Zoom lens and image capturing device having the same

Abstract

To provide a compact, light-weight zoom lens which offers high optical performance and, a high zoom ratio.SOLUTION: A zoom lens provided herein comprises a first lens group having positive refractive power, a second lens group having negative refractive power, and a succeeding lens group consisting of one or more lens groups, arranged in order from the object side to the image side, and is configured such that distances between adjacent lens groups change while zooming, where the first lens group moves toward the object side while zooming from the wide-angle end to the telephoto end, and the second lens group includes two or more lenses. The zoom lens satisfies given conditional expressions.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 are required to have small, lightweight zoom lenses that have high optical performance over the entire zoom range while having a long focal length at the telephoto end.

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

[0004] [Patent Document 1] JP 2009-86537 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the zoom lens of Patent Document 1, the first lens group does not move during zooming, and the second lens group has negative refractive power and moves toward the image side from the wide-angle end to the telephoto end. In this zoom lens, if you try to increase the focal length at the telephoto end, it is necessary to increase the overall lens length at the wide-angle end to ensure the amount of movement of the second lens group during zooming.

[0006] SUMMARY OF THE PRESENT EMBODIMENTS An object of the present invention is to provide a zoom lens that has high optical performance, a high zoom ratio, and is small and lightweight. [Means for solving the problem]

[0007] The optical system of the present invention is a zoom lens comprising, 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 subsequent lens group composed of one or more lens groups, and in which the distance between adjacent lens groups changes during zooming, the first lens group moves toward the object side during zooming from the wide-angle end to the telephoto end, and the second lens group has two or more lenses, wherein the axial distance from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the second lens group at the telephoto end is TD12t, the sum of the axial thicknesses of the lenses included in the first lens group and the second lens group is TG12, the axial distance from the lens surface closest to the object in the first lens group to the lens surface closest to the image is TD1, and the axial distance from the lens surface closest to the object in the second lens group to the lens surface closest to the image is TD2, 4.3 <TD12t / TG12<12.0 3.6 <TD1 / TD2<30.0 The present invention is characterized in that the following conditional expression is satisfied: Effect of the Invention

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

[0009] [Figure 1] FIG. 1 is a cross-sectional view of a zoom lens at a wide-angle end according to a first embodiment. [Diagram 2] Aberration diagrams of the zoom lens of Example 1 at (A) the wide-angle end and (B) the telephoto end. [Diagram 3] 1 is a cross-sectional view of a zoom lens at a wide-angle end according to a second embodiment of the present invention; [Figure 4] Aberration diagrams of the zoom lens of Example 2 at (A) the wide-angle end and (B) the telephoto end. [Diagram 5] 11 is a cross-sectional view of a zoom lens at a wide-angle end according to a third embodiment of the present invention; [Figure 6] Aberration diagrams of the zoom lens of Example 3 at (A) the wide-angle end and (B) the telephoto end. [Figure 7]11 is a cross-sectional view of a zoom lens at a wide-angle end according to a fourth embodiment of the present invention; [Figure 8] Aberration diagrams of the zoom lens of Example 4 at (A) the wide-angle end and (B) the telephoto end. [Figure 9] 13 is a cross-sectional view of a zoom lens at a wide-angle end according to a fifth embodiment of the present invention; [Figure 10] Aberration diagrams of the zoom lens of Example 5 at (A) the wide-angle end and (B) the telephoto end. [Figure 11] Schematic diagram showing an imaging device DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0011] 1, 3, 5, 7, and 9 are cross-sectional views of the zoom lens L0 of Examples 1 to 5. 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, silver halide film cameras, 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 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 of each embodiment is composed of a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, and a rear lens group LR composed of one or more lens groups, arranged in this order from the object side to the image side. The distance between adjacent lens groups changes during zooming. Each lens group may be composed of one lens or multiple lenses. The lens groups may also include an aperture stop.

[0014] The solid arrows pointing downward in each lens cross-sectional diagram indicate the movement trajectory of each lens group when zooming from the wide-angle end to the telephoto end. The focus group moves as shown by the arrow labeled FOCUS when focusing from infinity to a close distance. The image stabilization group moves as shown by the arrow labeled IS when image blur is compensated.

[0015] In each lens cross-sectional view, SP is an aperture stop. IP is an image plane, and when the zoom lens of each embodiment is used in a digital still camera or digital video camera, the imaging surface of a solid-state imaging element (photoelectric conversion element) such as a CCD sensor or CMOS sensor is disposed thereon. When the zoom lens of each embodiment is used as the photographing optical system of a silver halide film camera, a photosensitive surface equivalent to the film surface is disposed on the image plane IP.

[0016] 2, 4, 6, 8 and 10 are aberration diagrams of the zoom lenses of Examples 1 to 5, respectively, at the wide-angle end and the telephoto end, when the object distance is focused at infinity.

[0017] In the spherical aberration diagram, Fno is the F-number, and shows the amount of spherical aberration for the d-line (wavelength 587.6 nm) and g-line (wavelength 435.8 nm). In the astigmatism diagram, ΔS shows the amount of aberration on the sagittal image plane, and ΔM shows the amount of aberration on the meridional image plane. The distortion aberration 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 half angle of view (°).

[0018] Next, the characteristic configuration of the zoom lens of each embodiment will be described.

