JP6869740B2 - Zoom lens and imaging device with it - Google Patents

Description

The present invention relates to a zoom lens and an image pickup device having the same, and for example, an image pickup device using an image pickup element such as a video camera, an electronic still camera, a broadcasting camera, a surveillance camera, or a camera using a silver salt film. It is suitable for the imaging optical system used in the apparatus.

In recent years, the imaging optical system used in an imaging device is required to be a zoom lens having a high zoom ratio and high performance over the entire zoom range while the entire system is compact. Further, it is required that there is little aberration fluctuation during focusing and that the optical performance is high over the entire object distance.

As a zoom lens that can easily realize a high zoom ratio, a positive lead type zoom lens in which a lens group having a positive refractive power is arranged on the most object side is known. A zoom lens using a floating method in which two lens groups are moved during focusing is known as a positive lead type with little aberration fluctuation during focusing and high optical performance over the entire object distance (patented). Documents 1 and 2).

In Patent Document 1, the first lens group and the fifth lens are included in a five-group zoom lens composed of a first lens group to a fifth lens group having positive, negative, positive, positive, and negative refractive powers in order from the object side to the image side. Focusing is performed by moving the groups in opposite directions. Further, in Patent Document 2, in the fifth lens group consisting of the first lens group to the fifth lens group having positive, negative, positive, positive, and negative refractive powers in this order from the object side to the image side, the third lens group and the fifth lens group Focusing is performed by moving the lens groups in opposite directions.

Japanese Unexamined Patent Publication No. 8-15608 Japanese Unexamined Patent Publication No. 2011-180218

In order to improve the aberration fluctuation due to focusing, it is effective to use a floating method in which a plurality of lens groups are moved in the optical axis direction during focusing. When the floating method is used, the amount of movement of the focusing lens group can be shortened when focusing from infinity to a close distance, and it becomes easy to reduce aberration fluctuations while reducing the size of the entire lens system.

In particular, if a floating method is used in which a plurality of lens groups other than the first lens group on the object side are moved to perform focusing, the effective diameter of the lens group to be moved during focusing can be reduced. Focusing can be facilitated while reducing the size of the entire lens system and reducing aberration fluctuations over the entire object distance from infinity to close proximity.

In a positive lead type zoom lens, it is important to appropriately set each element constituting the zoom lens in order to obtain high optical performance over the entire object distance while reducing the size of the entire system. For example, it is important to appropriately set the zoom type (number of lens groups, refractive power of each lens group, etc.), selection of a lens group that moves during focusing, and a lens configuration of a lens group that moves during focusing.

For example, when using a floating method in which two lens groups are moved during focusing, it is important to select the two lens groups to be moved during focusing and to appropriately set the moving direction and the amount of movement.

An object of the present invention is to provide a zoom lens capable of easily obtaining high optical performance over a total object distance while reducing the size of the entire system, and an imaging device having the same.

The zoom lens of the present invention includes a first lens group having a positive refractive force, a second lens group having a positive refractive force, a third lens group having a negative refractive force, and a plurality of lenses arranged in order from the object side to the image side. In a zoom lens composed of a rear group including a lens group and the distance between adjacent lens groups changes during zooming, the rear group is a fourth lens group having a positive refractive force arranged in order from the object side to the image side. The second lens group and the lens system RF including one or more lenses included in the rear group move in different trajectories during focusing, and the second lens group is composed of a fifth lens group having a positive refractive force. When the group has a positive lens, the focal distance of the first lens group is f1, the focal distance of the second lens group is f2, and the Abbe number of the material of the positive lens with respect to the d line is νd2.
0.8 <f2 / f1 <2.0
80.0 <νd2
It is characterized by satisfying the conditional expression.

According to the present invention, it is possible to obtain a zoom lens that can easily obtain high optical performance over the entire object distance while reducing the size of the entire system.

