JP6452405B2 - Zoom lens and imaging apparatus having the same - Google Patents

Description

  The present invention relates to a zoom lens, and is suitable as an imaging optical system used in an imaging apparatus such as a digital still camera, a video camera, a surveillance camera, a broadcast camera, and a silver salt film camera.

  In recent years, an image pickup apparatus using a solid-state image pickup element has a large solid-state image pickup element, and accordingly, the function of the image pickup apparatus has been enhanced, and the entire apparatus has been downsized. As an imaging optical system used therefor, there is a demand for a zoom lens having a bright, wide angle of view at the wide-angle end, a high zoom ratio, and high optical performance over the entire zoom range. As one of the zoom lenses that satisfy these requirements, there is a five-unit zoom lens including first to fifth lens units having positive, negative, positive, negative, and positive refractive powers in order from the object side to the image side. Known (Patent Documents 1 and 2).

  Patent Document 1 discloses a zoom lens having a zoom ratio of about 10 in which the first to third lens groups and the fifth lens group move during zooming. Patent Document 2 discloses a zoom lens having a zoom ratio of about 5 in which each lens group moves during zooming and a fourth lens group moves during focusing.

JP 2007-264174 A JP 2013-117667 A

  The above-described five-group zoom lens having a refractive power arrangement is relatively easy to obtain high optical performance while achieving a large aperture ratio, a wide angle of view, and a high zoom ratio while reducing the size of the entire system. However, increasing the focal length at the telephoto end while increasing the aperture ratio, and further increasing the zoom ratio, increases various aberrations such as spherical aberration, astigmatism, and chromatic aberration, resulting in high optical performance. It becomes difficult to maintain. In particular, when the F-number is made small and brighter, various aberrations such as spherical aberration and coma increase at the telephoto end. Further, when attempting to widen the angle of view, the occurrence of various aberrations such as astigmatism and lateral chromatic aberration increases at the wide-angle end and the front lens diameter increases.

  In order to obtain high optical performance over the entire zoom range by reducing the size of the entire system while achieving a large aperture ratio, a wide angle of view, and a high zoom ratio in a 5-group zoom lens, the refractive power of each lens group Set the lens configuration appropriately. It is important to appropriately set the movement conditions associated with zooming of each lens group. For example, it is important to appropriately set the amount of movement of the first lens unit during zooming and the lens configuration of the third lens unit having a positive refractive power. If these elements are not set appropriately, the entire system will be reduced in size, and it will be very difficult to obtain high optical performance over the entire zoom range with a large aperture ratio, wide angle of view and high zoom ratio.

  In the zoom lens of Patent Document 1, since the amount of movement of the first lens group is reduced assuming a retractable lens barrel, an attempt to increase the aperture ratio and wide angle of view increases the effective diameter of the front lens, The whole system becomes larger. Since the zoom lens of Patent Document 2 is a telephoto type whose shooting angle of view at the wide-angle end is about 30 degrees, when trying to widen the angle of view and increase the zoom ratio, the effective diameter of the front lens increases and the entire system becomes larger. Come.

  An object of the present invention is to provide a zoom lens in which the entire system can be easily obtained with 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 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, arranged in order from the object side to the image side. A zoom lens comprising a fourth lens group having a refractive power and a fifth lens group having a positive or negative refractive power, wherein the distance between adjacent lens groups changes during zooming,
The third lens group has four or more lenses.
In the third lens group, the lens arranged closest to the image side, the second lens counted from the image side, and the third lens counted from the image side are arranged with air separated from each other. The focal length of the entire system at the end is ft, the focal length of the entire system at the wide-angle end is fw, the focal length of the fourth lens group is f4, and the amount of movement of the first lens group in zooming from the wide-angle end to the telephoto end is M1, the sign of the amount of movement when the lens group is located on the object side at the telephoto end compared to the wide-angle end is negative, the sign of the amount of movement when the lens group is located on the image side is positive, and the most image in the third lens group When the curvature radii of the lens surface on the object side of the lens arranged on the side and the lens surface on the image side of the second lens counted from the image side are Ro31 and Ri32, respectively .
−0.8 <M1 / ft <−0.4
-15.00 <f4 / fw <-2.50
−0.08 <(Ro31−Ri32) / (Ro31 + Ri32) <0.05
It satisfies the following conditional expression.

  According to the present invention, it is possible to obtain a zoom lens having a small overall size, which can easily obtain high optical performance over a full zoom range with a large aperture ratio and a wide angle of view.

