JP2017116702A - Zoom lens and imaging apparatus including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a zoom lens whose entire lens system is compact and which has a wide view angle, a high zoom ratio, and high optical performance over an entire zoom range.SOLUTION: A zoom lens is composed of a first lens group having negative refractive power, a second lens group having positive refractive power, and a third lens group having negative refractive power that are arranged in order from an object side to an image side. When zooming, each of the lens groups moves so that a distance between the lens groups adjacent to each other changes. The first lens group comprises a negative lens and a positive lens that are arranged in order from the object side to the image side. The third lens group comprises a positive lens and a negative lens that are arranged in order from the object side to the image side. A focal distance f2 of the second lens group, a focal distance f3 of the third lens group, and a focal distance fw of an entire system at a wide angle end are 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 used in an image pickup apparatus such as a still camera, a video camera, or a digital still camera.

  In recent years, there has been a demand for a zoom lens having high optical performance over a wide zoom range with a wide angle of view and a high zoom ratio as an imaging optical system used in an imaging apparatus using an imaging element, although the entire system is small. As a zoom lens satisfying these demands, a negative lead type zoom lens in which a lens group having a negative refractive power is disposed closest to the object side is known. As a negative lead type zoom lens, it is composed of first to third lens groups having negative, positive, and negative refractive powers in order from the object side to the image side, and a three-group zoom in which all the lens groups move during zooming. Lenses are known (Patent Documents 1 and 2).

  Patent Document 1 discloses a zoom lens having an imaging field angle of about 75 degrees at the wide-angle end and a zoom ratio of about 2.8 times. Patent Document 2 discloses a zoom lens having an imaging field angle of about 74 degrees and a zoom ratio of about 2.8 times at the wide-angle end.

Japanese Patent Laid-Open No. 8-184761 JP 2014006275 A

  The above-described three-group zoom lens is relatively easy to achieve a wide angle of view and a high zoom ratio while reducing the size of the entire system. However, in order to obtain a zoom lens having such characteristics, it is important to appropriately set the refractive power of each lens group (optical power = reciprocal of focal length), the lens configuration of each lens group, and the like. . For example, in order to widen the angle of view and reduce the size of the entire system, the refractive power of each lens group may be increased. However, if the refractive power of the first lens unit is made too strong, distortion, field curvature, and astigmatism increase particularly at the wide-angle end, and fluctuations in these various aberrations increase during zooming.

  Further, when the refractive power of the second lens group is increased, the amount of movement of the second lens group for zooming is shortened, and the entire system can be easily downsized. However, if the refractive power is increased too much, spherical aberration, coma aberration, and axial chromatic aberration increase in the entire zoom range. Further, when the refractive power of the third lens group is increased, the entire system can be easily downsized by shortening the exit pupil. However, if the refractive power is increased too much, the angle of incidence of off-axis rays on the image sensor becomes too large, and a lot of shading occurs that makes the periphery of the screen dark.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a zoom lens that has a small overall lens system, has a wide angle of view and a high zoom ratio, and can easily obtain high optical performance in the entire zoom range, and an image pickup apparatus having the zoom lens.

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 third lens group having a negative refractive power, which are arranged in order from the object side to the image side. In a zoom lens in which each lens group moves so that the interval between adjacent lens groups changes during zooming,
The first lens group includes a negative lens and a positive lens arranged in order from the object side to the image side, and the third lens group includes a positive lens and a negative lens arranged in order from the object side to the image side. When the focal length of the second lens group is f2, the focal length of the third lens group is f3, and the focal length of the entire system at the wide angle end is fw,
1.10 <f2 / fw <2.00
−4.0 <f3 / fw <−0.5
It satisfies the following conditional expression.

  According to the present invention, it is possible to obtain a zoom lens in which the entire lens system is small, has a wide angle of view, a high zoom ratio, and can easily obtain high optical performance in the entire zoom range.

