0.4 1.0<f1 / (-f2)<4.2 0.1<T1 / f1<0.65 A zoom lens characterized by satisfying the following conditional expressions:

2. When the focal length of the zoom lens at the wide-angle end is fw, 0.5<-f2 / fw<1.5 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

3. When the focal length of the third lens group is f3 and the focal length of the zoom lens at the wide-angle end is fw, 1<f3 / fw<10 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

4. When the back focus of the zoom lens at the wide-angle end is BFw and the focal length of the zoom lens at the wide-angle end is fw, 0.2<BFw / fw<1.2 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

5. When the distance on the optical axis from the lens surface of the first lens group closest to the image side to the lens surface of the second lens group closest to the object side at the telephoto end is D12t and the focal length of the zoom lens at the wide-angle end is fw, 0.9<D12t / fw<2.5 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

6. When the focal length of the lens located closest to the object in the second lens group is f12, 0.9<f21 / f2<1.8 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

7. When the lateral magnification of the second lens group at the telephoto end is β2t, -2.0<β2t<-0.3 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

8. When the distance on the optical axis from the object-side lens surface of the single lens to the image-side lens surface of the single lens is T11 and the focal length of the zoom lens at the wide-angle end is fw, 0.02<T11 / fw<0.20 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

9. When the distance on the optical axis from the image-side lens surface of the single lens to the object-side lens surface of the lens arranged adjacent to the image-side of the single lens is D112, and the focal length of the zoom lens at the wide-angle end is fw, 0.03<D112 / fw<0.30 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

10. 2. The zoom lens according to claim 1, wherein the first lens group includes three or more lenses with positive refractive power, which are arranged on the image side of the single lens.

11. 2. The zoom lens according to claim 1, wherein the subsequent group comprises three or more lens groups.

12. 2. The zoom lens according to claim 1, wherein the subsequent group includes a plurality of lens groups that move during zooming from the wide-angle end to the telephoto end.

13. 2. The zoom lens according to claim 1, wherein the subsequent group includes a plurality of lens groups that move toward the object side during zooming from the wide-angle end to the telephoto end.

14. 2. The zoom lens according to claim 1, wherein all lenses included in said first lens group are fixed during focusing.

15. 2. The zoom lens according to claim 1, wherein the subsequent group includes a lens group that moves during focusing.

16. 2. The zoom lens according to claim 1, wherein the second lens group includes three or more lenses having negative refractive power.

17. 2. The zoom lens according to claim 1, wherein the third lens group includes a plurality of lenses having positive refractive power.

18. 2. The zoom lens according to claim 1, wherein the third lens group includes a lens having negative refractive power.

19. When the focal length of the single lens is f11, 0.6<f11 / f1<1.4 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

20. 20. An imaging device comprising: the zoom lens according to claim 1; and an imaging element that receives an image formed by the zoom lens.

21. 20. An imaging system comprising: a zoom lens according to claim 1; and a control unit that controls the zoom lens during zooming.

22. 22. The imaging system according to claim 21, wherein the control unit is configured as a separate unit from the zoom lens and includes a transmission unit that transmits a control signal for controlling the zoom lens.

23. 22. The imaging system according to claim 21, wherein the control unit is configured as a separate unit from the zoom lens and has an operation unit for operating the zoom lens.

24. 22. The imaging system according to claim 21, further comprising a display unit that displays information related to the zoom of the zoom lens.

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