JP2019184733A - Zoom lens and image capturing device having the same - Google Patents

Abstract

To provide a zoom lens which comprises a compact lens system and offers good optical performance over an entire zoom range from the wide-angle end to the telephoto end with a wide angle of view.SOLUTION: A zoom lens comprises a first lens group having negative refractive power and a second lens group having positive refractive power 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 and the second lens group are configured to move while zooming in such a way that a distance therebetween is smaller at the telephoto end than at the wide-angle end. A back focus BFw at the wide-angle end, a focal length fw of the zoom lens at the wide-angle end, a length D1 of the first lens group along an optical axis, and a focal length f1 of the first lens group 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 particularly suitable as an image pickup optical system of an image pickup apparatus such as a still camera, a video camera, a digital still camera, and a surveillance camera.

  In recent years, imaging apparatuses such as single-lens reflex cameras, interchangeable lens-less mirrorless cameras, and video cameras have become highly functional, and the entire apparatus has been downsized. The imaging lens (imaging optical system) used therefor is required to have a small lens overall length (distance from the object side surface of the first lens to the image plane) and to be small. Among imaging optical systems, for example, a negative lead zoom lens preceded by a lens unit having a negative refractive power is known as a wide-angle zoom lens having an imaging field angle of 55 degrees or more. Patent Documents 1 and 2).

  Patent Document 1 discloses a zoom lens having a wide angle of view having first to third lens groups having negative, positive, and positive refractive powers in order from the object side to the image side. Patent Document 2 discloses a zoom lens having a wide angle of view including a first lens group and a second lens group having negative and positive refractive powers in order from the object side to the image side.

JP 2012-194238 A Japanese Patent Laying-Open No. 2015-225145

  A negative lead type zoom lens is relatively easy to achieve a wide angle of view while reducing the size of the entire system. However, since the negative lead type zoom lens has an asymmetrical arrangement with respect to the aperture stop, many aberrations such as field curvature and distortion occur, making it difficult to correct these aberrations. In particular, a zoom lens including a wide angle of view where the imaging angle of view exceeds 100 degrees causes many of the above-described various aberrations.

  In a negative lead type zoom lens, it is important to appropriately set each lens group that constitutes the zoom lens in order to obtain a compact optical system and high optical performance over the entire zoom range while ensuring a wide angle of view. It is. For example, in order to increase the angle of view while reducing the size of the entire system while reducing the effective diameter of the front lens (effective diameter of the first lens group), the negative refractive power of the first lens group is increased. It ’s fine.

  However, when the negative refractive power of the first lens group is increased, various aberrations such as lateral chromatic aberration and distortion in a wide angle region increase, and it becomes difficult to correct these various aberrations. Further, fluctuations in various aberrations accompanying zooming increase, and it becomes very difficult to obtain high optical performance over the entire zoom range and the entire screen.

  An object of the present invention is to provide a zoom lens having a small overall system, a wide angle of view, and a good optical performance over the entire zoom range from the wide-angle end to the telephoto end, and an imaging apparatus having the zoom lens.

The zoom lens of the present invention includes a first lens group having a negative refractive power and a second lens group having a positive refractive power, which are arranged in order from the object side to the image side, and an interval between adjacent lens groups during zooming. In zoom lenses where
The first lens group and the second lens group move during zooming so that the distance between the first lens group and the second lens group is smaller at the telephoto end than at the wide-angle end,
The back focus at the wide angle end is BFw, the focal length of the entire system at the wide angle end is fw, and the length on the optical axis of the first lens group (from the lens surface closest to the object side of the first lens group to the most of the first lens group). When the length on the optical axis to the lens surface on the image side is D1, and the focal length of the first lens group is f1,
0.50 <BFw / fw <2.40
2.0 <D1 / | f1 | <10.0
It satisfies the following conditional expression.

  According to the present invention, it is possible to obtain a zoom lens that has a small overall system, a wide field angle, and good optical performance over the entire zoom range from the wide-angle end to the telephoto end.

Example 1 (a) Lens cross-sectional view at the wide-angle end and (b) Telephoto end Longitudinal aberration diagrams of Example 1 at (a) wide-angle end and (b) telephoto end Example 2 (a) Lens cross-sectional view at wide-angle end and (b) telephoto end Longitudinal aberration diagrams of Example 2 at (a) wide-angle end and (b) telephoto end Lens sectional view of Example 3 at (a) wide-angle end and (b) telephoto end Longitudinal aberration diagrams of Example 3 at (a) wide-angle end and (b) telephoto end Lens sectional view of Example 4 at (a) wide-angle end and (b) telephoto end Longitudinal aberration diagrams of Example 4 at (a) wide-angle end and (b) telephoto end Example 5 (a) Lens sectional view at the wide-angle end and (b) Telephoto end Longitudinal aberration diagrams of Example 5 at (a) wide-angle end and (b) telephoto end Example 6 (a) Lens cross-sectional view at the wide-angle end and (b) the telephoto end Longitudinal aberration diagrams of Example 6 at (a) wide-angle end and (b) telephoto end Schematic diagram of main parts of an imaging apparatus of the present invention

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The zoom lens of the present invention includes a first lens group having a negative refractive power and a second lens group having a positive refractive power, which are arranged in order from the object side to the image side, and an interval between adjacent lens groups during zooming. Changes.

  FIGS. 1A and 1B are lens cross-sectional views at the wide-angle end (short focal length end) and the telephoto end (long focal length end) of the zoom lens according to Embodiment 1 of the present invention. FIGS. 2A and 2B are aberration diagrams of the zoom lens of Example 1 at the wide-angle end and the telephoto end, respectively. The zoom lens according to the first exemplary embodiment has a zoom ratio of 2.26, an aperture ratio (F number) of 4.12, and an imaging half angle of view of about 64.54 degrees to 42.88 degrees.