Cross-sectional view of the lens at the wide-angle end of Example 1 (A), (B) Aberration diagram when focusing at infinity at the wide-angle end of Example 1 and when focusing closest to it. (A), (B) Aberration diagram when focusing at infinity at the telephoto end of Example 1 and when focusing closest to infinity Cross-sectional view of the lens at the wide-angle end of Example 2 (A), (B) Aberration diagram when focusing at infinity at the wide-angle end of Example 2 and when focusing closest to infinity (A), (B) Aberration diagram when focusing at infinity at the telephoto end of Example 2 and when focusing closest to infinity Cross-sectional view of the lens at the wide-angle end of Example 3 (A), (B) Aberration diagram when focusing at infinity at the wide-angle end of Example 3 and when focusing closest to infinity (A), (B) Aberration diagram when focusing at infinity at the telephoto end of Example 3 and when focusing closest to infinity Schematic diagram of the main part of the image pickup apparatus of the present invention

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The zoom lens of the present invention includes a first lens group having a positive refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a plurality of lenses arranged in order from the object side to the image side. It is composed of a rear group including a lens group, and the distance between adjacent lens groups changes during zooming. Then, at the time of focusing, the lens system RF including one or more lenses included in the second lens group and the rear group moves in different trajectories.

FIG. 1 is a cross-sectional view of a lens at the wide-angle end of Example 1 of the present invention. 2 (A) and 2 (B) are aberration diagrams of the case of focusing at infinity at the wide-angle end of Example 1 and the case of focusing at the closest point, respectively. 3 (A) and 3 (B) are aberration diagrams when the lens is focused at infinity at the telephoto end of the first embodiment and when the lens is focused closest to the point at infinity, respectively. The first embodiment is a zoom lens having a zoom ratio of 2.03 and an F number of 2.06. Here, the closest is when the imaging magnification shown in the numerical data described later is β.

FIG. 4 is a cross-sectional view of the lens at the wide-angle end of Example 2 of the present invention. 5 (A) and 5 (B) are aberration diagrams of the case of focusing at infinity at the wide-angle end of Example 2 and the case of focusing at the closest point, respectively. 6 (A) and 6 (B) are aberration diagrams when focusing at infinity at the telephoto end of Example 2 and when focusing closest to each other. The second embodiment is a zoom lens having a zoom ratio of 2.03 and an F number of 2.06.

FIG. 7 is a cross-sectional view of the lens at the wide-angle end of Example 3 of the present invention. 8 (A) and 8 (B) are aberration diagrams when the lens is focused at infinity at the wide-angle end of Example 3 and when the lens is closest to the focus, respectively. 9 (A) and 9 (B) are aberration diagrams when the lens is focused at infinity at the telephoto end of Example 3 and when the lens is focused closest to the point at infinity, respectively. Example 3 is a zoom lens having a zoom ratio of 1.62 and an F number of 2.06.

FIG. 10 is a schematic view of a main part of the image pickup apparatus of the present invention. The zoom lens of each embodiment is an imaging optical system used in an imaging device such as a video camera, a digital still camera, a silver salt film camera, and a TV camera. The zoom lens of each embodiment can also be used as a projection optical system for a projection device (projector).

In the cross-sectional view of the lens, the left side is the object side (front) and the right side is the image side (rear). Further, in the cross-sectional view of the lens, OL is a zoom lens. If i is the order of the lens groups from the object side, Li indicates the i-th lens group. The LR is a posterior group that includes one or more lens groups. RF is a lens system of a part of a plurality of lenses constituting the fifth lens group L5.

SP is an aperture stop. IP is an image plane. The image plane IP corresponds to the image pickup surface of an image pickup element (photoelectric conversion element) such as a CCD sensor or a CMOS sensor when a zoom lens is used as an image pickup optical system of a video camera or a digital camera. Further, the image plane IP corresponds to the film plane when a zoom lens is used as an imaging optical system of a silver halide film camera. The arrow indicates the movement locus of each lens group during zooming (magnification) from the wide-angle end to the telephoto end. The arrow on focus indicates the direction of movement of the lens group or lens system when focusing from infinity to a short distance.

