JP2019219679A - Zoom lens and image capturing device having the same - Google Patents

Abstract

To provide a positive-lead type zoom lens which is easy to control driving of a focusing lens group and allows for increasing a distance from an exit pupil to the image plane at the wide-angle end.SOLUTION: A zoom lens comprises a first lens group L1 having positive refractive power, a second lens group L2 having negative refractive power, and a rear group LB comprising a plurality of lens groups and having positive refractive power arranged in order from the object side to the image side. The rear group LB comprises a lens group LF with negative refractive power configured to move while focusing, a lens group LN with negative refractive power disposed on the image side of the lens group LF, and a lens group LP having the greatest positive refractive power among lens groups with positive refractive power disposed on the image side of the lens group LN. When zooming from the wide-angle end to the telephoto end, the lens group LP and the lens group LN independently move toward the object side along predefined trajectories. The lens group LP and the lens group LF satisfy predefined conditional expressions.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a zoom lens, and is suitable for a digital video camera, a digital still camera, a broadcast camera, a silver halide film camera, a surveillance camera, and the like.

  As one form of the zoom lens, a positive lead type adopting an inner focus method or a rear focus method in which a first lens group having a positive refractive power is arranged closest to the object side and focusing is performed by lens groups subsequent to the second lens group. Zoom lenses are known.

  Patent Document 1 discloses 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 negative refractive power, and a negative refractive power. A positive lead type zoom lens comprising a fifth lens group having a positive refractive power and a sixth lens group having a positive refractive power is described. Patent Document 1 describes that it is preferable that the fourth lens group be a focus lens group.

JP 2013-182022 A

  In the zoom lens disclosed in Patent Document 1, the refractive power of the sixth lens group is extremely smaller than the refractive power of the fourth lens group that performs focusing. For this reason, when the zoom lens is configured to be small, it is difficult to increase the distance from the exit pupil to the image plane at the wide-angle end while setting the focus sensitivity to a value within a range in which drive control of the focus lens group can be easily performed. There was a problem that there was.

  SUMMARY OF THE INVENTION It is an object of the present invention to provide a positive lead type zoom lens in which drive control of a focus lens group is easy and a distance from an exit pupil to an image plane at a wide-angle end can be increased.

The zoom lens of the present invention includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a plurality of lens groups arranged in order from the object side to the image side, and has a positive refractive power. And a rear lens group having a negative refractive power, wherein the rear lens group moves to the image side during focusing from infinity to a short distance, and the distance between adjacent lens groups changes during zooming. LF, a lens group LN having a negative refractive power arranged on the image side of the lens group LF, and at least one lens group having a positive refractive power arranged on the image side of the lens group LN. And a lens unit LP having the largest refractive power among the at least one lens unit having a positive refractive power disposed on the image side of the lens unit LN and the lens unit LN are provided with a zoom lens from a wide-angle end to a telephoto end. In this case, the lens group LP and the lens group LN are moved toward the object side so as to increase the distance therebetween, the focal length of the lens group LP is fLP, the focal length of the lens group LF is fLF, and the zoom lens at a wide-angle end. Where fo is the focal length of
0.36 <| fLF / fLP | <1.30
2.0 <fLP / fw <7.0
The following conditional expression is satisfied.

Another zoom lens of the present invention includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a plurality of lens groups arranged in order from the object side to the image side. A zoom lens, comprising a rear group having a positive refractive power, in which the distance between adjacent lens groups changes during zooming, wherein the rear group moves to the image side during focusing from infinity to a close distance and has a negative refractive power. , A lens group LN having a negative refractive power disposed on the image side of the lens group LF, and at least one lens having a positive refractive power disposed on the image side of the lens group LN A lens group LP having the largest refractive power among the at least one lens group having a positive refractive power disposed on the image side of the lens group LN, and the lens group LN being telephoto from a wide-angle end. To the end During zooming, the lens groups LP and LN are moved toward the object side so that the distance between them increases, and the focal length of the lens group LP is fLP, the focal length of the lens group LF is fLF, and the focal length of the lens group LN is When the focal length is fLN,
0.36 <| fLF / fLP | <1.30
0.5 <fLF / fLN <1.5
The following conditional expression is satisfied.

  According to the present invention, it is possible to realize a positive lead type zoom lens in which the drive control of the focus lens group is easy and the distance from the exit pupil to the image plane at the wide angle end can be increased.

