Zoom lens and imaging apparatus having the same

Abstract

To provide a zoom lens that has high optical performance, a long focal length, and a small size and light weight.SOLUTION: A zoom lens consists of a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear group having one or more lens groups, which are arranged in order from an object side to an image side, and in zooming, the interval between the adjacent lens groups changes. The zoom lens has a first positive lens having a positive refractive power arranged on the most object side. The first lens group is immovable in zooming, and consists of a first partial group and a second partial group arranged adjacent on the image side of the first partial group. Of air gaps on an optical axis of the adjacent lenses in the first lens group, the maximum air gap on the optical axis is between the first partial group and the second partial group. Predetermined conditional expressions are satisfied.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a zoom lens, which is suitable for use in imaging devices such as digital video cameras, digital still cameras, broadcast cameras, and cameras for silver halide film. [Background technology]

[0002] In recent years, imaging optical systems used in imaging devices have been required to have a long focal length at the telephoto end, high optical performance over the entire zoom range, and be small and lightweight zoom lenses.

[0003] Patent Document 1 discloses a positive lead type optical system as a zoom lens having a long focal length at the telephoto end. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-173845 Summary of the Invention [Problem to be solved by the invention]

[0005] The zoom lens of Patent Document 1 has, arranged in order from the object side to the image side, a first lens group with positive refractive power and a second lens group with negative refractive power, with the first lens group not moving during zooming. However, the overall lens length is not sufficiently reduced.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a zoom lens that has high optical performance, a long focal length, and is small and lightweight. [Means for solving the problem]

[0007] A zoom lens of the present invention comprises, arranged in order from the object side to the image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear group having three or more lens groups, and the spacing between adjacent lens groups changes during zooming, The zoom lens has a first positive lens element having a positive refractive power and arranged closest to the object side, the first lens group is stationary during zooming and includes a first subgroup and a second subgroup arranged adjacent to the first subgroup on the image side, Among the air gaps on the optical axis between adjacent lenses in the first lens group, the air gap on the optical axis between the first subgroup and the second subgroup is the largest, the specific gravity of the material of at least one of the positive lenses in the first lens group is 3.0 or less; Let d1AB be the distance on the optical axis between the surface of the first sub-group closest to the image side and the surface of the second sub-group closest to the object side, f1A be the focal length of the first sub-group, sk be the shorter of the back focuses at the wide-angle end and the telephoto end, and Lt be the total lens length at the telephoto end. 0.020 <d1AB / f1A<0.200 0.100 <sk / Lt<0.250 The present invention is characterized in that the following conditional expression is satisfied: [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a zoom lens that has high optical performance, a long focal length, and is small and lightweight. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a zoom lens at the wide-angle end of the first embodiment; [Figure 2] Aberration diagrams of the zoom lens of Example 1 at (A) the wide-angle end and (B) the telephoto end when focusing at infinity. [Figure 3] Aberration diagrams of the zoom lens of Example 1 at (A) the wide-angle end and (B) the telephoto end when focusing at close range. [Figure 4] 10 is a cross-sectional view of a zoom lens at the wide-angle end of Example 2. [Figure 5] Aberration diagrams of the zoom lens of Example 2 at (A) the wide-angle end and (B) the telephoto end when focusing at infinity. [Figure 6] Aberration diagrams of the zoom lens of Example 2 at (A) the wide-angle end and (B) the telephoto end when focusing at close range. [Figure 7] 10 is a cross-sectional view of a zoom lens at the wide-angle end according to a third embodiment of the present invention; [Figure 8] Aberration diagrams of the zoom lens of Example 3 at (A) the wide-angle end and (B) the telephoto end when focusing at infinity. [Figure 9] Aberration diagrams of the zoom lens of Example 3 at (A) the wide-angle end and (B) the telephoto end when focusing at close range. [Figure 10] 10 is a cross-sectional view of a zoom lens at the wide-angle end according to a fourth embodiment of the present invention; [Figure 11] Aberration diagrams of the zoom lens of Example 4 at (A) the wide-angle end and (B) the telephoto end when focusing at infinity. [Figure 12] Aberration diagrams of the zoom lens of Example 4 at (A) the wide-angle end and (B) the telephoto end when focusing at close range. [Figure 13] 10 is a cross-sectional view of a zoom lens at the wide-angle end according to a fifth embodiment of the present invention; [Figure 14] Aberration diagrams of the zoom lens of Example 5 at (A) the wide-angle end and (B) the telephoto end when focusing at infinity. [Figure 15] Aberration diagrams of the zoom lens of Example 5 at (A) the wide-angle end and (B) the telephoto end when focusing at close range. [Figure 16] 10 is a cross-sectional view of a zoom lens at the wide-angle end according to a sixth embodiment of the present invention; [Figure 17] Aberration diagrams of the zoom lens of Example 6 at (A) the wide-angle end and (B) the telephoto end when focusing at infinity. [Figure 18]Aberration diagrams of the zoom lens of Example 6 at (A) the wide-angle end and (B) the telephoto end when focusing at close range. [Figure 19] 10 is a cross-sectional view of a zoom lens at the wide-angle end according to a seventh embodiment of the present invention; [Figure 20] Aberration diagrams of the zoom lens of Example 7 at (A) the wide-angle end and (B) the telephoto end when focusing at infinity. [Figure 21] Aberration diagrams of the zoom lens of Example 7 at (A) the wide-angle end and (B) the telephoto end when focusing at close range. [Figure 22] Diagram showing the placement of the flare cut aperture [Figure 23] Schematic diagram showing an imaging device DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a zoom lens and an image pickup apparatus having the same according to the present invention will be described with reference to the accompanying drawings.

[0011] 1, 4, 7, 10, 13, 16, and 19 are cross-sectional views of the zoom lens L0 at the wide-angle end according to Examples 1 to 7. The zoom lens L0 of each Example is a zoom lens used in imaging devices such as digital video cameras, digital still cameras, broadcast cameras, cameras using silver halide film, surveillance cameras, and vehicle-mounted cameras.

[0012] In each lens cross-sectional view, the left side is the object side and the right side is the image side. The zoom lens L0 of each embodiment may also be used as a projection lens for a projector, etc. In this case, the left side is the screen side and the right side is the projected image side.

[0013] The zoom lens L0 in 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, and a rear lens unit LR having one or more lens units. The spacing between adjacent lens units changes during zooming. Each lens unit may be composed of a single lens or multiple lenses. The lens units may also include an aperture stop.

[0014] The solid arrows pointing downward in each lens cross-sectional view indicate the movement locus of each lens group during zooming from the wide-angle end to the telephoto end, while the solid arrows pointing upward in each lens cross-sectional view indicate the movement direction of the lens group during focusing from infinity to a close distance and the movement direction of the lens group during image blur correction.

[0015] In each lens cross-sectional view, SP denotes an aperture stop. IP denotes an image plane, where 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 in a digital still camera or digital video camera. When the zoom lens L0 of each embodiment is used as the photographic optical system of a silver halide film camera, a photosensitive surface equivalent to the film surface is placed on the image plane IP.

[0016] 2, 5, 8, 11, 14, 17, and 20 are aberration diagrams of the zoom lenses of Examples 1 to 7, respectively, at the wide-angle end and the telephoto end, when focusing at infinity.

[0017] 3, 6, 9, 12, 15, 18, and 21 are aberration diagrams of the zoom lenses of Examples 1 to 7, respectively, at the wide-angle end and the telephoto end, when focusing at close range.

[0018] In the spherical aberration diagram, Fno is the F-number, the solid line shows the amount of spherical aberration for the d-line (wavelength 587.6 nm), and the dashed line shows the amount of spherical aberration for the g-line (wavelength 435.8 nm). In the astigmatism diagram, the solid line shows the amount of aberration on the sagittal image plane, and the dashed line shows the amount of aberration on the meridional image plane. The distortion diagram shows the amount of distortion for the d-line. The chromatic aberration diagram shows the amount of lateral chromatic aberration for the g-line. ω is the imaging half angle of view (°).

[0019] 22 is a diagram showing the arrangement of flare cut apertures in the zoom lens L0 of Example 1. FC1A is a flare cut aperture arranged adjacent to the object side of the first lens unit L1, and FC1B is a flare cut aperture arranged between the surface of the first lens unit L1 closest to the object and the surface closest to the image.

[0020] FC2A is a flare cut stop arranged adjacent to the object side of the second lens unit L2, FC2B is a flare cut stop arranged between the surface of the second lens unit L2 closest to the object and the surface closest to the image, FC3A is a flare cut stop arranged adjacent to the object side of the third lens unit L3, and FC3B is a flare cut stop arranged between the surface of the third lens unit L3 closest to the object and the surface closest to the image.

[0021] FCrA is a flare cut aperture arranged adjacent to the object side of the lens group arranged closest to the image in the zoom lens L0, and FCrB is a flare cut aperture arranged adjacent to the image side of the lens group arranged closest to the image in the zoom lens L0.

[0022] Next, the characteristic configuration of the zoom lens of each embodiment will be described.

[0023] In the zoom lens L0 of each embodiment, the refractive power of the first lens unit L1 is set to be positive, thereby positioning the principal point on the object side and shortening the overall lens length. The overall lens length is the sum of the axial distance from the surface of the zoom lens L0 closest to the object to the surface closest to the image, and the back focus. Here, the back focus is the air-equivalent value of the axial distance between the surface of the zoom lens L0 closest to the image and the image plane.

[0024] By making the refractive power of the second lens unit L2 negative, chromatic aberration of magnification, particularly at the wide-angle end, is corrected. Furthermore, by arranging the rear unit LR, which has one or more lens units, fluctuations in various aberrations that occur during zooming are suppressed.

[0025] In addition, the zoom lens L0 has a first positive lens GP1 with positive refractive power that is arranged closest to the object, thereby converging the axial light beam that passes through the first positive lens GP1 and reducing the diameter of each lens that is arranged closer to the image than the positive lens GP1.

