JP2011090190A - Zoom lens and imaging apparatus including the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a zoom lens which achieves miniaturization of an entire optical system, and a wide viewing angle and a high zoom ratio, and yields high optical performance all over the zoom range. <P>SOLUTION: The zoom lens includes, in order from an object side to an 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, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power. The lens groups move such that space between the first lens group and the second lens group becomes larger, space between the second lens group and the third lens group becomes smaller, and space between the third lens group and the fourth lens group becomes smaller at a telephoto end than at a wide angle end. When focusing from an infinity object to a short-distance object, the fifth lens group moves to an image surface side. Imaging lateral magnification &beta;iT of an i-th lens group at the telephoto end, imaging lateral magnification &beta;iW of the i-th lens group at the wide angle end, and a composite variable power ratio ZR of the lens group existing nearer to the image surface side than the second lens group, when a lens group existing nearest to an image surface side is set as a k-th lens group, are appropriately set respectively. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a zoom lens and an image pickup apparatus having the same, and is suitably used for an electrophotographic camera such as a video camera and a digital still camera, a surveillance camera, a film camera, a broadcast camera, and the like.

  As a zoom lens for an image pickup apparatus such as a digital camera or a video camera using a solid-state image pickup device, the entire optical system is required to be small and include a wide angle region and a high zoom ratio. As a zoom lens that can easily achieve a high zoom ratio, a positive lead type zoom lens is known in which the lens unit closest to the object side is a lens unit having a positive refractive power. A zoom lens using a so-called inner focus method or rear focus method in which a lens group after the second lens group is moved in the optical axis direction for focusing is known as a zoom lens in which the entire optical system can be easily reduced in size. A positive lead type rear focus system that is a compact zoom lens with a high zoom ratio. The zoom lens is composed of first to fifth lens units having positive, negative, positive, positive, and negative refractive power in order from the object side to the image side. A lens is known (Patent Document 1). Patent Document 1 discloses a zoom lens in which each lens group is moved to perform zooming, and a fifth lens group is moved to perform focusing.

JP-A-10-206736

  In a positive lead type zoom lens, it is common to increase the zoom ratio by giving a large zoom ratio to the second lens group, which is the main zoom lens group. However, if the second lens group has a large zoom ratio, in order to increase the zoom ratio, it is necessary to increase the interval change during zooming between the first lens group and the second lens group. Tend to be larger. In a positive lead type zoom lens, in order to obtain high optical performance over the entire zoom range and overall object distance, it is necessary to appropriately set the power, imaging magnification, lens configuration, and the like of each lens group. In particular, it is important to appropriately set a change in image forming magnification (image forming lateral magnification) accompanying zooming of each lens group in order to achieve a high zoom ratio and to reduce the size of the entire system.

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

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, and a positive lens having a positive refractive power. The fourth lens group includes a fifth lens group having a negative refractive power, and the distance between the first lens group and the second lens group is larger at the telephoto end than at the wide-angle end, and the second lens group and the third lens group The lens group moves so that the distance between the third lens group and the fourth lens group becomes small, and the fifth lens group moves to the image plane side when focusing from an object at infinity to a near object. The imaging lateral magnification of the i-th lens group at the telephoto end is βiT, the imaging lateral magnification of the i-th lens group at the wide-angle end is βiW, and the lens group closest to the image plane is the k-th lens group, The combined zoom ratio ZR of the lens unit existing on the image plane side with respect to the second lens unit is ZR = (β3T × 4T × ... × βkT) / (β3W × β4W × ... × βkW)
And when
−2.0 <β2T <−0.85
ZR> 2.0
It satisfies the following conditional expression.

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

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 at the telephoto end of Numerical Example 3 corresponding to Example 3 of the present invention. Cross-sectional view of a lens at a wide angle end according to Embodiment 4 of the present invention (A) (B) Aberration diagrams at the wide-angle end and at the telephoto end of Numerical Example 4 corresponding to Example 4 of the present invention. Lens cross-sectional view at the wide angle end according to Embodiment 5 of the present invention (A) (B) Aberration diagrams at the wide-angle end and at the telephoto end of Numerical Example 5 corresponding to Example 5 of the present invention. Cross-sectional view of a lens at a wide angle end according to Embodiment 6 of the present invention (A) (B) Aberration diagrams at the wide-angle end and at the telephoto end of Numerical Example 6 corresponding to Example 6 of the present invention. Schematic diagram of main parts of an imaging apparatus of the present invention

  Embodiments of the zoom lens of the present invention and an image pickup apparatus having the same will be described below. 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, and a positive lens having a positive refractive power. It has a fourth lens group and a fifth lens group having negative refractive power. The distance between the first lens group and the second lens group is larger at the telephoto end than at the wide-angle end, the distance between the second lens group and the third lens group is small, and the distance between the third lens group and the fourth lens group is small. The lens group moves to zoom. The fifth lens group moves to the image plane side, thereby focusing from an infinitely distant object to a close object. In many cases, the positive lead type zoom lens has a large zoom ratio in the second lens group which is the main zoom lens group. In general, when the second lens group has a large zoom ratio, it is necessary to increase the change in the lens group interval during zooming of the first lens group and the second lens group in order to increase the zoom ratio. For this reason, the whole lens system tends to be enlarged. Therefore, in the zoom lens of the present invention, not only the main zoom lens group but also the subsequent lens group has a constant zoom ratio, thereby realizing a zoom lens having a high zoom ratio and a small size as a whole.

