JP2014149428A - Zoom lens and imaging device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a zoom lens whose entire system is compact, having a high zoom ratio and achieving high optical performance over the entire zoom range.SOLUTION: The zoom lens comprises, in order from the object side to the image side: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; and a fourth lens group having positive refractive power. When zooming, the distances between the adjacent lens groups are changed. Each of the first lens group and the fourth lens group consists of one positive lens. The amount M1 of movement of the first lens group when zooming from the wide angle end to the telephoto end, and the focal distance fw of the entire system at the wide angle end are set appropriately.

Description

  The present invention relates to a zoom lens and an image pickup apparatus having the same, and is suitable for an image pickup optical system such as a video camera, a digital still camera, a TV camera, a surveillance camera, and a silver salt photograph camera.

  Recently, an imaging optical system used in an imaging apparatus such as a digital still camera or a video camera using a solid-state imaging device is required to be a small zoom lens with a high zoom ratio. As a zoom lens satisfying these requirements, in order from the object side to the image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, A four-unit zoom lens including a fourth lens unit having a refractive power is known (Patent Documents 1 to 4).

  Patent Document 1 discloses a small zoom lens having a zoom ratio of about 5 in which each lens group moves during zooming. Patent Document 2 discloses a small zoom lens having a zoom ratio of about 10 in which each lens group moves during zooming. Patent Document 3 discloses a small zoom lens having a zoom ratio of about 5 in which each lens group moves during zooming. Patent Document 4 discloses a small zoom lens having a zoom ratio of about 7 to 9 in which each lens group moves during zooming. In particular, Patent Documents 3 and 4 disclose zoom lenses in which the first lens group and the fourth lens group are constituted by a single positive lens, and the entire system is reduced in size.

JP 2008-076493 A JP 2002-365550 A JP 2008-145665 A JP 2009-294304 A

  In order to obtain high optical performance over the entire zoom range while reducing the size of the entire system and increasing the zoom ratio as the zoom lens used in the imaging device, the zoom type and the lens configuration of each lens group should be set appropriately. is important.

  Conventionally, in many cameras, the lens barrel (lens barrel) is divided into several stages to reduce the thickness of the camera when not shooting (thinning in the front-rear direction). A so-called collapsible system is often used which is folded in a direction and stored. In this retractable method, in order to effectively reduce the thickness of the camera, it is preferable to reduce the number of lenses in each lens group constituting the zoom lens and to reduce the thickness of the lens group.

  In the above-described four-group zoom lens, in order to achieve a high zoom ratio and to reduce the size of the entire system, among the lens configurations of each lens group, particularly the lens configuration of the first lens group and the fourth lens group, and zooming It is important to appropriately set the amount of movement of the first lens group. If these configurations are not set appropriately, it becomes very difficult to obtain high optical performance over the entire zoom range while reducing the size of the entire system and increasing the zoom ratio.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a zoom lens having a small overall system, a high zoom ratio, and high optical performance over the entire zoom range, and an image pickup apparatus having the zoom lens.

The zoom lens according to the present invention includes, in order from the object side to the image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, In a zoom lens that includes a fourth lens unit having a refractive power and in which the distance between adjacent lens units changes during zooming, each of the first lens unit and the fourth lens unit is composed of one positive lens, and is arranged from the wide-angle end. When the amount of movement of the first lens unit during zooming to the telephoto end is M1, and the focal length of the entire system at the wide-angle end is fw,
3.8 <| M1 | / fw <10.0
It satisfies the following conditional expression.

  According to the present invention, it is possible to obtain a zoom lens having a small overall system, a high zoom ratio, and high optical performance over the entire zoom range, and an image pickup apparatus having the zoom lens.