Among the aberration diagrams, in the spherical aberration diagram, the solid line d is the d line (wavelength 587.6 nm), the double-point chain line g is the g line (wavelength 435.8 nm), and in the astigmatism diagram, the solid line S is the d line. The sagittal image plane and the dotted line M are the meridional image planes on the d line. Distortion is shown for line d. In the chromatic aberration of magnification diagram, g is the g line. In each of the following examples, the wide-angle end and the telephoto end refer to the zoom positions when the lens group for scaling is mechanically located at both ends of the movable range on the optical axis.

The zoom lens of the present invention has a first lens group L1 having a positive refractive power, a second lens group L2 having a positive refractive power, and a third lens group L3 having a negative refractive power arranged in order from the object side to the image side. It is composed of a rear group including a plurality of lens groups. Then, the distance between adjacent lens groups changes during zooming. At the time of focusing, the lens system RF composed of one or more of the plurality of lenses included in the second lens group L2 and the rear group LR moves (independently) in different trajectories from each other. The first lens group L1 and the fifth lens group L5 are immobile during zooming.

In the zoom type zoom lens according to the present invention, at the telephoto end, the second lens group L2 having a positive refractive power is moved toward the object when focusing from infinity to a short distance. As a result, the spherical aberration becomes under and the curvature of field becomes over. When the lens system RF has a positive refractive power, the lens system RF is moved to the object side to reduce the variation in curvature of field and the amount of movement of the second lens group L2. When the lens system RF has a negative refractive power, the same effect is obtained by moving the lens system RF to the image side.

If the first lens group L1 is immovable (fixed) during focusing or zooming, the lens barrel can be configured to be resistant to external pressure. Further, since the effective light diameter of the first lens group L1 can be reduced, the size of the zoom lens in the radial direction can be easily reduced.

In each embodiment, the second lens group L2 and the third lens group L3 move to the image side when zooming from the wide-angle end to the telephoto end. As a result, the effective light diameters of the second lens group L2 and the third lens group L3 are reduced, and the size of the zoom lens in the radial direction is reduced.

The second lens group L2, which is a focus lens group, is composed of two or less lenses. The focus lens group is composed of two or less lenses to reduce the weight so that, for example, when this zoom lens is applied to an autofocus camera, a stable and high-speed autofocus function can be obtained. Further, by using a low-dispersion material as the material of the positive lens included in the second lens group L2, fluctuations in axial chromatic aberration and lateral chromatic aberration during focusing are satisfactorily corrected.

Further, by arranging the lens system RF for focusing on the image side from the aperture diaphragm SP, the effective light diameter of the lens system RF is reduced, and the size of the zoom lens in the radial direction is reduced. In addition, the lens system RF is composed of three or less lenses to reduce aberration fluctuations during focusing.

The amount of movement of the lens system RF during focusing from infinity to near at the telephoto end is DtRF, and the amount of movement of the second lens group L2 during focusing from infinity to near at the telephoto end is DtL2. Let BF be the back focus when focusing at infinity at the wide-angle end, and fw be the focal length of the entire system when focusing at infinity at the wide-angle end. Let f1 be the focal length of the first lens group. Let the focal length of the second lens group be f2. Let the focal length of the lens system RF be fRF.

The lateral magnification of the second lens group L2 when focusing at infinity at the telephoto end is β2, and it is arranged on the image side from the second lens group L2 when focusing at infinity at the telephoto end. The lateral magnification of the optical system is βr. The second lens group L2 has a positive lens, and the Abbe number of the material of the positive lens with respect to the d line is νd2. Here, the sign of the amount of movement when focusing the lens group (lens system) from infinity to the closest direction is negative when moving to the object side and positive when moving to the image side.