  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 longitudinal aberration diagrams at the wide-angle end and the telephoto end (long focal length end) of Embodiment 1 of the present invention. 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 longitudinal aberration diagrams at the wide-angle end and the telephoto end of Example 2 of the present invention. 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 and 6B are longitudinal aberration diagrams of the third embodiment of the present invention at the wide-angle end and the telephoto end. 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 and 8B are longitudinal aberration diagrams at the wide-angle end and the telephoto end of Example 4 of the present invention. FIG. 9 is a lens cross-sectional view at the wide-angle end of the zoom lens according to Embodiment 5 of the present invention. FIGS. 10A and 10B are longitudinal aberration diagrams of the fifth embodiment of the present invention at the wide-angle end and the telephoto end. FIG. 11 is a lens cross-sectional view at the wide-angle end of the zoom lens according to Embodiment 6 of the present invention. FIGS. 12A and 12B are longitudinal aberration diagrams of the sixth embodiment of the present invention at the wide-angle end and the telephoto end. FIG. 13 is a schematic diagram of a main part of a video camera (imaging device) including the zoom lens of the present invention.

  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 is a photographic lens system used in an imaging apparatus such as a video camera or a digital camera. In the lens cross-sectional view, L1 is a first lens group having a positive refractive power, L2 is a second lens group having a negative refractive power, L3 is a third lens group having a positive refractive power, and L4 is a positive refractive power. L5 is a fifth lens group having negative refractive power. L6 is a sixth lens unit having a positive refractive power. Here, the refractive power is optical power = reciprocal of focal length. SP is an aperture stop, which is disposed on the object side of the third lens unit L3. IP is an image plane. When used as a photographing optical system for a video camera or a digital still camera, an imaging surface of a solid-state imaging device (photoelectric conversion device) such as a CCD sensor or a CMOS sensor, or a camera for a silver salt film It corresponds to a photosensitive surface such as a film surface. In the spherical aberration diagram, the solid line, the two-dot chain line, and the dotted line are the d-line (wavelength 587.56 nm), g-line (wavelength 435.8 nm), and sine condition, respectively. In the astigmatism diagram, a dotted line and a solid line are a meridional image plane and a sagittal image plane for the d line, respectively. The lateral chromatic aberration is represented by the g-line. Fno is the F number, and ω is the half angle of view. In each of the following embodiments, zooming when the wide-angle end and the telephoto end are located at both ends of the range in which the zooming lens group (for example, the second and third lens groups L2 and L3) can move on the optical axis on the mechanism Says the position. The arrows indicate the movement trajectory of each lens unit and the movement direction during focusing during zooming from the wide-angle end to the telephoto end.

  In the zoom lenses of Examples 1, 2, 4 to 6, in order from the object side to the image side, the first lens unit L1 having a positive refractive power, the second lens unit L2 having a negative refractive power, and the third lens having a positive refractive power. The lens unit L3 includes a fourth lens unit L4 having a positive refractive power and a fifth lens unit L5 having a negative refractive power. During zooming from the wide-angle end to the telephoto end, the first to fifth lens units L1 to L5 are moved to the object side as indicated by arrows. In Examples 1, 4, and 5, each lens group is moved as follows during zooming from the wide-angle end to the telephoto end. The distance between the first lens group L1 and the second lens group L2 is large, the distance between the second lens group L2 and the third lens group L3 is small, and the distance between the third lens group L3 and the fourth lens group L4 is small. Each lens group is moved. The aperture stop SP moves together with the third lens unit L3. The fifth lens unit L5 is moved non-linearly so as to correct the change of the image point due to zooming. Further, a rear focus type is employed in which the fifth lens unit L5 is moved on the optical axis for focusing. For example, focusing from an infinitely distant object to a close object at the telephoto end is performed by moving the fifth lens unit L5 to the image side, as indicated by a straight line 5c in FIGS. Further, the solid line 5a and the dotted line 5b, which are the movement trajectories of the fifth lens unit L5, correct image plane fluctuations accompanying zooming from the wide-angle end to the telephoto end when focusing on an object at infinity and an object at close distance, respectively. The movement locus for this is shown. As described above, the movement locus in zooming of the fifth lens unit L5 differs depending on the object distance.