Lens cross-sectional view at the wide-angle end of the zoom lens of Example 1 (A), (B), (C) Various aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end of the zoom lens of Example 1. Lens sectional view at the wide-angle end of the zoom lens according to Embodiment 2 (A), (B), (C) Various aberration diagrams of the zoom lens of Example 2 at the wide-angle end, the intermediate zoom position, and the telephoto end. Lens sectional view at the wide-angle end of the zoom lens according to Embodiment 3 (A), (B), (C) Various aberration diagrams of the zoom lens of Example 3 at the wide-angle end, the intermediate zoom position, and the telephoto end. Lens sectional view at the wide-angle end of the zoom lens according to Embodiment 4 (A), (B), (C) Various aberration diagrams of the zoom lens of Example 4 at the wide-angle end, the intermediate zoom position, and the telephoto end (A), (B), (C) Optical path diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end of the zoom lens of Example 3 Main part schematic diagram as an example of imaging device

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The zoom lens according to the present invention includes 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, arranged in order from the object side to the image side. The lens unit includes a fourth lens unit having a refractive power and a fifth lens unit having a positive or negative refractive power. The distance between adjacent lens units 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, and FIGS. 2A, 2B, and 2C are respectively the wide-angle of the zoom lens according to Embodiment 1. FIG. 6 is an aberration diagram at an end, an intermediate zoom position, and a telephoto end (long focal length end). The zoom lens of Example 1 has a zoom ratio of 9.64 and an F number of 2.88 to 5.77.

  3 is a lens cross-sectional view at the wide-angle end of the zoom lens according to the second embodiment of the present invention. FIGS. 4A, 4B, and 4C are respectively the wide-angle end and the intermediate zoom position of the zoom lens according to the second embodiment. FIG. 6 is an aberration diagram at the telephoto end. The zoom lens of Example 2 has a zoom ratio of 9.56 and an F number of 2.88 to 5.77.

  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 respectively the wide-angle end and intermediate zoom position of the zoom lens according to Embodiment 3. FIG. 6 is an aberration diagram at the telephoto end. The zoom lens of Example 3 has a zoom ratio of 3.80 and an F number of 2.40 to 3.84.

  7 is a lens cross-sectional view at the wide-angle end of the zoom lens according to Embodiment 4 of the present invention. FIGS. 8A, 8B, and 8C are zoom positions at the wide-angle end and intermediate position of the zoom lens according to Embodiment 4, respectively. FIG. 6 is an aberration diagram at the telephoto end. The zoom lens of Example 4 has a zoom ratio of 3.80 and an F number of 2.88 to 4.86.

  FIGS. 9A, 9B, and 9C are optical path diagrams at the wide-angle end and the intermediate zoom position and the telephoto end of the zoom lens according to the third exemplary embodiment. FIG. 10 is a schematic view of the main part of the imaging apparatus of the present invention.

  The zoom lens of each embodiment is an imaging optical system used in an imaging apparatus such as a video camera, a digital camera, a surveillance camera, and a TV camera. 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, L1 is a first lens group having a positive refractive power (optical power = reciprocal of focal length), L2 is a second lens group having a negative refractive power, and L3 is a third lens group having a positive refractive power. , L4 is a fourth lens group having a negative refractive power, and L5 is a fifth lens group having a positive or negative refractive power.

  In Examples 1, 2, and 4, the refractive power of the fifth lens unit L5 is positive. In Example 3, the refractive power of the fifth lens unit L5 is negative. In the lens cross-sectional views of the respective embodiments, SP is an aperture stop that determines the light flux of the open F number, and is located on the object side of the third lens unit L3 or in the third lens unit L3. P is an optical block corresponding to an optical filter, a face plate, or the like. I denotes an image plane, which corresponds to an imaging plane of a solid-state imaging device (photoelectric conversion device) such as a CCD sensor or a CMOS sensor when used as an imaging optical system of a video camera or a digital camera. When used as an imaging optical system, it corresponds to a film surface.

  In the aberration diagrams, Fno is the F number, and ω is the half angle of view (degrees). In spherical aberration, d represents the d line (solid line), g represents the g line (dotted line), astigmatism, ΔM represents the meridional image plane at the d line, ΔS represents the sagittal image plane ΔS, and distortion aberration Indicates the d-line, and the chromatic aberration of magnification indicates the aberration of the g-line with respect to the d-line.