[0019] In the zoom lens L0 of each embodiment, the refractive power of the first lens group L1 is made positive, so that the principal point is located on the object side and the overall lens length (the distance on the optical axis from the lens surface of the zoom lens L0 closest to the object side to the image surface) is shortened. Also, the refractive power of the second lens group L2 is made negative, so that lateral chromatic aberration occurring in the first lens group L1, particularly at the wide-angle end, is corrected. Furthermore, by arranging a subsequent lens group LR consisting of one or more lens groups of the second lens group L2, fluctuations in various aberrations occurring during zooming are suppressed.

[0020] Furthermore, when zooming from the wide-angle end to the telephoto end, the first lens unit L1 moves toward the object side, thereby shortening the overall lens length at the wide-angle end.

[0021] Furthermore, the second lens group L2 has two or more lenses, which suppresses fluctuations in various aberrations that occur in the second lens group during zooming.

[0022] Moreover, the zoom lens L0 in each embodiment is configured to satisfy the following conditional expressions. 4.3 <TD12t / TG12<12.0 ···(1) 3.6 <TD1 / TD2<30.0 ···(2)

[0023] Here, TD12t is the axial distance from the lens surface of the first lens group L1 closest to the object to the lens surface of the second lens group L2 closest to the image at the telephoto end. TG12 is the sum of the axial thicknesses of the lenses included in the first lens group L1 and the second lens group L2. TD1 is the axial distance from the lens surface of the first lens group L1 closest to the object to the lens surface of the second lens group L2 closest to the image. TD2 is the axial distance from the lens surface of the second lens group L2 closest to the object to the lens surface of the second lens group L2 closest to the image.

[0024] Conditions (1) and (2) are intended to correct various aberrations, achieve a high zoom ratio, and reduce size and weight.

[0025] If the upper limit of conditional expression (1) is exceeded, the distance from the lens surface of the first lens group L1 closest to the object to the lens surface of the second lens group L2 closest to the image at the telephoto end becomes long. As a result, the overall lens length becomes long, which is undesirable. If the lower limit of conditional expression (1) is not exceeded, the sum of the thicknesses on the optical axis of the lenses arranged in the first lens group L1 and the second lens group L2 becomes large. As a result, the weight of each lens included in the first lens group L1 and the second lens group L2 becomes heavy, which is undesirable.

[0026] If the upper limit of conditional expression (2) is exceeded, the distance on the optical axis from the lens surface closest to the object in the first lens group L1 to the lens surface closest to the image becomes long. As a result, the diameter of the lens closest to the object becomes large, which is undesirable. If the lower limit of conditional expression (2) is not reached, the distance on the optical axis from the lens surface closest to the object in the second lens group L2 to the lens surface closest to the image becomes long. As a result, it becomes difficult to ensure the amount of movement of the second lens group L2 and the subsequent lens groups during zooming, and in order to obtain a desired zoom ratio, the overall lens length, especially at the wide-angle end, must be increased, which is undesirable.

[0027] With the above configuration, it is possible to realize a zoom lens that has high optical performance, a high zoom ratio, and is small and lightweight.

[0028] It is preferable that at least one of the upper limit and the lower limit of the numerical range of either condition (1) or (2) satisfies the numerical value of the following condition (1a) or (2a). 4.5 <TD12t / TG12<11.0 ···(1a) 3.8 <TD1 / TD2<20.0 ···(2a)

[0029] It is even more preferable that at least one of the upper limit and the lower limit of the numerical range of either conditional formula (1) or (2) satisfies the range of the following conditional formula (1b) or (2b). 4.7 <TD12t / TG12<10.5 ···(1b) 4.0 <TD1 / TD2<16.0 ···(2b)

[0030] Next, a preferred configuration of the zoom lens L0 in each embodiment will be described.

[0031] The first lens group L1 has a positive lens A and a positive lens B arranged in order from the object side, and it is preferable that the positive lens A and the positive lens B are arranged with the largest air gap in the first lens group L1. By increasing the air gap between the positive lens A and the positive lens B, the axial light beam incident on the positive lens B and the lens arranged on the image side of the positive lens B becomes small. As a result, the diameter of the positive lens B and the lens arranged on the image side of the positive lens B can be reduced, and the weight can be reduced.

[0032] Furthermore, in the first lens unit L1, it is preferable to place a negative lens closer to the image side than the positive lens B. By placing a negative lens, it is possible to satisfactorily correct spherical aberration, axial chromatic aberration, and the like, particularly at the telephoto end.

[0033] It is preferable that the second lens group L2 does not move during zooming, which can reduce decentering of the second lens group L2 that occurs during zooming and suppress fluctuations in various aberrations that occur in the second lens group L2.

[0034] It is preferable to dispose an aperture stop between the lens surface of the third lens group L3 closest to the object side and the lens surface of the third lens group L3 closest to the image side, or on the image side of the third lens group L3. Since the on-axis light flux is relatively small at the third lens group L3 or on the image side of the third lens group, the diameter of the aperture stop can be made small.

[0035] It is preferable that the surfaces of all the lenses constituting the zoom lens L0 have a spherical shape, which can reduce variations during manufacturing and suppress deterioration of optical performance.

[0036] It is preferable that the whole or a part of the second lens group L2 moves so as to include a component in the direction perpendicular to the optical axis during image blur correction. Since the second lens group L2 has a relatively strong negative refractive power, it is possible to increase the absolute value of the decentering sensitivity, and it is possible to prevent the diameter of the lens that moves during image stabilization from becoming large. Note that the decentering sensitivity is the ratio (Δ2 / Δ1) of the amount of movement of the lens Δ1 in the direction perpendicular to the optical axis to the amount of movement Δ2 of the image point on the image plane.