At this time,
0.005 << DtRF / DtL2 | <0.800 ... (1)
0.1 <BF / fw <0.5 ... (2)
1.5 <f2 / fw <4.0 ... (3)
0.3 <f2 / f1 <2.0 ... (4)
0.5 << | fRF / fw | <2.0 ... (5)
0.5 << 1-β2 ² | βr ² <3.0 ・ ・ ・ (6)
60.0 <νd2 ・ ・ ・ (7)
Satisfies the conditional expression.

Conditional expression (1) defines the ratio of the amount of movement of the lens system RF during focusing from infinity to near and the amount of movement of the second lens group L2 during focusing from infinity to near. Conditional expression (1) mainly reduces spherical aberration and curvature of field during focusing. If the upper limit of the conditional expression (1) is exceeded, the amount of movement of the lens system RF increases, and the curvature of field becomes insufficiently corrected. On the contrary, when the lower limit of the conditional expression (1) is exceeded, the amount of movement of the second lens group L2 increases, and the spherical aberration becomes insufficiently corrected.

Conditional expression (2) defines the ratio of the back focus to the focal length of the entire system at the wide-angle end when focusing at infinity. The conditional expression (2) mainly optimizes the length of the back focus in the zoom lens. If the back focus at the wide-angle end becomes too long beyond the upper limit of the conditional expression (2), the total length of the lens becomes long and it becomes difficult to miniaturize the entire system. If the back focus at the wide-angle end is too short beyond the lower limit of the conditional expression (2), the angle of incidence of the off-axis light rays on the image plane becomes large. As a result, the light flux that should reach the peripheral portion of the screen is less likely to reach the light receiving element (imaging element), and a lot of shading occurs.

Conditional expression (3) defines the ratio of the focal length of the second lens group L2 to the focal length of the entire system at the wide-angle end. The conditional expression (3) is obtained by optimizing the focal length of the second lens group L2. If the focal length of the second lens group L2 becomes too long beyond the upper limit of the conditional expression (3), the amount of movement of the second lens group L2 becomes large during focusing, which makes it difficult to reduce the size of the zoom lens. On the contrary, if the focal length of the second lens group L2 becomes too short beyond the lower limit of the conditional expression (3), it becomes difficult to correct the spherical aberration at the telephoto end.

The conditional expression (4) defines the ratio between the focal length of the second lens group L2 and the focal length of the first lens group L1. The conditional expression (4) is obtained by optimizing the focal length of the second lens group L2. If the focal length of the second lens group L2 becomes too long beyond the upper limit of the conditional expression (4), the amount of movement of the second lens group L2 becomes large during focusing, which makes it difficult to reduce the size of the zoom lens. On the contrary, if the focal length of the second lens group L2 becomes too short beyond the lower limit of the conditional expression (4), it becomes difficult to correct the spherical aberration at the telephoto end.

Conditional expression (5) defines the ratio of the focal length of the lens system RF to the focal length of the entire system at the wide-angle end. Conditional expression (5) is an optimized focal length of the lens system RF. If the focal length of the lens system RF becomes too long beyond the upper limit of the conditional expression (5), the amount of movement of the lens system RF becomes large during focusing, and it becomes difficult to miniaturize the zoom lens. On the contrary, if the focal length of the lens system RF becomes too short beyond the lower limit of the conditional expression (5), it becomes difficult to correct the curvature of field at the telephoto end.

Conditional expression (6) relates to the focus sensitivity of the second lens group L2. Focus sensitivity is the ratio of the amount of focus movement when the focus lens group moves by a unit amount in the optical axis direction. If the focus sensitivity becomes smaller than the lower limit of the conditional expression (6), the amount of movement of the focus lens group becomes large during focusing, and high-speed focusing becomes difficult.

On the contrary, if the upper limit of the conditional expression (6) is exceeded and the focus sensitivity becomes too large, the amount of movement of the focus lens group during focusing becomes small, and it becomes difficult to control the drive of the focus lens group with high accuracy during focusing.