  In the lens cross-sectional view, the arrows indicate the moving directions when focusing from an infinitely distant object to a close object during zooming from the wide-angle end to the telephoto end. In each of the following embodiments, the wide-angle end and the telephoto end are zoom positions when the variable power lens unit is positioned at both ends of the range in which the zoom lens unit can be moved on the optical axis due to the mechanism.

  In the first and second embodiments, the first lens unit L1 to the fourth lens unit L4 move as indicated by arrows during zooming. The fifth lens unit L5 is stationary. In Examples 3 and 4, the first lens unit L1 to the fifth lens unit L5 move as indicated by arrows during zooming.

  In the first to fourth embodiments, a rear focus type is employed in which focusing is performed by moving the fourth lens unit L4 on the optical axis. A solid curve 4a and a dotted curve 4b relating to the fourth lens unit L4 are movement trajectories for correcting image plane fluctuations accompanying zooming when focusing on an object at infinity and an object at close distance, respectively. Further, when focusing from an infinitely distant object to a close object at the telephoto end, the fourth lens unit L4 is retracted to the image side as indicated by an arrow 4c.

  In the zoom lens of the present invention, in order from the object side to the image side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, the third lens group having a positive refractive power, and a negative lens having a negative refractive power. The fourth lens group includes a fifth lens group having positive or negative refractive power. With this configuration, the entire system is downsized and a high zoom ratio is achieved.

  The distance between the lens groups is changed during zooming. If the first lens unit L1 is not moved during zooming, movement of the lens units after the second lens unit L2 is restricted. As a result, the positive refracting power of the first lens group is strengthened, and magnification is mainly changed by changing the distance between the first lens group L1 and the second lens group L2. On the other hand, when the positive refractive power of the first lens unit L1 is strong, it is difficult to correct axial chromatic aberration and spherical aberration at the telephoto end with a small number of constituent lenses.

  Therefore, in the present invention, by moving the first lens unit L1 during zooming, the positive refractive power is shared by the third lens unit L3 having the same positive refractive power as that of the first lens unit L1. The zooming is efficiently performed by both the change in the distance between the first lens unit L1 and the second lens unit L2 and the change in the interval between the second lens unit L2 and the third lens unit L3. Further, in order to reduce the size of the entire system, it is effective to increase the refractive power of each lens group as a whole, but the number of constituent lenses increases to correct aberrations. In particular, in a lens group having a large effective diameter, the size and mass increase.

  Therefore, in the present invention, the number of constituent lenses of the third lens unit L3 having a relatively small effective lens diameter is set to four or more, and various aberrations are favorably corrected while suppressing an increase in size and mass. The three lenses on the image side of the third lens unit L3 are arranged with air interposed therebetween. That is, in the third lens unit L3, the lens arranged closest to the image side, the lens arranged second from the image side, and the lens arranged third from the image side are spaced apart from each other by an air space. And the lens located on the image side in the third lens unit L3 corrects curvature of field.

  At the same time, spherical aberration that was not sufficiently corrected by the lens located on the object side in the third lens unit L3 is corrected. In order to correct aberrations satisfactorily with a smaller number of constituent lenses, the three lenses from the image side in the third lens unit L3 are arranged with air in between, and the number of lens surfaces for correcting aberrations is increased. Further, although the lens located on the object side in the third lens unit L3 tends to increase in spherical aberration due to a manufacturing error, the spherical aberration can be reduced by adjusting the three air intervals from the image side in the third lens unit L3. It makes correction easy.

  The two lenses counted from the image side of the third lens unit L3 are composed of a positive lens and a negative lens in order from the object side to the image side, or a negative lens and a positive lens in order from the object side to the image side. In the third lens unit L3, a negative lens is arranged on the first lens or the second lens from the image side where the incident height of the off-axis light beam is increased to correct the lateral chromatic aberration. However, when a lens having a negative refractive power is disposed on the image side in the third lens unit L3, the positive refractive power is increased on the object side of the third lens unit L3, and spherical aberration and coma aberration increase.

  Therefore, in the present invention, the two lenses on the image side of the third lens unit L3 are a positive lens and a negative lens, and the third lens unit L3 prevents the positive refractive power from shifting toward the object side.