[0037] Next, the conditional expressions that are preferably satisfied in the zoom lens L0 of each embodiment will be described.

[0038] It is preferable that the zoom lens L0 of each embodiment satisfies one or more of the following conditional expressions. 0.1 <m1 / f1<0.5 ···(3) 1.0 <f1 / fw<3.0 ···(4) -1.0 <f2 / fw<-0.2 ···(5) 1.0 <ft / TTDw<3.5 ···(6) 8.0 <ft / skw<35.0 ···(7) 5,0 <TTDw / skw<20.0 ···(8) 0.4 <D1max / TD1<0.9 ···(9) 4.0<|(1-βft 2 )βrt 2 |<20.0 ···(10) 2.0 <G1d<3.0 ···(11)

[0039] Here, m1 is the absolute value of the movement amount of the first lens unit L1 during zooming from the wide-angle end to the telephoto end, and f1 is the focal length of the first lens unit L1. fw is the focal length of the entire system at the wide-angle end. f2 is the focal length of the second lens unit L2. ft is the focal length of the entire system at the telephoto end, TTDw is the distance on the optical axis from the lens surface closest to the object to the image plane at the wide-angle end, and skw is the back focus at the wide-angle end.

[0040] D1max is the largest air gap on the optical axis within the first lens unit L1. βft is the lateral magnification at the telephoto end of the focus unit that moves during focusing. βrt is the combined lateral magnification at the telephoto end of all lens units located on the image side of the focus unit. G1d is the specific gravity of the material of the lens closest to the object in the first lens unit L1.

[0041] Next, the technical meanings of the above-mentioned conditional expressions (3) to (11) will be explained.

[0042] If the absolute value of the movement amount of the first lens group L1 during zooming from the wide-angle end to the telephoto end becomes large beyond the upper limit of conditional expression (3), the effective diameter of the lenses arranged in the first lens group L1 becomes large and the weight becomes heavy in order to ensure the peripheral light amount at the telephoto end. If the lower limit of conditional expression (3) is not reached and the refractive power of the first lens group L1 becomes weak, the principal point is located on the image side and the overall lens length becomes long.

[0043] When the refractive power of the first lens unit L1 becomes weaker by exceeding the upper limit of conditional expression (4), the principal point is located on the image side and the overall lens length becomes longer. When the refractive power of the first lens unit L1 becomes strong by falling below the lower limit of conditional expression (4), various aberrations generated in the first lens unit L1 become large.

[0044] When the refractive power of the second lens group L2 becomes strong beyond the upper limit of conditional expression (5), the fluctuation of various aberrations occurring in the second lens group L2 during zooming becomes large. When the refractive power of the second lens group L2 becomes weak below the lower limit of conditional expression (5), the movement amount of the second lens group L2 during zooming becomes large in order to obtain a desired magnification ratio. In other words, the total lens length becomes long in order to secure a space for the movement amount of the second lens group L2 during zooming.

[0045] If the upper limit of conditional expression (6) is exceeded and the focal length of the entire system at the telephoto end becomes long, the refractive power of the first lens unit L1, etc. becomes strong in order to prevent the overall lens length from becoming long, making it difficult to correct various aberrations. If the lower limit of conditional expression (6) is exceeded, the distance on the optical axis from the lens surface closest to the object to the image plane at the wide-angle end becomes long, resulting in a large size.

[0046] When the upper limit of conditional expression (7) is exceeded and the focal length of the entire system at the telephoto end becomes long, the refractive power of the first lens unit L1 and the like becomes strong in order to prevent the overall lens length from becoming long, making it difficult to correct various aberrations. When the lower limit of conditional expression (7) is exceeded, the back focus at the wide-angle end becomes long, and as a result, the overall lens length becomes long.

[0047] If the upper limit of conditional expression (8) is exceeded, the distance on the optical axis from the lens surface closest to the object at the wide-angle end to the image plane becomes long, resulting in an increase in size. If the lower limit of conditional expression (8) is not reached and the distance on the optical axis from the lens surface closest to the object at the wide-angle end to the image plane becomes short, the refractive power of the first lens group L1 etc. becomes strong, making it difficult to correct various aberrations.

[0048] If the upper limit of conditional expression (9) is exceeded and the maximum air gap on the optical axis within the first lens group L1 becomes large, the diameter of the lens closest to the object becomes large and the weight becomes heavy in order to ensure the amount of peripheral light. If the lower limit of conditional expression (9) is not reached and the maximum air gap on the optical axis within the first lens group L1 becomes small, the refractive power of the lens closest to the object becomes particularly strong, making it difficult to correct various aberrations.

[0049] Condition (10) represents the position sensitivity of the focus group at the telephoto end. Position sensitivity is the ratio (ΔL / Δd) of the amount of movement Δd of the focus group in the optical axis direction to the amount of movement ΔL of the image formation position in the optical axis direction due to movement of the focus group.

[0050] When the upper limit of conditional expression (10) is exceeded and the position sensitivity of the focus group at the telephoto end becomes high, the refractive power of the focus group becomes strong, and the fluctuations in various aberrations that occur when the focus group moves become large. When the lower limit of conditional expression (10) is exceeded and the position sensitivity of the focus group at the telephoto end becomes small, the amount of movement of the focus group during focusing increases. In other words, the overall lens length becomes longer to ensure the amount of movement of the focus group during focusing.