  In Examples 2 and 6, each lens unit is moved as follows during zooming from the wide-angle end to the telephoto end. The distance between the first lens group L1 and the second lens group L2 is large, the distance between the second lens group L2 and the third lens group L3 is small, and the distance between the third lens group L3 and the fourth lens group L4 is small. Each lens group is moved. In addition, the fourth lens unit L4 and the fifth lens unit L5 are moved so as to form a convex locus on the image plane side. The aperture stop SP is moved integrally with the third lens unit L3. During zooming and focusing, the fifth lens unit L5 moves in the same manner as in the first and fifth embodiments. The zoom lens of Embodiment 3 is different from the zoom lenses of Embodiments 1, 2, 4 to 6 in that a sixth lens unit L6 having a positive refractive power is disposed on the image side of the fifth lens unit L5. Is different. In Example 3, during zooming from the wide-angle end to the telephoto end, the distance between the first lens group L1 and the second lens group L2 is large, the distance between the second lens group L2 and the third lens group L3 is small, and the third lens. Each lens group is moved so that the distance between the group L3 and the fourth lens group L4 is small. The fourth lens unit L4 and the fifth lens unit L5 are moved so as to have a convex locus on the image plane side. The aperture stop SP is moved integrally with the third lens unit L3. During zooming and focusing, the fifth lens unit L5 moves in the same manner as in the first and fifth embodiments. In Example 3, the sixth lens unit L6 having a positive refractive power is arranged to increase the imaging magnification of the fifth lens unit L5 and to reduce the amount of movement of the fifth lens unit L5 during focusing. ing. The sixth lens unit L6 does not move for zooming.

  The zoom lens of each embodiment has a large interval between the first lens unit L1 and the second lens unit L2 and a small interval between the second lens unit L2 and the third lens unit L3 during zooming from the wide-angle end to the telephoto end. The distance between the third lens unit L3 and the fourth lens unit L4 is made small. Thereby, each lens group contributes to zooming, and a high zoom ratio is facilitated. Further, during zooming from the wide-angle end to the telephoto end, the first lens unit L1 is moved to the object side. For this reason, the total lens length at the wide-angle end is shortened so as to have a retrofocus type tendency at the wide-angle end and a telephoto type tendency at the telephoto end. Focusing is performed by moving the fifth lens unit L5 having negative refractive power. When the fifth lens unit L5 having negative refractive power is arranged, the magnification of the negative fifth lens unit L5 is larger than 1, so that the focus from the reference distance object to the short distance object is applied to the fifth lens group on the image plane. Will be moved to the side. In the case of a five-unit zoom lens, the fifth lens unit L5 is positioned closest to the image side, so that the amount of movement of the zoom unit is not limited due to the need to secure a space for focusing, and a high zoom ratio can be achieved. The lens configuration is advantageous for making the system compact.

In each embodiment, the imaging lateral magnification (magnification) of the i-th lens group at the telephoto end is βiT, and the imaging lateral magnification of the i-th lens group at the wide-angle end is βiW. The lens group that is closest to the image plane side is the k-th lens group. ZR = (β3T × β4T ×... × βkT) / (β3W × β4W ×... × βkW) is the combined zoom ratio ZR of the lens unit existing on the image plane side from the second lens unit L2.
And At this time,
−2.0 <β2T <−0.85 (1)
ZR> 2.0 (2)
The following conditional expression is satisfied. Conditional expression (1) relates to the magnification (imaging lateral magnification) of the second lens unit L2 at the telephoto end. If the upper limit of conditional expression (1) is exceeded, the change in the distance between the first lens unit L1 and the second lens unit L2 due to zooming increases, and the amount of extension of the first lens unit L1 at the telephoto end becomes too large. Is not preferable because it becomes complicated. Exceeding the lower limit of conditional expression (1) is not preferable because the refractive power of the first lens unit L1 becomes too strong, and spherical aberration and coma increase at the telephoto end. Conditional expression (2) relates to the combined zoom ratio by the lens unit existing on the image plane side from the second lens unit L2. If the lower limit of conditional expression (2) is exceeded, it will be difficult to increase the zoom ratio in the entire system, and it will be difficult to increase the zoom ratio. More preferably, the numerical ranges of conditional expressions (1) and (2) should be as follows.

−1.6 <β2T <−0.9 (1a)
ZR> 2.2 (2a)
The effects of conditional expressions (1a) and (2a) are the same as those of conditional expressions (1) and (2). Conditional expression (2a) is more preferably 3.20>ZR> 2.22 (2b)
It is good to do.

According to each embodiment, by configuring as described above, it is possible to obtain a zoom lens having a small overall optical system and high optical performance over the entire zoom range. In each embodiment, it is more preferable to satisfy one or more of the following conditions. The zoom ratio Z2 of the second lens unit L2 is Z2 = β2T / β2W
And The focal length of the i-th lens group is fi, and the focal length of the entire system at the wide angle end is fw. The air spaces between the fourth lens unit L4 and the fifth lens unit L5 at the wide-angle end and the telephoto end are D4W and D4T, respectively.

At this time,
1.5 <β5T <4.5 (3)
Z2> 4.0 (4)
1.7 <Z2 / ZR <3.0 (5)
f1 / fw> 3.2 (6)
f2 / fw <−0.65 (7)
D4T / D4W <0.28 (8)
0.10 <f4 / f3 <0.64 (9)
It is preferable to satisfy one or more of the following conditional expressions. Conditional expression (3) relates to the imaging lateral magnification of the fifth lens unit L5. If the imaging lateral magnification β5T becomes smaller than the lower limit of conditional expression (3), the focus sensitivity of the fifth lens unit L5 becomes too small at the telephoto end, and the amount of movement necessary for focusing becomes too large. For this reason, it becomes difficult to focus on a short-distance object. If the upper limit is exceeded, the refractive power of the fifth lens unit L5 becomes too large, and correction of various aberrations becomes extremely difficult. More preferably, the numerical range of conditional expression (3) should be set as follows.