  Each light ray in the optical path diagram of FIG. 9 represents an on-axis light beam and an off-axis light beam when Example 3 is taken as an example. Each line indicating the luminous flux is the outermost ray of the luminous flux and the central ray of the luminous flux. From FIG. 9, in the zoom lens of the present invention, the axial light beam incident on the third lens unit L3 is thick throughout the zoom range, and the lens on the object side in the third lens unit L3 greatly contributes to correction of spherical aberration and coma. I understand.

  Therefore, if a lens having a negative refractive power is disposed on the image side in the third lens unit L3 and the positive refractive power is increased on the object side in the third lens unit L3, it is difficult to correct spherical aberration and coma aberration. It becomes. It can also be seen that as the distance from the third lens unit L3 toward the image side, the axial light beam and the off-axis light beam are separated and the incident height of the off-axis light beam increases, so that the contribution ratio to the lateral chromatic aberration increases. .

  The zoom lens according to the present invention is configured as described above, and corrects the lateral chromatic aberration well while suppressing the negative refractive power in the third lens unit L3 from being arranged on the image side. Further, the second lens and the third lens counted from the image side in the third lens unit L3 are separated with air interposed therebetween to effectively correct the lateral chromatic aberration.

For the above reasons, in the zoom lens according to the present invention, the third lens unit L3 includes four or more lenses, and the three lenses on the image side of the third lens unit L3 are arranged with an air gap therebetween. . Let ft be the focal length of the entire system at the telephoto end. The amount of movement of the first lens unit L1 during zooming from the wide-angle end to the telephoto end is M1 (the sign of the amount of movement is negative when the lens unit is located on the object side at the telephoto end compared to the wide-angle end, and located on the image side) Time is positive.) At this time,
−0.8 <M1 / ft <−0.4 (1)
The following conditional expression is satisfied.

  Next, the technical meaning of the above conditional expression will be described. Conditional expression (1) defines the ratio of the focal length of the entire system at the telephoto end to the amount of movement of the first lens unit L1 during zooming from the wide-angle end to the telephoto end. When the upper limit of conditional expression (1) is exceeded, the positive refractive power of the first lens unit L1 becomes strong in order to maintain a high zoom ratio, and it becomes difficult to correct axial chromatic aberration and spherical aberration at the telephoto end. Or the space | interval of the 2nd lens group L2 and the 3rd lens group L3 spreads, the entrance pupil position of a wide angle end becomes long, and when aiming at a wide angle of view, the front lens effective diameter increases.

  On the other hand, if the lower limit is exceeded, the total lens length (the value obtained by adding a back focus in terms of air to the distance from the first lens surface to the final lens surface) at the telephoto end is undesirably long. Alternatively, in order to obtain a desired angle of view while shortening the distance between the second lens unit L2 and the third lens unit L3 at the wide-angle end, the second lens unit L2 is negative with respect to the positive refractive power of the first lens unit L1. This increases the refractive power, making it difficult to correct curvature of field and lateral chromatic aberration at the wide-angle end.

  In the zoom lens according to the present invention, it is more preferable to satisfy one or more of the following conditional expressions. Let the focal length of the second lens unit L2 be f2. Let the focal length of the third lens unit L3 be f3. Let the focal length of the fourth lens unit L4 be f4. The radius of curvature of the lens surface on the object side of the lens arranged closest to the image side of the third lens unit L3 and the lens surface on the image side of the lens arranged second from the image side in the third lens unit L3 Are Ro31 and Ri32. Let fw be the focal length of the entire system at the wide-angle end.

At this time, it is preferable to satisfy one of the following conditional expressions.
−0.08 <(Ro31−Ri32) / (Ro31 + Ri32) <0.05 (2)
-1.9 <f3 / f2 <-1.2 (3)
1.5 <f3 / fw <2.3 (4)
-1.5 <f2 / fw <-0.9 (5)
-15.00 <f4 / fw <-2.50 (6)
Next, the technical meaning of each conditional expression will be described.

  Conditional expression (2) defines an air shape factor (air lens) between the first lens and the second lens from the image side in the third lens group. When the upper limit value of conditional expression (2) is exceeded or when the lower limit value is exceeded, the refractive power of the air lens increases, so the first lens and the second lens from the image side in the third lens unit L3. The change in spherical aberration due to the change in the air spacing between the lenses increases. As a result, it becomes difficult to adjust the spherical aberration that has been reduced due to manufacturing errors.

  Conditional expression (3) defines the ratio between the focal length of the second lens unit L2 and the focal length of the third lens unit L3. If the upper limit of conditional expression (3) is exceeded, it will be difficult to correct spherical aberration mainly in the entire zoom range. Conversely, when the lower limit is exceeded, it is difficult to correct astigmatism at the wide-angle end.