[0051] If the upper limit of condition (11) is exceeded and the specific gravity of the material of the lens closest to the object in the first lens group L1 becomes large, the weight becomes heavy. If the specific gravity of the material of the lens closest to the object in the first lens group L1 becomes small and the lower limit of condition (11) is exceeded, the material has a relatively high dispersion, making it difficult to correct chromatic aberration.

[0052] It is more preferable to set at least one of the upper and lower limits of the conditional expressions (3) to (11) within the following numerical ranges. 0.2 <m1 / f1<0.4 ···(3a) 1.2 <f1 / fw<2.7 ···(4a) -0.8 <f2 / fw<-0.25 ···(5a) 1.2 <ft / TTDw<3.0 ···(6a) 12.0 <ft / skw<30.0 ···(7a) 6,0 <TTDw / skw<15,0 ···(8a) 0.5 <D1max / TD1<0.8 ···(9a) 4.1<|(1-βft 2 )×βrt 2 |<15.0 ···(10a) 2.35 <G1d<2.55 ···(11a)

[0053] Moreover, it is more preferable to set at least one of the upper and lower limits of the conditional expressions (3) to (11) to the following numerical ranges. 0.25 <m1 / f1<0.35 ···(3b) 1.4 <f1 / fw<2.5 ···(4b) -0.6 <f2 / fw<-0.3 ···(5b) 1.4 <ft / TTDw<2.8 ···(6b) 13.0 <ft / skw<25.0 ···(7b) 8,0 <TTDw / skw<12,0 ···(8b) 0.60 <D1max / TD1<0.75 ···(9b) 4.2<|(1-βft 2 )×βrt 2|<13.0 ···(10b) 2.4 <G1d<2.5 ···(11b)

[0054] Next, the configuration of the zoom lens L0 in each embodiment will be described in detail.

[0055] [Example 1] The zoom lens L0 of the first embodiment is composed of a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, and a rear group LR, which are arranged in this order from the object side to the image side. The rear group LR is composed of a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with negative refractive power, and a sixth lens L6 with negative refractive power, which are arranged in this order from the object side to the image side. By appropriately arranging the lens groups with negative refractive power and the lens groups with positive refractive power, various aberrations are excellently corrected throughout the entire zoom range.

[0056] By making the second lens group L2 immovable during zooming, the occurrence of aberrations due to decentering of the second lens group L2 is suppressed. The second lens group L2 is composed of three lenses arranged in that order from the object side to the image side: a positive lens, a negative lens, and a negative lens, and image blur is corrected by moving the second lens group L2 in a direction approximately perpendicular to the optical axis. By making the second lens group L2 consist of three lenses, decentering aberrations during image blur correction are suppressed.

[0057] Furthermore, the fifth lens group L5 moves toward the image side during focusing from infinity to a close distance. By moving the fifth lens group L5, which has a relatively small diameter, during focusing, high-speed focusing is possible. The aperture diaphragm, which determines the Fno, is located closest to the image side of the third lens group. By locating the aperture diaphragm closest to the image side of the third lens group, which has a relatively small diameter, the diameter of the aperture diaphragm can be made small.

[0058] [Example 2] The zoom lens L0 of the second embodiment is composed of a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, and a rear group LR, which are arranged in this order from the object side to the image side. The rear group LR is composed of a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, a fifth lens L5 with positive refractive power, and a sixth lens L6 with negative refractive power, which are arranged in this order from the object side to the image side.

[0059] In Example 2, a positive lens is added to the first lens unit L1 closest to the image side compared to Example 1. By adding a positive lens, spherical aberration is effectively corrected, particularly at the telephoto end.

[0060] [Example 3] The zoom lens L0 of the third embodiment is composed of a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, and a rear group LR, which are arranged in this order from the object side to the image side. The rear group LR is composed of a third lens L3 with positive refractive power, a fourth lens L4 with negative refractive power, and a fifth lens L5 with negative refractive power, which are arranged in this order from the object side to the image side.

[0061] In the third embodiment, the second lens unit L2 has two lenses, thereby reducing the weight.

[0062] [Example 4] The zoom lens L0 of the fourth embodiment is composed of a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, and a rear group LR, which are arranged in this order from the object side to the image side. The rear group LR is composed of a third lens L3 with positive refractive power, a fourth lens L4 with positive refractive power, and a fifth lens L5 with negative refractive power, which are arranged in this order from the object side to the image side.

[0063] In the fourth embodiment, the second lens group L2 has five lenses, and the fifth lens group L5 has four lenses, thereby suppressing fluctuations in various aberrations that occur in the second lens group L2 and the fifth lens group L5 during zooming. Also, the fourth lens group L4 moves toward the object side during focusing from infinity to a close distance.

[0064] [Example 5] The zoom lens L0 of the fifth embodiment is composed of, arranged in order from the object side to the image side, a first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, and a rear lens unit LR. The rear lens unit LR is composed of a third lens unit L3 having a positive refractive power.

[0065] In the fifth embodiment, the number of lens groups is reduced compared to the first embodiment, and a three-group configuration is used, thereby suppressing decentering of each lens group that occurs during zooming and improving optical performance.

[0066] Numerical examples 1 to 5 corresponding to the first to fifth embodiments, respectively, are given below.

