JP2019139172A - Zoom lens and image capturing device having the same - Google Patents

Abstract

To provide a zoom lens which comprises a compact system as a whole, has a wide view angle, and yet easily provides high optical performance throughout an entire zoom range over an entire screen.SOLUTION: A zoom lens comprises a first lens group having negative refractive power, a second lens group having positive refractive power, and a rear group comprising 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. The first lens group has a negative lens and another negative lens arranged in order from the object side to the image side. A focal length f1 of the first lens group, a displacement M2 of the second lens group L2 while zooming from the wide-angle end to the telephoto end, a total optical length Lw at the wide-angle end, a focal length fw of the entire system at the wide-angle end, and a focal length ft of the entire system at the telephoto end are each set appropriately.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a zoom lens and an image pickup apparatus having the same, and is suitable as an image pickup optical system used in, for example, a digital still camera, a digital video camera, and a surveillance camera.

  In recent years, an imaging optical system used in an imaging apparatus is desired to be a small zoom lens having a wide angle of view and high optical performance over the entire zoom range in order to cope with a wider range of imaging conditions. Yes.

  A negative lead type zoom lens in which a lens group having a negative refractive power is located on the object side is known as a zoom lens that is small in size and easy to widen the angle of view (Patent Document 1).

  In Japanese Patent Laid-Open No. 2004-26883, a five-unit zoom that includes first to fifth lens units having negative, positive, positive, negative, and positive refractive power in order from the object side to the image side, and performs zooming by moving each lens unit. A lens is disclosed. Patent Document 1 discloses a zoom lens having an imaging field angle of 100 degrees or more at the wide-angle end, reducing distortion and chromatic aberration generated when widening the field angle, and having high optical performance in the entire zoom range.

Japanese Patent Laying-Open No. 2015-206976

  A negative lead type zoom lens preceded by a lens unit having a negative refractive power is characterized in that a wide angle of view is relatively easy and a long back focus can be easily obtained. In a negative lead type zoom lens, in order to achieve a higher zoom ratio while further widening the angle of view, for example, the refractive power of a lens unit having a positive refractive power disposed on the image side from the aperture stop is further strengthened. Or the amount of movement of the lens group during zooming may be increased.

  However, when doing so, more distortion and lateral chromatic aberration occur than in the negative first lens group.

  The negative lead type zoom lens has an asymmetric lens structure with respect to the aperture stop. Therefore, when trying to reduce the size of the entire system while widening the angle of view, distortion and lateral chromatic aberration, among other aberrations, are particularly significant. Many occur.

  In a negative lead type zoom lens, while reducing the size of the entire system and having a wide angle of view and a predetermined zoom ratio, and obtaining high optical performance over the entire screen, the number of lens groups, the number of lens groups, It is important to appropriately set the refractive power and the lens configuration.

  In particular, the refractive power of the first lens unit having the negative refractive power arranged closest to the object side, the lens configuration, and the lens configuration of the second lens unit arranged closer to the image side than the first lens unit are appropriately set. It becomes important to do.

  An object of the present invention is to provide a zoom lens that can obtain high optical performance over the entire zoom range and the entire screen while the entire system is small and has a wide angle of view.

The zoom lens according to the present invention includes a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a rear group including one or more lens groups, which are arranged in order from the object side to the image side. In the zoom lens in which the interval between adjacent lens groups changes during zooming, the first lens group includes a negative lens and a negative lens arranged in order from the object side to the image side. The focal length is f1, the amount of movement of the second lens group during zooming from the wide-angle end to the telephoto end is M2, the total optical length at the wide-angle end is Lw, the focal length of the entire system at the wide-angle end is fw, and the entire system at the telephoto end is When the focal length is ft,
−0.38 <f1 / ft <−0.10
-4.0 <M2 / fw <-2.0
6.0 <Lw / fw <9.0
It satisfies the following conditional expression.

  According to the present invention, it is possible to obtain a zoom lens capable of obtaining high optical performance over the entire zoom range and the entire screen while the entire system is small and has a wide angle of view.