FIG. 2 is a cross-sectional view of the zoom lens according to the first embodiment when focused on infinity at the wide-angle end. FIG. 3 is an aberration diagram of the zoom lens according to the first embodiment when focused on infinity. FIG. 3 is an aberration diagram of the zoom lens according to the first embodiment when focused on an object with an object distance of 0.45 m. FIG. 9 is a cross-sectional view of the zoom lens according to the second embodiment when focused on infinity at the wide-angle end. FIG. 9 is an aberration diagram of the zoom lens according to the second embodiment when focused on infinity. FIG. 10 is an aberration diagram of the zoom lens according to the second embodiment when focused on an object with an object distance of 0.38 m. FIG. 10 is a cross-sectional view of the zoom lens according to a third embodiment when focused on infinity at the wide-angle end. FIG. 10 is an aberration diagram of the zoom lens according to the third embodiment when focused on infinity. FIG. 14 is an aberration diagram of the zoom lens according to the third embodiment when focused on an object with an object distance of 0.70 m. FIG. 14 is a cross-sectional view of the zoom lens according to a fourth embodiment when focused on infinity at the wide-angle end. FIG. 14 is an aberration diagram of the zoom lens according to the fourth embodiment when focused on infinity. FIG. 14 is an aberration diagram of the zoom lens according to the fourth embodiment when focused on an object with an object distance of 0.45 m. It is a schematic diagram of an imaging device.

  Hereinafter, embodiments of the zoom lens of the present invention and an image pickup apparatus having the same will be described. The zoom lens in each embodiment is an imaging optical system used in an imaging device such as a digital still camera, a digital video camera, a broadcast camera, a silver halide film camera, and a surveillance camera. Further, the zoom lens of each embodiment can be used as a projection optical system for a projector.

  FIGS. 1, 4, 7, and 10 are cross-sectional views of the zoom lenses of Examples 1 to 4 when focusing on infinity at the wide-angle end. SP shown in each sectional view is an aperture stop. IP is an image plane. When the zoom lens of each embodiment is used as an imaging optical system of a video camera or a digital camera, an image sensor such as a CCD sensor or a CMOS sensor is arranged on the image plane IP. When the zoom lens of each embodiment is used as an imaging optical system of a silver halide film camera, the film is arranged on an image plane IP. When the zoom lens of each embodiment is used as a projection optical system of a projector, a light modulation element that modulates light from a light source to form image light is disposed on the image plane IP. A liquid crystal panel or the like is used as the light modulation element.

  IS shown in each sectional view represents a lens group having an image stabilizing function. By moving the lens group IS in a direction including the vertical component, it is possible to correct a change in the image position due to camera shake or the like.

  The zoom lens according to each embodiment includes a first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, and a plurality of lens units arranged in order from the object side to the image side. Is a positive lead type zoom lens composed of a rear group LB having a refractive power of.

  The arrows shown in the cross-sectional views schematically represent the movement trajectories of the respective lens groups during zooming from the wide-angle end to the telephoto end. In the zoom lens of each embodiment, the distance between adjacent lens groups changes during zooming. In the lens cross-sectional view, the left side is the object side (the screen side in the projection optical system for a projector), and the right side is the image side (the original image side in the projection optical system for a projector).

  Here, the configuration of the rear group LB in the zoom lens of each embodiment will be described.

  The rear unit LB includes a lens unit LF having a negative refractive power and a lens unit LN having a negative refractive power disposed on the image side of the lens unit LF. The zoom lens according to each embodiment employs a rear focus method in which focusing is performed by moving the lens unit LF in a direction along the optical axis.

  In contrast to the front focus method in which focusing is performed by moving the first lens group, the rear focus method performs focusing with a lens group arranged at a position where the effective beam diameter is small, so that the focus lens group is reduced in size and weight. Can be configured. Therefore, focusing can be performed quickly. In addition, the effective lens beam diameter of the first lens group is smaller than that of the front lens focusing method, so that the zoom lens can be made smaller.

  Here, when the aperture ratio of the zoom lens is increased, the depth of field becomes shallower. Therefore, the ratio of the amount of movement of the imaging surface to the amount of movement of the focus lens group on the optical axis (hereinafter referred to as focus sensitivity) is compared. Needs to be smaller. If the focus sensitivity is high, it becomes necessary to drive the focus lens group with high accuracy, and it becomes difficult to control the drive of the focus lens group. On the other hand, if the focus sensitivity is too low, the drive amount of the focus lens group will increase, and the drive mechanism of the focus lens group will increase in size, and it will be difficult to reduce the size of the zoom lens.