[0067] 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. In addition, nd represents the refractive index of each optical member with respect to the d-line, and νd represents the Abbe number of the optical member. The Abbe number νd of a certain material is given by Nd, NF, and NC, respectively, when the refractive indices at the Fraunhofer lines 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:

[0068] [Numerical Example 1] Unit: mm Surface Data Surface number rd nd νd 1 208.140 8.30 1.48749 70.2 2 -575.227 39.20 3 117.400 11.35 1.49700 81.5 4 -270.733 2.70 1.61340 44.3 5 154.413 (variable) 6 -1313.396 3.50 1.80518 25.4 7 -65.332 1.40 1.77250 49.6 8 114.681 2.08 9 -137.293 1.40 1.83481 42.7 10 893.658 (variable) 11 48.839 8.05 1.49700 81.5 12 -79.168 0.55 13 301.466 1.35 1.77250 49.6 14 27.972 5.77 1.54072 47.2 15 776.993 0.48 16 93.677 6.14 1.51823 58.9 17 -33.663 1.30 1.77250 49.6 18 -558.826 6.04 19 (Aperture) ∞ (Variable) 20 71.179 1.30 2.00069 25.5 21 35.239 4.65 1.61340 44.3 22 -67.501 (variable) 23 112.661 2.56 1.51742 52.4 24 -88.341 1.22 25 -100.206 0.90 1.59522 67.7 26 29.728 (variable) 27 -43.800 1.30 1.49700 81.5 28 43.800 4.30 1.72047 34.7 29 -576.993 (variable) Image plane ∞ Various data Zoom ratio 3.82 Wide Angle Mid-Telephoto Focal length 203.00 390.84 776.00 F-number 6.42 7.30 9.18 Half angle of view 6.08 3.17 1.60 Image height 21.64 21.64 21.64 Lens total length 331.63 390.98 421.61 BF 37.98 61.62 96.27 d 5 39.49 98.84 129.47 d10 43.89 32.37 3.29 d19 46.32 45.47 47.31 d22 21.38 12.89 3.01 d26 26.74 23.95 26.42 d29 37.98 61.62 96.27 Zoom lens group data Group starting plane focal length L1 1 302.68 L2 6 -71.48 L3 11 99.38 L4 20 82.71 L5 23 -66.78 L6 27 -203.48

[0069] [Numerical Example 2] Unit: mm Surface Data Surface number rd nd νd 1 144.748 9.32 1.48749 70.2 2∞48.43 3 89.287 10.89 1.49700 81.6 4 -847.726 3.00 1.61340 44.3 5 74.191 1.97 6 100.080 4.93 1.51823 58.9 7 174.640 (variable) 8 ∞ 4.76 1.65412 39.7 9 -63.154 2.00 1.58913 61.1 10 767.732 3.37 11 682.775 1.50 1.72916 54.7 12 82.889 2.86 13 -101.488 1.50 1.69680 55.5 14 101.488 3.53 1.78472 25.7 15 ∞ (variable) 16 49.739 7.15 1.49700 81.6 17 -138.331 0.19 18 64.996 1.70 1.72916 54.7 19 27.598 9.12 1.53775 74.7 20 -231.045 0.97 21 -86.744 1.90 1.90525 35.0 22 1464.098 16.96 23(Aperture) ∞ 24.36 24 64.330 4.61 1.61340 44.3 25 -43.939 1.30 1.89190 37.1 26 -157.290 (variable) 27 271.506 2.33 1.85478 24.8 28 -74.228 1.00 1.83481 42.7 29 39.368 (variable) 30 67.122 1.70 1.92286 20.9 31 38.251 6.33 1.65412 39.7 32 -60.563 (variable) 33 -76.617 1.30 1.59522 67.7 34 166.663 1.15 35 -165.426 1.50 1.59522 67.7 36 23.838 6.86 1.61340 44.3 37 181.816 (variable) Image plane ∞ Various data Zoom ratio 3.7 Wide Angle Mid-Telephoto Focal length 206.00 384.91 778.20 F-number 5.71 6.70 9.18 Half angle of view 6.00 3.22 1.59 Image height 21.64 21.64 21.64 Lens length 330.11 387.57 420.11 BF 40.03 58.26 96.02 d 7 7.95 65.40 97.95 d15 41.76 29.34 2.97 d26 15.09 8.51 3.09 d29 17.80 24.37 29.79 d32 18.99 13.18 1.79 d37 40.03 58.26 96.02 Zoom lens group data Group starting plane focal length L1 1 298.92 L2 8 -73.88 L3 16 72.61 L4 27 -56.61 L5 30 58.15 L6 33 -55.76