The conditional expression (7) defines the Abbe number of the material of the positive lens included in the second lens group L2 with respect to the d-line. The conditional expression (7) satisfactorily corrects the fluctuation of the aberration at the time of focusing. If the lower limit of the conditional expression (7) is exceeded, it becomes difficult to satisfactorily correct fluctuations in axial chromatic aberration and lateral chromatic aberration during focusing.

Preferably, the numerical range of the conditional expressions (1) to (7) is preferably the following range.
0.008 << DtRF / DtL2 | <0.700 ... (1a)
0.13 <BF / fw <0.40 ... (2a)
1.6 <f2 / fw <3.5 ... (3a)
0.5 <f2 / f1 <1.5 ... (4a)
0.7 << | fRF / fw | <1.8 ... (5a)
0.7 << 1-β2 ² | βr ² <2.0 ・ ・ ・ (6a)
70.0 <νd2 ... (7a)
More preferably, the numerical range of the conditional expressions (1a) to (7a) is set to the following range.
0.009 << | DtRF / DtL2 | <0.600 ... (1b)
0.15 <BF / fw <0.35 ... (2b)
1.8 <f2 / fw <3.0 ... (3b)
0.8 <f2 / f1 <1.1 ... (4b)
0.8 << | fRF / fw | <1.6 ... (5b)
1.0 << | 1-β2 ² | βr ² <1.5 ... (6b)
80.0 <νd2 ... (7b)
In order to obtain high optical performance over the entire object distance while reducing the size of the entire system in each embodiment, it is preferable to configure as follows.

The first lens group L1 is preferably immobile during zooming and focusing. When zooming from the wide-angle end to the telephoto end, the second lens group L2 and the third lens group L3 are preferably moved from the object side to the image side. The rear group LR may be composed of a fourth lens group L4 having a positive refractive power and a fifth lens group L5 having a positive refractive power arranged in order from the object side to the image side. The lens system RF may consist of a part of a plurality of lenses constituting the fifth lens group L5. It is preferable that the aperture diaphragm SP is arranged on the object side of the fifth lens group L5.

Next, an example of a digital still camera (imaging apparatus) using the zoom lens of the present invention will be described with reference to FIG.

FIG. 10 is a schematic view of a main part of a single-lens reflex camera. In FIG. 10, 10 is an imaging optical system having the zoom lens 1 of any one of Examples 1 to 3. The imaging optical system 1 is held by a lens barrel 2 which is a holding member. Reference numeral 20 is a camera body. The camera body 20 is composed of a quick return mirror 3, a focus plate 4, a pentadha prism 5, an eyepiece 6, and the like.

The quick return mirror 3 reflects the light flux from the photographing optical system 10 upward. The focal plate 4 is arranged at an image forming position of the photographing optical system 10. The pentadha prism 5 converts the inverse image formed on the focal plate 4 into an upright image. The observer observes the erect image through the eyepiece lens 6. Reference numeral 7 denotes a photosensitive surface, on which a solid-state image sensor (photoelectric conversion element) such as a CCD sensor or CMOS sensor that receives an image or a silver salt film is arranged. At the time of shooting, the quick return mirror 3 retracts from the optical path and is formed on the photosensitive surface 7 on the image side by the imaging optical system 10.

As described above, by applying the zoom lens of the present invention to an imaging device such as an interchangeable lens for a single-lens reflex camera, high optical performance is obtained. In addition, the zoom lens of the present invention can be similarly applied to a mirrorless single-lens reflex camera without a quick return mirror. In addition, the zoom lens of the present invention can be applied to optical devices such as telescopes, binoculars, copiers, and projectors in addition to digital cameras, video cameras, cameras for silver salt films, and the like.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and modifications can be made within the scope of the gist thereof.

The numerical data 1 to 3 corresponding to Examples 1 to 3 are shown below. In each numerical data, i indicates the order of the surfaces from the object side, and ri is the i-th (i-plane) radius of curvature. di is the distance between the i-th plane and the i + 1-th plane. ndi and νdi indicate the refractive index and Abbe number of the material with respect to the d line, respectively. BF is the back focus. Table 1 shows the relationship between each of the above conditional expressions and various numerical values in the numerical examples.