Optical cross-sectional view of the zoom lens of Example 1 Aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end of the zoom lens of Example 1 Optical sectional view of the zoom lens of Example 2 Aberration diagrams at the wide-angle end, intermediate zoom position, and telephoto end of the zoom lens of Example 2 Optical sectional view of the zoom lens of Example 3 Aberration diagrams at the wide-angle end, intermediate zoom position, and telephoto end of the zoom lens of Example 3 Schematic diagram of imaging device of the present invention

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. The zoom lens according to the present invention includes a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a rear group including one or more lens groups, which are arranged in order from the object side to the image side. In zooming, the distance between adjacent lens groups changes. The first lens group has a negative lens and a negative lens arranged in order from the object side to the image side.

  FIG. 1 is a lens cross-sectional view at the wide-angle end (short focal length end) of the first embodiment. 2A, 2 </ b> B, and 2 </ b> C are the wide-angle end, the intermediate zoom position, and the telephoto end (long focus) when focusing on an object at infinity of the zoom lens of Embodiment 1 (when in focus). It is a longitudinal aberration diagram at the distance end). The first embodiment is a zoom lens having a zoom ratio of 3.95 and an F number of 3.57 to 5.85.

  FIG. 3 is a lens cross-sectional view at the wide angle end according to the second embodiment. 4A, 4B, and 4C are longitudinal aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end when the zoom lens of Example 2 is focused on an object at infinity. The second embodiment is a zoom lens having a zoom ratio of 4.25 and an F number of 3.57 to 5.85.

  FIG. 5 is a lens cross-sectional view at the wide angle end according to the third embodiment. 6A, 6B, and 6C are longitudinal aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end when the zoom lens of Example 3 is focused on an object at infinity. Example 3 is a zoom lens having a zoom ratio of 4.14 and an F number of 3.57 to 5.85.

  The zoom lens of each embodiment is an imaging optical system (optical system) used in an imaging apparatus such as a video camera, a digital camera, and a surveillance camera. In the lens cross-sectional view, the left side is the object side (front), and the right side is the image side (rear). The zoom lens of each embodiment may be used for a projector. In this case, the left side is the screen side and the right side is the projected image side. In the lens cross-sectional view, OL is a zoom lens. i indicates the order of the lens groups from the object side, and Li is the i-th lens group. LR is a rear group including one or more lens groups.

  SP is an aperture stop (open F number aperture). FS is a flare cut stop. IP is an image plane, and when used as an imaging optical system for a video camera or a digital still camera, an imaging plane of an imaging element (photoelectric conversion element) such as a CCD sensor or a CMOS sensor is located. An arrow (an arrow 2a for the second lens unit L2) indicates the moving direction of the lens unit during zooming from the wide-angle end to the telephoto end when focusing at infinity.

  An arrow 2b indicated by a dotted line related to the second lens unit L2 indicates a movement locus during zooming from the wide-angle end to the telephoto end when focusing on a short distance. In each of the following embodiments, the wide-angle end and the telephoto end are zoom positions when the zoom lens unit is positioned at both ends of the range in which the zoom lens unit can move on the optical axis. Among spherical aberrations in the aberration diagrams, the solid line d represents the d line (587.6 nm), and the two-dot chain line g represents the g line (435.8 nm).

  In the diagram showing astigmatism, the solid line ΔS represents the sagittal direction of the d line, and the broken line ΔM represents the meridional direction of the d line. Moreover, the figure which shows distortion represents the distortion in d line | wire. In the chromatic aberration diagram of magnification, g of the two-dot chain line indicates the chromatic aberration of magnification with respect to the d line. Fno is the F number, and ω is the half angle of view (degrees) of the shooting angle of view.

  The zoom lens according to each embodiment includes a first lens unit L1 having a negative refractive power, a second lens unit L2 having a positive refractive power, and one or more lens units arranged in order from the object side to the image side. Including rear group LR. The rear group LR includes a third lens unit L3 having a positive refractive power, a fourth lens unit L4 having a negative refractive power, an aperture stop SP, and a flare-cut stop whose position and aperture diameter in the optical axis direction can be changed according to zooming. (Auxiliary aperture) FS is provided. Further, the lens unit includes a fifth lens unit L5 having a positive refractive power and a sixth lens unit L6 having a negative refractive power. The distance between adjacent lens units changes during zooming.