[0070] [Numerical Example 3] Unit: mm Surface Data Surface number rd nd νd 1 276.825 6.18 1.48749 70.2 2 -600.775 39.20 3 119.101 7.36 1.49700 81.5 4 -496.322 2.70 1.61340 44.3 5 164.850 (variable) 6 -189.115 2.24 1.80518 25.4 7 -66.169 1.40 1.77250 49.6 8 121.138 (variable) 9 51.485 7.45 1.49700 81.5 10 -90.684 1.12 11 380.120 1.35 1.77250 49.6 12 30.296 5.13 1.54072 47.2 13 443.836 0.73 14 110.891 5.53 1.51823 58.9 15 -37.072 1.30 1.77250 49.6 16 -296.706 9.32 17(Aperture) ∞ 41.15 18 66.591 1.30 2.00069 25.5 19 34.650 3.94 1.61340 44.3 20 -83.966 (variable) 21 93.250 2.61 1.51742 52.4 22 -71.258 1.88 23 -69.994 0.90 1.59522 67.7 24 28.582 (variable) 25 -179.806 1.30 1.49700 81.5 26 30.669 3.65 1.72047 34.7 27 75.036 (variable) Image plane ∞ Various data Zoom ratio 2.46 Wide Angle Mid-Telephoto Focal length 203.01 395.08 500.04 F-number 6.43 8.04 9.18 Half angle of view 6.08 3.13 2.48 Image height 21.64 21.64 21.64 Lens length 321.37 404.17 420.39 BF 37.99 62.27 74.98 d 5 39.40 122.19 138.42 d 8 49.99 41.02 32.90 d20 17.25 6.96 3.00 d24 28.99 23.97 23.34 d27 37.99 62.27 74.98 Zoom lens group data Group starting plane focal length L1 1 342.38 L2 6 -98.13 L3 9 76.09 L4 21 -64.30 L5 25 -200.31

[0071] [Numerical Example 4] Unit: mm Surface Data Surface number rd nd νd 1 141.629 9.15 1.51823 58.9 2 7683.053 46.38 3 114.796 9.86 1.49700 81.5 4 -395.656 2.70 1.61340 44.3 5 80.183 1.45 6 101.475 5.71 1.49700 81.5 7 193.888 (variable) 8 56.915 5.47 1.59270 35.3 9 2310.622 0.97 10 245.283 1.65 1.83481 42.7 11 59.448 3.29 12 119.146 1.65 1.71989 55.4 13 74.599 3.31 14 -108.591 1.65 1.65394 60.9 15 89.528 2.66 1.84666 23.8 16 185.266 (variable) 17 81.580 5.72 1.49700 81.5 18 -103.333 0.20 19 61.959 6.95 1.49700 81.5 20 -70.310 1.80 1.90043 37.4 21 252.967 30.62 22(Aperture) ∞ 4.93 23 -35.634 1.30 1.60311 60.6 24 44.939 6.76 1.52584 49.7 25 -32.909 0.20 26 -43.510 1.95 1.48749 70.2 27 -37.860 (variable) 28 155.017 5.70 1.57714 42.3 29 -23.967 1.20 1.95375 32.3 30 -60.504 2.43 31 -31.133 2.56 1.58896 35.9 32 -26.486 (variable) 33 -106.469 1.00 1.53775 74.7 34 19.932 5.81 1.51653 52.8 35 122.631 3.44 36 -50.383 1.50 1.49700 81.5 37 30.867 5.46 1.51257 54.7 38 -294.673 (variable) Image plane ∞ Various data Zoom ratio 3.77 Wide Angle Mid-Telephoto Focal length 206.02 384.95 775.89 F-number 5.77 6.80 9.20 Half angle of view 5.99 3.22 1.60 Image height 21.64 21.64 21.64 Lens length 326.81 380.44 419.36 BF 31.57 53.56 91.89 d 7 8.62 62.25 101.18 d16 44.19 28.14 2.21 d27 18.16 26.33 35.76 d32 38.86 24.76 2.93 d38 31.57 53.56 91.89 Zoom lens group data Group starting plane focal length L1 1 342.32 L2 8 -89.16 L3 17 102.74 L4 28 130.20 L5 33 -54.45

[0072] [Numerical Example 5] Unit: mm Surface Data Surface number rd nd νd 1 218.302 5.89 1.48749 70.2 2 -738.944 39.20 3 251.266 6.97 1.49700 81.5 4 -222.883 2.70 1.61340 44.3 5 337.588 (variable) 6 453.827 3.22 1.80518 25.4 7 -79.739 1.40 1.77250 49.6 8 100.533 2.43 9 -89.220 1.40 1.83481 42.7 10 -393.480 (variable) 11 44.461 7.61 1.49700 81.5 12 -88.855 0.55 13 216.893 1.35 1.77250 49.6 14 25.104 5.51 1.54072 47.2 15 200.999 0.45 16 61.022 6.50 1.51823 58.9 17 -32.801 1.30 1.77250 49.6 18 912.404 11.86 19(Aperture) ∞ 23.62 20 134.867 1.30 2.00069 25.5 21 50.424 4.79 1.61340 44.3 22 -57.225 14.54 23 -67.250 1.98 1.51742 52.4 24 -38.172 10.00 25 -33.025 0.90 1.59522 67.7 26 -6071.683 29.02 27 -40.861 1.30 1.49700 81.5 28 49.832 3.84 1.72047 34.7 29 -471.630 (variable) Image plane ∞ Various data Zoom ratio 3.93 Wide Angle Mid-Telephoto Focal length 152.68 299.59 600.00 F-number 6.34 8.05 9.18 Half angle of view 8.07 4.13 2.07 Image height 21.64 21.64 21.64 Lens length 331.63 386.74 427.64 BF 39.31 65.54 82.78 d 5 35.90 93.92 153.22 d10 66.79 37.64 2.00 d29 39.31 65.54 82.78 Zoom lens group data Group starting plane focal length L1 1 379.81 L2 6 -78.52 L3 11 62.16

[0073] The table below gives various values ​​for each example.