  FIGS. 3A and 3B are lens cross-sectional views at the wide-angle end and the telephoto end of the zoom lens according to Embodiment 2 of the present invention. 4A and 4B are aberration diagrams at the wide-angle end and the telephoto end of the zoom lens according to Embodiment 2, respectively. The second embodiment is a zoom lens having a zoom ratio of 2.26, an aperture ratio of 4.12, and an imaging half angle of view of about 64.54 degrees to 42.88 degrees.

  FIGS. 5A and 5B are lens cross-sectional views at the wide-angle end and the telephoto end of the zoom lens according to Embodiment 3 of the present invention. FIGS. 6A and 6B are aberration diagrams of the zoom lens of Example 3 at the wide-angle end and the telephoto end, respectively. Example 3 is a zoom lens having a zoom ratio of 2.26, an aperture ratio of 4.12, and an imaging half angle of view of about 64.54 degrees to 42.88 degrees.

  FIGS. 7A and 7B are lens cross-sectional views at the wide-angle end and the telephoto end of the zoom lens according to Embodiment 4 of the present invention. 8A and 8B are aberration diagrams of the zoom lens of Example 4 at the wide-angle end and the telephoto end, respectively. Example 4 is a zoom lens having a zoom ratio of 2.26, an aperture ratio of 4.12, and an imaging half angle of view of about 64.54 degrees to 42.88 degrees.

  FIGS. 9A and 9B are lens cross-sectional views at the wide-angle end and the telephoto end of the zoom lens according to Embodiment 5 of the present invention. 10A and 10B are aberration diagrams of the zoom lens of Example 5 at the wide-angle end and the telephoto end, respectively. The fifth embodiment is a zoom lens having a zoom ratio of 2.26, an aperture ratio of 4.12, and an imaging half angle of view of about 64.54 degrees to 42.88 degrees.

  FIGS. 11A and 11B are lens cross-sectional views at the wide-angle end and the telephoto end of the zoom lens according to Embodiment 6 of the present invention. FIGS. 12A and 12B are aberration diagrams of the zoom lens of Example 6 at the wide-angle end and the telephoto end, respectively. Example 6 is a zoom lens having a zoom ratio of 1.89, an aperture ratio of 4.12, and an imaging half angle of view of about 60.26 degrees to 42.88 degrees. FIG. 13 is a schematic diagram of a main part of an image pickup apparatus including the zoom lens according to the present invention.

  The zoom lens of each embodiment is an imaging optical system used in an imaging apparatus such as a digital still camera or a video camera. In the lens cross-sectional view, the left side is the object side (front), and the right side is the image side (rear). In addition, the zoom lens of each embodiment can also be used as a projection optical system for a projection apparatus (projector). In this case, the left side is the screen and the right side is the projection surface. In the lens cross-sectional view, Bi is the i-th lens group. B1 is a first lens group having negative refractive power (optical power = reciprocal of focal length). B2 is a second lens unit having a positive refractive power. SP is an aperture stop, and SSP is a flare cut stop.

  IP is an image plane, and when used as a photographing optical system of a video camera or a digital still camera, an imaging plane of a solid-state imaging device (photoelectric conversion device) such as a CCD sensor or a CMOS sensor is placed.

  In the spherical aberration diagram, the solid line d is the d line (wavelength 587.6 nm), and the two-dot chain line g is the g line (wavelength 435.8 nm). In the astigmatism diagram, the dotted line ΔM represents the d-line meridional image plane, and the solid line ΔS represents the d-line sagittal image plane. The distortion is shown for the d line. Further, the chromatic aberration of magnification represents the difference of the g-line when the d-line is used as a reference. Fno is an F number. ω is an imaging half angle of view (degrees).

  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 movable on the optical axis due to the mechanism. In the lens cross-sectional view, arrows indicate the movement trajectory of each lens unit during zooming from the wide-angle end to the telephoto end. The arrow related to the focus indicates the moving direction of the lens group when focusing from infinity to a short distance.

  The zoom lens of each embodiment includes a first lens group having a negative refractive power and a second lens group having a positive refractive power, which are arranged in order from the object side to the image side. The distance between adjacent lens units changes during zooming. The distance between the first lens group and the second lens group is narrower at the telephoto end than at the wide-angle end.

  The first lens unit B1 has, in order from the object side to the image side, a meniscus negative lens G1 having a convex surface facing the object side, a meniscus negative lens G2 having a convex surface facing the object side, and a convex surface facing the object side. A negative lens G3 having a meniscus shape is included. By disposing three meniscus negative lenses of the negative lens G1, the negative lens G2, and the negative lens G3 on the object side, a light beam with a wide imaging field angle is captured. In addition, the three negative lenses G1, G2, and G3 have a meniscus shape with a convex surface facing the object side to reduce the occurrence of distortion at the wide angle end.

  In this way, the three negative lenses arranged in order from the object side to the image side of the first lens unit B1 have a meniscus shape with the convex surface facing the object side, so that the optical system has a wide optical performance while having high optical performance. The angle of view is easy.

  In each embodiment, the first lens unit B1 and the second lens unit B2 are different from each other during zooming so that the distance between the first lens unit B1 and the second lens unit B2 is smaller at the telephoto end than at the wide-angle end. Move with.

The back focus at the wide-angle end is BFw, the focal length of the zoom lens (the entire system) at the wide-angle end is fw, the length on the optical axis of the first lens unit B1 is D1, and the focal length of the first lens unit B1 is f1. . At this time,
0.50 <BFw / fw <2.40 (1)
2.0 <D1 / | f1 | <10.0 (2)
The following conditional expression is satisfied.