  The first lens unit L1 includes a negative lens and a negative lens arranged in order from the object side to the image side. The first lens unit L1 has a strong negative refractive power as a whole, realizes a short focal length at the wide-angle end, and generates distortion aberration and lateral chromatic aberration by sharing the negative refractive power among a plurality of lenses. I try to reduce it. The rear group LR composed of the second lens group L2 and subsequent (image side) lens groups as a whole has a positive refractive power. When zooming from the wide-angle end to the telephoto end, the zoom is extended to the object side to obtain a high zoom ratio.

  By disposing the sixth lens unit L6 having negative refractive power on the most image side with respect to the aperture stop SP, distortion and lateral chromatic aberration are reduced due to the objectivity with the first lens unit L1. During focusing from infinity to short distance, the second lens unit L2 moves to the image side as indicated by an arrow 2c relating to focus.

The focal length of the first lens unit L1 is f1, the movement amount of the second lens unit L2 during zooming from the wide-angle end to the telephoto end is M2, and the total optical length at the wide-angle end is Lw. The focal length of the entire system at the wide-angle end is fw, and the focal length of the entire system at the telephoto end is ft. At this time,
−0.38 <f1 / ft <−0.10 (1)
-4.0 <M2 / fw <-2.0 (2)
6.0 <Lw / fw <9.0 (3)
The following conditional expression is satisfied.

  Here, the optical total length is a distance from the most object side lens surface to the most image side lens surface. The amount of movement of the lens group refers to the difference between the position on the optical axis of the lens group at the wide-angle end and the position on the optical axis of the lens group at the telephoto end. The sign of the amount of movement is positive when the lens group is positioned on the image side at the telephoto end and negative when it is positioned on the object side, compared to the wide-angle end.

  Next, the technical meaning of each conditional expression described above will be described. Conditional expression (1) defines the focal length of the first lens group.

  If the upper limit value of conditional expression (1) is exceeded and the negative focal length of the first lens unit L1 becomes shorter (the absolute value of the negative focal length becomes smaller), the first step is to reduce distortion and lateral chromatic aberration. It is necessary to arrange many lenses in the lens unit L1, and the effective diameter of the front lens is increased. Furthermore, it is not good because ghost increases. Further, when the negative focal length of the first lens unit L1 becomes longer (when the absolute value of the negative focal length becomes larger) below the lower limit value of the conditional expression (1), the focal length of the entire lens system at the wide angle end becomes shorter. (To widen the angle of view) becomes difficult.

  Conditional expression (2) defines the amount of movement of the second lens unit L2 during zooming. If the upper limit of conditional expression (2) is exceeded and the amount of movement of the second lens unit L2 is too small, it is necessary to shorten the focal length of the second lens unit L2 in order to obtain a sufficient zoom ratio. . This makes it difficult to satisfactorily correct spherical aberration and axial chromatic aberration at the telephoto end.

  In addition, if the amount of movement of the second lens unit L2 becomes too large below the lower limit value of the conditional expression (2), the first lens unit L1 and the second lens at the wide-angle end in order to secure a space for movement. The interval between the groups L2 must be increased. As a result, the effective diameter of the front lens increases and distortion increases.

  Conditional expression (3) defines the total optical length at the wide-angle end. If the upper limit of conditional expression (3) is exceeded and the optical total length becomes too long, the effective diameter of the front lens increases. If the lower limit value of conditional expression (3) is not reached, the distance between the first lens unit L1 and the sixth lens unit L6 closest to the image side becomes too close. If it does so, it will become difficult to correct | amend the distortion aberration and lateral chromatic aberration which generate | occur | produced in the 1st lens group L1 by the 6th lens group L6. More preferably, the numerical ranges of the conditional expressions (1) to (3) are set as follows.