FIG. 5 is a diagram of a lens cross section and a movement locus at the wide angle end according to the first embodiment. (A), (B), (C) Various aberration diagrams in Example 1 at the wide-angle end, the intermediate zoom position, and the telephoto end FIG. 10 is a diagram of a lens cross section and a movement locus at the wide angle end according to the second embodiment. (A), (B), (C) Various aberration diagrams in Example 2 at the wide-angle end, the intermediate zoom position, and the telephoto end FIG. 12 is a diagram of a lens cross section and a movement locus at the wide angle end according to the third embodiment. (A), (B), (C) Various aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end of Example 3. FIG. 12 is a diagram of a lens cross section and a movement locus at the wide angle end according to the fourth embodiment. (A), (B), (C) Various aberration diagrams of Example 4 at the wide-angle end, the intermediate zoom position, and the telephoto end Embodiment of the digital camera of the present invention

  Hereinafter, a zoom lens of the present invention and an image pickup apparatus having the same will be described with reference to the 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 third lens group having a negative refractive power, which are arranged in order from the object side to the image side. Yes. Then, each lens group moves so that the interval between adjacent lens groups changes during zooming.

  FIG. 1 is a lens cross-sectional view at the wide-angle end (short focal length end) of the zoom lens according to Embodiment 1 of the present invention. 2A, 2B, and 2C are aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end (long focal length end) of the zoom lens according to the first exemplary embodiment of the present invention. Example 1 is a zoom lens having a zoom ratio of 2.90 and an aperture ratio (F number) of 4.12 to 5.60.

  FIG. 3 is a lens cross-sectional view at the wide-angle end of the zoom lens according to Embodiment 2 of the present invention. FIGS. 4A, 4B, and 4C are aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end of the zoom lens according to the second embodiment of the present invention. The second exemplary embodiment is a zoom lens having a zoom ratio of 2.90 and an aperture ratio of 3.09 to 5.55.

  FIG. 5 is a lens cross-sectional view at the wide-angle end of the zoom lens according to Embodiment 3 of the present invention. FIGS. 6A, 6B, and 6C are aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end of the zoom lens according to the third exemplary embodiment of the present invention. The third embodiment is a zoom lens having a zoom ratio of 2.90 and an aperture ratio of 4.12 to 5.60.

  FIG. 7 is a lens cross-sectional view at the wide-angle end of the zoom lens according to a fourth exemplary embodiment of the present invention. FIGS. 8A, 8B, and 8C are aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end of the zoom lens according to the fourth exemplary embodiment of the present invention. Example 4 is a zoom lens having a zoom ratio of 2.88 and an aperture ratio of 4.12 to 5.60. FIG. 9 is a schematic view of a main part of a digital camera (imaging device) having the zoom lens of the present invention.

  The zoom lens of each embodiment is an image pickup optical system used in the image pickup apparatus. 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 in an optical device such as a projector. In this case, the left side is a screen and the right side is a projected image.

  In the lens cross-sectional view, L0 is a zoom lens. L1 is a first lens unit having negative refractive power (optical power = reciprocal of focal length), L2 is a second lens unit having positive refractive power, and third lens unit L3 is a focus lens. SP is an F number determining member (hereinafter also referred to as “aperture stop”) that functions as an aperture stop that determines (limits) an open F number (Fno) light beam.

  GS is an optical block corresponding to an optical filter, a face plate, a quartz low-pass filter, an infrared cut filter, or the like. 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 lens cross-sectional view, arrows indicate the movement trajectory of each lens unit during zooming from the wide-angle end to the telephoto end.

  During zooming from the wide-angle end to the telephoto end, the first lens unit L1 moves along a locus convex toward the image side. The second lens unit L2 and the third lens unit L3 move to the object side along different paths. The aperture stop SP moves (integrally) along the same locus as the second lens unit L2.

  An arrow 3a related to the third lens unit L3 indicates a movement locus during zooming from the wide-angle end to the telephoto end when focusing at infinity. An arrow 3b relating to the third lens unit L3 indicates a movement locus during zooming from the wide-angle end to the telephoto end when focusing on a short distance. An arrow 3c relating to the third lens unit L3 indicates a moving direction during focusing from infinity to a short distance. Focusing may be performed by moving an arbitrary lens unit on the optical axis instead of the third lens unit L3.

  The aperture stop SP is disposed on the object side of the second lens unit L2. The aperture diameter of the aperture stop SP may be constant during zooming or may be changed. When the aperture diameter of the aperture stop SP is changed, underlined coma flare due to off-axis light flux that is largely generated at the telephoto end can be cut, and it becomes easy to obtain better optical performance.