2.5 <β5T <4.2 (3a)
The effect of conditional expression (3a) is the same as that of conditional expression (3). Conditional expression (4) relates to the zoom ratio of the second lens unit L2. If the lower limit of conditional expression (4) is exceeded, it will be difficult to achieve a high zoom ratio. More preferably, conditional expression (4) should be as follows.

Z2> 4.4 (4a)
The effect of conditional expression (4a) is the same as that of conditional expression (4). More preferably 7.00>Z2> 4.41 (4b)
It is good to do. Conditional expression (5) relates to the variable magnification ratio sharing between the second lens unit L2 and the subsequent lens unit. If the upper limit of conditional expression (5) is exceeded, the variable magnification ratio sharing of the second lens unit L2 becomes too large, and it becomes difficult to correct aberration variations in the second lens unit L2. If the lower limit is exceeded, the magnification ratio sharing by the subsequent lens group becomes too large, and aberrations that occur outside the second lens group L2 become large, making it difficult to correct these. More preferably, the numerical range of conditional expression (5) is set to be as follows.

1.72 <Z2 / ZR <2.90 (5a)
Conditional expression (6) relates to the refractive power of the first lens unit L1. If the lower limit of conditional expression (6) is exceeded, the refractive power of the first lens unit L1 becomes too strong, and spherical aberration and coma increase particularly at the telephoto end, making it difficult to correct these. More preferably, the numerical value of conditional expression (6) should be as follows.

f1 / fw> 4.2 (6a)
The effect of conditional expression (6a) is the same as that of conditional expression (6). More preferably, conditional expression (6a) should be as follows.

6.5> f1 / fw> 4.3 (6b)
Conditional expression (7) relates to the refractive power of the second lens unit L2. Exceeding the lower limit of conditional expression (7) is not preferable because the refractive power of the second lens unit L2 becomes too strong and fluctuations in various aberrations accompanying zooming become large. More preferably, the numerical value of conditional expression (7) should be as follows.

f2 / fw <−0.7 (7a)
The effect of conditional expression (7a) is the same as that of conditional expression (7). More preferably, conditional expression (7a) should be as follows.

−0.95 <f2 / fw <−0.72 (7b)
Conditional expression (8) relates to a change in the distance between the third lens unit L3 and the fourth lens unit L4 during zooming. Exceeding the upper limit of conditional expression (8) is not preferable because a sufficient zoom ratio cannot be obtained in the subsequent lens group. More preferably, the numerical value of conditional expression (8) should be set as follows.

0.05 <D4T / D4W <0.28 (8a)
Conditional expression (9) relates to the ratio of refractive powers of the third lens unit L3 and the fourth lens unit L4. When the upper limit of conditional expression (9) is exceeded, the refractive power of the fourth lens unit L4 becomes too small, and the tendency of the retrofocus type is weakened. As a result, it is not preferable because it is difficult to lengthen the back focus at the wide-angle end and correct various aberrations. On the other hand, if the lower limit is exceeded, the moving amount of the first lens unit L1 must be increased in order to make the entire system telephoto at the telephoto end, and the refractive power of the first lens unit L1 must be increased. . More preferably, the numerical range of the conditional expression (9) is set to the following.

0.20 <f4 / f3 <0.55 (9a)
The effect of conditional expression (9a) is the same as that of conditional expression (9). As described above, according to each embodiment, it is possible to obtain a small zoom lens having a high zoom ratio and a wide angle region and having good optical performance in the entire zoom range and the entire object distance range. In addition, in each embodiment, the first lens unit L1 includes a cemented lens in which a negative meniscus lens having a convex surface facing the object side and a positive lens are cemented, and a meniscus positive lens having a convex surface facing the object side. Have. Thereby, coma aberration, spherical aberration at the telephoto end, etc. are corrected well. The second lens unit L2 has, in order from the object side to the image side, a meniscus negative lens having a convex surface facing the object side, a negative lens having both concave surfaces, and a positive lens having both convex surfaces. Yes. Thereby, aberration variation is reduced in the entire zoom range, and good optical performance is achieved. In addition, it is desirable that the second lens unit L2 has an aspherical lens in which at least one surface has an aspherical shape. This facilitates correction of field curvature at the wide-angle end. In particular, it is more desirable that the most object side lens surface of the second lens unit L2 be aspherical.