  In addition, the rear focus method has a large aberration variation at the time of focusing compared to the front lens focus method, and tends to increase spherical aberration particularly when focusing on a short distance object.

  For this reason, in a large-diameter zoom lens using the rear focus method, it is important to set the focus sensitivity in an appropriate range and reduce aberration fluctuations in focusing.

  Therefore, in the zoom lens of each embodiment, a lens unit LN having a negative refractive power is provided on the image side of the lens unit LF that moves during focusing. The lens group having a negative refractive power in the rear unit LB is divided into the lens unit LF and the lens unit LN, thereby reducing the focus sensitivity of the lens unit LF and facilitating the drive control of the focus lens unit. . Further, by reducing the negative refractive power of the lens unit LF, the fluctuation of aberration due to focusing is reduced.

  In the zoom lens of each embodiment, at least one lens group having a positive refractive power is disposed on the image side of the lens group LN. By arranging a lens unit having a positive refractive power on the image side of the lens unit LN, the distance from the exit pupil to the image plane IP on the wide angle side can be increased, and good telecentricity can be obtained. In addition, the amount of decrease in the amount of peripheral light can be reduced.

  In the zoom lens of each embodiment, the lens unit LP having the largest refractive power among the lens units having the positive refractive power arranged on the image side of the lens unit LN during zooming from the wide-angle end to the telephoto end is used as an object. Has been moved to the side. This makes it possible to reduce the effective beam diameter of the lens unit LP at the telephoto end, and to reduce the size of the lens unit LP. In addition, it is possible to reduce the fluctuation of the exit pupil position due to zooming, and it is possible to reduce the fluctuation of the incident angle of an off-axis light beam entering the imaging device.

  Further, in order to compensate for the demagnification caused by moving the lens unit LP to the object side, the lens unit LN is moved so that the distance between the lens unit LP and the lens unit LN becomes large during zooming from the wide-angle end to the telephoto end. Has been moved to. That is, in the zoom lens of each embodiment, during zooming from the wide-angle end to the telephoto end, the lens units LP and LN are moved to the object side so that the distance between the lens units LP and LN increases. As a result, the variable power share of the rear unit LB can be increased, and the overall length of the zoom lens at the telephoto end can be reduced.

Further, the zoom lens of each embodiment has a configuration satisfying the following expression (1) when the focal length of the lens unit LF is fLF and the focal length of the lens unit LP is fLP.
0.36 <| fLF / fLP | <1.30 (1)

  Equation (1) relates to the ratio of the focal length of the lens group LF, which is the focus lens group, to the focal length of the lens group LP. By satisfying Expression (1), the distance from the exit pupil to the image plane IP at the wide-angle end can be increased while facilitating drive control of the focus lens group.

  If the refractive power of the lens unit LF decreases so as to exceed the upper limit of Expression (1), the focus sensitivity becomes too small. In this case, the amount of movement of the lens unit LF required for focusing on a desired object distance becomes too large, and it becomes difficult to shorten the entire length at the telephoto end in particular. Alternatively, the refractive power of the lens group LP becomes too large, and it becomes difficult to correct the field curvature and the distortion at the wide-angle end.

  On the other hand, if the refractive power of the lens unit LF becomes large below the lower limit of the expression (1), the focus sensitivity becomes too large, and it becomes difficult to control the drive of the lens unit LF during focusing. Alternatively, the refractive power of the lens group LP becomes too small, and it becomes difficult to sufficiently increase the distance from the exit pupil to the image plane IP at the wide angle end.

Further, it is preferable that the zoom lens of each embodiment satisfies the following expression (2) when the focal length of the zoom lens at the telephoto end is ft.
0.2 <| fLF / ft | <1.0 (2)
It is better to satisfy the following conditional expression.

  Equation (2) sets the focal length of the lens unit LF appropriately. By satisfying the expression (2), it is possible to obtain good optical performance while making the lens unit LF small.