  Next, the technical meaning of each conditional expression described above will be described. Conditional expression (1) defines an appropriate range of the ratio between the back focus at the wide angle end and the focal length of the entire system. If the upper limit of conditional expression (1) is exceeded and the back focus becomes too long, the total lens length becomes long, and it becomes difficult to downsize the entire system. If the back focus is too short beyond the lower limit value of conditional expression (1), the effective diameter of the final lens closest to the image becomes large, and it becomes difficult to reduce the size of the entire system.

  Conditional expression (2) defines an appropriate range of the ratio between the length of the first lens unit B1 on the optical axis and the focal length of the first lens unit B1. In order to capture a light beam with a very wide angle of view and guide it to the image plane, the first lens unit B1 needs to have many lens surfaces. In addition, in zooming with a wide angle of view, the incident height of off-axis rays is increased in the first lens unit B1, so that the occurrence of off-axis aberrations such as lateral chromatic aberration and distortion in the first lens unit B1 increases. In order to reduce the various aberrations, the first lens unit B1 needs to have an appropriate thickness.

  When the upper limit of conditional expression (2) is exceeded and the length of the first lens unit B1 on the optical axis becomes longer, it becomes difficult to reduce the size of the entire system. On the other hand, when the negative refracting power of the first lens unit B1 becomes weaker than the lower limit value of the conditional expression (2) (when the absolute value of the negative refracting power becomes small), it becomes difficult to widen the angle of view. Therefore, by satisfying conditional expressions (1) and (2), a zoom lens having a wide angle of view is obtained in which the entire system is small and has high optical performance.

  In each embodiment, it is more preferable to satisfy one or more of the following conditional expressions. The total lens length of the zoom lens at the wide angle end is Lw. Here, the total lens length is the distance from the first lens surface to the image plane. The first lens unit B1 has one or more negative lenses, and the Abbe number of the material of at least one negative lens NL included in the first lens unit B1 is νd_NL.

  In the image pickup apparatus having the zoom lens of each embodiment and the image pickup element that receives an image formed by the zoom lens, the main image is incident at a position farthest from the optical axis of the image pickup surface of the image pickup element at the zoom position at the wide angle end. The angle between the light beam and the optical axis is ωw. At this time, one or more of the following conditional expressions should be satisfied.

5.0 <Lw / fw <18.0 (3)
νd_NL> 60 (4)
ωw> 55 (5)

  Next, the technical meaning of each conditional expression described above will be described. Conditional expression (3) defines an appropriate range of the ratio of the total lens length at the wide angle end and the focal length of the entire system at the wide angle end. If the total lens length at the wide-angle end becomes longer than the upper limit value of conditional expression (3), it becomes difficult to reduce the size of the entire system. If the total length of the lens at the wide-angle end becomes shorter than the lower limit of conditional expression (3), it is easy to downsize the entire system, but the refractive power of each lens group becomes too strong, and the entire lens from the wide-angle end to the telephoto end is reduced. It becomes difficult to suppress various aberrations such as field curvature and lateral chromatic aberration in the zoom range.

  Conditional expression (4) defines the Abbe number of the material of at least one negative lens NL included in the first lens unit B1. If the lower limit of conditional expression (4) is not reached, it is difficult to correct lateral chromatic aberration at the wide-angle end, which is not preferable. Conditional expression (5) defines the imaging half angle of view at the wide-angle end. If the lower limit of conditional expression (5) is not reached, it is difficult to widen the entire system.

More preferably, the numerical ranges of the conditional expressions (1) to (5) are set as follows.
0.80 <BFw / fw <2.20 (1a)
2.05 <D1 / | f1 | <8.00 (2a)
7.0 <Lw / fw <17.0 (3a)
νd_NL> 62 (4a)
ωw> 57 (5a)

More preferably, the numerical ranges of the conditional expressions (1a) to (5a) are set as follows.
1.00 <BFw / fw <2.10 (1b)
2.06 <D1 / | f1 | <5.00 (2b)
10.0 <Lw / fw <16.0 (3b)
νd_NL> 66 (4b)
ωw> 60 (5b)

  The zoom lens of each embodiment preferably has a lens surface AL1 having an aspheric shape in the first lens unit B1. This aspherical shape preferably has a positive refracting power (or a negative refracting power becomes weak) from the center to the periphery. When such an aspherical shape is provided in the first lens unit B1, it becomes easy to reduce distortion at the wide-angle end. More preferably, the lens surface AL1 is preferably the lens surface closest to the object side of the zoom lens.

As described above, in each of the embodiments, a zoom lens having a wide angle of view is obtained in which the entire system is small and has high optical performance.
Next, the lens configuration of the zoom lens of each embodiment will be described.

[Example 1]
The zoom lens of Example 1 includes a first lens unit B1 having a negative refractive power and a second lens unit B2 having a positive refractive power, which are arranged in order from the object side to the image side. Further, a third lens unit B3 having a positive refractive power and a fourth lens unit B4 having a positive refractive power are formed adjacent to the second lens unit B2. The second lens group B2 is a focus lens group, and moves from the object side to the image side during focusing from infinity to close.

  During zooming from the wide-angle end to the telephoto end, the first lens unit B1 moves while drawing a convex locus on the image side, and the second lens unit B2 and the third lens unit B3 move monotonously to the object side. The fourth lens unit B4 does not move during zooming. Further, during zooming from the wide-angle end to the telephoto end, the distance between the first lens group B1 and the second lens group B2 is narrowed, the distance between the second lens group B2 and the third lens group B3 is narrowed, and the third lens group B3 and The distance between the fourth lens unit B4 is increased.

[Example 2]
The zoom lens of Example 2 includes a first lens unit B1 having a negative refractive power and a second lens unit B2 having a positive refractive power, which are arranged in order from the object side to the image side. Further, the third lens unit B3 having a positive refractive power is adjacent to the second lens unit B2. The second lens group B2 is a focus lens group, and moves from the object side to the image side during focusing from infinity to close.