  The third lens unit L3 includes, in order from the object side to the image side, a positive lens, a cemented lens in which a meniscus negative lens and a positive lens having convex surfaces are cemented, and a cemented lens having negative refractive power as a whole. have. This suppresses the occurrence of spherical aberration in the third lens unit L3 having a high incident height of axial rays. In addition, the lens configuration of the third lens unit L3 can be a telephoto type by disposing a bonded lens having a negative refractive power as a whole on the image plane side. For this reason, the space for zooming of the second lens unit L2 is increased to facilitate a high zoom ratio. The third lens unit L3 preferably includes an aspheric lens having at least one aspheric surface. This facilitates correction of spherical aberration in the entire zoom range. The fourth lens unit L4 includes a positive lens, a cemented lens in which a positive lens and a meniscus negative lens having a convex surface facing the image surface are cemented. The fourth lens unit L4 preferably includes an aspheric lens having at least one aspheric surface. This facilitates correction of distortion at the wide angle end. The fifth lens unit L5 includes a cemented lens in which a positive lens and a negative lens having a concave surface facing the image surface are cemented. This suppresses aberration fluctuation due to focus. In addition, since the number of lenses in the lens group that performs focusing is small, quicker focusing becomes easier. You may make it have the 6th lens group L6 of positive refractive power in the image side of the 5th lens group L5. According to this, the imaging magnification of the fifth lens unit L5 can be increased, and the amount of movement of the fifth lens unit L5 during focusing can be reduced over the entire object distance.

Next, numerical examples 1 to 6 corresponding to the first to sixth embodiments of the present invention will be described. In each numerical example, i indicates the number of the surface counted from the object side. ri is the radius of curvature of the i-th optical surface (i-th surface). di is the axial distance between the i-th surface and the (i + 1) -th surface. ndi and νdi are the refractive index and Abbe number of the material of the i-th optical member with respect to the d-line, respectively. The focal length and F number are shown for wide angle (wide angle end), middle (intermediate zoom position), and telephoto (telephoto end). An aspherical surface is marked with * next to the surface number. The paraxial radius of curvature is R, the eccentricity is K, and the aspheric coefficients are A2, A4, A6, A8, and A10. When 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 ] + A 2 · H ² + A 4 · H ⁴ + A 6 · H ⁶ + A 8 · H ⁸ + A 10 · H ¹⁰
It is represented by Note that “E ± XX” in each aspheric coefficient means “× 10 ± XX”. Table 1 shows the correspondence with the above-described conditional expressions in each numerical example. Table 2 shows the focal length of each lens unit in each numerical example.

[Numerical Example 1]
Wide angle Medium Telephoto focal length 18.63 62.47 271.55
F number 3.10 4.85 5.88
Angle of view 36.25 12.33 2.88
d 5 0.38 26.46 58.50
d13 34.08 16.25 1.76
d22 9.70 3.15 1.14


Surface data surface number rd nd νd
1 126.641 1.35 1.74950 35.3
2 58.919 8.72 1.49700 81.5
3 -356.314 0.08
4 54.866 5.32 1.49700 81.5
5 277.257 (variable)
6 * 65.890 1.33 1.77250 49.6
7 15.628 7.54
8 -38.780 0.98 1.81600 46.6
9 108.366 0.15
10 29.465 4.79 1.84666 23.9
11 -55.763 1.16
12 -30.342 0.97 1.77250 49.6
13 73.952 (variable)
14 (Aperture) ∞ 0.66
15 30.615 2.86 1.48749 70.2
16 * 228.864 0.08
17 25.006 1.41 1.80809 22.8
18 17.418 5.10 1.48749 70.2
19 -72.689 1.10
20 * -80.758 1.66 1.75562 51.3
21 14.380 3.78 1.74950 35.3
22 53.947 (variable)
23 * 40.952 4.45 1.60 300 65.4
24 -31.103 0.26
25 60.716 5.06 1.49700 81.5
26 -21.561 2.07 1.84666 23.9
27 -44.374 0.45
28 405.087 2.44 1.92286 18.9
29 -58.212 1.32 1.88300 40.8
30 28.655


Aspheric data 6th surface
K = 0.00000e + 000 A 4 = 8.85222e-008 A 6 = 6.36381e-009 A 8 = -2.73075e-011 A10 = 5.61055e-014

16th page
K = 0.00000e + 000 A 4 = 1.51665e-005 A 6 = -2.49724e-009 A 8 = 1.76128e-010 A10 = -6.89658e-013

20th page
K = 0.00000e + 000 A 4 = 6.59751e-006 A 6 = -1.85615e-008 A 8 = 2.00223e-010 A10 = -7.17867e-013

23rd page
K = 0.00000e + 000 A 4 = -1.82328e-005 A 6 = 1.65842e-008 A 8 = 1.59532e-011 A10 = -1.19232e-013

[Numerical Example 2]
Wide angle Medium Telephoto focal length 18.01 57.48 260.00
F number 3.32 5.08 5.88
Angle of view 37.19 13.37 3.01
d 5 0.38 19.26 46.57
d13 32.66 14.87 1.98
d22 7.83 3.77 1.65
d27 2.52 3.36 0.45