  Conditional expression (4) defines the ratio between the focal length of the third lens unit L3 and the focal length of the entire system at the wide-angle end. When the upper limit of conditional expression (4) is exceeded, the amount of movement of the third lens unit L3 increases during zooming, and the total lens length increases. Conversely, if the lower limit is exceeded, it will be difficult to satisfactorily correct mainly spherical aberration over the entire zoom range.

  Conditional expression (5) defines the ratio of the focal length of the second lens unit L2 to the focal length of the entire system at the wide angle end. If the upper limit of conditional expression (5) is exceeded, it will be difficult to correct astigmatism at the wide-angle end. On the contrary, if the lower limit is exceeded, the distance between the second lens unit L2 and the third lens unit L3 tends to increase in order to widen the shooting angle of view at the wide angle end, the entrance pupil becomes longer, and the first lens unit L1 and the first lens unit L1. The effective diameter of the two lens unit L2 increases.

  Conditional expression (6) defines the ratio of the focal length of the fourth lens unit L4 to the focal length of the entire system at the wide angle end. If the upper limit of conditional expression (6) is exceeded, distortion will increase on the telephoto side, and correction of this aberration will be difficult. On the other hand, when the lower limit is exceeded, the amount by which the fourth lens unit L4 moves to correct the image plane variation accompanying zooming increases and the total lens length increases.

It is more desirable to specify the numerical ranges of conditional expressions (1) to (6) as follows.
−0.73 <M1 / ft <−0.4 (1a)
−0.040 <(Ro31−Ri32) / (Ro31 + Ri32) <0.045
... (2a)
-1.90 <f3 / f2 <−1.24 (3a)
1.62 <f3 / fw <2.06 (4a)
-1.38 <f2 / fw <-1.00 (5a)
-14.60 <f4 / fw <-2.67 (6a)

  In the zoom lens of the present invention, it is desirable that both the fourth lens unit L4 and the fifth lens unit L4 are composed of two or less lenses. The effective diameter of the lens group on the image side with respect to the fourth lens group L4 tends to be larger than the effective diameter of the third lens group L3, the number of constituent lenses increases, and the mass increases. Further, the fourth lens unit L4 and the fifth lens unit L5 have a smaller contribution ratio to the aberration variation during zooming than the second lens unit L2. Therefore, it is easy to satisfactorily correct aberrations even with two or less lenses. In the zoom lens of the present invention, it is desirable that the first lens unit L1 is composed of four or less lenses.

  The first lens unit L1 is important in correcting various aberrations, but is the lens unit having the largest effective diameter. For this reason, it is difficult to reduce the size of the entire system unless the bright lens is limited to four or less. In the zoom lens according to the present invention, the lens disposed closest to the image side of the third lens unit L3 and the lens disposed second from the image side have a component perpendicular to the optical axis. It is preferable to move the lens to the position and perform camera shake correction (image blur correction).

  Although it is desirable to perform camera shake correction in order to obtain a high-quality shooting result even if it is held by hand, the camera system with a large image sensor increases the overall lens system, and the camera shake correction lens becomes heavy. The effective diameter of the third lens unit L3 tends to be small, and the two lenses on the image side of the third lens unit L3 are composed of a positive lens and a negative lens. For this reason, the minimum number of lenses that can suppress a change in lateral chromatic aberration due to eccentricity during camera shake correction is set. In the zoom lens of the present invention, the fourth lens unit L4 moves during focusing.

  In the zoom lens according to the present invention, a lens group that moves only for focusing is not provided, and the mechanism is simplified by also serving as a lens group that corrects image plane movement during zooming. Further, it is preferable that the change of the shooting angle of view is small at the time of focusing. In the zoom lens of the present invention, it is preferable to perform focusing with a lens group disposed on the image side from the third lens group L3 having a small zooming action. Considering weight reduction of the focus lens group, the effective diameter tends to be small near the third lens group L3. Therefore, it is desirable to perform focusing with the fourth lens group L4.

  In addition, the spherical aberration of the lens located on the object side in the third lens unit L3 increases due to a manufacturing error, and the spherical aberration is reduced by adjusting the air spacing of the three lenses from the image side in the third lens unit L3. When corrected, the focal position changes. Therefore, the focal position is adjusted by the fourth lens unit L4 having a small influence on the spherical aberration, so that the spherical aberration is kept good even after the focal position is adjusted.