Sectional view of the lens at the wide-angle end of Embodiment 1 of the present invention (A), (B) Aberration diagrams at the wide-angle end and at the telephoto end of Numerical Example 1 corresponding to Example 1 of the present invention. Sectional view of the lens at the wide-angle end of Embodiment 2 of the present invention (A), (B) Aberration diagrams at the wide-angle end and at the telephoto end of Numerical Example 2 corresponding to Example 2 of the present invention. Sectional view of the lens at the wide-angle end of Embodiment 3 of the present invention (A), (B) Aberration diagrams at the wide-angle end and the telephoto end of Numerical Example 3 corresponding to Example 3 of the present invention. 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, in order from the object side to the image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, A fourth lens unit having a refractive power; The zoom lens performs zooming by changing the interval between the lens groups. In the zoom lens according to the present invention, each of the first lens group and the fourth lens group includes one positive lens.

  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. FIGS. 2A and 2B are aberration diagrams at the wide-angle end and the telephoto end (long focal length end), respectively, of the zoom lens according to the first exemplary embodiment. The first embodiment is a zoom lens having a zoom ratio of 6.74 and an F number of about 2.92 to 6.09. 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. 4A and 4B are aberration diagrams of the zoom lens of Example 2 at the wide-angle end and the telephoto end, respectively. The second embodiment is a zoom lens having a zoom ratio of 6.86 and an F number of about 2.69 to 4.91.

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. 6A and 6B are aberration diagrams of the zoom lens of Example 3 at the wide-angle end and the telephoto end, respectively. The third embodiment is a zoom lens having a zoom ratio of 10.15 and an F number of about 2.90 to 6.87. FIG. 7 is a schematic diagram of a main part of a camera (image pickup apparatus) including the zoom lens of the present invention. The zoom lens of each embodiment is a photographing lens system used in an image pickup apparatus such as a video camera, a digital camera, and a silver salt film camera. It is.
In the lens cross-sectional view, the left side is the subject side (object side) (front), and the right side is the image side (rear). In the lens cross-sectional view, i indicates the order of the lens groups from the object side, and Li is the i-th lens group.

  1, 3, and 5, L1 is a first lens unit having a positive refractive power, L2 is a second lens unit having a negative refractive power, and L3 is a positive refractive power. The third lens unit L4 is a fourth lens unit having a negative refractive power. Examples 1 to 3 are four-group zoom lenses. In the lens cross-sectional view, SP is an aperture stop, and an intersection point between the object-side surface of the lens G31 on the object side of the third lens unit L3 in the optical axis direction and the outer peripheral portion (edge portion) of the lens G31. It is arranged between.

  FP is a flare stop, which is disposed on the image side of the third lens unit L3 and shields unnecessary light. G 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. When used as a photographing optical system for a video camera or a digital still camera, the image plane of a solid-state imaging device (photoelectric conversion device) such as a CCD sensor or a CMOS sensor is used for a silver salt film camera. Is provided with a photosensitive surface corresponding to the film surface.

  The arrows indicate the movement trajectory of each lens unit during zooming from the wide-angle end to the telephoto end. In the spherical aberration diagram, the solid line is the d line, and the two-dot chain line is the g line. In the astigmatism diagram, ΔM and ΔS are a meridional image surface and a sagittal image surface, respectively. Lateral chromatic aberration is represented by the g-line. ω is a half angle of view (degree) (a value half of the shooting angle of view), and Fno is an F number. In the following embodiments, the wide-angle end and the telephoto end refer to zoom positions when the zoom lens unit is positioned at both ends of a range in which the mechanism can move on the optical axis.

  The zoom lens of each embodiment includes, in order from the object side to the image side, a first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, and a third lens unit L3 having a positive refractive power. And a fourth lens unit L4 having a positive refractive power. Then, zooming is performed by changing the interval between the lens groups. The first lens unit L1 and the fourth lens unit L4 are each configured by a lens having a positive refractive power (positive lens). The amount by which the first lens unit moves toward the object side during zooming from the wide-angle end to the telephoto end is appropriately set. As a result, while realizing a high zoom ratio of 7 or more, good optical performance is obtained while reducing the size of the entire system with a small number of lenses.