[0026] Furthermore, by keeping the first lens unit L1 stationary during zooming from the wide-angle end to the telephoto end, decentering of the first lens unit L1 during zooming caused by manufacturing errors and the like is suppressed, and fluctuations in various aberrations due to decentering are suppressed.

[0027] The zoom lens L0 in each embodiment is configured to satisfy the following conditional expressions.

[0028] 0.020 <d1AB / f1A<0.200···(1) 0.100 <sk / Lt<0.250···(2) Here, the first lens group L1 is composed of a first subgroup L1A and a second subgroup L1B arranged adjacent to the first subgroup L1A on the image side. Of the air spaces on the optical axis between adjacent lenses in the first lens group L1, the air space on the optical axis between the first subgroup L1A and the second subgroup L1B is the largest. In this case, d1AB is the distance on the optical axis between the surface of the first subgroup L1A closest to the image and the surface of the second subgroup L1B closest to the object.

[0029] f1A is the focal length of the first subgroup L1A. sk is the shorter of the back focuses at the wide-angle end and the telephoto end. If the back focuses at the wide-angle end and the telephoto end are the same, either the back focus at the wide-angle end or the telephoto end is taken as sk. Lt is the total lens length at the telephoto end.

[0030] Conditions (1) and (2) are intended to achieve good correction of various aberrations, a long focal length, and a compact, lightweight design.

[0031] If the upper limit of conditional expression (1) is exceeded, the distance on the optical axis between the first sub-unit L1A and the second sub-unit L1B becomes too long, increasing the overall lens length. If the lower limit of conditional expression (1) is not reached, the height from the optical axis of the on-axis light beam incident on the second sub-unit L1B becomes too high, increasing the diameter of the second sub-unit L1B. As a result, it becomes difficult to reduce the weight.

[0032] If the upper limit of conditional expression (2) is exceeded, the overall lens length at the telephoto end becomes too short, resulting in strong refractive power for each lens group. As a result, it becomes difficult to suppress fluctuations in various aberrations that occur during zooming. If the lower limit of conditional expression (2) is exceeded, the back focus at the wide-angle end or telephoto end becomes too short. As a result, when an image sensor is placed, ghost light that is generated by reflection between the image sensor and the image-side surface of the lens closest to the image side is likely to be imaged on the image sensor, which is undesirable.

[0033] With the above configuration, it is possible to realize a zoom lens that has high optical performance, a long focal length, and is small and lightweight.

[0034] It is preferable that at least one of the upper and lower limits of the range of values ​​in either conditional expressions (1) or (2) is set to the value of the following conditional expressions (1a) or (2a).

[0035] 0.023 <d1AB / f1A<0.160···(1a) 0.105 <sk / Lt<0.230···(2a) It is more preferable that at least one of the upper and lower limits of the numerical range of either conditional formula (1) or (2) satisfies the range of the following conditional formula (1b) or (2b).

[0036] 0.026 <d1AB / f1A<0.130···(1b) 0.110 <sk / Lt<0.210···(2b) It is even more preferable that at least one of the upper and lower limits of the numerical range of either conditional formula (1) or (2) is set to the range of the following conditional formula (1c) or (2c).

[0037] 0.030 <d1AB / f1A<0.110···(1c) 0.115 <sk / Lt<0.180···(2c) Next, a preferred configuration of the zoom lens L0 in each embodiment will be described.

[0038] The rear group LR preferably has a first focus lens group LRF that moves during focusing from infinity to a close distance. Because the lenses in the rear group LR have relatively small diameters, the first focus lens group LRF moves during focusing, which allows the lens groups that move during focusing to be lightweight.

[0039] Furthermore, it is preferable that the first focus lens group LRF has negative refractive power and moves toward the image side during focusing from infinity to close range. This increases the position sensitivity of the first focus lens group LRF, i.e., the absolute value of the amount of movement of the image plane position relative to the amount of movement of the first focus lens group LRF. As a result, the amount of movement of the first focus lens group LRF during focusing can be reduced, and the diameter of the first focus lens group LRF can be made smaller.

[0040] Furthermore, it is preferable that the rear group LR includes a second focus lens unit LF2, and that the first focus lens unit LRF and the second focus lens unit LF2 move along different loci during focusing from infinity to close range. By moving along different loci, it becomes easier to suppress fluctuations in various aberrations that occur during focusing.

[0041] The first lens group L1 is preferably made up of four or fewer lenses. Since the diameter of the lenses arranged in the first lens group L1 is relatively large, by making it up of four or fewer lenses, it is possible to reduce the weight.

[0042] It is preferable that the first sub-unit L1A be composed of two or less lenses. Because the diameter of the lens arranged on the object side in the first lens unit L1 is relatively large, by composing the first sub-unit L1A of two or less lenses, it is possible to reduce the weight.

[0043] It is preferable that the zoom lens L0 of each embodiment satisfies one or more of the following conditional expressions.

[0044] -5.00 <f1 / f2<-0.80···(3) 0.40 <Lt / ft<0.80···(4) 1.1<βLRF1<4.0 (5) -10.0<(1-βLRF1×βLRF1)×βR1×βR1<-3.0 (6) 1.2 <f1 / fLP<6.0···(7) 0.0<(r2+r1) / (r2-r1)<1.5...(8) 0.10 <f1 / ft<0.80···(9) -3.5<(r2LRF+r1LRF) / (r2LRF-r1LRF)<-0.2...(10) 0.04 <dsum / f1<0.35···(11) -0.010<θgF_N-(-0.0016178×νd_N+0.64146)<0.010...(12) -0.012<θgF_PR-(-0.0016178×νd_PR+0.64146)<0.005...(13) 0.4 <fLF1 / fLF2<3.0···(14) 0.2 <MLF1 / MLF2<5.0···(15) 0.01 <T×|(1-βLRF2×βLRF2)×βR2×βR2| / f<0.50···(16) 50<νd_RF1N<100···(17) -1.00 <fLRF / f1<-0.05···(18) 1.0 <f1 / f3<5.0···(19) Here, f1 is the focal length of the first lens group L1, f2 is the focal length of the second lens group L2, and ft is the focal length of the entire system at the telephoto end.

[0045] βLRF1 is the lateral magnification of the first focus lens unit LRF when focusing at an object distance where the lateral magnification of the entire system is −0.2 at the telephoto end. βR1 is the combined lateral magnification of all lens units located on the image side of the first focus lens unit LRF when focusing at an object distance where the lateral magnification of the entire system is −0.2 at the telephoto end.

[0046] fLP is the focal length of the lens group with positive refractive power arranged in the rear group LR that is located closest to the object side, r1 is the radius of curvature of the object-side surface of the first positive lens GP1, and r2 is the radius of curvature of the image-side surface of the first positive lens GP1.

[0047] r1LRF is the radius of curvature of the surface of the first focus lens group LRF closest to the object, r2LRF is the radius of curvature of the surface of the first focus lens group LRF closest to the image, and dsum is the sum of the air spaces on the optical axis in the first lens group L1.

[0048] νd_N and θgF_N are the Abbe number and the partial dispersion ratios for the g-line and F-line, respectively, of the negative lens GN1 that is arranged closest to the object among the negative lenses arranged in the first lens unit L1.

[0049] The rear group LR has an aperture stop SP that determines the axial light beam, and νd_PR and θgF_PR are the Abbe number and partial dispersion ratios for the g-line and F-line of at least two positive lenses arranged on the image side of the aperture stop SP, respectively.

[0050] The zoom lens L0 has a second focus lens group LF2, and of the first focus lens group LRF and the second focus lens group LF2, the lens group located on the object side is referred to as the object-side focus lens group, and the lens group located on the image side is referred to as the image-side focus lens group, where fLF1 is the focal length of the object-side focus lens group, and fLF2 is the focal length of the image-side focus lens group.

[0051] MLF1 and MLF2 are the absolute values ​​of the movement amounts of the object-side focus lens unit and the image-side focus lens unit, respectively, at the telephoto end when focusing from infinity to an object distance where the lateral magnification of the entire system is −0.2.

[0052] T is the distance on the optical axis between the surface of the first focus lens group LRF closest to the image side and the object side surface of the lens arranged adjacent to and on the image side of the first focus lens group LRF when focusing at an object distance where the lateral magnification of the entire system is −0.3 at the telephoto end.

[0053] βLRF2 and βR2 are, respectively, the lateral magnification of the first focus lens unit LRF when focusing at an object distance where the lateral magnification of the entire system is −0.3, and the combined lateral magnification of all lens units arranged on the image side of the first focus lens unit LRF.

[0054] The first focus lens group LRF has a cemented lens consisting of a positive lens and a negative lens, where νd_RF1N is the Abbe number of the negative lens, and fLRF is the focal length of the first focus lens group LRF.

[0055] The rear group LR includes a third lens unit L3 with positive refractive power that is located closest to the object, where f3 is the focal length of the third lens unit L3.

[0056] Next, the technical meaning of the above-mentioned conditional expressions (3) to (19) will be explained.

[0057] If the upper limit of conditional expression (3) is exceeded, the refractive power of the first lens unit L1 becomes too strong, making it difficult to correct spherical aberration and axial chromatic aberration, particularly at the telephoto end. If the lower limit of conditional expression (3) is not reached, the refractive power of the first lens unit L1 becomes too weak, causing the principal point of the entire system to be located on the image side. As a result, the overall lens length becomes long, which is undesirable.

[0058] Exceeding the upper limit of conditional expression (4) is undesirable because the overall lens length at the telephoto end becomes too long. Falling below the lower limit of conditional expression (4) makes the overall lens length at the telephoto end too short, resulting in strong refractive power for each lens group. As a result, it becomes difficult to suppress fluctuations in various aberrations that occur during zooming.

[0059] If the upper limit of conditional expression (5) is exceeded, the refractive power of the first focus lens group LRF becomes too strong, making it difficult to suppress fluctuations in spherical aberration and field curvature during focusing.If the lower limit of conditional expression (5) is not reached, the amount of movement of the first focus lens group LRF that occurs during focusing becomes too large, making the overall lens length long.