  Next, an embodiment of a digital still camera using the zoom lens of the present invention as an imaging optical system will be described with reference to FIG. In FIG. 10, reference numeral 10 denotes a camera body, and 11 denotes an imaging optical system configured by any one zoom lens described in the first to fourth embodiments. Reference numeral 12 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 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 solid-state imaging device 12. Reference numeral 14 denotes a finder for observing a subject image formed on the solid-state imaging device 12, which includes a liquid crystal display panel or the like.

  The present invention can be similarly applied to a video camera (imaging apparatus) using the zoom lens of the present invention as an imaging optical system. Thus, by applying the zoom lens of the present invention to an imaging apparatus such as a digital still camera or a video camera, an imaging apparatus having a small size and high optical performance is realized. If an electronic image sensor such as a CCD is used as the image sensor, the output image can be further improved in image quality by electronically correcting aberrations.

  Numerical examples corresponding to the respective embodiments of the present invention will be shown below. 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, di is the i-th surface interval, and 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 back focus (BF) is a distance in terms of air from the final lens surface to the paraxial image surface. The total lens length is a value obtained by adding back focus (BF) to the distance from the first lens surface to the final lens surface.

  In the numerical example, the last two surfaces are surfaces of an optical block such as a filter and a face plate. Further, when K is an eccentricity, A4, A6, and A8 are aspherical coefficients, 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

[Numerical Example 1]
Unit mm

Surface data surface number rd nd νd
1 60.515 1.40 1.90366 31.3
2 33.620 4.81 1.59522 67.7
3 213.334 0.17
4 39.550 3.95 1.59522 67.7
5 344.053 (variable)
6 428.645 0.80 1.88300 40.8
7 9.873 4.70
8 -27.499 0.70 1.62299 58.2
9 37.697 0.39
10 19.346 2.11 1.95906 17.5
11 91.549 0.65 1.83481 42.7
12 42.465 (variable)
13 * 9.580 2.37 1.69350 53.2
14 * 493.816 1.49
15 27.070 0.70 1.85478 24.8
16 8.227 0.55
17 14.036 1.17 1.91082 35.3
18 31.141 2.86
19 (Aperture) ∞ 5.99
20 * 21.347 2.70 1.58313 59.4
21 -13.971 0.20
22 -14.044 0.60 1.69895 30.1
23 -43.495 (variable)
24 -27.858 0.60 1.49700 81.5
25 67.925 (variable)
26 15.819 3.66 1.49700 81.5
27 112.668 3.09
28 ∞ 2.39 1.51633 64.1
29 ∞ 1.00
Image plane ∞

Aspherical data 13th surface
K = -3.80870e-001 A 4 = -1.93618e-005

14th page
K = 3.79865e + 003 A 4 = 7.61748e-006

20th page
K = -4.63980e + 000 A 4 = 3.70395e-005

Various data Zoom ratio 9.64
Wide angle Medium telephoto focal length 9.17 35.39 88.38
F number 2.88 4.95 5.77
Half angle of view (degrees) 41.5 12.6 5.05
Image height 6.68 8.00 8.00
Total lens length 76.89 97.29 113.20
BF 5.66 5.66 5.66

d 5 0.65 18.71 33.11
d12 20.00 5.24 0.32
d23 4.57 11.69 11.79
d25 3.43 13.41 19.73

Zoom lens group data group Start surface Focal length
1 1 61.90
2 6 -9.80
3 13 18.01
4 24 -39.67
5 26 36.57
6 28 ∞

[Numerical Example 2]
Unit mm

Surface data surface number rd nd νd
1 57.406 1.38 1.90366 31.3
2 34.849 4.71 1.49700 81.5
3 337.524 0.17
4 38.962 3.96 1.59522 67.7
5 347.617 (variable)
6 25449.906 0.79 1.83481 42.7
7 9.857 4.70
8 -25.748 0.60 1.59522 67.7
9 27.610 0.17
10 18.412 1.80 1.95906 17.5
11 52.779 (variable)
12 * 13.033 1.96 1.76802 49.2
13 * -602.983 0.42
14 8.828 2.16 1.49700 81.5
15 39.399 0.72 1.69895 30.1
16 7.024 3.38
17 (Aperture) ∞ 5.44
18 * 19.947 2.55 1.58313 59.4
19 -14.028 0.17
20 -13.916 0.60 2.00 100 29.1
21 -24.185 (variable)
22 -25.187 0.61 1.49700 81.5
23 153.490 (variable)
24 16.153 3.56 1.49700 81.5
25 127.840 2.60
26 ∞ 2.93 1.51633 64.1
27 ∞ 1.00
Image plane ∞