  Specifically, the positive lens constituting the first lens unit L1 has a biconvex shape in which the curvature of the object-side lens surface is larger than the curvature of the image-side lens surface. During zooming from the wide-angle end to the telephoto end, the first lens unit L1 and the second lens unit L2 move along a locus convex toward the image side, and both the third lens unit L3 and the fourth lens unit L4 move to the object side. Moving.

The zoom lens of each embodiment has the following configuration under the above-described configuration. In zooming from the wide-angle end to the telephoto end, the movement amount of the first lens unit L1 is M1, and the focal length of the entire system at the wide-angle end is fw. At this time,
3.8 <| M1 | / fw <10.0 (1)
The following conditional expression is satisfied.

  Note that the amount of movement of the first lens unit during zooming from the wide-angle end to the telephoto end refers to the difference between the position of the first lens unit at the wide-angle end and the position of the first lens unit at the telephoto end. However, the sign of the amount of movement is positive when the first lens group is located on the image side at the telephoto end, and negative when it is located on the object side, compared to the wide-angle end.

  In order to realize a high zoom ratio with a small number of lenses, in the zoom lens of each embodiment, the first lens unit L1 having a positive refractive power and the second lens unit having a negative refractive power are sequentially arranged from the object side to the image side. The lens unit L2 includes a third lens unit L3 having a positive refractive power and a fourth lens unit L4 having a positive refractive power. Each of the first lens unit L1 and the fourth lens unit L4 is composed of one positive lens. As a result, the number of lenses of the first lens unit L1 and the fourth lens unit L4, in which the lens diameter and lens thickness tend to be large, is minimized, the total lens length (distance from the first lens surface to the image plane), and the collapsed thickness. Is shortened.

  Conditional expression (1) defines the amount of movement of the first lens unit L1 during zooming. If the lower limit of conditional expression (1) is not reached, the amount of movement of the first lens unit L1 with respect to the focal length of the entire system at the wide angle end will be too small. For this reason, in order to obtain a sufficient zoom ratio, it is necessary to shorten the focal length of the positive lens of the first lens unit L1 (increase the refractive power). As a result, spherical aberration and lateral chromatic aberration occur at the telephoto end. It is not good because it increases. If the upper limit of conditional expression (1) is exceeded, the amount of movement of the first lens unit L1 becomes too large.

  Then, in order to secure a sufficient amount of peripheral light at the wide-angle end, the effective diameter of the positive lens of the first lens unit L1 is enlarged, and the entire system is enlarged, which is not good. More preferably, the numerical range of conditional expression (1) is set as follows.

3.8 <| M1 | / fw <6.5 (1a)
It is good to do.

  In the present invention, it is more preferable to satisfy one or more of the following conditional expressions. The Abbe number of the material of the positive lens constituting the fourth lens unit L4 is νd4. The focal length of the third lens unit L3 is f3, and the lateral magnifications at the wide-angle end and the telephoto end of the third lens unit L3 are β3w and β3t, respectively. A lens surface on the object side of the positive lens of the first lens unit L1 when the aperture stop SP is provided between the first lens unit L1 and the fourth lens unit L4 and focusing on an object at infinity at the wide angle end. The distance on the optical axis from the aperture stop SP to the aperture stop SP is L1s. The interval on the optical axis from the aperture stop SP to the image side lens surface of the positive lens in the fourth lens unit L4 is denoted by Ls4.

  The thickness of the positive lens of the first lens unit L1 on the optical axis is D1, the thickness of the positive lens of the fourth lens unit L4 on the optical axis is D4, and the focal length of the entire system at the telephoto end is ft. At this time, it is preferable to satisfy one or more of the following conditional expressions.

10.0 <νd4 <40.0 (2)
0.50 <β3t / (β3w × f3)> 5.00 (3)
0.10 <Ls4 / L1s <0.31 (4)
0.02 <(D1 + D4) / ft <0.10 (5)
Next, the technical meaning of each conditional expression will be described.