Surface data surface number rd nd νd
1 88.041 1.35 2.00330 28.3
2 55.215 9.96 1.49700 81.5
3 -508.198 0.08
4 48.889 5.21 1.60300 65.4
5 206.674 (variable)
6 * 83.941 1.33 1.77250 49.6
7 15.573 8.03
8 -38.816 0.98 1.81600 46.6
9 58.359 0.15
10 30.783 5.45 1.84666 23.9
11 -41.568 1.14
12 -26.930 0.97 1.77250 49.6
13 100.170 (variable)
14 (Aperture) ∞ 0.66
15 25.541 3.15 1.48749 70.2
16 * -3012.970 0.10
17 35.087 1.47 1.84666 23.9
18 22.820 3.80 1.49700 81.5
19 -118.718 1.61
20 * -40.715 1.66 1.77250 49.6
21 14.139 4.65 1.74950 35.3
22 199.733 (variable)
23 * 55.299 4.54 1.60 300 65.4
24 -30.787 0.96
25 44.500 5.47 1.48749 70.2
26 -18.750 1.76 1.84666 23.9
27 -38.586 (variable)
28 378.207 2.19 1.92286 18.9
29 -68.510 1.27 1.88300 40.8
30 31.634

Aspheric data 6th surface
K = 0.00000e + 000 A 4 = 3.23962e-007 A 6 = 4.07860e-009 A 8 = -2.28206e-011 A10 = 4.08809e-014

16th page
K = 0.00000e + 000 A 4 = 1.38369e-005 A 6 = -1.32457e-008 A 8 = 4.90002e-010 A10 = -2.23123e-012

20th page
K = 0.00000e + 000 A 4 = 9.96644e-006 A 6 = -4.11960e-008 A 8 = 5.14339e-010 A10 = -1.83818e-012

23rd page
K = 0.00000e + 000 A 4 = -1.38115e-005 A 6 = 3.73660e-008 A 8 = -4.30926e-011 A10 = 1.79388e-013

[Numerical Example 3]
Wide angle Medium telephoto focal length 18.64 53.91 271.53
F number 3.38 4.83 5.88
Angle of view 36.24 14.22 2.88
d 5 0.38 24.88 58.67
d13 38.80 20.94 2.22
d22 8.30 4.35 1.17
d27 0.44 1.80 0.55
d30 3.89 30.92 51.39

Surface data surface number rd nd νd
1 120.744 1.35 1.74950 35.3
2 58.787 8.47 1.49700 81.5
3 -351.293 0.08
4 56.465 5.35 1.49700 81.5
5 304.464 (variable)
6 * 171.064 1.33 1.77250 49.6
7 17.627 7.19
8 -58.477 0.98 1.77250 49.6
9 102.821 0.15
10 27.251 4.85 1.84666 23.9
11 -162.186 0.85
12 -64.955 0.97 1.77250 49.6
13 42.113 (variable)
14 (Aperture) ∞ 0.66
15 25.377 2.39 1.48749 70.2
16 * 61.889 0.10
17 29.492 1.43 1.84666 23.9
18 21.258 4.04 1.51633 64.1
19 -64.743 1.44
20 * -37.299 1.66 1.59021 65.9
21 23.037 2.13 1.74950 35.3
22 44.101 (variable)
23 * 40.145 4.43 1.60300 65.4
24 -27.966 0.27
25 80.573 4.68 1.49700 81.5
26 -21.423 1.67 1.84666 23.9
27 -46.218 (variable)
28 -216.102 2.14 1.90933 19.6
29 -50.235 1.24 1.81600 46.6
30 29.372 (variable)
31 -10952.216 3.00 1.48749 70.2
32 -60.605

Aspheric data 6th surface
K = 0.00000e + 000 A 4 = -3.94197e-007 A 6 = 4.85327e-009 A 8 = -1.66645e-011 A10 = 1.50163e-014

16th page
K = 0.00000e + 000 A 4 = 1.39928e-005 A 6 = -1.72084e-009 A 8 = 4.87058e-010 A10 = -2.19495e-012

20th page
K = 0.00000e + 000 A 4 = 8.97550e-006 A 6 = -1.37873e-008 A 8 = 2.14476e-010 A10 = -9.73716e-013

23rd page
K = 0.00000e + 000 A 4 = -2.19370e-005 A 6 = 1.08104e-008 A 8 = 1.45068e-010 A10 = -8.03880e-013

[Numerical Example 4]
Wide angle Medium telephoto focal length 16.55 56.69 242.48
F number 3.09 4.81 5.88
Angle of view 39.54 13.55 3.22
d 5 0.38 27.21 58.52
d13 32.28 14.46 1.47
d22 9.90 3.52 1.19

Surface number rd nd νd
1 120.227 1.35 1.74950 35.3
2 57.757 10.24 1.49700 81.5
3 -404.565 0.08
4 54.940 5.43 1.49700 81.5
5 294.621 (variable)
6 * 103.279 1.33 1.77250 49.6
7 14.738 7.76
8 -42.114 0.98 1.81600 46.6
9 88.149 0.15
10 29.666 5.20 1.84666 23.9
11 -57.905 0.91
12 -35.716 0.97 1.77250 49.6
13 83.646 (variable)
14 (Aperture) ∞ 0.66
15 27.330 2.82 1.48749 70.2
16 * 77.059 0.26
17 24.746 2.09 1.78470 26.3
18 16.506 4.70 1.48749 70.2
19 -79.603 1.20
20 * -69.769 1.66 1.76291 51.2
21 14.390 4.12 1.74950 35.3
22 58.545 (variable)
23 * 42.860 4.55 1.60 300 65.4
24 -31.400 0.43
25 58.262 5.54 1.49700 81.5
26 -19.235 2.67 1.84666 23.9
27 -35.997 0.45
28 218.765 2.77 1.92286 18.9
29 -87.152 1.32 1.88300 40.8
30 31.041