The image height is the image height that determines the half-angle of view. The total length of the lens is the length from the first lens surface to the image surface. The back focus BF is the length from the final lens surface to the image surface. β is the imaging magnification at the closest object distance.

(Numerical data 1)
Unit mm

Surface data Surface number rd nd ν d
1 131.595 2.80 2.00069 25.5
2 106.546 7.73 1.43875 94.7
3 430.966 0.15
4 88.247 7.25 1.43875 94.7
5 320.211 (variable)
6 56.149 2.22 1.67542 34.8
7 44.749 1.09
8 50.178 9.44 1.43387 95.1
9 ∞ (variable)
10 -505.442 1.50 1.77250 49.6
11 43.525 6.90
12 -69.454 1.40 1.43875 94.7
13 52.232 3.95 1.89286 20.4
14 173.933 3.25
15 -92.629 1.40 1.72916 54.7
16 ∞ (variable)
17 -416.819 3.40 2.00100 29.1
18 -83.689 0.15
19 64.810 8.56 1.43875 94.7
20 -61.334 1.80 1.85896 22.7
21 -306.739 (variable)
22 (Aperture) ∞ 0.40
23 93.818 3.68 1.80400 46.6
24 -1474.268 0.15
25 45.526 5.89 1.77250 49.6
26 -887.323 0.15
27 -1138.266 1.50 1.70154 41.2
28 24.815 5.99 1.49700 81.5
29 73.811 4.66
30 -358.190 2.42 1.95906 17.5
31 -74.879 1.00 1.51742 52.4
32 40.090 4.42
33 -114.059 1.00 1.84666 23.8
34 533.833 4.70
35 390.940 2.69 1.83481 42.7
36 -76.120 1.00
37 90.331 5.02 1.59522 67.7
38 -40.616 1.40 2.00069 25.5
39 -185.243 22.58
40 75.861 5.04 1.78472 25.7
41 -125.998 1.70 1.69680 55.5
42 59.785 21.80
Image plane ∞

Various data Zoom ratio 2.03

Focal length 72.00 114.84 146.00 92.60 123.41
F number 2.06 2.06 2.06 2.06 2.06
Half angle of view (degrees) 16.72 10.67 8.43 13.15 9.94
Image height 21.64 21.64 21.64 21.64 21.64
Lens overall length 210.32 210.32 210.32 210.32 210.32
BF 21.80 21.80 21.80 21.80 21.80
β -0.06 -0.1 -0.13 -0.08 -0.11

d 5 11.95 23.80 30.44 17.21 26.03
d 9 0.99 13.38 17.10 8.95 14.57
d16 21.74 9.52 1.00 15.72 7.17
d21 15.46 3.45 1.60 8.26 2.38

Zoom lens group Data group Start surface Focal length
1 1 201.95
2 6 175.08
3 10 -30.78
4 17 78.73
5 22 89.04


(Numerical data 2)
Unit mm

Surface data Surface number rd nd ν d
1 139.374 2.80 2.00069 25.5
2 115.300 7.85 1.43875 94.7
3 635.431 0.15
4 91.418 5.89 1.43875 94.7
5 200.474 (variable)
6 70.132 2.22 1.80610 33.3
7 52.943 0.64
8 57.626 8.54 1.49700 81.5
9 ∞ (variable)
10 -442.238 1.50 1.77250 49.6
11 52.172 6.03
12 -87.693 1.40 1.43875 94.7
13 62.453 3.80 1.89286 20.4
14 270.800 2.71
15 -104.881 1.40 1.72916 54.7
16 ∞ (variable)
17 -443.844 3.03 2.00100 29.1
18 -101.537 0.15
19 68.475 8.22 1.43875 94.7
20 -67.703 1.80 1.85896 22.7
21 -324.295 (variable)
22 (Aperture) ∞ 0.40
23 86.239 4.38 1.80400 46.6
24 1079.334 0.15
25 47.329 5.55 1.77250 49.6
26 -9386.765 0.15
27 8263.433 1.50 1.70154 41.2
28 28.174 5.23 1.49700 81.5
29 72.329 4.86
30 -261.542 2.56 1.95906 17.5
31 -67.200 1.00 1.51742 52.4
32 39.577 4.42
33 -108.121 1.00 1.84666 23.8
34 485.370 4.90
35 339.101 2.76 1.83481 42.7
36 -78.196 1.00
37 83.036 5.30 1.59522 67.7
38 -40.616 1.40 2.00069 25.5
39 -181.717 23.11
40 53.767 6.31 1.78472 25.7
41 800.402 1.70 1.69680 55.5
42 43.575 22.47
Image plane ∞