  Conditional expression (2) defines a preferable range of the Abbe number of the material of the positive lens constituting the fourth lens unit L4, and is mainly for correcting chromatic aberration favorably. Below the lower limit of conditional expression (2), the dispersion of the material of the positive lens of the fourth lens unit L4 is too large, and the variation in lateral chromatic aberration becomes large during focusing. When the third lens unit L3 is moved so as to have a component in the direction perpendicular to the optical axis and the image formation position is shifted in the direction perpendicular to the optical axis to perform camera shake correction, color misalignment on the axis is performed. It is not good because it increases.

  If the upper limit of conditional expression (2) is exceeded, the dispersion of the material of the positive lens of the fourth lens unit L4 is too small, and the lateral chromatic aberration is insufficiently corrected. As a result, it is necessary to reduce lateral chromatic aberration generated by the first lens unit L1. For this purpose, it is necessary to increase the number of lenses of the first lens unit L1, or to use a low dispersion and low refractive index material as the material of the positive lens of the first lens unit L1.

As a result, the total lens length increases and spherical aberration increases at the telephoto end. More preferably, the range of conditional expression (2) is
10.0 <νd4 <25.0 (2a)
It is good to do.

  Conditional expression (3) defines a preferable arrangement of the focal length and zoom ratio of the third lens unit L3. If the lower limit of conditional expression (3) is not reached, the refractive power and zoom ratio of the third lens unit L3 become too small, so that the zoom ratio of the second lens unit is increased to obtain a sufficient zoom ratio in the entire system. There is a need to. As a result, unless the number of lenses of the second lens unit L2 is increased, it is necessary to reduce the radius of curvature of the lens surface of each lens of the second lens unit L2 or increase the amount of movement during zooming.

As a result, the change in field curvature due to zooming increases, making it difficult to correct field curvature. If the upper limit of conditional expression (3) is exceeded, the focal length of the third lens unit L3 will be too short or the zoom ratio will be too large. As a result, in the third lens unit L3, it becomes difficult to satisfactorily correct various aberrations such as coma over the entire zoom range. More preferably, the numerical range of conditional expression (3) is set as follows.
0.90 <β3t / (β3w × f3)> 3.00 (3a)

  In each embodiment, preferably, an aperture stop SP is disposed between the first lens unit L1 and the fourth lens unit L4.

  Conditional expression (4) indicates that the distance from the object-side lens surface of the positive lens of the first lens unit L1 to the aperture stop SP when the object distance is infinity at the wide-angle end from the aperture stop SP with respect to L1s. This relates to the ratio of the distance Ls4 to the image side lens surface of the positive lens in the four lens unit L4. Conditional expression (4) defines a preferable arrangement of the aperture stop SP, the first lens unit L1, and the fourth lens unit L4 at the wide-angle end. If the lower limit of conditional expression (4) is not reached, the aperture stop SP is too close to the fourth lens unit L4 at the wide-angle end, and the lateral chromatic aberration is insufficiently corrected.

If the upper limit of conditional expression (4) is exceeded, the aperture stop SP becomes too close to the first lens unit L1 at the wide-angle end, which is not good because the lateral chromatic aberration becomes overcorrected. More preferably, the numerical range of conditional expression (4) is set as follows.
0.15 <Ls4 / L1s <0.26 (4a)

  Conditional expression (5) defines the thickness on the optical axis of the positive lens of the first lens unit L1 and the positive lens of the fourth lens unit L4 with respect to the focal length of the entire system at the telephoto end. If the lower limit of conditional expression (5) is not reached, the positive lens thicknesses of the first lens unit L1 and the fourth lens unit L4 are reduced when the focal length of the entire system at the telephoto end is set within an allowable range of chromatic aberration. It is necessary to do. As a result, it is difficult to manufacture because a sufficient edge thickness cannot be secured.