  During zooming from the wide-angle end to the telephoto end, the first lens unit B1 moves while drawing a convex locus on the image side, and the second lens unit B2 and the third lens unit B3 move monotonously to the object side. During zooming from the wide-angle end to the telephoto end, the distance between the first lens group B1 and the second lens group B2 and the distance between the second lens group B2 and the third lens group B3 are reduced.

[Example 3]
The zoom lens according to the third exemplary embodiment includes a first lens unit B1 having a negative refractive power and a second lens unit B2 having a positive refractive power, which are arranged in order from the object side to the image side. Further, a third lens group B3 having a positive refractive power and a fourth lens group B4 having a negative refractive power are adjacent to the second lens group B2. The second lens group B2 is a focus lens group, and moves from the object side to the image side during focusing from infinity to close.

  During zooming from the wide-angle end to the telephoto end, the first lens unit B1 moves while drawing a convex locus on the image side, and the second lens unit B2 and the third lens unit B3 move monotonously to the object side. The fourth lens unit B4 does not move during zooming. Further, during zooming from the wide-angle end to the telephoto end, the distance between the first lens group B1 and the second lens group B2 is narrowed, the distance between the second lens group B2 and the third lens group B3 is narrowed, and the third lens group B3 and The distance between the fourth lens unit B4 is increased.

[Example 4]
The zoom lens according to the fourth exemplary embodiment includes, in order from the object side to the image side, a first lens unit B1 having a negative refractive power, a second lens unit B2 having a positive refractive power, and a third lens unit having a positive refractive power. B3 includes a fourth lens unit B4 having a positive refractive power. The second lens group B2 is a focus lens group, and moves from the object side to the image side during focusing from infinity to close.

  During zooming from the wide-angle end to the telephoto end, the first lens unit B1 moves while drawing a convex locus on the image side, and the second lens unit B2 and the third lens unit B3 move monotonously to the object side. The fourth lens unit B4 does not move during zooming. Further, during zooming from the wide-angle end to the telephoto end, the distance between the first lens group B1 and the second lens group B2 is narrowed, the distance between the second lens group B2 and the third lens group B3 is narrowed, and the third lens group B3 and The distance between the fourth lens unit B4 is increased.

[Example 5]
The zoom lens of Example 5 includes a first lens unit B1 having a negative refractive power, a second lens unit B2 having a positive refractive power, and a third lens unit having a positive refractive power, which are arranged in order from the object side to the image side. Consists of B3. The second lens group B2 is a focus lens group, and moves from the object side to the image side during focusing from infinity to close.

  During zooming from the wide-angle end to the telephoto end, the first lens unit B1 moves while drawing a convex locus on the image side, and the second lens unit B2 and the third lens unit B3 move monotonously to the object side. During zooming from the wide-angle end to the telephoto end, the distance between the first lens group B1 and the second lens group B2 and the distance between the second lens group B2 and the third lens group B3 are reduced.

[Example 6]
The zoom lens according to the sixth exemplary embodiment includes a first lens unit B1 having a negative refractive power and a second lens unit B2 having a positive refractive power, which are arranged in order from the object side to the image side. The second lens unit B2 has two lens portions, a second a lens portion and a second b lens portion, which are arranged in order from the object side to the image side. Specifically, it is composed of a second a lens unit B2a having a positive refractive power and a second b lens unit B2b having a positive refractive power. The second-a lens unit B2a is a focus lens unit, and moves from the object side to the image side during focusing from infinity to close. Note that the distance between the 2a lens unit B2a and the 2b lens unit B2b is constant during zooming.

  During zooming from the wide-angle end to the telephoto end, the first lens unit B1 moves while drawing a convex locus on the image side, and the second lens unit B2 moves monotonously to the object side. During zooming from the wide-angle end to the telephoto end, the distance between the first lens unit B1 and the second lens unit B2 is reduced.

  Next, an embodiment of a digital camera (imaging apparatus) using the zoom lens of the present invention as an imaging optical system will be described with reference to FIG. In FIG. 13, reference numeral 20 denotes a digital camera body, and 21 denotes an imaging optical system constituted by the zoom lenses of the above-described embodiments. Reference numeral 22 denotes an image pickup device (photoelectric conversion device) such as a CCD that receives a subject image (image) by the image pickup optical system 21, and 23 denotes a recording unit that records the subject image received by the image pickup device 22. Reference numeral 24 denotes a finder for observing a subject image displayed on a display element (not shown).

  The display element is constituted by a liquid crystal panel or the like, and a subject image formed on the image sensor 22 is displayed. Thus, by applying the zoom lens of the present invention to an imaging apparatus such as a digital camera, an imaging apparatus having a small size and high optical performance is realized.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary. For example, although the present embodiment does not have an anti-vibration lens group, all or some lens groups in the optical system may be used as the anti-vibration lens group.

  As for focusing, in the present embodiment, focusing is performed with one lens group, but a system (floating focusing system) in which a plurality of lens groups are moved along different trajectories may be used. Further, not only a refractive optical element (so-called lens) but also an optical system having a diffractive optical element or an optical system including a reflective optical member may be used.

  Next, numerical data of each embodiment of the present invention will be shown. In each numerical data, i indicates the order of the surfaces from the object side, ri is the radius of curvature of the lens surface, di is the lens thickness and air spacing between the i-th surface and the (i + 1) -th surface, and ndi and νdi are respectively The refractive index and the Abbe number for the d-line of the i-th lens material are shown.