  Among the aberration diagrams, in the spherical aberration diagram, d indicates the d-line (wavelength 587.6 nm), and g indicates the g-line (wavelength 435.8 nm). Fno is an F number. In the astigmatism diagram, M is a meridional image plane of d line, and S is a sagittal image plane of d line. Lateral chromatic aberration is represented by the g-line. ω is a half angle of view (degree). 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.

In the zoom lens of the present invention, the first lens unit L1 includes a negative lens and a positive lens arranged in order from the object side to the image side. The third lens unit L3 includes a positive lens and a negative lens arranged in order from the object side to the image side. The focal length of the second lens unit L2 is f2, the focal length of the third lens unit L3 is f3, and the focal length of the entire system at the wide angle end is fw. At this time,
1.10 <f2 / fw <2.00 (1)
−4.0 <f3 / fw <−0.5 (2)
The following conditional expression is satisfied.

  The present invention provides a first lens unit L1 having a negative refractive power arranged in order from the object side to the image side in order to obtain a zoom lens having a wide angle of view, a small overall system, and good optical performance. The second lens unit L2 has a strong power and the third lens unit L3 has a negative refractive power.

  The first lens unit L1 is composed of a negative lens and a positive lens in order from the object side to the image side, so that axial chromatic aberration and lateral chromatic aberration are favorably corrected with a small number of lenses. In addition, since the third lens unit L3 is composed of a positive lens and a negative lens in order from the object side to the image side, various aberrations generated in the first lens unit L1 and the second lens unit L2 can be corrected with a small number of lenses. doing. Further, by satisfying conditional expressions (1) and (2), a zoom lens having a wide angle of view and good optical performance over the entire zoom range is obtained while the entire system is small.

  Conditional expression (1) defines the ratio between the focal length of the second lens unit L2 and the focal length at the wide-angle end of the entire system. Satisfying conditional expression (1) provides good optical performance while reducing the size of the entire system. If the lower limit of conditional expression (1) is exceeded and the focal length of the second lens unit L2 becomes too short, the amount of movement of the second lens unit L2 for zooming becomes short and the lens system can be easily downsized. However, a lot of spherical aberration and axial chromatic aberration occur at the telephoto end. On the other hand, if the focal length of the second lens unit L2 exceeds the upper limit value of the conditional expression (1), the amount of movement of the second lens unit L2 for zooming increases, and the total lens length increases. come.

  Conditional expression (2) defines the ratio between the focal length of the third lens unit L3 and the focal length at the wide-angle end of the entire system. When the upper limit of conditional expression (2) is exceeded and the negative focal length of the third lens unit L3 becomes too short (the absolute value of the negative focal length becomes too small), the lens system can be easily downsized. However, the incident angle of off-axis rays to the image sensor becomes too large, and a lot of shading occurs.

On the other hand, when the negative focal length of the third lens unit L3 becomes too long (when the absolute value of the negative focal length becomes too large) exceeding the lower limit value of the conditional expression (2), the imaging element for off-axis rays is used. However, the effective diameter of the third lens unit L3 is increased. In each embodiment, it is preferable to set the numerical ranges of conditional expressions (1) and (2) as follows.
1.12 <f2 / fw <1.70 (1a)
−3.6 <f3 / fw <−0.8 (2a)

  As described above, according to the present invention, it is possible to obtain a zoom lens having a wide angle of view, a small entire system, and good optical performance.

  Further, in the present invention, it is preferable to satisfy one or more of the following conditional expressions in order to obtain good optical performance while reducing the size of the entire system. Let the focal length of the first lens unit L1 be f1. The zoom ratio of the second lens unit L2 during zooming from the wide-angle end to the telephoto end is z2, and the zoom ratio of the third lens unit L3 during zooming from the wide-angle end to the telephoto end is z3. The refractive index of the negative lens material included in the first lens unit L1 is N1n. The average value of the refractive indexes of the materials of all the lenses included in the third lens unit L3 is aveN3.

When the zoom lens of the present invention is used in an image pickup apparatus having an image pickup device, the thickness on the optical axis of the first lens unit L1, the thickness on the optical axis of the second lens unit L2, and the light of the third lens unit L3. Let D be the total thickness on the shaft. Let Y be the half of the diagonal length of the effective imaging surface of the imaging device. At this time, one or more of the following conditional expressions should be satisfied.
-4.0 <f1 / fw <-2.0 (3)
0.5 <z3 / z2 <1.7 (4)
1.75 <N1n <2.50 (5)
1.72 <aveN3 <2.50 (6)
1.9 <D / Y <3.0 (7)

  Next, the technical meaning of each conditional expression described above will be described. Conditional expression (3) defines the focal length of the first lens unit L1.