If the upper limit of conditional expression (5) is exceeded, when the thicknesses of the positive lenses of the first lens unit L1 and the fourth lens unit L4 are made appropriate, the focal length of the entire system at the telephoto end is increased. It becomes difficult. More preferably, the numerical range of conditional expression (5) is set as follows.
0.040 <(D1 + D4) / ft <0.085 (5a)

  As described above, according to each embodiment, it is possible to obtain a zoom lens having a good optical performance with a small size of the entire system and a small number of lenses while realizing a high zoom ratio of about 7 to 10.

  Next, the lens configuration of each example will be described. In each embodiment, the first lens unit L1 having a positive refractive power is constituted by one positive lens, and is moved along a locus convex toward the image side during zooming from the wide-angle end to the telephoto end. This configuration facilitates a high zoom ratio with a minimum number of lenses while suppressing an increase in lens diameter.

  In each embodiment, the second lens unit L2 having a negative refractive power is constituted by a negative lens and a positive lens having a meniscus shape with a convex lens surface on the object side in order from the object side to the image side. When zooming from the wide-angle end to the telephoto end, the lens moves along a convex locus toward the image side. This configuration facilitates a high zoom ratio while suppressing an increase in lens diameter. Further, the object side lens surface and the image side lens surface of the negative lens of the second lens group, and the object side lens surface and the image side lens surface of the positive lens are all aspherical. Thus, various aberrations such as spherical aberration and field curvature are corrected satisfactorily with the minimum number of lenses.

  In each embodiment, in order from the object side to the image side, the third lens unit L3 having a positive refractive power, a positive lens having a convex lens surface on the object side, and a negative lens having a concave lens surface on the image side, It consists of. The zoom lens moves to the object side during zooming from the wide-angle end to the telephoto end. The object-side lens surface and the image-side lens surface of the positive lens of the third lens group, and the object-side lens surface and the image-side lens surface of the negative lens are all aspherical. As a result, various aberrations such as spherical aberration and coma are corrected satisfactorily with the minimum number of lenses.

  The third lens unit L3 is moved so as to have a component in the direction perpendicular to the optical axis, and the imaging position is moved in the direction perpendicular to the optical axis. That is, vibration isolation is performed. In each embodiment, the third lens unit L3 is moved in the direction perpendicular to the optical axis to perform image stabilization. However, the moving method uses the third lens unit L3 in the direction perpendicular to the optical axis. If it is moved as if it were held, image blur can be corrected. For example, if the lens barrel structure is allowed to be complicated, the third lens unit L3 may be rotated so as to have a center of rotation on the optical axis, thereby performing vibration isolation. Further, vibration isolation may be performed by a part of the third lens group.

  In each embodiment, the fourth lens unit L4 is composed of one positive lens, which makes it easy to reduce the thickness of the entire lens system. In each embodiment, focusing is performed by moving the fourth lens unit L4 in the optical axis direction. The numerical values in the numerical examples described later are those when focusing on an object at infinity. The aperture stop SP moves integrally with each lens group during zooming.

  In each embodiment, it is preferable that the positive lens of the first lens unit L1 has a biconvex shape in which the lens surface on the object side has a stronger curvature than the lens surface on the image side. According to this, since it is easy to secure the principal point interval, it becomes easy to reduce the refractive power of the first lens group, and it becomes easy to shorten the entire lens length and to reduce spherical aberration.

  In each embodiment, the first lens unit L1 and the fourth lens unit L4 are constituted by a single positive lens. As a result, the camera is made thinner when retracted. According to each embodiment, by configuring as described above, the entire optical system is small, the camera is thinned when retracted, and a zoom lens having a high zoom ratio and high optical performance over the entire zoom range is obtained. ing.

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

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

  In this way, by applying the zoom lens of the present invention to an imaging apparatus such as a digital still camera, a compact imaging apparatus having high optical performance can be realized.