Various data Zoom ratio 2.03

Focal length 72.03 115.04 145.99 92.39 123.70
F number 2.06 2.06 2.06 2.06 2.06
Half angle of view (degrees) 16.72 10.65 8.43 13.18 9.92
Image height 21.64 21.64 21.64 21.64 21.64
Lens overall length 217.72 217.72 217.72 217.72 217.72
BF 22.47 22.47 22.47 22.47 22.47
β -0.06 -0.10 -0.13 -0.08 -0.11

d 5 15.38 29.18 37.01 21.47 31.81
d 9 0.98 15.66 19.85 10.32 17.04
d16 28.93 12.33 0.99 20.89 9.13
d21 14.16 2.28 1.59 6.77 1.47

Zoom lens group Data group Start surface Focal length
1 1 233.21
2 6 199.78
3 10 -38.39
4 17 92.96
5 22 94.80


(Numerical data 3)
Unit mm

Surface data Surface number rd nd ν d
1 164.075 2.80 2.00069 25.5
2 118.631 12.59 1.43875 94.7
3 -331.573 0.15
4 105.658 8.90 1.49700 81.5
5 374.308 (variable)
6 56.026 2.22 1.78470 26.3
7 47.071 0.59
8 51.845 7.18 1.43875 94.7
9 ∞ (variable)
10 -571.511 1.50 1.77250 49.6
11 44.416 6.59
12 -82.153 1.40 1.43875 94.7
13 48.223 4.12 1.89286 20.4
14 150.352 3.53
15 -87.327 1.40 1.72916 54.7
16 ∞ (variable)
17 -182.286 4.57 2.00100 29.1
18 -70.255 0.15
19 82.179 8.14 1.43875 94.7
20 -58.006 1.80 1.85896 22.7
21 -371.518 (variable)
22 (Aperture) ∞ 0.40
23 129.873 2.06 1.80400 46.6
24 249.113 0.15
25 50.484 5.76 1.77250 49.6
26 5658.724 0.15
27 898.451 1.50 1.70154 41.2
28 47.812 1.77 1.49700 81.5
29 49.251 3.81
30 219.309 5.29 1.90366 31.3
31 -72.339 1.00 1.53172 48.8
32 261.075 4.42
33 -56.754 1.00 1.51742 52.4
34 85.951 13.34
35 280.987 4.38 1.83481 42.7
36 -60.016 1.00
37 802.530 8.64 1.59522 67.7
38 -40.616 1.40 2.00069 25.5
39 -189.656 42.44
40 45.636 5.10 1.78472 25.7
41 65.924 1.70 1.69680 55.5
42 47.432 16.70
Image plane ∞

Various data Zoom ratio 1.62

Focal length 90.00 125.01 145.99 109.96 130.49
F number 2.06 2.06 2.06 2.06 2.06
Half angle of view (degrees) 13.52 9.82 8.43 11.13 9.41
Image height 21.64 21.64 21.64 21.64 21.64
Lens overall length 242.35 242.35 242.35 242.35 242.35
BF 16.70 16.70 16.70 16.70 16.70
β -0.08 -0.11 -0.13 -0.10 -0.12

d 5 18.49 34.75 42.87 26.30 37.50
d 9 3.28 4.63 4.29 5.23 4.37
d16 21.96 10.47 3.97 14.99 8.84
d21 9.01 2.89 1.60 6.20 2.02