−0.34 <f1 / ft <−0.25 (1a)
−3.5 <M2 / fw <−2.5 (2a)
6.8 <Lw / fw <8.5 (3a)

  In each embodiment, it is preferable to satisfy one or more of the following conditional expressions. Let the focal length of the second lens unit L2 be f2. Let Lt be the total optical length at the telephoto end. Further, when the zoom lens of each embodiment is used in an image pickup apparatus having an image pickup element that receives an image formed by the zoom lens, Img is half of the effective imaging diameter of the image pickup element. At this time, one or more of the following conditional expressions should be satisfied.

-20.0 <f2 / f1 <-2.8 (4)
1.3 <Lw / Lt <1.8 (5)
−1.3 <f1 / Img <−0.1 (6)

  Next, the technical periodic meaning of each conditional expression described above will be described. Conditional expression (4) defines the ratio of the focal lengths of the second lens unit L2 and the first lens unit L1. If the upper limit of conditional expression (4) is exceeded and the positive refracting power of the second lens unit L2 becomes too strong, aberration fluctuation will increase when focusing is performed with the second lens unit L2, which is not good. If the lower limit of conditional expression (4) is not reached, the axial light beam diverging from the first lens unit L1 cannot be sufficiently converged by the second lens unit L2, and the aperture diameter of the aperture stop SP becomes large. This is not good because the lens outer diameter increases.

  Conditional expression (5) defines the ratio of the total optical length at the wide-angle end to the total optical length at the telephoto end. If the upper limit of conditional expression (5) is exceeded, the difference in optical total length becomes too large. Then, it becomes difficult to pull the cam necessary to extend the lens into one lens barrel, and it is necessary to make the lens barrel have a double structure. As a result, the outer diameter of the lens becomes large, or between each lens group. The eccentricity accuracy is reduced.

  If the lower limit of conditional expression (5) is not reached, the sixth image closest to the image side with respect to the amount by which the negative distortion and lateral chromatic aberration generated by the first lens unit L1 change during zooming from the wide-angle end to the telephoto end. The amount of change that occurs in the lens group L6 in the opposite direction to the first lens group L1 is reduced. For this reason, as a result, aberration variation becomes large during zooming.

  Conditional expression (6) defines a preferable ratio of values obtained by normalizing the focal length of the first lens unit L1 with a value (maximum image height) half of the effective diameter of the imaging element. If the upper limit of conditional expression (6) is exceeded and the focal length of the first lens unit L1 becomes small, it is necessary to arrange a large number of lenses in the first lens unit L1 in order to sufficiently reduce distortion and lateral chromatic aberration. It becomes.

  This is not good because the effective diameter of the front lens increases and ghosting increases. Further, if the negative focal length of the first lens unit L1 becomes too long below the lower limit value of the conditional expression (1), it is difficult to shorten the focal length of the entire lens system (widening the angle of view). It becomes. It is preferable to set the numerical ranges of the conditional expressions (4) to (6) as follows.

-10.0 <f2 / f1 <-3.5 (4a)
1.4 <Lw / Lt <1.7 (5a)
−1.2 <f1 / Img <−0.9 (6a)

More preferably, the numerical ranges of the conditional expressions (1a) to (6a) are set as follows.
−0.34 <f1 / ft <−0.28 (1b)
-3.30 <M2 / fw <−2.55 (2b)
7.0 <Lw / fw <8.3 (3b)
-6.0 <f2 / f1 <-3.8 (4b)
1.4 <Lw / Lt <1.6 (5b)
−1.15 <f1 / Img <−0.95 (6b)

  In each embodiment, by specifying each element as described above, a zoom lens having a high zoom ratio and high optical performance is obtained while the wide-angle end has an ultra-wide angle of view.

  Next, the lens configuration of each example will be described. The first lens unit L1 includes two or more aspheric lenses having at least one aspheric surface. Specifically, the first lens unit L1 having a negative refractive power has a negative lens and a negative lens arranged in order from the object side to the image side. The two negative lenses have an aspheric surface. With this configuration, the strong negative refracting power of the first lens unit L1 is shared by a plurality of lenses, and an aspheric surface is arranged on a lens surface having a different light incident height, so that distortion and curvature of field are improved. It is corrected.