The Abbe number νd is the refractive index of the material for the Fraunhofer line g-line (wavelength 435.8 nm), F-line (486.1 nm), d-line (587.6 nm), and C-line (656.3 nm), respectively. , NF, Nd, NC. At this time, the Abbe number νd is
νd = (Nd−1) / (NF−NC)
Represent as

  BF is a back focus, and is a length in which the distance from the last lens surface (lens surface on the most image side) to the image surface is expressed in terms of air conversion length. The total lens length is a length obtained by adding back focus to the distance on the optical axis from the lens frontmost surface (first lens surface) to the lens final surface. The aspherical shape is the X-axis in the optical axis direction, the H-axis in the direction perpendicular to the optical axis, the light traveling direction is positive, R is the paraxial radius of curvature, K is the conic constant, A4, A6, A8, A10, A12, A14. Are respectively aspherical coefficients,

It is expressed by the following formula. [E-X] means [× 10 ^−X ]. An aspherical surface is indicated by adding * after the surface number. Further, the portion where the distance d between the optical surfaces is (variable) changes during zooming. Table 1 shows the relationship between the above conditional expressions and numerical data.

[Numeric data 1]
Surface data surface number rd nd νd Effective diameter
1 * 148.910 3.50 1.77250 49.6 84.00
2 33.301 12.14 62.59
3 45.473 3.20 1.85400 40.4 58.76
4 * 35.979 3.78 48.32
5 35.839 2.80 1.85400 40.4 46.47
6 * 21.390 5.83 37.11
7 35.657 2.00 1.95906 17.5 36.01
8 19.083 9.66 29.97
9 -51.112 1.30 1.53775 74.7 29.88
10 29.928 0.15 29.10
11 28.887 6.57 1.85478 24.8 29.27
12 -181.295 (variable) 28.66
13 (Aperture) ∞ 1.00 17.56
14 19.556 1.00 2.00069 25.5 18.80
15 13.463 6.94 1.65 160 58.5 18.05
16 -32.677 0.64 17.85
17 -29.508 1.00 1.88300 40.8 17.54
18 15.989 4.37 1.84666 23.8 17.64
19 -366.695 (variable) 17.71
20 ∞ 0.00 18.28
21 21.751 1.00 1.95375 32.3 20.01
22 12.653 5.74 1.59522 67.7 19.42
23 72.654 0.15 20.05
24 20.593 8.45 1.43875 94.9 22.01
25 -22.353 0.15 22.11
26 * 1502.818 1.00 1.85400 40.4 20.86
27 14.366 5.35 1.49700 81.5 20.34
28 71.915 (variable) 21.13
29 -22.552 1.80 1.85478 24.8 27.60
30 -50.351 0.15 31.51
31 -122.838 7.20 1.59522 67.7 33.50
32 -27.095 12.00 35.12
Image plane ∞

Aspheric data 1st surface
K = 0.00000e + 000 A 4 = 6.72681e-006 A 6 = -4.93403e-009
A 8 = 3.92095e-012 A10 = -1.70058e-015 A12 = 3.90513e-019
4th page
K = 7.88570e-001 A 4 = -2.45094e-006 A 6 = 3.51685e-008
A 8 = -1.12274e-010 A10 = 2.49809e-013 A12 = -2.99118e-016
A14 = 9.35114e-020
6th page
K = 0.00000e + 000 A 4 = 9.15412e-006 A 6 = -7.47527e-008
A 8 = 8.91733e-011
26th page
K = 0.00000e + 000 A 4 = -4.29139e-005 A 6 = -4.62758e-008
A 8 = 1.38302e-010 A10 = 2.50678e-012

Various data Zoom ratio 2.26
Wide angle Medium telephoto focal length 10.30 14.94 23.30
F number 4.12 4.12 4.12
Half angle of view (degrees) 64.54 55.38 42.88
Image height 21.64 21.64 21.64
Total lens length 156.50 145.83 144.37
BF 12.00 12.00 12.00
d12 33.73 17.55 5.17
d19 6.33 4.45 2.59
d28 7.56 14.96 27.73

Lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -15.91 50.94 13.65 -26.75
2 13 55.46 14.95 -2.98 -11.65
3 20 47.51 21.84 -5.38 -17.49
4 29 67218.01 9.15 8985.53 10365.59

Single lens Data lens Start surface Focal length
1 1 -56.27
2 3 -238.88
3 5 -68.22
4 7 -45.49
5 9 -34.91
6 11 29.58
7 14 -47.04
8 15 15.56
9 17 -11.62
10 18 18.19
11 21 -33.52
12 22 24.85
13 24 25.99
14 26 -16.99
15 27 35.04
16 29 -49.26
17 31 56.81

[Numeric data 2]
Surface data surface number rd nd νd Effective diameter
1 * 158.729 3.50 1.58913 61.1 74.57
2 29.126 8.54 54.74
3 36.860 3.00 1.85400 40.4 52.77
4 * 23.852 8.31 40.91
5 42.641 1.90 1.95375 32.3 39.09
6 17.123 11.67 29.66
7 -53.096 1.40 1.43875 94.7 28.99
8 24.373 0.15 27.34
9 24.377 6.43 1.69895 30.1 27.38
10 -181.295 (variable) 26.72
11 (Aperture) ∞ 1.00 16.36
12 18.634 0.80 2.00069 25.5 17.42
13 13.095 6.03 1.58913 61.1 16.81
14 -24.704 0.62 16.74
15 -22.913 0.80 1.90043 37.4 16.44
16 19.118 3.91 1.84666 23.8 16.88
17 -92.700 (variable) 17.09
18 ∞ 0.00 17.56
19 20.729 0.90 1.88300 40.8 19.44
20 14.086 5.22 1.49700 81.5 19.11
21 78.998 1.00 1.74100 52.6 19.76
22 31.274 0.15 20.23
23 21.962 7.96 1.43875 94.9 21.74
24 -22.588 0.15 22.26
25 26.560 7.71 1.43875 94.9 21.49
26 -17.679 1.00 1.88300 40.8 20.74
27 113.702 1.98 21.15
28 -42.907 1.20 1.85400 40.4 21.20
29 * -69.753 (variable) 22.15
Image plane ∞