Zoom lens group Data group Start surface Focal length
1 1 165.01
2 6 167.99
3 10 -31.83
4 17 102.78
5 22 85.19

OL Zoom Lens L1 1st Lens Group L2 2nd Lens Group L3 3rd Lens Group L4 4th Lens Group L5 5th Lens Group LR Rear Group RF Lens System SP Aperture Aperture

Claims (14)

From the first lens group with positive refractive power, the second lens group with positive refractive power, the third lens group with negative refractive power, and the rear group including multiple lens groups arranged in order from the object side to the image side. In a zoom lens that is configured and the spacing between adjacent lens groups changes during zooming
The rear group is composed of a fourth lens group having a positive refractive power and a fifth lens group having a positive refractive power arranged in order from the object side to the image side.
At the time of focusing, the lens system RF including one or more lenses included in the second lens group and the rear group moves in different trajectories.
The second lens group has a positive lens and has a positive lens.
When the focal length of the first lens group is f1, the focal length of the second lens group is f2, and the Abbe number of the material of the positive lens with respect to the d line is νd2.
0.8 <f2 / f1 <2.0
80.0 <νd2
A zoom lens characterized by satisfying the conditional expression. When the amount of movement of the lens system RF during focusing from infinity to near at the telephoto end is DtRF, and the amount of movement of the second lens group during focusing from infinity to near at the telephoto end is DtL2.
0.005 << DtRF / DtL2 | <0.800
The zoom lens according to claim 1, wherein the zoom lens satisfies the conditional expression. When the back focus when focusing at infinity at the wide-angle end is BF, and the focal length of the entire system when focusing at infinity at the wide-angle end is fw,
0.1 <BF / fw <0.5
The zoom lens according to claim 1 or 2, wherein the zoom lens satisfies the conditional expression. When the focal length of the state of focusing on infinity in the wide-angle end and fw,
1.5 <f2 / fw <4.0
The zoom lens according to any one of claims 1 to 3, wherein the zoom lens satisfies the conditional expression. When the focal length of the lens system RF is fRF and the focal length of the entire system when focusing at infinity at the wide-angle end is fw
0.5 << | fRF / fw | <2.0
The zoom lens according to any one of claims 1 to 4, wherein the zoom lens satisfies the conditional expression. The lateral magnification of the second lens group when focusing at infinity at the telephoto end is β2, and the optics arranged on the image side of the second lens group when focusing at infinity at the telephoto end. When the lateral magnification of the system is βr,
0.5 << 1-β2 ² | × βr ² <3.0
The zoom lens according to any one of claims 1 to 5, wherein the zoom lens satisfies the conditional expression. The zoom lens according to any one of claims 1 to 6 , wherein the first lens group is immovable during zooming and focusing. The zoom lens according to any one of claims 1 to 7 , wherein the second lens group and the third lens group move from the object side to the image side when zooming from the wide-angle end to the telephoto end. .. The zoom lens according to any one of claims 1 to 8 , wherein the second lens group is composed of two or less lenses. The zoom lens according to any one of claims 1 to 9 , wherein the aperture diaphragm is arranged on the object side of the lens system RF. The zoom lens according to any one of claims 1 to 10 , wherein the lens system RF is composed of three or less lenses. The zoom lens according to any one of claims 1 to 11, wherein the lens system RF is composed of a part of a lens among a plurality of lenses constituting the fifth lens group. The zoom lens according to any one of claims 1 to 12, wherein an aperture diaphragm is arranged on the object side of the fifth lens group. An image pickup apparatus comprising the zoom lens according to any one of claims 1 to 13 and an image pickup element that receives an image formed by the zoom lens.

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