  Next, numerical examples 1 to 3 corresponding to the first to third embodiments of the present invention will be described. In each numerical example, 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 value of d7 in the numerical example is negative because it is counted as the aperture stop and the third lens group in order from the object side to the image side. When k is the eccentricity A4, A6, A8 is an aspheric coefficient, and the displacement in the optical axis direction at the position of the height h from the optical axis is x with respect to the surface vertex, the aspherical shape is
x = (h ² / R) / [1+ [1- (1 + k) (h / R) ² ] ^1/2 ] + A4h ⁴ + A6h ⁶ + A8h ⁸
Is displayed.

Where R is the paraxial radius of curvature. For example, “E-Z” means “10-Z”. In the numerical example, the last two surfaces are surfaces of an optical block such as a filter and a face plate. In each embodiment, the back focus (BF) represents the distance from the lens final surface to the paraxial image surface by an air-converted length. The total lens length is the distance from the lens surface closest to the object side to the final lens surface plus back focus. Table 1 shows the correspondence with the above-described conditional expressions in each numerical example.

[Numerical Example 1]
Unit mm

Surface data surface number rd nd νd
1 42.747 1.60 1.48749 70.2
2 -151.315 (variable)
3 * 2475.562 0.50 1.76802 49.2
4 * 4.727 2.30
5 * 9.959 1.50 2.00178 19.3
6 * 15.377 (variable)
7 (Aperture) ∞ -0.50
8 * 4.428 2.05 1.55332 71.7
9 * -22.066 1.00
10 * 9.557 0.50 2.00178 19.3
11 * 4.911 0.60
12 ∞ (variable) (Flare cut aperture)
13 55.021 0.65 1.84666 23.9
14 -33.412 (variable)
15 ∞ 1.00 1.51633 64.1
16 ∞ 1.00
Image plane ∞

Aspheric data 3rd surface
K = 8.64501e + 004 A 4 = -1.32893e-004 A 6 = 8.13446e-009

4th page
K = -7.00865e-001 A 4 = 1.15052e-004 A 6 = 5.42168e-006
A 8 = -1.09223e-007

5th page
K = 1.51353e + 000 A 4 = -7.12784e-004 A 6 = 3.14078e-008

6th page
K = -2.78857e + 000 A 4 = -6.05411e-004 A 6 = 5.28043e-006
A 8 = -3.39288e-008

8th page
K = -6.72832e-001 A 4 = 5.17099e-004 A 6 = 3.27977e-005
A 8 = 1.54393e-006

9th page
K = -2.13397e + 001 A 4 = 6.73556e-004 A 6 = 4.96603e-009

10th page
K = -2.80342e + 000 A 4 = -6.00235e-004 A 6 = 1.15276e-006

11th page
K = -1.74942e + 000 A 4 = 1.55253e-003 A 6 = 5.93153e-005
A 8 = 2.01322e-005

Various data Zoom ratio 6.74

Focal length 4.39 8.99 29.57 5.35 23.43
F number 2.92 3.73 6.09 3.10 5.98
Half angle of view (degrees) 37.22 23.31 7.47 33.09 9.39
Image height 3.33 3.88 3.88 3.49 3.88
Total lens length 39.84 37.65 58.39 38.88 47.05
BF 7.41 10.96 21.54 8.05 21.43

d 2 0.60 5.23 20.50 2.24 11.36
d 6 19.18 8.49 0.99 15.71 1.41
d12 2.45 2.78 5.16 2.68 2.66
d14 5.75 9.30 19.88 6.39 19.77

Zoom lens group data group Start surface Focal length
1 1 68.56
2 3 -8.72
3 7 11.28
4 13 24.64