  In each embodiment, the second lens unit L2 includes one or more positive lenses and one or more negative lenses, and has a positive refractive power as a whole. In each embodiment, focusing is performed by moving the second lens unit L2 having a relatively small effective diameter and a light weight in the optical axis direction. Specifically, during focusing from infinity to a short distance, the second lens unit L2 moves to the image side. Thereby, even in an optical system corresponding to a relatively large image sensor, high-speed focusing is facilitated by driving a lightweight lens group.

  Numerical data of each embodiment described later is obtained when focusing on an object at infinity. During zooming from the wide-angle end to the telephoto end, the second lens unit L2 moves to the object side. An aperture stop SP is provided on the image side of the second lens unit L2, and a flare cut stop is provided on the image side of the aperture stop SP. The flare-cut stop moves along a different locus from the object-side and image-side lens groups of the flare-cut stop during zooming.

  Specifically, an aperture stop SP is provided adjacent to the fourth lens unit L4 on the image side of the fourth lens unit L4. Further, on the image side of the aperture stop SP, there is a flare cut stop FS that determines the central light flux at the open F number adjacent to the aperture stop SP and cuts the flare component outside thereof.

  The flare cut stop FS moves (independently) in a direction different from that of other lens units in the optical axis direction during zooming. This reduces the fluctuation of the F number during zooming and effectively cuts the flare component. A lens unit having negative refractive power (sixth lens unit L6) is disposed on the most image side of the rear unit LR. A lens having a positive refractive power is disposed on the most image side of the rear group LR.

  As described above, the sixth lens unit L6 has negative refractive power. A positive lens is arranged on the most image side of the zoom lens. With this configuration, while correcting distortion and lateral chromatic aberration generated in the first lens unit having a negative refractive power, the incidence of shading is reduced by allowing light rays to enter the image plane as close to perpendicular as possible. .

  Next, an embodiment of a digital still camera using the zoom lens shown in each example as an imaging optical system will be described with reference to FIG.

  In FIG. 7, reference numeral 20 denotes a camera body, and 21 denotes an imaging optical system formed by any of the zoom lenses described in the first to third embodiments. Reference numeral 22 denotes an imaging element (photoelectric conversion element) such as a CCD sensor or a CMOS sensor that receives a subject image formed by the imaging optical system 21 and is built in the camera body. A memory 23 records information corresponding to the subject image photoelectrically converted by the image sensor 22. Reference numeral 24 denotes a finder configured by a liquid crystal display panel or the like for observing a subject image formed on the image sensor 22.

  Thus, by applying the zoom lens of the present invention to an image pickup apparatus such as a digital still camera, a small image pickup apparatus having high optical performance is realized. The zoom lens of each embodiment can be similarly applied to a single-lens reflex camera with a quick return mirror and a mirrorless single-lens reflex camera without a quick return mirror.

  Specific numerical data of the zoom lens corresponding to Examples 1 to 3 will be described below. i indicates the order counted from the object. The surface number i is counted in order from the object side. ri is the radius of curvature, and di is the i-th and i + 1-th surface spacing. ndi and νdi represent the refractive index and Abbe number of the medium between the i-th surface and the (i + 1) -th surface with respect to the d-line, respectively.

  BF is a back focus, which is an air-converted length from the final lens surface to the image plane. The total lens length is a value obtained by adding back focus to the distance from the first lens surface to the final lens surface.

An aspherical surface is represented by adding a symbol * after the surface number. In the aspherical shape, X is the amount of displacement from the surface apex 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, A4, A6, When A8, A10, and A12 are aspherical coefficients of respective orders,
x = (h ² / R) / [1+ {1− (1 + k) (h / R) ² } ^1/2 + A4 × h ⁴ + A6 × h ⁶ + A8 × h ⁸ + A10 × h ¹⁰ + A12 × h ¹²
Represented by Note that “e ± XX” in each aspheric coefficient means “× 10 ^{± XX} ”. Table 1 shows numerical values related to the above conditional expressions.