[0060] Conditional expression (6) expresses the position sensitivity of the first focus lens group LRF when focusing at an object distance where the lateral magnification of the entire system is -0.2. If the upper limit of conditional expression (6) is exceeded, the amount of movement of the first focus lens group LRF during focusing becomes too large, resulting in a long overall lens length. If the lower limit of conditional expression (6) is not satisfied, the refractive power of the first focus lens group LRF becomes too strong, making it difficult to suppress fluctuations in spherical aberration and field curvature that occur during focusing.

[0061] If the upper limit of conditional expression (7) is exceeded, the refractive power of the lens group with positive refractive power arranged in the rear group LR that is located closest to the object becomes too strong, making it difficult to correct spherical aberration, particularly at the wide-angle end.If the lower limit of conditional expression (7) is not reached, the refractive power of the lens group with positive refractive power arranged in the rear group LR that is located closest to the object becomes too weak, making it difficult to correct spherical aberration, particularly at the wide-angle end.

[0062] Conditional expression (8) defines the shape factor of the first positive lens GP1. If the upper limit of conditional expression (8) is exceeded and the absolute value of the radius of curvature of the object-side surface of the first positive lens GP1 becomes small, it becomes difficult to correct spherical aberration, particularly at the telephoto end. If the lower limit of conditional expression (8) is exceeded and the absolute value of the radius of curvature of the image-side surface of the first positive lens GP1 becomes small, the principal point of the entire system is positioned relatively close to the image side, and the overall lens length becomes long.

[0063] If the upper limit of conditional expression (9) is exceeded, the refractive power of the first lens unit L1 becomes too weak, and the principal point of the entire system is located on the image side. As a result, the overall lens length becomes long, which is undesirable. If the lower limit of conditional expression (9) is not reached, the refractive power of the first lens unit L1 becomes too strong, and it becomes difficult to correct spherical aberration and axial chromatic aberration, especially at the telephoto end.

[0064] If the upper limit of conditional expression (10) is exceeded, the surface of the first focus lens group LRF closest to the object will be concave toward the object side, and the absolute value of the radius of curvature will be too small. As a result, the fluctuation of spherical aberration that occurs during focusing will be large. If the lower limit of conditional expression (10) is not reached, the surface of the first focus lens group LRF closest to the object will be convex toward the object side, and the absolute value of the radius of curvature will be too small. As a result, the fluctuation of field curvature that occurs during focusing will be large.

[0065] Conditional expression (11) defines the ratio of the sum of the air gaps on the optical axis in the first lens group L1 to the focal length of the first lens group L1. By increasing the air gaps between the lenses in the first lens group L1, the diameters of the lenses located closer to the image than the lens located closest to the object in the first lens group L1 can be reduced. This is preferable because it results in a lighter weight. If the upper limit of conditional expression (11) is exceeded, the refractive power of the first lens group L1 becomes too strong. As a result, it becomes difficult to correct spherical aberration and chromatic aberration of magnification, particularly at the telephoto end. If the lower limit of conditional expression (11) is exceeded, the diameters of the lenses in the first lens group L1 become too large, making it difficult to reduce the weight.

[0066] Conditional expression (12) defines the anomalous dispersion of the negative lens GN1, which is located closest to the object among the negative lenses arranged in the first lens unit L1. If the upper limit of conditional expression (12) is exceeded, it becomes difficult to correct chromatic aberration of magnification at the telephoto end. If the lower limit of conditional expression (12) is not met, it becomes difficult to correct chromatic aberration of magnification at the wide-angle end.

[0067] Conditional expression (13) defines the anomalous dispersion of at least two positive lenses arranged closer to the image side than the aperture stop SP. If the upper limit of conditional expression (13) is exceeded, it becomes difficult to correct lateral chromatic aberration at the telephoto end. If the lower limit of conditional expression (13) is not reached, it becomes difficult to correct lateral chromatic aberration at the wide-angle end. Furthermore, by using three to five positive lenses that satisfy conditional expression (13), it is possible to further reduce lateral chromatic aberration at the wide-angle end and the telephoto end.

[0068] If the upper limit of conditional expression (14) is exceeded, the refractive power of the image-side focus lens unit becomes too strong, making it difficult to suppress fluctuations in various aberrations that occur during focusing.If the lower limit of conditional expression (14) is not reached, the refractive power of the object-side focus lens unit becomes too strong, making it difficult to suppress fluctuations in various aberrations that occur during focusing.

[0069] If the upper limit of conditional expression (15) is exceeded, the amount of movement of the object-side focus lens group becomes too large, which is undesirable because the diameter of the object-side focus lens group must be large in order to ensure the amount of peripheral illumination.If the lower limit of conditional expression (15) is not exceeded, the amount of movement of the image-side focus lens group becomes too large, which is undesirable because the diameter of the image-side focus lens group must be large in order to ensure the amount of peripheral illumination.

[0070] Conditional expression (16) defines the condition for enabling focusing at the telephoto end at an object distance where the lateral magnification of the entire system is -0.3. Due to lens manufacturing errors, the actual image plane position may deviate from the designed image plane position. Therefore, it is preferable to be able to change the position of the first focus lens group LRF in the optical axis direction from a predetermined designed position by adjustment that takes lens manufacturing errors into account, so as to correct the deviation of the image plane position to a predetermined image plane position.

[0071] Therefore, it is necessary to ensure the distance T on the optical axis in accordance with the position sensitivity of the first focus lens group LRF. When the absolute value of the position sensitivity of the first focus lens group LRF is large, the distance T on the optical axis can be small, and when the absolute value of the position sensitivity of the first focus lens group LRF is small, it is preferable to ensure the distance T on the optical axis is large.

[0072] If the upper limit of conditional expression (16) is exceeded, the distance T on the optical axis becomes too large, undesirably increasing the overall lens length. If the lower limit of conditional expression (16) is not reached, the distance T on the optical axis becomes too small, making it difficult to focus at an object distance at which the lateral magnification of the entire system is -0.3. The position sensitivity of the first focus lens unit LRF is a value calculated by (1-βLRF2×βLRF2)×βR2×βR2.

[0073] If the upper limit of conditional expression (17) is exceeded, the refractive index of the negative lens disposed in the first focus lens unit LRF will be small. As a result, the absolute value of the curvature of the object-side or image-side surface of the negative lens will be large, resulting in large fluctuations in spherical aberration or curvature of field that occur particularly during focusing. If the lower limit of conditional expression (17) is not reached, large fluctuations in chromatic aberration that occur during focusing will occur.

[0074] If the upper limit of conditional expression (18) is exceeded and the refractive power of the first focus lens group LRF becomes strong, fluctuations in field curvature and the like during focusing become large. If the lower limit of conditional expression (18) is not reached and the refractive power of the first focus lens group LRF becomes weak, the amount of movement of the first focus lens group LRF during focusing becomes too large. As a result, the overall lens length becomes long.

[0075] If the upper limit of conditional expression (19) is exceeded, the refractive power of the third lens unit L3 becomes too strong, making it difficult to suppress fluctuations in spherical aberration, axial chromatic aberration, and the like that occur during zooming.

[0076] If the lower limit of conditional expression (19) is not reached, the refractive power of the third lens unit L3 becomes too weak, and as a result, in order to obtain a desired zoom ratio, the movement amount of the third lens unit L3 during zooming becomes too large, and the overall lens length becomes long.

[0077] It is more preferable to set at least one of the upper and lower limits of the conditional expressions (3) to (19) to the following numerical ranges.

[0078] -4.50 <f1 / f2<-1.00···(3a) 0.43 <Lt / ft<0.75···(4a) 1.3<βLRF1<3.7···(5a) -9.5<(1-βLRF1×βLRF1)×βR1×βR1<-3.5 (6a) 1.6 <f1 / fLP<5.0···(7a) 0.1<(r2+r1) / (r2-r1)<1.2...(8a) 0.15 <f1 / ft<0.70···(9a) -3.0<(r2LRF+r1LRF) / (r2LRF-r1LRF)<-0.3...(10a) 0.05 <dsum / f1<0.30···(11a) -0.005<θgF_N-(-0.0016178×νd_N+0.64146)<0.005...(12a) -0.010<θgF_PR-(-0.0016178×νd_PR+0.64146)<0.004...(13a) 0.8 <fLF1 / fLF2<2.5···(14a) 0.8 <MLF1 / MLF2<4.0···(15a) 0.03 <T×|(1-βLRF2×βLRF2)×βR2×βR2| / f<0.40···(16a) 55<νd_RF1N<90···(17a) -0.80 <fLRF / f1<-0.10···(18a) 1.5 <f1 / f3<4.5···(19a) It is more preferable to set at least one of the upper and lower limits of the conditional expressions (3) to (19) to the following numerical ranges.

[0079] -4.00 <f1 / f2<-1.30···(3b) 0.48 <Lt / ft<0.70···(4b) 1.5<βLRF1<3.4 (5b) -9.0<(1-βLRF1×βLRF1)×βR1×βR1<-4.0 (6b) 2.0 <f1 / fLP<4.0···(7b) 0.2<(r2+r1) / (r2-r1)<0.9...(8b) 0.20 <f1 / ft<0.50···(9b) -2.5<(r2LRF+r1LRF) / (r2LRF-r1LRF)<-0.4...(10b) 0.06 <dsum / f1<0.20···(11b) -0.003<θgF_N-(-0.0016178×νd_N+0.64146)<0.003...(12b) -0.008<θgF_PR-(-0.0016178×νd_PR+0.64146)<0.003...(13b) 1.2 <fLF1 / fLF2<2.0···(14b) 1.4 <MLF1 / MLF2<3.0···(15b) 0.05 <T×|(1-βLRF2×βLRF2)×βR2×βR2| / f<0.30···(16b) 60<νd_RF1N<80···(17b) -0.60 <fLRF / f1<-0.20···(18b) 2.0 <f1 / f3<4.0···(19b) Next, the configuration of the zoom lens L0 in each embodiment will be described in detail. From embodiment 2 onwards, differences from embodiment 1 will be mainly described.