  By satisfying conditional expression (3), curvature of field and lateral chromatic aberration are effectively corrected particularly at the wide-angle end. If the upper limit of conditional expression (3) is exceeded and the negative focal length of the first lens unit L1 becomes too short, a lot of field curvature and lateral chromatic aberration will occur at the wide angle end. On the other hand, if the lower limit of conditional expression (3) is exceeded and the focal length of the first lens unit L1 becomes too long, the distance between the first lens unit L1 and the second lens unit L2 becomes longer at the wide angle end, and the total lens length becomes longer. It ’s getting longer.

  Conditional expression (4) defines the zoom ratio of the second lens unit L2 and the third lens unit L3. By satisfying conditional expression (4), a zoom lens having good optical performance is obtained while the entire system is small. If the lower limit of conditional expression (4) is exceeded and the zoom ratio of the second lens unit L2 becomes too large, the focal length of the second lens unit L2 will be shortened accordingly, and spherical aberration and axis at the telephoto end will be shortened. Many upper chromatic aberrations occur.

  On the other hand, if the zoom ratio of the third lens unit L3 becomes too large exceeding the upper limit value of the conditional expression (4), the negative focal length of the third lens unit L3 is shortened, and as a result, imaging of off-axis rays is performed. The incident angle to the element becomes large, and a lot of shading occurs.

  Conditional expression (5) defines the refractive index of the material of the negative lens included in the first lens unit L1. If the lower limit of conditional expression (5) is exceeded and the refractive index of the material of the negative lens included in the first lens unit L1 becomes too small, the effective diameter of the negative lens becomes large and the entire system becomes large. .

  On the other hand, if the refractive index of the material of the negative lens of the first lens unit L1 exceeds the upper limit value of conditional expression (5), the Petzval sum becomes small, and field curvature and astigmatism over the entire zoom range. Will occur greatly.

  Conditional expression (6) defines the refractive index of the positive lens material and the average refractive index of all the lens materials of the negative lens material included in the third lens unit L3. When the lower limit of conditional expression (6) is exceeded and the average value of the refractive index of the positive lens material and the refractive index of the negative lens material included in the third lens unit L3 becomes too small, the third lens unit L3 becomes effective. The diameter increases, and as a result, the entire system becomes larger.

  On the other hand, if the refractive index of the material of the positive lens or the material of the negative lens included in the third lens unit L3 exceeds the upper limit value of the conditional expression (6) and the refractive index of the material of the negative lens becomes too large, The effect of correcting in the negative direction becomes smaller. Then, field curvature and astigmatism are greatly generated in the entire zoom range.

  Conditional expression (7) indicates that the thickness of the first lens unit L1 on the optical axis, the thickness of the second lens unit L2 on the optical axis, and the third lens unit L3 when the zoom lens of the present invention is used in an imaging apparatus. Defines the sum of the thicknesses on the optical axis. If the lower limit of conditional expression (7) is exceeded and the sum of the thicknesses of each lens group becomes too small, the number of lenses constituting each lens group must be reduced, and it is difficult to obtain good optical performance. become. On the other hand, if the upper limit of conditional expression (7) is exceeded and the sum of the thicknesses of the lens groups becomes too large, the total lens length becomes long.

In each embodiment, the numerical ranges of conditional expressions (3) to (7) are preferably set as follows.
−3.6 <f1 / fw <−2.2 (3a)
0.6 <z3 / z2 <1.5 (4a)
1.76 <N1n <2.30 (5a)
1.73 <aveN3 <2.30 (6a)
2.0 <D / Y <2.8 (7a)

  In each embodiment, by configuring each element as described above, a zoom lens having a wide field angle, a small overall system, and high optical performance over the entire zoom range is obtained. Moreover, the effect of the present invention can be further enhanced by arbitrarily combining a plurality of the above conditional expressions.

  Next, the lens configuration of each lens group in each embodiment will be described. The lens configuration of each lens group is assumed to be arranged in order from the object side to the image side unless otherwise specified.