Aspheric data 12th surface
K = -8.50368e-001 A 4 = 1.36385e-005

Side 13
K = -1.00382e + 004 A 4 = 4.51561e-006

18th page
K = -3.72187e + 000 A 4 = 4.33347e-005

Various data Zoom ratio 9.56
Wide angle Medium telephoto focal length 9.47 36.56 90.54
F number 2.88 4.86 5.77
Half angle of view (degrees) 40.5 12.2 4.94
Image height 6.72 8.00 8.00
Total lens length 74.29 95.50 110.83
BF 5.53 5.53 5.53

d 5 0.88 19.91 33.41
d11 19.84 5.65 0.35
d21 4.48 10.71 11.23
d23 3.71 13.87 20.47

Zoom lens group data group Start surface Focal length
1 1 62.23
2 6 -10.05
3 12 17.77
4 22 -43.49
5 24 36.81
6 26 ∞

[Numerical Example 3]
Unit mm

Surface data surface number rd nd νd
1 61.699 1.29 2.00069 25.5
2 48.638 2.22 1.49700 81.5
3 115.615 0.17
4 39.550 3.44 1.49700 81.5
5 345.681 (variable)
6 -530.324 0.80 2.00330 28.3
7 12.541 4.90
8 -28.125 0.68 1.53775 74.7
9 41.668 0.29
10 25.897 2.27 1.95906 17.5
11 -1354.956 (variable)
12 (Aperture) ∞ 2.55
13 * 14.421 2.60 1.88300 40.8
14 * 124.769 3.35
15 37.704 0.60 1.84666 23.8
16 10.974 0.30
17 13.112 2.88 1.56907 71.3
18 -24.623 0.17
19 -56.698 0.75 1.54814 45.8
20 17.421 0.81
21 * 73.621 1.49 1.88300 40.8
22 71.695 1.51
23 16.259 3.32 1.56907 71.3
24 -12.559 0.34
25 -11.758 0.75 1.78590 44.2
26 -29.598 (variable)
27 679.067 0.60 1.75700 47.8
28 21.577 1.59
29 46.498 1.37 1.90366 31.3
30 -141.491 (variable)
31 -174.010 0.58 1.69895 30.1
32 711.809 (variable)
33 ∞ 3.80 1.51633 64.1
34 ∞ 1.00
Image plane ∞

Aspherical data 13th surface
K = 3.97031e-001 A 4 = -2.96707e-005 A 6 = 7.00951e-008 A 8 = -2.29304e-009

14th page
K = 1.63357e + 001 A 4 = 2.62704e-005 A 6 = 2.77825e-007 A 8 = -2.52376e-009

21st page
K = -7.55889e + 001 A 4 = 2.32380e-006 A 6 = 2.61899e-007 A 8 = -6.88004e-009

Various data Zoom ratio 3.80
Wide angle Medium Tele focal length 10.31 22.74 39.16
F number 2.40 3.33 3.84
Half angle of view (degrees) 38.9 19.8 11.5
Image height 6.80 8.00 8.00
Total lens length 79.06 82.15 96.51
BF 6.52 10.89 19.45

d 5 0.85 12.05 26.34
d11 23.17 7.01 2.53
d26 1.82 2.64 1.82
d30 5.08 7.94 4.74
d32 3.01 7.39 15.95

Zoom lens group data group Start surface Focal length
1 1 78.66
2 6 -14.03
3 12 17.96
4 27 -149.42
5 31 -200.00
6 33 ∞