[Numeric data 1]
Unit mm

Surface data surface number rd nd νd
1 * 176.098 2.50 1.85400 40.4
2 * 21.017 14.00
3 * -72.107 2.00 1.59522 67.7
4 50.481 0.61
5 60.785 4.00 1.85478 24.8
6 6114.033 (variable)
7 * 25.708 3.70 1.76385 48.5
8 -1043.504 0.20
9 58.039 1.00 1.85478 24.8
10 18.177 2.10 1.56732 42.8
11 24.944 (variable)
12 28.752 4.45 1.76385 48.5
13 -95.681 (variable)
14 -58.493 0.80 1.88300 40.8
15 33.626 0.68
16 34.406 2.30 1.89286 20.4
17 137.540 1.00
18 (Aperture) ∞ (Variable)
19 ∞ (variable) (Flare cut aperture)
20 32.361 4.75 1.43875 94.9
21 -36.636 0.20
22 41.794 5.10 1.51742 52.4
23 -22.463 1.10 1.83400 37.2
24 -719.152 (variable)
25 -79.075 2.77 1.49700 81.5
26 -19.819 1.35 1.91082 35.3
27 16.884 4.87 1.58313 59.4
28 * 299.719 4.78
29 87.686 4.74 1.80518 25.4
30 -73.464 (variable)
Image plane ∞

Aspheric data 1st surface
K = 0.00000e + 000 A 4 = 1.81176e-005 A 6 = -3.55029e-008 A 8 = 2.95484e-011 A10 = -9.56065e-015 A12 = 1.94598e-018

Second side
K = 0.00000e + 000 A 4 = 1.28680e-005 A 6 = 6.31262e-009 A 8 = -1.01994e-010 A10 = -9.04564e-014

Third side
K = 0.00000e + 000 A 4 = -1.44279e-006 A 6 = 1.51279e-008 A 8 = -3.09273e-011 A10 = -9.66454e-016

7th page
K = 0.00000e + 000 A 4 = -4.39514e-006 A 6 = -4.54286e-009 A 8 = -5.51719e-012 A10 = -1.03216e-014

28th page
K = 0.00000e + 000 A 4 = 6.27796e-006 A 6 = -2.80249e-008 A 8 = 7.77700e-011 A10 = -2.10301e-012

Various data Zoom ratio 3.95
Wide angle Medium Telephoto focal length 17.40 35.02 68.69
F number 3.57 4.18 5.85
Half angle of view (degrees) 51.19 31.71 17.48
Image height 21.64 21.64 21.64
Total lens length 149.59 133.68 150.50
BF 13.43 27.63 57.99

d 6 47.80 13.39 1.00
d11 1.95 3.74 3.78
d13 2.50 1.16 3.58
d18 7.59 8.78 0.89
d19 6.52 0.67 1.80
d24 0.80 9.30 12.46
d30 13.43 27.63 57.99

Lens group data group Start surface Focal length
1 1 -22.75
2 7 99.77
3 12 29.40
4 14 -46.50
5 19 ∞
6 20 38.38
7 25 -49.61

[Numeric data 2]
Unit mm

Surface data surface number rd nd νd
1 * 76.426 2.50 1.85400 40.4
2 * 19.512 15.95
3 * -72.107 2.00 1.59522 67.7
4 38.735 0.03
5 39.127 4.10 1.85478 24.8
6 117.967 (variable)
7 * 28.465 3.50 1.76385 48.5
8 -718.649 0.20
9 55.534 1.00 1.85478 24.8
10 19.642 2.25 1.54814 45.8
11 28.651 (variable)
12 30.845 4.80 1.76385 48.5
13 -76.415 (variable)
14 -57.590 0.80 1.88300 40.8
15 42.722 0.23
16 38.642 1.90 1.89286 20.4
17 94.679 1.00
18 (Aperture) ∞ (Variable)
19 ∞ (variable) (Flare cut aperture)
20 46.943 4.00 1.43875 94.9
21 -42.812 0.20
22 37.565 5.90 1.51742 52.4
23 -23.647 1.10 1.83400 37.2
24 -104.873 (variable)
25 -47.733 1.20 1.49700 81.5
26 -32.631 1.35 1.91082 35.3
27 14.927 7.50 1.58313 59.4
28 * 95.899 4.00
29 72.919 5.20 1.80000 29.8
30 -80.370 (variable)
Image plane ∞