Aspheric data 6th surface
K = 0.00000e + 000 A 4 = 7.39183e-007 A 6 = 6.78728e-009 A 8 = -3.00714e-011 A10 = 1.61197e-014

16th page
K = 0.00000e + 000 A 4 = 1.71917e-005 A 6 = -4.70363e-009 A 8 = 1.36153e-010 A10 = -7.17468e-014

20th page
K = 0.00000e + 000 A 4 = 7.28701e-006 A 6 = -1.50379e-008 A 8 = 1.92961e-010 A10 = -6.25677e-013

23rd page
K = 0.00000e + 000 A 4 = -1.62695e-005 A 6 = 2.24495e-008 A 8 = 1.99040e-012 A10 = 1.14234e-013

[Numerical Example 5]
Wide angle Medium telephoto focal length 18.54 63.03 271.54
F number 3.27 4.99 5.88
Angle of view 36.38 12.23 2.88
d 5 0.38 32.96 71.85
d13 32.65 14.83 2.33
d22 12.47 3.84 0.98

Surface data surface number rd nd νd
1 131.604 1.35 1.74950 35.3
2 65.291 7.37 1.49700 81.5
3 -702.345 0.08
4 65.218 4.99 1.49700 81.5
5 364.514 (variable)
6 * 55.591 1.33 1.77250 49.6
7 16.542 7.67
8 -43.193 0.98 1.81600 46.6
9 78.106 0.05
10 29.420 4.52 1.84666 23.9
11 -59.349 1.93
12 -26.265 0.97 1.77250 49.6
13 87.916 (variable)
14 (Aperture) ∞ 0.66
15 35.405 2.64 1.48749 70.2
16 * -137.713 0.01
17 30.763 1.44 1.80809 22.8
18 20.416 4.69 1.48749 70.2
19 -40.590 0.96
20 * -45.681 1.66 1.70000 48.1
21 25.533 2.18 1.84666 23.8
22 55.234 (variable)
23 * 112.010 3.32 1.61800 63.3
24 -34.365 0.20
25 93.454 4.35 1.49700 81.5
26 -26.396 1.74 1.84666 23.9
27 -171.723 1.00
28 -154.177 3.23 1.76200 40.1
29 -30.530 0.45
30 126.548 2.96 1.84666 23.9
31 -43.538 1.35 1.88300 40.8
32 29.863

Aspheric data 6th surface
K = 0.00000e + 000 A 4 = 1.46281e-006 A 6 = 9.66485e-009 A 8 = -4.57867e-011 A10 = 1.57972e-013

16th page
K = 0.00000e + 000 A 4 = 1.27772e-005 A 6 = 2.23979e-008 A 8 = -2.99813e-010 A10 = 1.91078e-012

20th page
K = 0.00000e + 000 A 4 = 5.92286e-006 A 6 = -4.63496e-009 A 8 = 3.19538e-011 A10 = -4.22086e-014

23rd page
K = 0.00000e + 000 A 4 = -2.11736e-005 A 6 = 1.50553e-009 A 8 = -5.32365e-011 A10 = 3.02288e-013

[Numerical Example 6]
Wide angle Medium telephoto focal length 18.29 61.80 207.19
F number 3.31 5.06 5.88
Angle of view 36.75 12.46 3.77
d 5 0.38 26.36 55.66
d13 32.52 12.53 0.97
d22 7.52 3.06 2.04
d29 1.57 2.00 0.45

Surface data surface number rd nd νd
1 125.854 1.35 1.74950 35.3
2 58.876 8.51 1.49700 81.5
3 -341.062 0.08
4 55.551 4.51 1.49700 81.5
5 292.313 (variable)
6 * 74.376 1.33 1.77250 49.6
7 16.082 7.80
8 -33.548 0.98 1.81600 46.6
9 118.462 0.15
10 40.406 4.61 1.84666 23.9
11 -41.718 1.25
12 -25.943 0.97 1.77250 49.6
13 -393.081 (variable)
14 (Aperture) ∞ 0.66
15 29.124 2.63 1.48749 70.2
16 * 179.437 2.35
17 36.679 4.10 1.48749 70.2
18 -29.192 1.44 1.66680 33.0
19 -213.782 1.13
20 * -101.689 1.66 1.77085 49.3
21 17.288 3.13 1.74950 35.3
22 74.165 (variable)
23 * 67.845 4.27 1.60 300 65.4
24 -28.620 0.28
25 73.950 5.06 1.49700 81.5
26 -21.281 1.71 1.66680 33.0
27 -298.678 0.00
28 69.998 3.20 1.48749 70.2
29 -98.101 (variable)
30 77.140 2.84 1.84666 23.9
31 -85.855 1.35 1.88300 40.8
32 28.318