  In each embodiment, the first lens unit L1 includes a negative meniscus lens having a concave surface on the image side and a positive lens having a meniscus shape having a convex surface on the object side. With this lens configuration, the entire system is reduced in size, and the lateral chromatic aberration is effectively corrected in the entire zoom range while favorably correcting curvature of field particularly at the wide-angle end. The aperture stop SP moves along the same locus as the second lens unit L2 during zooming. The second lens unit L2 includes a cemented lens obtained by cementing a positive lens and a negative lens, and a positive lens. The most positive lens on the image side has both aspheric surfaces.

  With this lens configuration, spherical aberration and axial chromatic aberration are effectively corrected over the entire zoom range. The third lens unit L3 includes a positive lens and a negative lens. This lens configuration shortens the exit pupil, facilitating downsizing of the entire system. In particular, the field curvature is corrected well at the wide-angle end, and the lateral chromatic aberration is effectively corrected over the entire zoom range.

  Next, an embodiment of a video 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. 9, reference numeral 10 denotes a video camera body, and 11 denotes an imaging optical system constituted by any of the zoom lenses described in the first to fourth embodiments. Reference numeral 12 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 11 and is built in the camera body. Reference numeral 13 denotes a memory for recording information corresponding to the subject image photoelectrically converted by the image sensor 12. Reference numeral 14 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 12 is displayed.

  The image pickup apparatus according to the present invention may include a correction unit that electrically corrects one or both of distortion and lateral chromatic aberration in addition to any of the zoom lenses described above. With such a correction means, the zoom lens can be configured to allow distortion, etc., the number of lenses in the entire zoom lens can be reduced, and the entire system can be easily downsized. Further, by electrically correcting the chromatic aberration of magnification, it becomes easier to reduce the color blur of the captured image and improve the resolution.

  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.

  Next, numerical data 1 to 4 corresponding to the first to fourth embodiments of the present invention will be shown. In each numerical data, i indicates the order of the optical surfaces from the object side. ri is the radius of curvature of the i-th optical surface (i-th surface), di is the distance between the i-th surface and the i + 1-th surface, and ndi and νdi are the refractions of the material of the i-th optical member with respect to the d-line, respectively. Indicates the rate and Abbe number.

The two surfaces closest to the image side are parallel flat plates such as face plates. BF denotes a back focus, which is an air-converted distance from the lens surface closest to the image side to the image surface. 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. Further, when k is an eccentricity, A4, A6, A8, and A10 are aspherical coefficients, and a displacement in the optical axis direction at a position of height h from the optical axis with respect to the lens surface apex is x, the aspherical shape is ,
x = (h ² / R) / [1+ {1− (1 + k) (h / R) ² } ^1/2 ] + A4h ⁴ + A6h ⁶ + A8h ⁸ + A10h ¹⁰
It is represented by Where R is the paraxial radius of curvature. “E−x” means “× 10 ^−x ”. Table 1 shows the correspondence with the above-described conditional expressions in each numerical data.

[Numeric data 1]
Unit mm

Surface data surface number rd nd νd
1 -278.224 0.60 1.80 400 46.6
2 11.317 2.30
3 12.645 1.63 2.00272 19.3
4 19.352 (variable)
5 (Aperture) ∞ 0.60
6 8.321 2.78 1.60311 60.6
7 -7.524 0.30 1.90366 31.3
8 94.495 2.12
9 * 28.437 3.58 1.58313 59.4
10 * -9.029 (variable)
11 -30.939 1.45 1.88300 40.8
12 -11.959 2.00
13 * -6.464 0.50 1.69350 53.2
14 * 37.981 (variable)
15 ∞ 2.36 1.51633 64.1
16 ∞ 2.01
Image plane ∞

Aspheric data 9th surface
K = -1.16197e + 002 A 4 = 1.75886e-004 A 6 = -4.04005e-005 A 8 = 1.76353e-006 A10 = -4.14003e-008

10th page
K = 0.00000e + 000 A 4 = 1.63731e-004 A 6 = -3.08486e-006 A 8 = 1.27800e-007 A10 = -3.85554e-009

Side 13
K = 1.13930e-001 A 4 = 5.52941e-004 A 6 = 2.83448e-006 A 8 = -1.35332e-007 A10 = 1.10240e-008