[0080] [Example 1] The zoom lens L0 of Example 1 comprises, arranged in order from the object side to the image side, a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, and a rear group LR having one or more lens groups. The rear group LR comprises, arranged in order from the object side to the image side, a third lens group L3 with positive refractive power, a fourth lens group L4 with positive refractive power, a fifth lens group L5 with negative refractive power, a sixth lens group L6 with negative refractive power, and a seventh lens group L7 with positive refractive power. By appropriately arranging the lens groups with positive refractive power and negative refractive power, various aberrations are effectively corrected throughout the entire zoom range.

[0081] During focusing, the fifth lens unit L5 and the sixth lens unit L6 move toward the image side along different trajectories, thereby suppressing fluctuations in various aberrations that occur during focusing.

[0082] During image blur correction, the vibration reduction group LVR arranged in the third lens group L3 moves so as to include a direction perpendicular to the optical axis. Because the diameter of each lens arranged in the third lens group L3 is relatively small, by arranging the vibration reduction group LVR in the third lens group L3, the diameter of the vibration reduction group LVR can be made small.

[0083] [Example 2] The rear group LR in the zoom lens L0 of Example 2 is composed of, arranged in order from the object side to the image side, a third lens group L3 with positive refractive power, a fourth lens group L4 with negative refractive power, and a fifth lens group L5 with positive refractive power. By reducing the number of lens groups compared to Example 1, it becomes even easier to suppress fluctuations in aberrations caused by relative decentering of each lens group that occurs during zooming due to manufacturing errors and the like.

[0084] When focusing from infinity to a close distance, the fourth lens unit L4 moves toward the image side, thereby suppressing fluctuations in various aberrations that occur during focusing.

[0085] The fifth lens unit L5 has an aspherical lens, which makes it easier to suppress fluctuations in field curvature and distortion that occur during zooming.

[0086] [Example 3] The rear group LR in the zoom lens L0 of Example 3 includes, arranged in order from the object side to the image side, a third lens group L3 with negative refractive power, a fourth lens group L4 with positive refractive power, and a fifth lens group L5 with positive refractive power. Further, the rear group LR includes, arranged closer to the image side than the fifth lens group L5, a sixth lens group L6 with negative refractive power, a seventh lens group L7 with negative refractive power, and an eighth lens group L8 with positive refractive power.

[0087] Compared to the first embodiment, the number of lens groups having negative refractive power is increased, making it easier to correct chromatic aberration of magnification, axial chromatic aberration, and the like.

[0088] During focusing, the sixth lens unit L6 and the seventh lens unit L7 move toward the image side along different trajectories, thereby suppressing fluctuations in various aberrations that occur during focusing.

[0089] [Example 4] The rear group LR in the zoom lens L0 of Example 4 is composed of, arranged in order from the object side to the image side, a third lens group L3 with negative refractive power, a fourth lens group L4 with positive refractive power, a fifth lens group L5 with negative refractive power, a sixth lens group L6 with negative refractive power, and a seventh lens group L7 with positive refractive power. By appropriately arranging the lens groups with positive refractive power and negative refractive power, various aberrations are effectively corrected throughout the entire zoom range.

[0090] [Example 5] The rear group LR in the zoom lens L0 of Example 5 is composed of, arranged in order from the object side to the image side, a third lens group L3 with positive refractive power, a fourth lens group L4 with negative refractive power, a fifth lens group L5 with negative refractive power, and a sixth lens group L6 with positive refractive power. By appropriately arranging the lens groups with positive refractive power and negative refractive power, various aberrations are effectively corrected throughout the entire zoom range.

[0091] [Example 6] The rear group LR in the zoom lens L0 of Example 6 includes, arranged in order from the object side to the image side, a third lens group L3 with negative refractive power, a fourth lens group L4 with positive refractive power, and a fifth lens group L5 with positive refractive power. Furthermore, arranged closer to the image side than the fifth lens group L5 are a sixth lens group L6 with negative refractive power, a seventh lens group L7 with negative refractive power, and an eighth lens group L8 with positive refractive power. By appropriately arranging the lens groups with positive refractive power and the lens groups with negative refractive power, various aberrations are effectively corrected throughout the entire zoom range.

[0092] By keeping the third lens unit L3 stationary during zooming, decentering of the third lens unit L3 that occurs during zooming due to manufacturing errors and the like is suppressed, making it easier to suppress fluctuations in various aberrations.

[0093] [Example 7] In the zoom lens L0 of Example 7, the lens group arranged closest to the image side is fixed during zooming, thereby suppressing decentering of the lens group arranged closest to the image side that occurs during zooming due to manufacturing errors and the like, and making it easier to suppress fluctuations in various aberrations.

[0094] In the zoom lens L0 of Examples 1, 2, 5, and 7, it is preferable that the first lens unit L1 or the third lens unit L3 includes one or more positive lenses made of a material with an Abbe number of 80 or more and 100 or less. This makes it possible to effectively correct axial chromatic aberration at the telephoto end. It is more preferable that the zoom lens L0 includes one or more positive lenses made of a material with an Abbe number of 90 or more and 96 or less.

[0095] In the zoom lens L0 of Examples 3, 4, and 6, it is preferable that the first lens unit L1 or the second lens unit L2 includes one or more positive lenses made of a material with an Abbe number of 80 or more and 100 or less. This makes it possible to effectively correct axial chromatic aberration at the telephoto end. It is more preferable that the zoom lens L0 includes one or more positive lenses made of a material with an Abbe number of 90 or more and 96 or less.

[0096] In the zoom lens L0 of each embodiment, it is preferable that the material of at least one of the positive lenses in the first lens group L1 has a specific gravity of 3.0 or less and an Abbe number of 65 or more and 100 or less. As a result, the weight of the first lens group L1 can be reduced while effectively correcting axial chromatic aberration at the telephoto end. In each embodiment, the first positive lens GP1 is Ohara's S-FSL7, which has a specific gravity of 2.46. As another example, optical glass J-FK5, which has a specific gravity of 2.45, may also be used, but is not limited to this.

[0097] In the zoom lens L0 of each embodiment, it is preferable that the Abbe number of the material of the negative lens GN1 is not less than 25 and not more than 40. This makes it easier to correct axial chromatic aberration and chromatic aberration of magnification over the entire zoom range.

[0098] In the zoom lens L0 of each embodiment, it is preferable to deposit a fluorine coating on the object-side surface of the lens positioned closest to the object and the image-side surface of the lens positioned closest to the image. Because the object-side surface of the lens positioned closest to the object and the image-side surface of the lens positioned closest to the image are easily exposed to the outside world, depositing a fluorine coating on them can improve water and oil repellency, suppress flare, and achieve high optical performance. In particular, because the object-side surface of the lens positioned closest to the object has a large diameter, it is preferable to deposit a fluorine coating on them.

[0099] In the zoom lens L0 of each embodiment, the positive lens and negative lens constituting the cemented lens are preferably bonded with an adhesive having an axial thickness of 0.005 mm or more and 0.05 mm or less. If it is less than 0.005 mm, the adhesive is prone to peeling, and if it is more than 0.03 mm, the axial distance from the surface of the cemented lens closest to the object to the surface closest to the image becomes long, resulting in a long overall lens length. More preferably, it should be 0.008 mm or more and 0.02 mm or less.

[0100] At least one lens element in the zoom lens L0 of each embodiment is provided with an anti-reflection coating to prevent reflections, and the anti-reflection coating is composed of multiple films. Here, when the refractive index of the film closest to the air interface is Nd, the anti-reflection coating PC preferably has an Nd of 1.32 or less. By setting Nd to 1.32 or less, the difference in refractive index with air can be reduced, thereby further reducing light reflection and reducing ghosting. Specific examples of the anti-reflection coating PC include, but are not limited to, multilayer films formed using a wet method, as described in JP 2012-230211 A and JP 2014-95877 A. More preferably, setting Nd to 1.30 or less can further reduce ghosting.

[0101] Here, it is preferable to provide an anti-reflection coating PC on the image-side surface of the negative lens element with a concave surface facing the image side among the negative lenses arranged in the zoom lens L0. Light reflected by a negative lens element with a concave surface facing the image side is likely to be reflected at a large angle relative to the normal to the surface of the negative lens element with a concave surface facing the image side, and therefore tends to have a high reflectivity. Furthermore, light reflected by a negative lens element with a concave surface facing the image side is likely to be focused on the image plane, making ghosting more noticeable. Therefore, ghosting can be reduced by providing an anti-reflection coating PC on the image-side surface of a negative lens element with a concave surface facing the image side.

[0102] In each embodiment, it is preferable to provide a flare cut diaphragm that blocks light rays. Fig. 22 is a diagram showing the arrangement of a flare cut diaphragm in the zoom lens L0 of Example 1, and a preferable configuration for providing a flare cut diaphragm will be described using Fig. 22.

[0103] It is preferable to have at least one of a flare cut aperture FC1A arranged adjacent to the object side of the first lens unit L1, and a flare cut aperture FC1B arranged between the surface of the first lens unit L1 closest to the object and the surface closest to the image, thereby appropriately blocking unnecessary marginal rays on the axis at the telephoto end and reducing ghosts.

[0104] It is preferable to have at least one of a flare cut aperture FC2A arranged adjacent to the object side of the second lens unit L2, and a flare cut aperture FC2B arranged between the surface of the second lens unit L2 closest to the object and the surface closest to the image side, thereby appropriately blocking unnecessary off-axis marginal rays and chief rays at the wide-angle end and in the intermediate zoom range, thereby reducing coma aberration and ghosting.

[0105] It is preferable to have at least one of a flare cut aperture FC3A located adjacent to the object side of the third lens unit L3, and a flare cut aperture FC3B located between the surface of the third lens unit L3 closest to the object and the surface closest to the image, thereby appropriately blocking unnecessary off-axis marginal rays and chief rays at the wide-angle end and in the intermediate zoom range, thereby reducing coma aberration and ghosting.

[0106] It is preferable that the zoom lens L0 has at least one of a flare-cut aperture FCrA arranged adjacent to the lens group arranged closest to the image on the object side, and a flare-cut aperture FCrB arranged adjacent to the lens group arranged closest to the image on the image side, which appropriately blocks unnecessary off-axis marginal rays and chief rays at the wide-angle end, thereby reducing coma aberration and ghosts.