Aspheric data 6th surface
K = 0.00000e + 000 A 4 = 3.52443e-006 A 6 = 1.85345e-009 A 8 = -2.69201e-011 A10 = 9.22124e-014

16th page
K = 0.00000e + 000 A 4 = 1.40188e-005 A 6 = 1.45497e-008 A 8 = -2.17178e-010 A10 = 1.61108e-012

20th page
K = 0.00000e + 000 A 4 = 5.27751e-006 A 6 = -4.34088e-009 A 8 = 1.41238e-010 A10 = -8.46623e-013

23rd page
K = 0.00000e + 000 A 4 = -1.18065e-005 A 6 = 1.84074e-008 A 8 = -1.87876e-010 A10 = 1.00320e-012

Next, an embodiment of a digital camera using a zoom lens as shown in each example as a photographing optical system will be described with reference to FIG. In FIG. 13, reference numeral 20 denotes a camera body, and 21 denotes an imaging optical system constituted by the zoom lens of the present invention. Reference numeral 22 denotes a solid-state imaging device such as a CCD that receives a subject image formed by the imaging optical system 21. Reference numeral 23 denotes a recording means for recording a subject image received by the solid-state imaging device 22, and reference numeral 24 denotes a finder for observing the 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 solid-state image sensor 22 is displayed. In this way, by applying the zoom lens of the present invention to an optical apparatus such as a video camera, an imaging apparatus having a high zoom ratio and a small zoom lens of the entire system 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.

L1 is a first lens group, L2 is a second lens group, L3 is a third lens group, L4 is a fourth lens group, L5 is a fifth lens group, SP is an aperture stop or light amount adjusting device, IP is an image plane, d Is d line, g is g line, dotted line is sine condition, ΔS is sagittal image plane, ΔM is meridional image plane

Claims (15)

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 group having a positive refractive power, and a negative lens group A fifth lens unit having a refractive power, wherein the distance between the first lens unit and the second lens unit is larger at the telephoto end than at the wide-angle end, and the interval between the second lens unit and the third lens unit is small; The lens group moves so that the distance between the third lens group and the fourth lens group becomes small, and the fifth lens group moves to the image plane side during focusing from an object at infinity to an object at a short distance. The imaging lateral magnification of the i lens group is βiT, the imaging lateral magnification of the i-th lens group at the wide-angle end is βiW, the lens group that is closest to the image plane is the k-th lens group, and the image is taken from the second lens group. The combined zoom ratio ZR of the lens group existing on the surface side is ZR = (β3T × β4T ×... × βkT) / (β3 W × β4W × ... × βkW)
And when
−2.0 <β2T <−0.85
ZR> 2.0
A zoom lens satisfying the following conditional expression: The imaging magnification β5T at the telephoto end of the fifth lens group is
1.5 <β5T <4.5
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. The zoom ratio Z2 of the second lens group is Z2 = β2T / β2W
And when
Z2> 4.0
The zoom lens according to claim 1 or 2, wherein the following conditional expression is satisfied. The zoom ratio Z2 of the second lens group is Z2 = β2T / β2W
And when
1.7 <Z2 / ZR <3.0
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the focal length of the first lens group is f1, and the focal length of the entire system at the wide angle end is fw,
f1 / fw> 3.2
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the focal length of the second lens group is f2, and the focal length of the entire system at the wide angle end is fw,
f2 / fw <−0.65
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the air spaces between the fourth lens group and the fifth lens group at the wide-angle end and the telephoto end are D4W and D4T, respectively.
D4T / D4W <0.28
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the focal length of the i-th lens group is fi,
0.10 <f4 / f3 <0.64
The zoom lens according to claim 1, wherein the following conditional expression is satisfied.   The first lens group includes a cemented lens in which a meniscus negative lens having a convex surface facing the object side and a positive lens are cemented, and a meniscus positive lens having a convex surface facing the object side. The zoom lens according to claim 1.   The second lens group includes, in order from the object side to the image side, a meniscus negative lens with a convex surface facing the object side, a negative lens with both lens surfaces concave, and a positive lens with both lens surfaces convex. The zoom lens according to claim 1, wherein the zoom lens is a zoom lens.   The third lens group includes, in order from the object side to the image side, a positive lens, a cemented lens in which a meniscus negative lens and a positive lens having convex surfaces are cemented, and a cemented lens having a negative refractive power as a whole. The zoom lens according to claim 1, comprising:   12. The fourth lens group according to claim 1, wherein the fourth lens group includes a positive lens, a cemented lens in which a positive lens and a meniscus negative lens having a convex surface facing the image surface side are cemented. Zoom lens of the term.   The zoom lens according to any one of claims 1 to 12, wherein the fifth lens group includes a cemented lens in which a positive lens and a negative lens having a concave surface facing the image surface side are cemented together.   14. The zoom lens according to claim 1, further comprising a sixth lens group having a positive refractive power on the image side of the fifth lens group.   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.