[Numerical Example 2]
Unit mm

Surface data surface number rd nd νd
1 23.881 1.80 1.69680 55.5
2 125.520 (variable)
3 * -3210.375 0.50 1.76802 49.2
4 * 4.824 2.30
5 * 9.986 1.50 2.00178 19.3
6 * 14.038 (variable)
7 (Aperture) ∞ -0.50
8 * 4.465 2.05 1.55332 71.7
9 * -39.653 1.00
10 * 8.796 0.50 2.00178 19.3
11 * 4.987 0.60
12 ∞ (variable) (Flare cut aperture)
13 16.240 0.65 1.83400 37.2
14 -337.210 (variable)
15 ∞ 1.00 1.51633 64.1
16 ∞ 1.00
Image plane ∞

Aspheric data 3rd surface
K = 2.18518e + 005 A 4 = -1.15780e-004 A 6 = 4.63088e-007

4th page
K = -6.96649e-001 A 4 = 1.75350e-004 A 6 = 7.71965e-006
A 8 = -1.48410e-007

5th page
K = 1.47045e + 000 A 4 = -7.41119e-004 A 6 = -1.02694e-006

6th page
K = -2.86970e + 000 A 4 = -6.55986e-004 A 6 = 4.63133e-006
A 8 = -1.40621e-010

8th page
K = -6.88856e-001 A 4 = 5.87374e-004 A 6 = 2.44728e-005
A 8 = 1.15570e-006

9th page
K = -2.20006e + 001 A 4 = 4.61271e-004 A 6 = 4.04654e-006

10th page
K = -2.72016e + 000 A 4 = -6.01199e-004 A 6 = 3.56629e-005

11th page
K = -1.60894e + 000 A 4 = 1.44931e-003 A 6 = 8.47283e-005
A 8 = 1.70839e-005

Various data Zoom ratio 6.86

Focal length 4.39 12.92 30.11 5.49 24.06
F number 2.69 3.80 4.80 2.85 4.91
Half angle of view (degrees) 37.20 16.70 7.33 32.43 9.15
Image height 3.33 3.88 3.88 3.49 3.88
Total lens length 38.95 37.38 55.80 38.02 46.05
BF 7.18 12.03 14.67 7.70 17.37

d 2 0.60 6.55 16.32 2.29 10.56
d 6 18.53 4.76 0.70 15.02 0.57
d12 2.24 3.64 13.71 2.61 7.16
d14 5.52 10.37 13.01 6.04 15.71

Zoom lens group data group Start surface Focal length
1 1 42.02
2 3 -8.26
3 7 11.71
4 13 18.59

[Numerical Example 3]
Unit mm

Surface data surface number rd nd νd
1 29.008 1.50 1.49700 81.5
2 340.607 (variable)
3 * 4326.288 0.50 1.76802 49.2
4 * 5.368 2.30
5 * 9.394 1.50 2.00178 19.3
6 * 12.472 (variable)
7 (Aperture) ∞ -0.50
8 * 4.521 2.05 1.55332 71.7
9 * -25.746 1.00
10 * 9.935 0.50 2.00178 19.3
11 * 5.050 0.60
12 ∞ (variable) (Flare cut aperture)
13 42.922 0.70 1.92286 18.9
14 -59.897 (variable)
15 ∞ 1.00 1.51633 64.1
16 ∞ 1.00
Image plane ∞

Aspheric data 3rd surface
K = 4.59684e + 005 A 4 = 5.01581e-005 A 6 = -1.45365e-006

4th page
K = -6.06 180e-001 A 4 = 1.17288e-004 A 6 = 2.11416e-005
A 8 = -6.78568e-008

5th page
K = 1.37190e + 000 A 4 = -8.09828e-004

6th page
K = -1.68604e + 000 A 4 = -6.34556e-004 A 6 = 7.11026e-007
A 8 = 1.29143e-007

8th page
K = -7.04308e-001 A 4 = 5.61786e-004 A 6 = 3.33764e-005
A 8 = 7.44954e-007

9th page
K = -5.82012e + 000 A 4 = 7.16026e-004 A 6 = 1.68866e-006
A 8 = -1.34458e-006