14th page
K = 0.00000e + 000 A 4 = 1.10735e-004 A 6 = -4.21269e-006 A 8 = 2.45161e-008

Various data Zoom ratio 2.90
Wide angle Medium Telephoto focal length 9.50 24.41 27.51
F number 4.12 5.24 5.60
Half angle of view (degrees) 40.10 18.14 16.21
Statue height 8.00 8.00 8.00
Total lens length 40.78 37.31 40.22
BF 5.08 17.19 20.92

d 4 14.18 1.12 1.00
d10 3.66 1.14 0.45
d14 1.52 13.63 17.35

Zoom lens group data group Start surface Focal length
1 1 -24.38
2 5 10.97
3 11 -14.30

[Numeric data 2]
Unit mm

Surface data surface number rd nd νd
1 430.380 0.45 1.77250 49.6
2 9.536 2.10
3 9.694 1.70 2.10205 16.8
4 11.192 (variable)
5 (Aperture) ∞ 0.41
6 6.081 2.78 1.59282 68.6
7 -5.150 0.30 1.80610 33.3
8 1001.591 2.18
9 * 61.071 1.97 1.69350 53.2
10 * -11.440 (variable)
11 -22.714 1.24 1.90043 37.4
12 -9.740 1.23
13 * -5.961 0.35 1.58313 59.4
14 * 49.155 (variable)
15 ∞ 1.62 1.51633 64.1
16 ∞ 1.39
Image plane ∞

Aspheric data 9th surface
K = -1.74303e + 003 A 4 = 1.05456e-003 A 6 = -1.20336e-004 A 8 = 2.18192e-005 A10 = -8.05275e-007

10th page
K = 0.00000e + 000 A 4 = 9.88645e-004 A 6 = 9.56274e-006 A 8 = 6.76774e-006 A10 = 1.88959e-007

Side 13
K = -9.87221e-001 A 4 = -9.10861e-004 A 6 = 1.45925e-005 A 8 = 6.68973e-006 A10 = -1.64030e-007

14th page
K = 0.00000e + 000 A 4 = -1.04059e-003 A 6 = 4.55671e-005 A 8 = 3.87905e-007

Various data Zoom ratio 2.90
Wide angle Medium telephoto focal length 6.50 16.43 18.87
F number 3.09 5.01 5.55
Half angle of view (degrees) 40.22 18.51 16.25
Image height 5.50 5.50 5.50
Total lens length 37.69 30.79 32.00
BF 4.11 12.84 15.58

d 4 16.01 2.52 1.63
d10 2.86 0.74 0.08
d14 1.66 10.38 13.13

Zoom lens group data group Start surface Focal length
1 1 -17.49
2 5 9.37
3 11 -20.00

[Numeric data 3]
Unit mm

Surface data surface number rd nd νd
1 104.830 0.80 1.91082 35.3
2 14.425 4.64
3 16.884 2.54 1.94595 18.0
4 28.109 (variable)
5 (Aperture) ∞ 0.81
6 9.842 3.79 1.59282 68.6
7 -11.155 0.35 2.00 100 29.1
8 126.483 3.09
9 * 94.145 3.21 1.85135 40.1
10 * -14.959 (variable)
11 -37.371 1.97 1.90366 31.3
12 -15.279 2.73
13 * -8.956 0.60 1.88202 37.2
14 * 69.517 (variable)
15 ∞ 3.19 1.51633 64.1
16 ∞ 2.72
Image plane ∞

Aspheric data 9th surface
K = -8.58622e + 002 A 4 = -1.32926e-004 A 6 = -8.91674e-006 A 8 = 1.77498e-007 A10 = -2.76752e-009

10th page
K = 0.00000e + 000 A 4 = -7.33397e-005 A 6 = -3.40893e-006 A 8 = 8.50194e-008 A10 = -1.48331e-009

Side 13
K = 4.82425e-001 A 4 = 6.04427e-005 A 6 = 7.02941e-006 A 8 = 7.12610e-008 A10 = -1.22246e-009

14th page
K = 0.00000e + 000 A 4 = -8.22187e-005 A 6 = 5.71345e-006 A 8 = -6.73158e-008