Aspheric data 1st surface
K = 0.00000e + 000 A 4 = 1.20979e-005 A 6 = -1.33749e-008
A 8 = 1.31549e-011 A10 = -6.85499e-015 A12 = 1.76441e-018
4th page
K = -4.93336e-001 A 4 = 1.44172e-005 A 6 = 1.30146e-008
A 8 = -1.92171e-010 A10 = 8.47403e-013 A12 = -1.36882e-015
A14 = 6.39635e-019
29th page
K = 0.00000e + 000 A 4 = 3.81691e-005 A 6 = 2.81578e-009
A 8 = 8.23053e-010 A10 = -6.42955e-012 A12 = 1.80682e-014

Various data Zoom ratio 2.26
Wide angle Medium telephoto focal length 10.30 14.94 23.30
F number 4.12 4.12 4.12
Half angle of view (degrees) 64.54 55.37 42.88
Image height 21.64 21.64 21.64
Total lens length 138.50 131.12 132.41
BF 20.19 27.74 41.15
d10 28.69 14.34 3.11
d17 4.29 3.71 2.81
d29 20.19 27.74 41.15

Lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -17.10 44.90 11.15 -27.67
2 11 64.36 13.16 -1.93 -10.10
3 18 45.88 27.27 -9.98 -22.61

Single lens Data lens Start surface Focal length
1 1 -61.16
2 3 -88.55
3 5 -31.13
4 7 -37.86
5 9 31.14
6 12 -47.45
7 13 15.44
8 15 -11.47
9 16 19.02
10 19 -53.15
11 20 33.59
12 21 -70.49
13 23 26.84
14 25 25.55
15 26 -17.27
16 28 -133.29

[Numeric data 3]
Surface data surface number rd nd νd Effective diameter
1 * 140.597 3.50 1.77250 49.6 84.00
2 34.025 13.21 63.95
3 49.148 3.20 1.85400 40.4 59.88
4 * 32.554 3.90 47.44
5 34.252 2.80 1.85400 40.4 45.67
6 * 22.143 3.42 37.05
7 26.769 2.00 1.95906 17.5 36.11
8 17.004 11.17 29.66
9 -48.272 1.30 1.49700 81.5 29.54
10 25.344 0.15 28.18
11 24.929 6.96 1.75520 27.5 28.30
12 -181.295 (variable) 27.61
13 (Aperture) ∞ 1.00 16.83
14 20.782 1.00 2.00 100 29.1 17.89
15 12.427 5.92 1.76385 48.5 17.16
16 -37.947 0.62 16.99
17 -33.903 1.00 1.90043 37.4 16.68
18 15.229 3.80 1.84666 23.8 16.50
19 266.981 (variable) 16.49
20 ∞ 0.00 16.90
21 20.388 1.00 1.95375 32.3 18.60
22 12.409 5.28 1.53775 74.7 18.14
23 74.497 0.15 18.93
24 20.403 8.00 1.43875 94.9 20.94
25 -19.889 0.15 21.15
26 * 1159.650 1.00 1.85400 40.4 19.97
27 14.795 5.06 1.49700 81.5 19.76
28 61.160 (variable) 20.68
29 -25.036 1.50 1.85478 24.8 28.05
30 -56.601 6.01 1.62299 58.2 31.39
31 -24.366 12.00 33.11
Image plane ∞

Aspheric data 1st surface
K = 0.00000e + 000 A 4 = 6.91999e-006 A 6 = -5.03792e-009
A 8 = 4.10220e-012 A10 = -1.90751e-015 A12 = 4.67814e-019
4th page
K = 5.21399e-001 A 4 = 1.83230e-006 A 6 = 2.04765e-008
A 8 = -9.09722e-011 A10 = 1.84852e-013 A12 = -1.86138e-016
A14 = 1.66752e-020
6th page
K = 0.00000e + 000 A 4 = 6.54521e-006 A 6 = -4.58649e-008
A 8 = 6.73608e-011
26th page
K = 0.00000e + 000 A 4 = -4.96518e-005 A 6 = -9.81464e-008
A 8 = 4.07959e-010 A10 = 1.25223e-012

Various data Zoom ratio 2.26
Wide angle Medium telephoto focal length 10.30 14.91 23.30
F number 4.12 4.12 4.12
Half angle of view (degrees) 64.54 55.42 42.88
Image height 21.64 21.64 21.64
Total lens length 149.00 138.88 137.50
BF 12.00 12.00 12.00
d12 31.21 15.46 3.14
d19 5.14 3.90 2.73
d28 7.55 14.42 26.54

Lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -16.36 51.61 13.71 -27.50
2 13 52.01 13.33 -3.70 -10.92
3 20 46.10 20.64 -4.13 -16.01
4 29 -1213.66 7.51 -143.70 -168.10

Single lens Data lens Start surface Focal length
1 1 -58.95
2 3 -123.91
3 5 -82.09
4 7 -54.02
5 9 -33.24
6 11 29.45
7 14 -32.85
8 15 12.91
9 17 -11.56
10 18 18.94
11 21 -35.41
12 22 26.89
13 24 24.43
14 26 -17.56
15 27 37.89
16 29 -53.70
17 30 64.09