[0107] The preferable arrangement of the flare cut diaphragm described above is not limited to the first embodiment, and similar arrangements can also be used in the second to seventh embodiments to reduce coma and ghosts.

[0108] Numerical Examples 1 to 7 corresponding to Examples 1 to 7, respectively, are shown below.

[0109] 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. Furthermore, nd represents the refractive index of each optical element at the d-line, and vd represents the Abbe number of the optical element. Note that the Abbe number vd of a certain material is given by Nd, NF, and NC, respectively, when the refractive indices at the Fraunhofer d-line (wavelength 587.6 nm), F-line (wavelength 486.1 nm), C-line (wavelength 656.3 nm), and g-line (wavelength 435.8 nm) are: νd=(Nd-1) / (NF-NC) It is expressed as:

[0110] The back focus BF is the distance from the final lens surface to the image plane. The total lens length is the sum of the back focus and the distance from the first lens surface to the final lens surface.

[0111] 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, and A10 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 In addition, "e±XX" in each aspherical coefficient is "×10± XX " means.

[0112] The lens construction length represents the distance on the optical axis from the surface closest to the object to the surface closest to the image in each lens group.

[0113] [Numerical Example 1] Unit: mm Surface Data Surface number rd nd νd 1 167.158 10.93 1.48749 70.2 2 -530.668 20.46 3 169.404 5.80 1.48749 70.2 4 591.385 10.33 5 387.580 7.05 1.49700 81.5 6 -219.751 2.00 1.66565 35.6 7 297.419 (variable) 8 871.935 2.70 1.84666 23.8 9 -304.082 1.65 1.72916 54.7 10 107.194 5.86 11 -113.371 1.65 1.72916 54.7 12 133.337 2.99 1.90110 27.1 13 458.489 (variable) 14 85.565 8.57 1.43700 95.1 15 -137.102 0.15 16 67.456 5.62 1.49700 81.5 17 329.100 0.20 18 58.187 8.00 1.49700 81.5 19 -224.988 1.50 1.91082 35.2 20 160.562 4.19 21 (Aperture) ∞ 16.52 22 116.011 6.09 1.85478 24.8 23 -40.755 1.40 1.95375 32.3 24 31.344 5.48 25 50.873 1.40 2.00069 25.5 26 32.043 5.14 1.65412 39.7 27 -429.859 (variable) 28 36.500 6.98 1.48749 70.2 29 -46.788 0.20 30 -111.598 1.20 1.72916 54.7 31 26.589 4.52 1.65412 39.7 32 2444.126 (variable) 33 175.783 1.81 1.67300 38.3 34 -161.521 1.20 1.59282 68.6 35 33.443 (variable) 36 654.549 2.26 1.73037 32.2 37 -47.624 3.57 38 -37.539 1.20 1.81600 46.6 39 56.403 (variable) 40 -286.811 4.81 1.61340 44.3 41 -56.435 (variable) 42 ∞ 1.30 1.51633 64.1 43 ∞ (variable) Image plane ∞ Various data Zoom ratio 3.15 Focal length 185.00 300.00 582.00 F-number 5.15 5.70 6.48 Angle of view 6.67 4.12 2.13 Image height 21.64 21.64 21.64 Lens total length 329.56 329.56 329.56 BF 41.56 41.56 41.56 d 7 4.46 26.23 47.00 d13 89.79 51.76 1.40 d27 2.71 1.95 1.83 d32 4.24 5.83 2.10 d35 4.60 3.90 17.03 d39 18.76 34.90 55.20 d41 39.90 39.90 39.90 d43 0.80 0.80 0.80 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position L1 1 227.83 56.58 -5.68 -50.65 L2 8 -78.24 14.84 6.20 -4.49 L3 14 96.05 64.27 -44.76 -67.86 L4 28 70.46 12.89 -0.07 -8.35 L5 33 -75.34 3.01 2.41 0.56 L6 36 -56.70 7.03 9.32 3.26 L7 40 113.64 4.81 3.68 0.72 Single lens data Lens starting surface focal length 1 1 262.10 2 3 484.82 3 5 283.26 4 6 -189.56 5 8 266.57 6 9 -108.51 7 11 -83.80 8 12 207.75 9 14 121.99 10 16 169.51 11 18 93.90 12 19 -102.68 13 22 35.93 14 23 -18.40 15 25 -89.85 16 26 45.79 17 28 43.25 18 30 -29.34 19 31 41.07 20 33 125.34 21 34 -46.63 22 36 60.87 23 38 -27.46 24 40 113.64

[0114] [Numerical Example 2] Unit: mm Surface Data Surface number rd nd νd 1 176.894 7.94 1.48749 70.2 2 -539.249 15.12 3 183.239 5.56 1.49700 81.5 4 4269.499 11.55 5 128.849 8.13 1.43387 95.1 6 -293.177 2.00 1.66565 35.6 7 174.927 (variable) 8 84.148 3.22 1.84666 23.8 9 499.988 1.80 1.83481 42.7 10 54.038 3.38 11 -282.062 1.65 1.72916 54.7 12 200.603 2.65 13 -74.139 1.65 1.72916 54.7 14 132.561 2.22 1.85478 24.8 15 -1362.082 (variable) 16 70.769 4.63 1.49700 81.5 17 -295.413 0.15 18 58.198 4.92 1.43700 95.1 19 -521.660 0.20 20 45.166 5.20 1.49700 81.5 21 -322.470 1.50 1.91082 35.2 22 97.680 12.87 23 (Aperture) ∞ 4.17 24 86.277 4.89 1.85478 24.8 25 -34.201 1.40 2.00100 29.1 26 32.815 3.25 27 49.167 1.40 2.05090 26.9 28 28.311 4.19 1.74400 44.8 29 -220.692 1.70 30 39.501 4.73 1.66565 35.6 31 -46.637 0.94 32 -63.679 1.20 1.77250 49.6 33 85.743 (variable) 34 -108.317 2.00 1.76200 40.1 35 -32.315 1.20 1.59282 68.6 36 32.651 (variable) 37* -104.797 2.00 1.58313 59.4 38 461.269 4.76 1.54072 47.2 39 -54.337 (variable) 40 ∞ 1.30 1.54400 66.3 41 ∞ (variable) Image plane ∞ Aspheric data Page 37 K = 0.00000e+00 A 4=-8.21845e-07 A 6= 1.61295e-09 A 8=-7.79751e-12 A10= 1.42897e-14 Various data Zoom ratio 3.88 Focal length 125.00 250.00 485.00 F-number 5.15 5.70 6.48 Angle of view 9.82 4.95 2.55 Image height 21.64 21.64 21.64 Lens total length 299.54 299.54 299.54 BF 67.21 59.21 50.54 d 7 5.00 35.92 57.00 d15 78.26 38.37 1.40 d33 2.92 8.76 8.07 d36 12.00 23.13 48.37 d39 65.57 57.57 48.90 d41 0.80 0.80 0.80 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position L1 1 188.52 50.30 -2.03 -42.05 L2 8 -51.03 16.57 8.45 -3.61 L3 16 54.90 57.32 7.67 -42.18 L4 34 -49.79 3.20 1.41 -0.46 L5 37 220.36 6.76 9.52 5.40 Single lens data Lens starting surface focal length 1 1 274.23 2 3 385.05 3 5 207.52 4 6 -164.31 5 8 119.08 6 9 -72.71 7 11 -160.54 8 13 -64.99 9 14 141.42 10 16 115.36 11 18 120.12 12 20 80.09 13 21 -82.17 14 24 29.20 15 25 -16.56 16 27 -65.77 17 28 33.97 18 30 32.85 19 32 -47.14 20 34 59.76 21 35 -27.21 22 37 -146.25 23 38 90.19

[0115] [Numerical Example 3] Unit: mm Surface Data Surface number rd nd νd 1 186.421 10.49 1.48749 70.2 2 -466.525 11.50 3 135.341 9.89 1.43387 95.1 4 -1438.911 2.00 1.73800 32.3 5 686.001 (variable) 6 93.339 1.65 1.72916 54.7 7 72.899 6.75 8 -215.052 1.65 1.72916 54.7 9 64.949 5.43 1.84666 23.8 10 199.894 (variable) 11 -133.210 1.80 1.90366 31.3 12 578.154 (variable) 13 111.820 7.72 1.49700 81.5 14 -142.924 0.15 15 82.174 7.02 1.49700 81.5 16 -451.436 0.20 17 55.602 9.20 1.49700 81.5 18 -173.646 1.50 1.83481 42.7 19 114.871 4.91 20 (Aperture) ∞ 19.67 21 78.725 6.51 1.85478 24.8 22 -46.613 1.40 2.00100 29.1 23 34.007 4.69 24 50.855 1.40 2.00069 25.5 25 31.361 5.54 1.67300 38.3 26 -605.488 (variable) 27 41.440 6.59 1.61340 44.3 28 -54.456 0.20 29 -120.699 1.20 1.80400 46.5 30 30.249 3.63 1.72047 34.7 31 151.149 (variable) 32 165.608 2.20 1.71700 47.9 33 -468.190 1.20 1.59282 68.6 34 36.191 (variable) 35 510.018 2.04 1.66565 35.6 36 -56.736 5.59 37 -42.376 1.30 1.81600 46.6 38 60.290 (variable) 39 -430.294 4.50 1.73800 32.3 40 -67.815 (variable) 41 ∞ 1.30 1.51633 64.1 42 ∞ (variable) Image plane ∞ Various data Zoom ratio 3.15 Focal length 185.00 300.00 582.00 F-number 5.15 5.70 6.48 Angle of view 6.67 4.12 2.13 Image height 21.64 21.64 21.64 Lens total length 329.56 329.56 329.56 BF 41.93 41.93 41.93 d 5 11.18 28.57 48.18 d10 44.08 26.69 7.08 d12 51.85 32.59 1.40 d26 3.21 2.15 1.72 d31 4.36 6.19 2.10 d34 5.04 3.93 17.21 d38 18.39 37.98 60.41 d40 40.28 40.28 40.28 d42 0.80 0.80 0.80 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position L1 1 181.47 33.88 6.05 -20.62 L2 6 -124.51 15.48 8.70 -2.86 L3 11 -119.66 1.80 0.18 -0.77 L4 13 75.96 69.91 -31.38 -62.88 L5 27 80.72 11.62 -2.39 -9.15 L6 32 -85.91 3.40 2.83 0.77 L7 35 -57.54 8.93 12.50 4.08 L8 39 108.51 4.50 3.06 0.48 Single lens data Lens starting surface focal length 1 1 274.68 2 3 285.66 3 4 -629.20 4 6 -472.62 5 8 -68.24 6 9 111.57 7 11 -119.66 8 13 127.51 9 15 140.49 10 17 85.88 11 18 -82.62 12 21 35.09 13 22 -19.47 14 24 -84.80 15 25 44.46 16 27 39.39 17 29 -29.98 18 30 51.84 19 32 170.87 20 33 -56.62 21 35 76.81 22 37 -30.32 23 39 108.51