[0074] [Table 1]

[0075] [Imaging device] Next, an embodiment of a digital still camera (imaging device) using the zoom lens of the present invention as an imaging optical system will be described with reference to Fig. 11. In Fig. 11, 11 denotes an imaging optical system constituted by any of the zoom lenses described in Examples 1 to 5. 12 denotes an imaging element (photoelectric conversion element) such as a CCD sensor or CMOS sensor that is built into a camera body 10 and receives an optical image formed by the imaging optical system 11 and photoelectrically converts it. The 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.

[0076] 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 a high-resolution image with a wide angle of view.

[0077] The disclosure of each embodiment includes the following configuration.

[0078] (Configuration 1) A zoom lens comprising, in order from the object side to the image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a subsequent lens group consisting of one or more lens groups, in which the spacing between adjacent lens groups changes during zooming, the first lens group moves toward the object side during zooming from the wide-angle end to the telephoto end, the second lens group has two or more lenses, Let TD12t be the axial distance from the lens surface closest to the object in the first lens group to the lens surface closest to the image in the second lens group at the telephoto end, TG12 be the sum of the axial thicknesses of the lenses included in the first lens group and the second lens group, TD1 be the axial distance from the lens surface closest to the object in the first lens group to the lens surface closest to the image, and TD2 be the axial distance from the lens surface closest to the object in the second lens group to the lens surface closest to the image, 4.3 <TD12t / TG12<12.0 3.6 <TD1 / TD2<30.0 A zoom lens characterized by satisfying the following conditional expressions:

[0079] (Configuration 2) Let m1 be the absolute value of the movement amount of the first lens group during zooming from the wide-angle end to the telephoto end, and f1 be the focal length of the first lens group. 0.1 <m1 / f1<0.5 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

[0080] (Configuration 3) Let f1 be the focal length of the first lens group, and fw be the focal length of the entire system at the wide-angle end. 1.0 <f1 / fw<3.0 3. The zoom lens according to configuration 1 or 2, wherein the following condition is satisfied:

[0081] (Configuration 4) Let f2 be the focal length of the second lens group, and fw be the focal length of the entire system at the wide-angle end. -1.0 <f2 / fw<-0.2 4. The zoom lens according to any one of configurations 1 to 3, which satisfies the following conditional expression:

[0082] (Configuration 5) Let ft be the focal length of the entire system at the telephoto end, and TTDw be the distance on the optical axis from the lens surface closest to the object to the image plane at the wide-angle end. 1.0 <ft / TTDw<3.5 5. The zoom lens according to any one of configurations 1 to 4, which satisfies the following condition:

[0083] (Configuration 6) If the focal length of the entire system at the telephoto end is ft and the back focus at the wide-angle end is skw, 8.0 <ft / skw<35.0 6. The zoom lens according to any one of configurations 1 to 5, wherein the following condition is satisfied:

[0084] (Configuration 7) If the distance on the optical axis from the lens surface closest to the object at the wide-angle end to the image plane is TTDw, and the back focus at the wide-angle end is skw, then 5.0 <TTDw / skw<20.0 7. The zoom lens according to any one of configurations 1 to 6, wherein the following condition is satisfied:

[0085] (Configuration 8) When the largest air gap in the first lens group on the optical axis is D1max, 0.4 <D1max / TD1<0.9 8. The zoom lens according to any one of configurations 1 to 7, wherein the following condition is satisfied:

[0086] (Configuration 9) The zoom lens has a focus group that moves during focusing. Let βft be the lateral magnification of the focus group at the telephoto end, and βrt be the combined lateral magnification of all lens groups disposed on the image side of the focus group at the telephoto end. Then, 4.0<|(1-βft2 )×βrt 2 |<20.0 9. The zoom lens according to any one of configurations 1 to 8, which satisfies the following conditional expression:

[0087] (Configuration 10) Let G1d be the specific gravity of the material of the lens in the first lens group that is located closest to the object, 2.0 <G1d<3.0 10. The zoom lens according to any one of configurations 1 to 9, wherein the following condition is satisfied:

[0088] (Configuration 11) The zoom lens described in any one of configurations 1 to 10, characterized in that the first lens group has a positive lens A and a positive lens B arranged in order from the object side, and the positive lens A and the positive lens B are arranged on the optical axis with the largest air gap between them in the first lens group.

[0089] (Configuration 12) 12. The zoom lens according to claim 11, wherein the first lens group comprises, in order from the object side to the image side, the positive lens A, the positive lens B, and a negative lens.

[0090] (Configuration 13) 13. The zoom lens according to any one of configurations 1 to 12, wherein the second lens group is stationary during zooming.

[0091] (Configuration 14) The zoom lens according to any one of configurations 1 to 13, wherein the subsequent lens group comprises a third lens group having positive refractive power, a fourth lens group having positive refractive power, a fifth lens group having negative refractive power, and a sixth lens group having negative refractive power.

[0092] (Configuration 15) The zoom lens according to any one of configurations 1 to 13, wherein the rear lens group comprises a third lens group having positive refractive power, a fourth lens group having negative refractive power, a fifth lens group having positive refractive power, and a sixth lens group having negative refractive power.

[0093] (Configuration 16) The zoom lens according to any one of configurations 1 to 13, wherein the subsequent lens group comprises a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, and a fifth lens group having a negative refractive power.

[0094] (Configuration 17) The zoom lens according to any one of configurations 1 to 13, wherein the subsequent lens group comprises a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, and a fifth lens group having a negative refractive power.