[Numerical Example 4]
Unit mm

Surface data surface number rd nd νd
1 58.520 1.38 1.95906 17.5
2 49.486 2.26 1.49700 81.5
3 106.201 0.17
4 40.287 4.14 1.45600 90.3
5 -2204.520 (variable)
6 -385.783 0.72 1.95375 32.3
7 11.428 5.05
8 -24.555 0.62 1.59282 68.6
9 33.755 0.18
10 24.025 2.00 1.95906 17.5
11 1298.567 (variable)
12 (Aperture) ∞ 2.55
13 * 14.471 2.28 1.88300 40.8
14 * 168.057 2.98
15 25.340 0.75 1.92286 20.9
16 11.049 0.63
17 14.154 2.21 1.56907 71.3
18 -20.386 0.28
19 -71.292 0.75 1.54814 45.8
20 22.603 1.00
21 * 101.998 1.47 1.74 100 52.6
22 83.394 1.97
23 25.039 0.75 1.72000 50.2
24 13.723 1.43
25 14.865 2.30 1.59282 68.6
26 -140.605 (variable)
27 -51.718 0.75 1.60323 42.5
28 30.730 0.52
29 76.990 0.98 2.00 100 29.1
30 239.026 (variable)
31 15.854 3.45 1.49700 81.5
32 64.949 (variable)
33 ∞ 3.80 1.51633 64.1
34 ∞ 1.00
Image plane ∞

Aspherical data 13th surface
K = -4.49467e-001 A 4 = 6.36803e-006 A 6 = -9.68889e-008 A 8 = -5.42751e-009

14th page
K = 4.92473e + 002 A 4 = 3.10116e-005 A 6 = -3.11498e-007 A 8 = -8.48583e-009

21st page
K = 2.38764e + 000 A 4 = -3.00330e-005 A 6 = 2.04655e-007 A 8 = -8.87921e-009

Various data Zoom ratio 3.80
Wide angle Medium Telephoto focal length 10.19 29.64 38.73
F number 2.88 4.35 4.86
Half angle of view (degrees) 39.6 15.5 11.7
Image height 6.80 8.00 8.00
Total lens length 77.00 94.15 101.38
BF 7.83 9.46 8.63

d 5 1.50 18.66 23.15
d11 18.41 4.78 3.24
d26 2.85 8.27 8.82
d30 2.83 9.40 13.96
d32 4.33 5.96 5.12

Zoom lens group data group Start surface Focal length
1 1 72.26
2 6 -11.41
3 12 18.07
4 27 -44.58
5 31 41.24
6 33 ∞

L1 1st lens group L2 2nd lens group L3 3rd lens group L4 4th lens group L5 5th lens group SP Aperture P Filters I Image surface

Claims (9)

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 negative refractive power, which are arranged in order from the object side to the image side. A zoom lens composed of a fifth lens group having a positive or negative refractive power, wherein the interval between adjacent lens groups changes during zooming,
The third lens group has four or more lenses.
In the third lens group, the lens arranged closest to the image side, the second lens counted from the image side, and the third lens counted from the image side are arranged with air separated from each other.
The focal length of the entire system at the telephoto end is ft, the focal length of the entire system at the wide-angle end is fw, the focal length of the fourth lens group is f4, and the amount of movement of the first lens group during zooming from the wide-angle end to the telephoto end the M1, negative movement amount of the code when the lens unit is positioned on the object side at the telephoto end than at the wide-angle end, a positive movement amount of the code when located at the image side, in the third lens group, and most When the curvature radii of the lens surface on the object side of the lens arranged on the image side and the lens surface on the image side of the second lens counted from the image side are Ro31 and Ri32, respectively .
−0.8 <M1 / ft <−0.4
-15.00 <f4 / fw <-2.50
−0.08 <(Ro31−Ri32) / (Ro31 + Ri32) <0.05
A zoom lens satisfying the following conditional expression:   The zoom lens according to claim 1, wherein the fourth lens group moves during focusing. When the focal length of the second lens group is f2, and the focal length of the third lens group is f3,
-1.9 <f3 / f2 <-1.2
The zoom lens according to claim 1 or 2, characterized by satisfying the conditional expression. When the focal length of the third lens group is f3,
1.5 <f3 / fw <2.3
The zoom lens according to any one of claims 1 to 3, characterized by satisfying the conditional expression. When the focal length of the second lens group is f2,
−1.5 <f2 / fw <−0.9
The zoom lens according to any one of claims 1 to 4, characterized by satisfying the conditional expression. The zoom lens according to any one of claims 1 to 5 , wherein each of the fourth lens group and the fifth lens group includes two or less lenses. The zoom lens according to any one of claims 1 to 6 the first lens group is characterized by consisting of 4 or less lenses. At the time of image blur correction, the lens disposed closest to the image side and the second lens counted from the image side in the third lens group move in a direction having a component perpendicular to the optical axis. The zoom lens according to any one of claims 1 to 7 . A zoom lens according to any one of claims 1 to 8, the image pickup apparatus characterized by having an image pickup device which receives an image formed by the zoom lens.