[0116] [Numerical Example 4] Unit: mm Surface Data Surface number rd nd νd 1 213.453 9.63 1.48749 70.2 2 -469.778 19.37 3 184.507 5.87 1.49700 81.5 4 772.141 14.98 5 176.591 8.58 1.43387 95.1 6 -313.802 2.00 1.66565 35.6 7 236.485 (variable) 8 95.748 2.97 1.84666 23.8 9 184.174 1.80 1.72916 54.7 10 69.858 3.70 11 841.564 1.65 1.83481 42.7 12 142.634 (variable) 13 -103.641 1.65 1.72916 54.7 14 105.417 3.39 1.85883 30.0 15 867.386 (variable) 16 109.472 5.57 1.49700 81.5 17 -230.044 0.15 18 64.810 6.17 1.43700 95.1 19 5042.936 0.20 20 50.914 6.71 1.49700 81.5 21 -1365.584 1.50 1.91082 35.2 22 119.771 18.39 23 (Aperture) ∞ 4.57 24 96.343 6.24 1.85478 24.8 25 -43.187 1.40 2.00100 29.1 26 32.403 3.36 27 45.458 1.40 2.05090 26.9 28 29.764 4.81 1.63930 44.9 29 -252.034 1.70 30 36.697 6.05 1.62004 36.3 31 -54.642 1.11 32 -111.891 1.20 1.80400 46.5 33 26.796 3.22 1.65412 39.7 34 102.082 (variable) 35 -264.632 2.21 1.71700 47.9 36 -38.807 1.20 1.59282 68.6 37 31.134 (variable) 38 -75.102 1.30 1.49700 81.5 39 -497.161 (variable) 40 927.872 3.97 1.66565 35.6 41 -93.927 (variable) 42 ∞ 1.30 1.51633 64.1 43 ∞ (variable) Image plane ∞ Various data Zoom ratio 2.85 Focal length 204.00 350.00 582.00 F-number 5.15 5.70 6.48 Angle of view 6.05 3.54 2.13 Image height 21.64 21.64 21.64 Lens total length 339.56 339.56 339.56 BF 49.56 47.21 45.56 d 7 2.60 31.23 48.79 d12 6.40 7.88 9.20 d15 82.65 41.51 1.40 d34 2.63 4.62 2.63 d37 35.70 28.91 32.01 d39 2.00 20.18 41.95 d41 47.90 45.55 43.90 d43 0.80 0.80 0.80 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position L1 1 222.93 60.43 -2.52 -51.45 L2 8 -147.55 10.12 9.66 2.14 L3 13 -146.97 5.04 0.23 -2.54 L4 16 66.53 73.75 0.24 -56.22 L5 35 -53.77 3.41 1.86 -0.17 L6 38 -178.18 1.30 -0.15 -1.02 L7 40 128.33 3.97 2.17 -0.22 Single lens data Lens starting surface focal length 1 1 302.46 2 3 486.19 3 5 261.83 4 6 -202.30 5 8 231.97 6 9 -155.38 7 11 -205.95 8 13 -71.44 9 14 139.44 10 16 150.06 11 18 150.18 12 20 98.92 13 21 -120.84 14 24 35.62 15 25 -18.32 16 27 -85.96 17 28 41.92 18 30 36.33 19 32 -26.79 20 33 54.62 21 35 63.17 22 36 -28.96 23 38 -178.18 24 40 128.33

[0117] [Numerical Example 5] Unit: mm Surface Data Surface number rd nd νd 1 181.713 10.52 1.48749 70.2 2 -483.402 19.69 3 230.376 5.10 1.49700 81.5 4 1064.139 16.34 5 151.939 9.64 1.43387 95.1 6 -240.468 2.00 1.66565 35.6 7 254.929 (variable) 8 97.520 3.08 1.85451 25.2 9 217.504 1.80 1.77250 49.6 10 66.713 4.14 11 -1179.870 1.65 1.77250 49.6 12 177.890 4.06 13 -94.438 1.65 1.72916 54.7 14 126.363 2.89 1.90110 27.1 15 1147.770 (variable) 16 104.598 5.76 1.49700 81.5 17 -217.233 0.15 18 70.984 5.66 1.43700 95.1 19 4294.947 0.20 20 51.051 7.05 1.49700 81.5 21 -518.420 1.50 1.91082 35.2 22 122.099 18.33 23 (Aperture) ∞ 4.00 24 83.308 6.50 1.85478 24.8 25 -48.401 1.40 2.00100 29.1 26 33.649 3.72 27 54.384 1.40 2.05090 26.9 28 31.273 4.81 1.76200 40.1 29 -533.025 1.70 30 35.819 5.76 1.63980 34.5 31 -65.314 1.15 32 -157.318 1.20 1.83481 42.7 33 25.812 3.74 1.61340 44.3 34 122.673 (variable) 35 -848.310 2.13 1.71700 47.9 36 -49.083 1.20 1.59282 68.6 37 31.138 (variable) 38 -77.004 1.30 1.49700 81.5 39 515.651 (variable) 40 789.296 4.17 1.66565 35.6 41 -88.873 (variable) 42 ∞ 1.30 1.51633 64.1 43 ∞ (variable) Image plane ∞ Various data Zoom ratio 2.85 Focal length 204.00 350.00 582.00 F-number 5.15 5.70 6.48 Angle of view 6.05 3.54 2.13 Image height 21.64 21.64 21.64 Lens total length 334.56 334.56 334.56 BF 45.84 45.84 45.84 d 7 3.50 26.91 43.59 d15 76.39 38.52 1.40 d34 2.49 5.02 2.49 d37 36.69 28.85 34.13 d39 4.27 24.05 41.73 d41 44.18 44.18 44.18 d43 0.80 0.80 0.80 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position L1 1 206.60 63.30 -0.91 -52.56 L2 8 -65.76 19.26 10.44 -4.03 L3 16 64.52 74.02 4.82 -54.01 L4 35 -57.65 3.33 2.00 0.01 L5 38 -134.71 1.30 0.11 -0.76 L6 40 120.23 4.17 2.26 -0.25 Single lens data Lens starting surface focal length 1 1 272.33 2 3 590.41 3 5 216.21 4 6 -185.60 5 8 204.47 6 9 -125.22 7 11 -200.00 8 13 -73.89 9 14 157.37 10 16 142.91 11 18 165.10 12 20 93.90 13 21 -108.38 14 24 36.65 15 25 -19.66 16 27 -72.27 17 28 38.91 18 30 36.98 19 32 -26.48 20 33 52.52 21 35 72.58 22 36 -31.96 23 38 -134.71 24 40 120.23

[0118] [Numerical Example 6] Unit: mm Surface Data Surface number rd nd νd 1 159.557 11.16 1.48749 70.2 2 -529.629 18.97 3 125.568 10.90 1.43387 95.1 4 -490.915 2.00 1.66565 35.6 5 457.032 (variable) 6 102.786 1.65 1.61997 63.9 7 67.367 6.36 8 -160.190 1.65 1.72916 54.7 9 67.365 4.95 1.84666 23.8 10 269.731 (variable) 11 -170.769 1.80 1.90366 31.3 12 402.081 (variable) 13 91.062 7.42 1.49700 81.5 14 -165.695 0.15 15 76.562 6.64 1.49700 81.5 16 -453.476 0.20 17 54.670 8.34 1.49700 81.5 18 -158.708 1.50 1.83481 42.7 19 106.871 4.84 20 (Aperture) ∞ 16.22 21 83.477 6.10 1.85478 24.8 22 -42.470 1.40 2.00100 29.1 23 33.891 5.33 24 51.540 1.40 2.00069 25.5 25 32.301 4.94 1.65412 39.7 26 -479.326 (variable) 27 42.394 6.22 1.54814 45.8 28 -48.164 0.20 29 -98.945 1.20 1.69680 55.5 30 25.085 4.01 1.65412 39.7 31 130.862 (variable) 32 154.029 1.79 1.61340 44.3 33 -191.171 1.20 1.59282 68.6 34 39.056 (variable) 35 300.416 2.33 1.61340 44.3 36 -44.797 4.04 37 -36.817 1.30 1.77250 49.6 38 59.478 (variable) 39 -185.587 4.09 1.73800 32.3 40 -58.563 (variable) 41 ∞ 1.30 1.51633 64.1 42 ∞ (variable) Image plane ∞ Various data Zoom ratio 3.35 Focal length 204.00 300.00 682.50 F-number 5.15 5.70 7.65 Angle of view 6.05 4.12 1.82 Image height 21.64 21.64 21.64 Lens total length 344.56 344.56 344.56 BF 46.13 46.13 46.13 d 5 19.60 32.29 51.07 d10 37.06 24.38 5.59 d12 58.65 43.16 1.40 d26 2.80 2.05 1.93 d31 7.64 8.27 2.10 d34 3.63 3.63 28.92 d38 18.77 34.38 57.15 d40 44.47 44.47 44.47 d42 0.80 0.80 0.80 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position L1 1 183.58 43.03 5.93 -29.32 L2 6 -108.66 14.60 6.91 -4.02 L3 11 -132.44 1.80 0.28 -0.66 L4 13 79.69 64.47 -33.27 -61.59 L5 27 90.71 11.63 -2.61 -9.65 L6 32 -91.11 2.99 2.57 0.68 L7 35 -62.26 7.66 10.84 3.95 L8 39 114.38 4.09 3.39 1.07 Single lens data Lens starting surface focal length 1 1 252.87 2 3 231.70 3 4 -355.27 4 6 -321.06 5 8 -64.84 6 9 104.88 7 11 -132.44 8 13 119.39 9 15 132.35 10 17 82.89 11 18 -76.31 12 21 33.68 13 22 -18.66 14 24 -89.73 15 25 46.44 16 27 42.16 17 29 -28.61 18 30 46.74 19 32 139.34 20 33 -54.60 21 35 63.72 22 37 -29.27 23 39 114.38