Aspheric data 1st surface
K = 0.00000e + 000 A 4 = 1.33943e-005 A 6 = -4.72091e-009 A 8 = -4.02848e-011 A10 = 5.03031e-014 A12 = -1.18947e-017

Second side
K = 0.00000e + 000 A 4 = 1.03995e-005 A 6 = 8.14345e-009 A 8 = 1.08994e-010 A10 = -7.49033e-013

Third side
K = 0.00000e + 000 A 4 = -1.44279e-006 A 6 = 1.51279e-008 A 8 = -3.09273e-011 A10 = -9.66454e-016

7th page
K = 0.00000e + 000 A 4 = -4.24524e-006 A 6 = -5.31225e-009 A 8 = 2.79093e-011 A10 = -1.02283e-013

28th page
K = 0.00000e + 000 A 4 = -6.28270e-007 A 6 = 1.40126e-008 A 8 = -4.10340e-010 A10 = -7.55276e-014

Various data Zoom ratio 4.25
Wide angle Medium Telephoto focal length 17.10 34.82 72.70
F number 3.57 4.18 5.85
Half angle of view (degrees) 51.68 31.85 16.57
Image height 21.64 21.64 21.64
Total lens length 151.00 135.57 157.71
BF 13.13 27.81 63.49

d 6 47.80 13.39 1.00
d11 1.95 3.74 3.78
d13 2.50 1.16 3.58
d18 7.59 8.78 0.89
d19 6.52 0.67 1.80
d24 0.80 9.30 12.46
d30 13.13 27.81 63.49

Lens group data group Start surface Focal length
1 1 -21.75
2 7 89.29
3 12 29.34
4 14 -44.69
5 19 ∞
6 20 35.71
7 25 -45.99

[Numeric data 3]
Unit mm

Surface data surface number rd nd νd
1 * 230.682 2.50 1.85400 40.4
2 * 24.401 11.80
3 * -72.107 2.00 1.59522 67.7
4 45.973 4.00 1.85478 24.8
5 192.131 (variable)
6 * 27.898 3.50 1.76385 48.5
7 -335.048 0.20
8 61.408 1.00 1.85478 24.8
9 23.916 (variable)
10 30.462 4.60 1.76385 48.5
11 -72.118 (variable)
12 -46.657 0.80 1.88300 40.8
13 51.687 0.20
14 37.353 1.60 1.89286 20.4
15 67.159 1.00
16 (Aperture) ∞ (Variable)
17 ∞ (variable) (Flare cut aperture)
18 197.291 3.50 1.43875 94.9
19 -28.908 0.20
20 23.789 6.15 1.51742 52.4
21 -27.262 1.10 1.83400 37.2
22 2568.752 (variable)
23 -89.143 2.00 1.43875 94.9
24 -34.840 1.30 1.91082 35.3
25 14.554 6.50 1.58313 59.4
26 * 136.719 6.00
27 72.885 4.20 1.84666 23.8
28 -138.921 (variable)
Image plane ∞

Aspheric data 1st surface
K = 0.00000e + 000 A 4 = 3.36705e-005 A 6 = -9.88738e-008 A 8 = 1.37417e-010 A10 = -7.95697e-014 A12 = 1.23226e-017

Second side
K = 0.00000e + 000 A 4 = 3.42341e-005 A 6 = -1.43410e-008 A 8 = -3.35257e-010 A10 = 6.86187e-013

Third side
K = 0.00000e + 000 A 4 = -1.44279e-006 A 6 = 1.51279e-008 A 8 = -3.09273e-011 A10 = -9.66454e-016