[Numeric data 4]
Surface data surface number rd nd νd Effective diameter
1 * 78.022 3.50 1.65 160 58.5 82.00
2 * 20.912 19.60 53.97
3 41.385 2.80 1.85400 40.4 47.15
4 * 33.699 5.00 38.68
5 49.096 1.90 2.00069 25.5 36.77
6 18.190 9.49 28.87
7 -47.936 1.40 1.43875 94.7 28.77
8 24.670 0.15 27.55
9 24.683 6.75 1.72825 28.5 27.62
10 -181.295 (variable) 26.92
11 (Aperture) ∞ 1.00 17.27
12 21.338 0.90 2.00069 25.5 18.40
13 14.201 6.36 1.71700 47.9 17.81
14 -39.539 2.50 17.60
15 -28.172 0.90 1.90366 31.3 16.41
16 25.825 2.87 1.92286 18.9 16.52
17 -4151.440 (variable) 16.56
18 ∞ 0.00 17.51
19 23.972 1.00 1.90043 37.4 19.02
20 13.091 4.90 1.59522 67.7 18.84
21 49.872 0.15 19.51
22 20.577 7.55 1.43875 94.7 21.55
23 -25.845 0.15 21.82
24 * 130.595 1.00 1.85400 40.4 21.24
25 15.477 5.62 1.49700 81.5 21.04
26 140.912 (variable) 21.91
27 -36.065 1.60 1.95375 32.3 29.94
28 -100.859 0.15 32.50
29 -1946.720 7.57 1.48749 70.2 34.13
30 -30.846 12.00 35.58
Image plane ∞

Aspheric data 1st surface
K = 0.00000e + 000 A 4 = 1.04786e-005 A 6 = -1.20292e-008
A 8 = 9.15265e-012 A10 = -3.99926e-015 A12 = 8.53227e-019
Second side
K = -4.80530e-001 A 4 = 1.03925e-005 A 6 = 5.91597e-009
A 8 = 6.09734e-012 A10 = -2.83551e-014 A12 = -2.32616e-017
4th page
K = 0.00000e + 000 A 4 = 6.88196e-006 A 6 = -5.20051e-008
A 8 = 3.98749e-010 A10 = -1.10429e-012 A12 = 1.36141e-015
24th page
K = 0.00000e + 000 A 4 = -3.49568e-005 A 6 = -5.41561e-008
A 8 = 1.20125e-010 A10 = 1.39174e-012

Various data Zoom ratio 2.26
Wide angle Medium Telephoto focal length 10.30 14.99 23.30
F number 4.12 4.12 4.12
Half angle of view (degrees) 64.54 55.29 42.88
Image height 21.64 21.64 21.64
Total lens length 150.46 141.61 142.30
BF 12.00 12.00 12.00
d10 30.83 15.17 3.24
d17 5.08 3.92 2.82
d26 7.76 15.72 29.44

Lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -15.77 50.60 13.05 -27.48
2 11 51.82 14.52 -5.99 -13.87
3 18 45.41 20.36 -1.30 -14.03
4 27 1941.14 9.32 199.17 215.24

Single lens Data lens Start surface Focal length
1 1 -44.93
2 3 -255.31
3 5 -29.79
4 7 -36.91
5 9 30.25
6 12 -45.29
7 13 15.33
8 15 -14.79
9 16 27.82
10 19 -33.49
11 20 28.41
12 22 27.47
13 24 -20.64
14 25 34.47
15 27 -59.58
16 29 64.21

[Numeric data 5]
Surface data surface number rd nd νd Effective diameter
1 * 86.706 3.50 1.58913 61.1 75.00
2 * 28.500 16.17 57.86
3 52.910 2.50 1.88300 40.8 48.44
4 19.676 6.00 34.08
5 31.339 1.90 1.77250 49.6 32.86
6 16.649 9.74 27.07
7 -52.063 1.40 1.43875 94.7 26.38
8 21.706 0.15 24.66
9 21.556 6.01 1.66565 35.6 24.71
10 -181.295 (variable) 24.02
11 (Aperture) ∞ 1.00 16.64
12 18.807 0.80 2.00069 25.5 17.81
13 13.070 6.27 1.57250 57.7 17.17
14 -24.463 0.54 17.16
15 -23.902 0.80 1.90043 37.4 16.90
16 19.332 3.81 1.92119 24.0 17.45
17 -209.970 (variable) 17.63
18 ∞ 0.00 18.03
19 17.586 0.90 1.91082 35.3 20.69
20 14.147 6.25 1.49700 81.5 20.10
21 -189.024 0.15 20.27
22 20.325 1.00 1.88300 40.8 20.55
23 12.448 9.05 1.43875 94.7 19.22
24 -21.807 0.15 19.32
25 -30.032 5.27 1.49700 81.5 18.97
26 -11.489 1.20 1.77250 49.6 18.92
27 -56.793 0.22 20.90
28 -52.820 1.50 1.85400 40.4 20.95
29 * -161.845 (variable) 22.02
Image plane ∞

Aspheric data 1st surface
K = 0.00000e + 000 A 4 = 1.32608e-005 A 6 = -1.96827e-008
A 8 = 1.91310e-011 A10 = -9.51436e-015 A12 = 2.21845e-018
Second side
K = -2.16265e-001 A 4 = 1.06842e-005 A 6 = -3.88464e-009
A 8 = -5.48411e-011 A10 = 9.90361e-014 A12 = -5.57043e-017
29th page
K = 0.00000e + 000 A 4 = 3.69516e-005 A 6 = -1.41972e-008
A 8 = 2.96805e-010 A10 = -3.84306e-012 A12 = 1.06932e-014

Various data Zoom ratio 2.26
Wide angle Medium telephoto focal length 10.30 14.93 23.30
F number 4.12 4.12 4.12
Half angle of view (degrees) 64.54 55.39 42.88
Image height 21.64 21.64 21.64
Total lens length 137.00 131.48 134.45
BF 20.76 28.56 42.46
d10 25.48 12.84 3.00
d17 4.49 3.80 2.72
d29 20.76 28.56 42.46

Lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -15.80 47.36 14.49 -26.05
2 11 72.02 13.22 -3.03 -10.97
3 18 39.55 25.69 -9.89 -21.55

Single lens Data lens Start surface Focal length
1 1 -73.71
2 3 -36.77
3 5 -48.73
4 7 -34.71
5 9 29.29
6 12 -46.03
7 13 15.84
8 15 -11.77
9 16 19.37
10 19 -90.74
11 20 26.76
12 22 -38.68
13 23 19.64
14 25 34.21
15 26 -18.86
16 28 -92.40

[Numeric data 6]
Surface data surface number rd nd νd Effective diameter
1 * 146.279 3.50 1.58913 61.1 72.05
2 28.338 5.70 52.71
3 32.070 3.00 1.85400 40.4 51.15
4 * 25.658 8.77 42.29
5 44.567 1.90 1.95375 32.3 40.54
6 17.934 12.10 31.06
7 -57.657 1.40 1.43875 94.7 30.53
8 29.329 0.15 29.36
9 27.892 6.51 1.69895 30.1 29.49
10 -181.295 (variable) 28.90
11 ∞ 7.94 13.94
12 (Aperture) ∞ 1.00 16.12
13 18.184 0.80 2.00069 25.5 16.97
14 12.619 5.94 1.58913 61.1 16.32
15 -23.657 0.59 16.20
16 -22.248 0.80 1.90043 37.4 15.87
17 18.721 3.97 1.84666 23.8 16.78
18 -133.085 4.29 17.54
19 ∞ 0.00 20.93
20 20.233 0.90 1.88300 40.8 23.79
21 15.474 9.87 1.49700 81.5 23.04
22 -25.466 0.15 23.25
23 31.305 8.28 1.43875 94.9 21.47
24 -15.915 1.00 1.88300 40.8 20.15
25 69.906 1.87 20.50
26 -55.832 1.20 1.85400 40.4 20.57
27 * -91.093 (variable) 21.37
Image plane ∞

Aspheric data 1st surface
K = 0.00000e + 000 A 4 = 1.12141e-005 A 6 = -1.05607e-008
A 8 = 9.48511e-012 A10 = -4.37430e-015 A12 = 1.05908e-018
4th page
K = -6.60458e-001 A 4 = 1.12403e-005 A 6 = 4.55459e-008
A 8 = -2.53780e-010 A10 = 7.73217e-013 A12 = -9.44920e-016
A14 = 3.30501e-019
27th page
K = 0.00000e + 000 A 4 = 3.67999e-005 A 6 = 3.46843e-008
A 8 = 3.48927e-010 A10 = -4.09546e-012 A12 = 1.26140e-014

Various data Zoom ratio 1.89
Wide angle Medium Telephoto focal length 12.36 14.94 23.30
F number 4.12 4.12 4.12
Half angle of view (degrees) 60.26 55.38 42.88
Image height 21.64 21.64 21.64
Total lens length 138.50 133.67 130.79
BF 22.49 26.06 37.65
d10 24.37 15.97 1.50
d27 22.49 26.06 37.65

Lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -20.84 43.03 9.82 -27.96
2 11 28.89 48.61 4.43 -23.53

Single lens Data lens Start surface Focal length
1 1 -60.32
2 3 -191.53
3 5 -32.60
4 7 -44.09
5 9 35.03
6 13 -44.40
7 14 14.87
8 16 -11.19
9 17 19.62
10 20 -81.77
11 21 21.05
12 23 25.41
13 24 -14.60
14 26 -171.58

B1 First lens group B2 Second lens group B3 Third lens group B4 Fourth lens group

Claims (12)

In a zoom lens having a first lens group having a negative refractive power and a second lens group having a positive refractive power, which are arranged in order from the object side to the image side, and the interval between adjacent lens groups changes during zooming.
The first lens group and the second lens group move during zooming so that the distance between the first lens group and the second lens group is smaller at the telephoto end than at the wide-angle end,
When the back focus at the wide angle end is BFw, the focal length of the zoom lens at the wide angle end is fw, the length on the optical axis of the first lens group is D1, and the focal length of the first lens group is f1.
0.50 <BFw / fw <2.40
2.0 <D1 / | f1 | <10.0
A zoom lens satisfying the following conditional expression: When the total lens length of the zoom lens at the wide angle end is Lw,
5.0 <Lw / fw <18.0
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the first lens group has one or more negative lenses and the Abbe number of the material of at least one negative lens NL included in the first lens group is νd_NL,
νd_NL> 60
The zoom lens according to claim 1, wherein the following conditional expression is satisfied.   4. The zoom lens according to claim 1, wherein the first lens group has an aspherical lens surface AL <b> 1 whose positive refractive power increases from the center to the periphery. 5.   The zoom lens according to claim 4, wherein the lens surface AL1 is a lens surface closest to the object side of the first lens group.   The zoom lens according to claim 1, further comprising a third lens group having a positive refractive power and disposed adjacent to the image side of the second lens group.   The zoom lens according to claim 6, further comprising a fourth lens group having a positive refractive power and disposed on the image side of the third lens group.   The zoom lens according to claim 6, further comprising a fourth lens unit having a negative refractive power disposed on the image side of the third lens unit.   9. The zoom lens according to claim 6, wherein the second lens unit moves toward the object side during focusing from infinity to a short distance. 10.   The second lens group includes a 2a lens unit having a positive refractive power and a 2b lens unit having a positive refractive power arranged in order from the object side to the image side. The zoom lens according to claim 1, wherein the lens unit moves toward the image side.   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 the angle formed by the optical axis of the principal ray incident at the position farthest from the optical axis of the imaging surface of the imaging element at the zoom position at the wide angle end is ωw,
ωw> 55
The imaging apparatus according to claim 11, wherein the following conditional expression is satisfied.