[0119] [Numerical Example 7] Unit: mm Surface Data Surface number rd nd νd 1 180.758 10.48 1.48749 70.2 2 -510.006 10.00 3 188.802 4.88 1.48749 70.2 4 418.922 9.80 5 289.430 7.54 1.49700 81.5 6 -293.920 2.00 1.66565 35.6 7 324.215 (variable) 8 617.339 2.70 1.84666 23.8 9 -399.616 1.65 1.72916 54.7 10 112.827 5.89 11 -125.912 1.65 1.72916 54.7 12 139.065 2.92 1.90110 27.1 13 417.829 (variable) 14 86.838 8.69 1.43700 95.1 15 -153.598 0.15 16 68.417 5.60 1.49700 81.5 17 274.043 0.20 18 60.299 7.91 1.49700 81.5 19 -300.460 1.50 1.91082 35.2 20 158.787 5.49 21 (Aperture) ∞ 18.39 22 125.245 5.81 1.85478 24.8 23 -40.645 1.40 1.95375 32.3 24 31.973 6.06 25 49.633 1.40 2.00069 25.5 26 31.367 5.13 1.65412 39.7 27 -526.078 (variable) 28 37.424 6.69 1.48749 70.2 29 -48.106 0.20 30 -115.268 1.20 1.72916 54.7 31 25.743 4.42 1.65412 39.7 32 435.640 (variable) 33 160.727 1.64 1.67300 38.3 34 -277.482 1.20 1.59282 68.6 35 34.958 (variable) 36 1930.682 2.18 1.73037 32.2 37 -50.000 4.54 38 -37.955 1.20 1.81600 46.6 39 65.023 (variable) 40 -338.944 4.88 1.61340 44.3 41 -57.089 (variable) 42 ∞ 1.30 1.51633 64.1 43 ∞ (variable) Image plane ∞ Various data Zoom ratio 3.15 Focal length 185.00 300.00 582.00 F-number 5.15 5.70 6.48 Angle of view 6.67 4.12 2.13 Image height 21.64 21.64 21.64 Lens total length 329.56 329.56 329.56 BF 41.56 41.56 41.56 d 7 6.61 30.81 55.77 d13 95.29 54.94 1.40 d27 2.71 1.90 2.08 d32 6.54 7.98 2.10 d35 4.39 3.90 18.34 d39 17.09 33.09 52.93 d41 39.90 39.90 39.90 d43 0.80 0.80 0.80 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position L1 1 232.46 44.70 -3.32 -38.17 L2 8 -85.54 14.81 6.49 -4.21 L3 14 102.50 67.73 -50.86 -73.74 L4 28 79.31 12.50 -0.94 -8.87 L5 33 -80.93 2.84 2.35 0.60 L6 36 -59.59 7.92 11.04 3.88 L7 40 111.19 4.88 3.61 0.61 Single lens data Lens starting surface focal length 1 1 275.13 2 3 700.19 3 5 294.68 4 6 -231.30 5 8 286.87 6 9 -120.50 7 11 -90.39 8 12 230.17 9 14 128.36 10 16 181.82 11 18 101.79 12 19 -113.88 13 22 36.49 14 23 -18.59 15 25 -88.57 16 26 45.42 17 28 44.31 18 30 -28.76 19 31 41.65 20 33 151.45 21 34 -52.30 22 36 66.76 23 38 -29.22 24 40 111.19 The amount of extension of each lens group when focusing from infinity to each object distance in each numerical example is summarized in the following Table 1. In Table 1, the direction from the object side to the image side is defined as positive.

[0120] [Table 1]

[0121] The various values ​​in each numerical example are summarized in Table 2 below.

[0122] [Table 2]

[0123] The lenses that satisfy conditional expression (13) in each numerical example and their numerical values ​​are summarized in Table 3 below.

[0124] [Table 3]

[0125] [Imaging device] Next, an embodiment of a digital still camera (imaging device) using a zoom lens of the present invention as an imaging optical system will be described with reference to Fig. 23. In Fig. 23, reference numeral 11 denotes an imaging optical system constituted by any of the zoom lenses described in Examples 1 to 7. Reference numeral 12 denotes an imaging element (photoelectric conversion element) such as a CCD sensor or CMOS sensor that is built into camera body 10 and receives and photoelectrically converts an optical image formed by imaging optical system 11. Camera body 10 may be a so-called single-lens reflex camera having a quick-turn mirror, or a so-called mirrorless camera having no quick-turn mirror.

[0126] In this way, by applying the zoom lens L0 of the present invention to an imaging device such as a digital still camera, it is possible to obtain high-resolution images with a wide angle of view.

[0127] The disclosure of each embodiment includes the following configuration.

[0128] (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, and a rear group having one or more lens groups, in which the spacing between adjacent lens groups changes during zooming, The zoom lens has a first positive lens element having a positive refractive power and arranged closest to the object side, the first lens group is stationary during zooming and includes a first subgroup and a second subgroup arranged adjacent to the first subgroup on the image side, Among the air gaps on the optical axis between adjacent lenses in the first lens group, the air gap on the optical axis between the first subgroup and the second subgroup is the largest, Let d1AB be the distance on the optical axis between the surface of the first sub-group closest to the image side and the surface of the second sub-group closest to the object side, f1A be the focal length of the first sub-group, sk be the shorter of the back focuses at the wide-angle end and the telephoto end, and Lt be the total lens length at the telephoto end. 0.020 <d1AB / f1A<0.200 0.100 <sk / Lt<0.250 A zoom lens characterized by satisfying the following conditional expressions:

[0129] (Configuration 2) When the focal length of the first lens group is f1 and the focal length of the second lens group is f2, -5.00 <f1 / f2<-0.80 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

[0130] (Configuration 3) When the focal length of the entire system at the telephoto end is ft, 0.40 <Lt / ft<0.80 3. The zoom lens according to configuration 1 or 2, wherein the following condition is satisfied:

[0131] (Configuration 4) 4. A zoom lens according to any one of configurations 1 to 3, wherein the rear group has a first focus lens group that moves during focusing from infinity to a close distance.

[0132] (Configuration 5) 5. The zoom lens according to configuration 4, wherein the first focus lens group has negative refractive power and moves toward the image side during focusing from infinity to a close distance.

[0133] (Configuration 6) 6. The zoom lens according to any one of configurations 1 to 5, wherein the first lens group is made up of four or less lenses.

[0134] (Configuration 7) At the telephoto end, when focusing is performed at an object distance where the lateral magnification of the entire system is −0.2, the lateral magnification of the first focus lens group is βLRF1, 1.1<βLRF1<4.0 5. The zoom lens according to configuration 4, wherein the following condition is satisfied:

[0135] (Configuration 8) At the telephoto end, when focusing is performed at an object distance where the lateral magnification of the entire system is −0.2, the lateral magnification of the first focus lens group is βLRF1, and the combined lateral magnification of all lens groups arranged on the image side of the first focus lens group is βR1. -10.0<(1-βLRF1×βLRF1)×βR1×βR1<-3.0 5. The zoom lens according to configuration 4, wherein the following condition is satisfied:

[0136] (Configuration 9) Let f1 be the focal length of the first lens group, and fLP be the focal length of the lens group with positive refractive power arranged in the rear group that is located closest to the object side. 1.2 <f1 / fLP<6.0 9. The zoom lens according to any one of configurations 1 to 8, wherein the following condition is satisfied:

[0137] (Configuration 10) When the radius of curvature of the object-side surface of the first positive lens is r1 and the radius of curvature of the image-side surface of the first positive lens is r2, 0.0<(r2+r1) / (r2-r1)<1.5 10. The zoom lens according to any one of configurations 1 to 9, wherein the following condition is satisfied:

[0138] (Configuration 11) 11. A zoom lens according to any one of configurations 1 to 10, wherein the first lens group remains stationary during focusing from infinity to close range.

[0139] (Configuration 12) When the focal length of the first lens group is f1 and the focal length of the entire system at the telephoto end is ft, 0.10 <f1 / ft<0.80 12. The zoom lens according to any one of configurations 1 to 11, wherein the following condition is satisfied:

[0140] (Configuration 13) When the radius of curvature of the surface of the first focus lens group closest to the object side is r1LRF and the radius of curvature of the surface of the first focus lens group closest to the image side is r2LRF, -3.5<(r2LRF+r1LRF) / (r2LRF-r1LRF)<-0.2 5. The zoom lens according to configuration 4, wherein the following condition is satisfied:

[0141] (Configuration 14) When the focal length of the first lens group is f1 and the sum of the air gaps on the optical axis in the first lens group is dsum, 0.04 <dsum / f1<0.35 14. The zoom lens according to any one of configurations 1 to 13, wherein the following condition is satisfied:

[0142] (Configuration 15) 15. A zoom lens according to any one of configurations 1 to 14, wherein the rear group has at least three lens groups.