Various data Zoom ratio 2.90
Wide angle Medium Telephoto focal length 12.20 30.57 35.35
F number 4.12 5.24 5.60
Half angle of view (degrees) 41.57 19.49 17.02
Image height 10.82 10.82 10.82
Total lens length 56.55 51.95 54.74
BF 6.30 22.64 27.21

d 4 21.32 4.00 2.77
d10 4.41 0.78 0.24
d14 1.47 17.82 22.38

Zoom lens group data group Start surface Focal length
1 1 -39.04
2 5 14.10
3 11 -15.00

[Numeric data 4]
Unit mm

Surface data surface number rd nd νd
1 47.157 0.80 2.00 100 29.1
2 13.285 5.04
3 16.250 2.42 2.10420 17.0
4 23.642 (variable)
5 (Aperture) ∞ 0.81
6 10.017 4.05 1.59282 68.6
7 -10.499 0.35 2.00 100 29.1
8 524.841 2.38
9 * 91.520 3.10 1.88202 37.2
10 * -16.356 (variable)
11 -30.588 1.37 1.90366 31.3
12 -14.974 2.89
13 * -9.298 0.60 1.88202 37.2
14 * 54.121 (variable)
15 ∞ 3.19 1.51633 64.1
16 ∞ 2.02
Image plane ∞

Aspheric data 9th surface
K = -9.88590e + 001 A 4 = -1.57967e-004 A 6 = -1.01974e-007 A 8 = 4.36418e-008

10th page
K = 0.00000e + 000 A 4 = -2.41797e-005 A 6 = 8.75069e-007 A 8 = 2.75707e-008

Side 13
K = -5.01176e-001 A 4 = 6.65892e-006 A 6 = 1.06307e-006

14th page
K = 0.00000e + 000 A 4 = 9.71320e-005

Various data Zoom ratio 2.88
Wide angle Medium Telephoto focal length 12.05 29.38 34.68
F number 4.12 5.24 5.60
Half angle of view (degrees) 41.93 20.22 17.33
Image height 10.82 10.82 10.82
Total lens length 58.11 52.30 53.54
BF 6.12 21.11 25.17

d 4 23.70 6.19 3.73
d10 4.48 1.21 0.83
d14 2.00 16.98 21.05

Zoom lens group data group Start surface Focal length
1 1 -40.05
2 5 13.95
3 11 -14.00

  L1 First lens group L2 Second lens group L3 Third lens group

Claims (10)

A first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a negative refractive power arranged in order from the object side to the image side. In the zoom lens where each lens group moves so that the interval changes,
The first lens group includes a negative lens and a positive lens arranged in order from the object side to the image side, and the third lens group includes a positive lens and a negative lens arranged in order from the object side to the image side. When the focal length of the second lens group is f2, the focal length of the third lens group is f3, and the focal length of the entire system at the wide angle end is fw,
1.10 <f2 / fw <2.00
−4.0 <f3 / fw <−0.5
A zoom lens satisfying the following conditional expression: When the focal length of the first lens group is f1,
−4.0 <f1 / fw <−2.0
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the zoom ratio of the second lens group in zooming from the wide-angle end to the telephoto end is z2, and the zoom ratio of the third lens group in zooming from the wide-angle end to the telephoto end is z3,
0.5 <z3 / z2 <1.7
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the refractive index of the material of the negative lens included in the first lens group is N1n,
1.75 <N1n <2.50
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the average value of the refractive indexes of the materials of all the lenses included in the third lens group is aveN3,
1.72 <aveN3 <2.50
The zoom lens according to claim 1, wherein the following conditional expression is satisfied.   The first lens group moves along a convex locus toward the image side during zooming from the wide-angle end to the telephoto end, and the second lens group and the third lens group move toward the object side. The zoom lens according to any one of 1 to 5.   The said 2nd lens group is comprised in order from the object side to the image side, and is comprised from the cemented lens which cemented the positive lens and the negative lens, and the positive lens, The one of Claim 1 thru | or 6 characterized by the above-mentioned. 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. The sum of the thickness on the optical axis of the first lens group, the thickness on the optical axis of the second lens group, and the thickness on the optical axis of the third lens group is D, and the effective imaging surface of the imaging device When Y is half of the diagonal length of
1.9 <D / Y <3.0
The imaging apparatus according to claim 8, wherein the following conditional expression is satisfied.   The imaging apparatus according to claim 8, further comprising a correction unit that corrects an aberration caused by the zoom lens by electrical correction.