[0095] (Configuration 18) 14. The zoom lens according to any one of configurations 1 to 13, wherein the rear lens group is a third lens group having a positive refractive power.

[0096] (Configuration 19) A zoom lens according to any one of configurations 1 to 18, characterized in that an aperture stop is disposed between the lens surface of the third lens group closest to the object side and the lens surface of the third lens group closest to the image side, or on the image side of the third lens group.

[0097] (Configuration 20) 20. The zoom lens according to any one of configurations 1 to 19, wherein all of the lens surfaces constituting the zoom lens have a spherical shape.

[0098] (Configuration 21) 21. The zoom lens according to any one of configurations 1 to 20, wherein the second lens group, in whole or in part, moves during image blur correction so as to include a component in a direction perpendicular to the optical axis.

[0099] (Configuration 22) A zoom lens according to any one of configurations 1 to 21, an imaging device having an image sensor for receiving an image formed by the zoom lens;

[0100] 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]

[0101] L0 Zoom Lens L1 First lens group L2 Second lens group LR rear group

Claims

1. A zoom lens comprising, in order from the object side to the image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a subsequent lens group consisting of one or more lens groups, wherein the spacing between adjacent lens groups changes during zooming, the first lens group moves toward the object side during zooming from the wide-angle end to the telephoto end, the second lens group has three or more lenses, Let TD12t be the distance on the optical axis from the lens surface of the first lens group closest to the object to the lens surface of the second lens group closest to the image at the telephoto end, TG12 be the sum of the thicknesses of the lenses included in the first lens group and the second lens group on the optical axis, TD1 be the distance on the optical axis from the lens surface of the first lens group closest to the object to the lens surface of the second lens group closest to the image, and TD2 be the distance on the optical axis from the lens surface of the second lens group closest to the object to the lens surface of the second lens group closest to the image. 4.3<TD12t / TG12<12.0 3.6<TD1 / TD2<30.0 A zoom lens characterized by satisfying the following conditional expressions:

2. When the absolute value of the movement amount of the first lens group during zooming from the wide-angle end to the telephoto end is m1 and the focal length of the first lens group is f1, 0.1<m1 / f1<0.5 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

3. When the focal length of the first lens group is f1 and the focal length of the entire system at the wide-angle end is fw, 1.0<f1 / fw<3.0 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

4. When the focal length of the second lens group is f2 and the focal length of the entire system at the wide-angle end is fw, -1.0<f2 / fw<-0.2 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

5. When the focal length of the entire system at the telephoto end is ft and the distance on the optical axis from the lens surface closest to the object to the image plane at the wide-angle end is TTDw, 1.0<ft / TTDw<3.5 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

6. When the focal length of the entire system at the telephoto end is ft and the back focus at the wide-angle end is skw, 8.0<ft / skw<35.0 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

7. When the distance on the optical axis from the lens surface closest to the object at the wide-angle end to the image plane is TTDw and the back focus at the wide-angle end is skw, 5.0<TTDw / skw<20.0 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

8. When the largest air gap within the first lens group on the optical axis is D1max, 0.4<D1max / TD1<0.9 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

9. The zoom lens has a focus group that moves during focusing. When the lateral magnification of the focus group at the telephoto end is βft and the combined lateral magnification of all lens groups arranged on the image side of the focus group at the telephoto end is βrt, then: 4.0<|(1-βft ２ )×βrt ２ |<20.0 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

10. When the specific gravity of the material of the lens arranged closest to the object in the first lens group is G1d, 2.0<G1d<3.0 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

11. 2. The zoom lens according to claim 1, wherein the first lens group includes a positive lens A and a positive lens B arranged in this order from the object side, and the positive lens A and the positive lens B are arranged on the optical axis with the largest air gap therebetween within the first lens group.

12. 12. The zoom lens according to claim 11, wherein the first lens group comprises, in order from the object side to the image side, the positive lens A, the positive lens B, and a negative lens.

13. 2. The zoom lens according to claim 1, wherein the second lens group remains stationary during zooming.

14. 2. The zoom lens according to claim 1, wherein the subsequent lens group comprises a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, a fifth lens group having a negative refractive power, and a sixth lens group having a negative refractive power.

15. 2. The zoom lens according to claim 1, wherein the subsequent lens group comprises a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, a fifth lens group having a positive refractive power, and a sixth lens group having a negative refractive power.

16. 2. The zoom lens according to claim 1, wherein the subsequent lens group comprises a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, and a fifth lens group having a negative refractive power.

17. 2. The zoom lens according to claim 1, wherein the subsequent lens group comprises a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, and a fifth lens group having a negative refractive power.

18. 2. The zoom lens according to claim 1, wherein the subsequent lens group comprises a third lens group having a positive refractive power.

19. 2. The zoom lens according to claim 1, wherein an aperture stop is disposed between the lens surface of said third lens group closest to the object side and the lens surface of said third lens group closest to the image side, or on the image side of said third lens group.

20. 2. The zoom lens according to claim 1, wherein all lens surfaces constituting said zoom lens are spherical.

21. 2. The zoom lens according to claim 1, wherein the second lens group moves in whole or in part during image blur correction so as to include a component in a direction perpendicular to the optical axis.

22. A zoom lens according to any one of claims 1 to 21; an imaging device having an imaging element that receives an image formed by the zoom lens;

Images