[0143] (Configuration 16) Of the negative lenses arranged in the first lens group, the negative lens arranged closest to the object has an Abbe number of νd_N and a partial dispersion ratio of θgF_N for the g-line and the F-line. -0.010<θgF_N-(-0.0016178×νd_N+0.64146)<0.010 16. The zoom lens according to any one of configurations 1 to 15, wherein the following condition is satisfied:

[0144] (Configuration 17) the rear group has an aperture stop that determines an axial ray bundle, and a plurality of positive lenses that are arranged closer to the image side than the aperture stop, and when the Abbe number of at least two positive lenses among the plurality of positive lenses is νd_PR and the partial dispersion ratios for the g line and the F line are θgF_PR, -0.012<θgF_PR-(-0.0016178×νd_PR+0.64146)<0.005 17. The zoom lens according to any one of configurations 1 to 16, wherein the following condition is satisfied:

[0145] (Configuration 18) The zoom lens according to configuration 4, wherein the zoom lens has a second focus lens group, and the first focus lens group and the second focus lens group move on different trajectories when focusing from infinity to a close distance.

[0146] (Configuration 19) of the first focus lens group and the second focus lens group, the lens group arranged on the object side is referred to as an object-side focus lens group, and the lens group arranged on the image side is referred to as an image-side focus lens group, When the focal length of the object-side focus lens unit is fLF1 and the focal length of the image-side focus lens unit is fLF2, 0.4 <fLF1 / fLF2<3.0 19. The zoom lens according to configuration 18, wherein the following condition is satisfied:

[0147] (Configuration 20) of the first focus lens group and the second focus lens group, the lens group arranged on the object side is referred to as an object-side focus lens group, and the lens group arranged on the image side is referred to as an image-side focus lens group, At the telephoto end, when focusing from infinity to an object distance where the lateral magnification of the entire system is −0.2, the absolute value of the movement amount of the object-side focus lens unit is defined as MLF1, and the absolute value of the movement amount of the image-side focus lens unit is defined as MLF2. 0.2 <MLF1 / MLF2<5.0 19. The zoom lens according to configuration 18, wherein the following condition is satisfied:

[0148] (Configuration 21) At the telephoto end, when focusing is performed at an object distance where the lateral magnification of the entire system is −0.3, the distance on the optical axis between the surface of the first focus lens group closest to the image side and the surface of the lens arranged adjacent to the first focus lens group on the image side is T, the lateral magnification of the first focus lens group is βLRF2, and the combined lateral magnification of all lens groups arranged closer to the image side than the first focus lens group is βR2. 0.01 <T×|(1-βLRF2×βLRF2)×βR2×βR2| / f<0.50 5. The zoom lens according to configuration 4, wherein the following condition is satisfied:

[0149] (Configuration 22) The first focus lens group has a cemented lens made up of a positive lens and a negative lens, and when the Abbe number of the negative lens is νd_RF1N, 50<νd_RF1N<100 5. The zoom lens according to configuration 4, characterized in that the following condition is satisfied:

[0150] (Configuration 23) The zoom lens according to any one of configurations 1 to 22, wherein the first subgroup is composed of two or less lenses.

[0151] (Configuration 24) When the focal length of the first lens group is f1 and the focal length of the first focus lens group is fLRF, -1.00 <fLRF / f1<-0.05 5. The zoom lens according to configuration 4, wherein the following condition is satisfied:

[0152] (Configuration 25) The rear group has a third lens group having positive refractive power and arranged closest to the object. When the focal length of the first lens group is f1 and the focal length of the third lens group is f3, 1.0 <f1 / f3<5.0 25. The zoom lens according to any one of configurations 1 to 24, wherein the following condition is satisfied:

[0153] (Configuration 26) An imaging device comprising the zoom lens according to any one of configurations 1 to 25, and an imaging element that receives an image formed by the zoom lens.

[0154] 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]

[0155] L0 zoom lens L1 First lens group L2 Second lens group LR rear group GP1 First positive lens

Claims

1. A zoom lens comprising a first lens group with positive refractive power, a second lens group with negative refractive power, and a rear group having three or more lens groups, arranged sequentially from the object side to the image side, wherein the spacing between adjacent lens groups changes during zooming. The zoom lens has a first positive lens with positive refractive power positioned closest to the object, The aforementioned first lens group is immovable during zooming and consists of a first subgroup and a second subgroup positioned adjacent to the image side of the first subgroup. Of the air gaps along the optical axes of adjacent lenses in the first lens group, the air gap between the first subgroup and the second subgroup is the largest. The specific gravity of the material of at least one of the positive lenses in the first lens group is 3.0 or less. The lens group positioned closest to the object in the aforementioned rear group has a negative refractive power. When d1AB is the distance on the optical axis between the image-side surface of the first subgroup and the object-side surface of the second subgroup, f1A is the focal length of the first subgroup, sk is the shorter of the back focus at the wide-angle and telephoto ends, Lt is the total lens length at the telephoto end, f1 is the focal length of the first lens group, and f2 is the focal length of the second lens group, 0.020<d1AB / f1A<0.200 0.100<sk / Lt<0.250 -5.00<f1 / f2<-1.30 A zoom lens characterized by satisfying the following conditional equation.

2. When the total focal length of the system at the telephoto end is ft, 0.40<Lt / ft<0.80 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

3. The zoom lens according to claim 1, characterized in that the rear group has a first focusing lens group that moves when focusing from infinity to near.

4. The zoom lens according to claim 3, characterized in that the first focusing lens group has a negative refractive power and moves toward the image side when focusing from infinity to close.

5. The zoom lens according to claim 1, characterized in that the first lens group consists of four or fewer lenses.

6. When focusing on an object distance at the telephoto end where the lateral magnification of the entire system is -0.2, the lateral magnification of the first focusing lens group is βLRF1, 1.1<βLRF1<4.0 The zoom lens according to claim 4, characterized in that it satisfies the following condition.

7. When focusing at the telephoto end to an object distance where the lateral magnification of the entire system is -0.2, the lateral magnification of the first focusing lens group is βLRF1, and the combined lateral magnification of all lens groups positioned on the image side of the first focusing lens group is βR1. -10.0 < (1 - βLRF1 × βLRF1) × βR1 × βR1 < -3.0 The zoom lens according to claim 4, characterized in that it satisfies the following condition.

8. When the focal length of the first lens group is f1, and the focal length of the lens group with positive refractive power arranged in the rear group, and the lens group positioned closest to the object, is fLP, 1.2<f1 / fLP<6.0 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

9. When the radius of curvature of the object-side surface of the first positive lens is r1 and the radius of curvature of the image-side surface of the first positive lens is r2, 0.0<(r2+r1) / (r2-r1)<1.5 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

10. The zoom lens according to claim 1, characterized in that the first lens group remains stationary when focusing from infinity to close.

11. When the focal length of the entire system at the telephoto end is ft, 0.10<f1 / ft<0.80 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

12. When the radius of curvature of the object-side surface of the first focusing lens group is r1LRF and the radius of curvature of the image-side surface of the first focusing lens group is r2LRF, -3.5<(r2LRF+r1LRF) / (r2LRF-r1LRF)<-0.2 The zoom lens according to claim 4, characterized in that it satisfies the following condition.

13. In the first lens group, when the sum of the air gaps on the optical axis is dsum, 0.04<dsum / f1<0.35 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

14. When the Abbe number of the negative lens positioned closest to the object among the negative lenses arranged in the first lens group is νd_N, and the partial dispersion ratio with respect to the g-line and F-line is θgF_N, -0.010<θgF_N-(-0.0016178×νd_N+0.64146)<0.010 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

15. The aforementioned rear group has an aperture diaphragm that determines the on-axial light beam, and has a plurality of positive lenses positioned on the image side of the aperture diaphragm, and when the Abbe number of at least two of the plurality of positive lenses is νd_PR and the partial dispersion ratio with respect to the g-line and F-line is θgF_PR, -0.012<θgF_PR-(-0.0016178×νd_PR+0.64146)<0.005 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

16. The zoom lens according to claim 3, wherein the zoom lens has a second focusing lens group, and the first focusing lens group and the second focusing lens group move along different trajectories when focusing from infinity to near.

17. Of the first and second focusing lens groups, the lens group positioned on the object side is referred to as the object-side focusing lens group, and the lens group positioned on the image side is referred to as the image-side focusing lens group. When the focal length of the object-side focusing lens group is fLF1 and the focal length of the image-side focusing lens group is fLF2, 0.4<fLF1 / fLF2<3.0 The zoom lens according to claim 16, characterized in that it satisfies the following condition.

18. Of the first and second focusing lens groups, the lens group positioned on the object side is referred to as the object-side focusing lens group, and the lens group positioned on the image side is referred to as the image-side focusing lens group. When focusing at the telephoto end to an object distance from infinity to a distance where the lateral magnification of the entire system is -0.2, let MLF1 be the absolute value of the movement of the object-side focusing lens group and MLF2 be the absolute value of the movement of the image-side focusing lens group. 0.2<MLF1 / MLF2<5.0 The zoom lens according to claim 16, characterized in that it satisfies the following condition.

19. When focusing at the telephoto end to an object distance where the lateral magnification of the entire system is -0.3, the distance on the optical axis between the image-side surface of the first focusing lens group and the object-side surface of a lens adjacent to the image-side of the first focusing lens group is T, the lateral magnification of the first focusing lens group is βLRF2, and the combined lateral magnification of all lens groups positioned closer to the image than the first focusing lens group is βR2. 0.01<T×|(1-βLRF2×βLRF2)×βR2×βR2| / f<0.50 The zoom lens according to claim 3, characterized in that it satisfies the following condition.

20. The first focusing lens group has a cemented lens consisting of a positive lens and a negative lens, and when the Abbe number of the negative lens is νd_RF1N, 50<νd_RF1N<100 The zoom lens according to claim 3, characterized in that it satisfies the following condition.

21. The zoom lens according to claim 1, characterized in that the first subgroup consists of two or fewer lenses.

22. When the focal length of the first focus lens group is fLRF, -1.00<fLRF / f1<-0.05 The zoom lens according to claim 3, characterized in that it satisfies the following condition.

23. An imaging device characterized by having a zoom lens according to any one of claims 1 to 22 and an image sensor that receives an image formed by the zoom lens.

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