10th page
K = -4.76863e + 000 A 4 = -6.90866e-004 A 6 = 1.35432e-005
A 8 = -3.50037e-006

11th page
K = -2.12725e + 000 A 4 = 1.36702e-003 A 6 = 6.34823e-005
A 8 = 1.08057e-005

Various data Zoom ratio 10.15

Focal length 4.63 9.13 47.00 5.57 29.35
F number 2.90 3.76 6.08 3.08 6.87
Half angle of view (degrees) 35.48 22.99 4.71 32.03 7.52
Image height 3.30 3.88 3.88 3.49 3.88
Total lens length 41.42 35.58 70.65 39.46 45.80
BF 8.88 12.45 21.11 9.50 26.22

d 2 0.60 2.22 30.88 1.41 9.62
d 6 20.91 9.56 0.69 17.27 1.26
d12 0.88 1.20 7.82 1.13 -1.45
d14 7.22 10.79 19.45 7.84 24.56

Zoom lens group data group Start surface Focal length
1 1 63.70
2 3 -9.26
3 7 12.08
4 13 27.18

L1 First lens group L2 Second lens group L3 Third lens group L4 Fourth lens group SP Aperture stop

Claims (12)

In order from the object side to the image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power. In a zoom lens that is configured to change the interval between adjacent lens groups during zooming,
Each of the first lens group and the fourth lens group includes one positive lens,
When the movement amount of the first lens unit in zooming from the wide-angle end to the telephoto end is M1, and the focal length of the entire system at the wide-angle end is fw,
3.8 <| M1 | / fw <10.0
A zoom lens satisfying the following conditional expression: When the Abbe number of the material of the positive lens in the fourth lens group is νd4,
10.0 <νd4 <40.0
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the focal length of the third lens group is f3, and the lateral magnifications at the wide-angle end and the telephoto end of the third lens group are β3w and β3t, respectively.
0.50 <β3t / (β3w × f3)> 5.00
The zoom lens according to claim 1 or 2, wherein the following conditional expression is satisfied. An aperture stop is provided between the first lens group and the fourth lens group, and the aperture extends from the object-side lens surface of the positive lens of the first lens group when focusing on an object at infinity at the wide-angle end. When the interval on the optical axis to the stop is L1s, and the interval on the optical axis from the aperture stop to the lens surface on the image side of the positive lens in the fourth lens group is Ls4,
0.10 <Ls4 / L1s <0.31
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the thickness on the optical axis of the positive lens of the first lens group is D1, the thickness on the optical axis of the positive lens of the fourth lens group is D4, and the focal length of the entire system at the telephoto end is ft.
0.02 <(D1 + D4) / ft <0.10
The zoom lens according to claim 1, wherein the following conditional expression is satisfied.   The zoom according to any one of claims 1 to 5, wherein the positive lens of the first lens group has a biconvex shape in which the curvature of the lens surface on the object side is larger than the curvature of the lens surface on the image side. lens.   During zooming from the wide-angle end to the telephoto end, the first lens group and the second lens group move along a locus convex toward the image side, and both the third lens group and the fourth lens group move toward the object side. The zoom lens according to claim 1, wherein the zoom lens moves.   8. The zoom according to claim 1, wherein the second lens group includes, in order from the object side to the image side, a negative lens, and a positive lens having a meniscus shape with a convex lens surface on the object side. lens.   9. The third lens group includes, in order from the object side to the image side, a positive lens having a convex lens surface on the object side and a negative lens having a concave lens surface on the image side. The zoom lens according to any one of the above.   10. The image forming position is moved in a direction perpendicular to the optical axis by moving the third lens group so as to have a component perpendicular to the optical axis. 1 zoom lens.   The zoom lens according to claim 1, wherein an image is formed on a solid-state image sensor.   An image pickup apparatus comprising: the zoom lens according to claim 1; and a solid-state image pickup device that receives an image formed by the zoom lens.