6th page
K = 0.00000e + 000 A 4 = -3.89468e-006 A 6 = -2.38732e-009 A 8 = -8.63331e-013 A10 = -7.43066e-014

26th page
K = 0.00000e + 000 A 4 = 7.75371e-006 A 6 = -5.99874e-008 A 8 = 3.19953e-010 A10 = -3.66968e-012

Various data Zoom ratio 4.14
Wide angle Medium Telephoto focal length 18.70 37.55 77.50
F number 3.57 4.18 5.85
Half angle of view (degrees) 49.16 29.95 15.60
Image height 21.64 21.64 21.64
Total lens length 146.50 128.90 147.50
BF 15.19 27.72 59.84

d 5 47.80 13.39 1.00
d 9 1.95 3.74 3.78
d11 2.50 1.16 3.58
d16 7.59 8.78 0.89
d17 6.52 0.67 1.80
d22 0.80 9.30 12.46
d28 15.19 27.72 59.84

Lens group data group Start surface Focal length
1 1 -24.39
2 6 101.52
3 10 28.59
4 12 -39.20
5 17 ∞
6 18 34.56
7 23 -49.61

L0 Zoom lens LR Rear group L1 First lens group L2 Second lens group

Claims (14)

A first lens group having a negative refractive power, a second lens group having a positive refractive power, and a rear group including one or more lens groups, which are arranged in order from the object side to the image side, and are adjacent to each other during zooming In zoom lenses where the distance between groups changes,
The first lens group includes a negative lens and a negative lens arranged in order from the object side to the image side,
The focal length of the first lens group is f1, the amount of movement of the second lens group during zooming from the wide-angle end to the telephoto end is M2, the total optical length at the wide-angle end is Lw, and the focal length of the entire system at the wide-angle end is fw, When the focal length of the entire system at the telephoto end is ft,
−0.38 <f1 / ft <−0.10
-4.0 <M2 / fw <-2.0
6.0 <Lw / fw <9.0
A zoom lens satisfying the following conditional expression: When the focal length of the second lens group is f2,
-20.0 <f2 / f1 <-2.8
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the total optical length at the telephoto end is Lt,
1.3 <Lw / Lt <1.8
The zoom lens according to claim 1, wherein the following conditional expression is satisfied.   4. The zoom lens according to claim 1, wherein a lens group having a negative refractive power is disposed closest to the image side of the rear group. 5.   5. The zoom lens according to claim 1, wherein a lens having a positive refractive power is disposed closest to the image side of the rear group.   6. The zoom lens according to claim 1, wherein the second lens unit moves to the image side during focusing from infinity to a short distance. 7.   7. The zoom lens according to claim 1, wherein the first lens group includes two or more aspherical lenses each having at least one aspherical surface. 8.   8. The zoom lens according to claim 1, further comprising an aperture stop closer to the image side than the second lens group, and a flare-cut stop closer to the image side than the aperture stop.   9. The zoom lens according to claim 8, wherein the flare-cut stop moves along a locus different from the object-side and image-side lens groups of the flare-cut stop during zooming.   The rear group is arranged in order from the object side to the image side. The third lens group having a positive refractive power, the fourth lens group having a negative refractive power, the fifth lens group having a positive refractive power, and a negative lens having a negative refractive power. The zoom lens according to claim 1, comprising a sixth lens group.   11. An aperture stop adjacent to the fourth lens group is provided on the image side of the fourth lens group, and the aperture stop moves along the same locus as the fourth lens group during zooming. Zoom lens described in 1.   The flare-cut stop is adjacent to the aperture stop on the image side of the aperture stop, and the flare-cut stop moves along a different locus from the aperture stop and the fifth lens group. The described zoom lens.   An image pickup apparatus comprising: the zoom lens according to claim 1; and an image pickup element that receives an image formed by the zoom lens. When half the effective imaging diameter of the image sensor is Img,
−1.3 <f1 / Img <−0.1
The imaging apparatus according to claim 13, wherein the following conditional expression is satisfied.