  If the refractive power of the lens unit LF becomes smaller so as to exceed the upper limit of Expression (2), the focus sensitivity becomes too small. In this case, the amount of movement of the lens group LF necessary for focusing on a desired object distance becomes too large, and the driving mechanism of the focus lens group becomes large. If the refractive power of the lens unit LF increases so as to fall below the lower limit of Expression (2), it becomes difficult to correct axial chromatic aberration and spherical aberration. In addition, the focus sensitivity becomes too large, and it becomes difficult to control the driving of the lens group LF with high accuracy during focusing.

Further, it is preferable that the zoom lens of each embodiment satisfies the following conditional expression (3) when the focal length of the zoom lens at the wide-angle end is fw.
1.0 <fLP / fw <7.0 (3)

  Equation (3) sets the focal length of the lens group LP appropriately. By satisfying the expression (3), the distance from the exit pupil to the image plane IP at the wide-angle end can be made sufficiently long.

  If the refractive power of the lens group LP becomes smaller as the upper limit of the equation (3) is exceeded, it becomes difficult to sufficiently increase the distance from the exit pupil to the image plane IP at the wide-angle end. Further, if the refractive power of the lens unit LP increases so as to fall below the lower limit of Expression (3), it becomes difficult to correct the field curvature and the distortion at the wide-angle end.

Further, in the zoom lens of each embodiment, when the movement amount of the lens group LP accompanying zooming from the wide-angle end to the telephoto end is mLP and the focal length of the zoom lens at the telephoto end is ft, the following equation (4) is used. Is preferably satisfied. The sign of the mLP is positive when the lens group LP moves from the image side toward the object side.
0.05 <mLP / ft <0.50 (4)

  Equation (4) is for appropriately setting the amount of movement of the lens unit LP during zooming from the wide-angle end to the telephoto end. By satisfying the expression (4), it is possible to reduce the fluctuation of the exit pupil position due to zooming while reducing the size of the zoom lens.

  If the value of mLP becomes larger than the upper limit of the expression (4), the overall length of the zoom lens at the telephoto end becomes too large.

  On the other hand, if the mLP is smaller than the lower limit of Expression (4), the position of the lens unit LP at the telephoto end is too close to the image plane IP, so that the diameter of the lens unit LP is too large. In addition, the fluctuation of the exit pupil position due to zooming increases.

The zoom lens of each embodiment has the following conditional expression, where the distance between the lens group LN and the lens group LP at the wide-angle end is dw, and the distance between the lens group LN and the lens group LP at the telephoto end is dt. It is preferable to satisfy (5). Note that the distance between the lens unit LN and the lens unit LP refers to a distance on the optical axis from the most image-side lens surface of the lens unit LN to the most object-side lens surface of the lens unit LP.
0.05 <(dt−dw) / ft <0.50 (5)

  Equation (5) is for appropriately setting the amount of change in the distance between the lens unit LN and the lens unit LP at the wide-angle end and the telephoto end. By satisfying the expression (5), when zooming from the wide-angle end to the telephoto end, it is possible to increase the zooming share of the lens unit LN and the lens unit LP, and shorten the overall length of the zoom lens at the telephoto end. be able to.

  If the amount of change in the distance between the lens unit LN and the lens unit LP at the wide-angle end and the telephoto end increases as the upper limit of Expression (5) is exceeded, the overall length of the zoom lens at the telephoto end increases. In addition, the fluctuation of the exit pupil position due to zooming increases. On the other hand, if the value falls below the lower limit of Expression (5), it becomes difficult to secure an appropriate magnification by the lens units LN and LP when zooming from the wide-angle end to the telephoto end. Double sharing becomes large. In this case, since the refractive power of the other lens groups is increased, it becomes difficult to correct spherical aberration and curvature of field.

The zoom lens according to each embodiment has a composite lateral magnification of βrw of the lens unit disposed on the image side of the lens unit LF at the wide-angle end, and a composite lateral magnification of the lens unit disposed on the image side of the lens unit LF at the telephoto end. When the magnification is βrt, it is preferable that the following expression (6) is satisfied.
1.0 <| βrt / βrw | <2.0 (6)

  Equation (6) is to appropriately set the zoom ratio of the lens group arranged on the image side of the lens group LF. By satisfying the expression (6), when zooming from the wide-angle end to the telephoto end, the magnification can be increased by the lens unit arranged on the image side of the lens unit LF, and the zoom lens at the telephoto end can be enlarged. The overall length can be reduced.

  When the value exceeds the upper limit value of the expression (6), the magnification change of the lens unit disposed on the image side of the lens unit LF becomes too large, and it becomes difficult to correct distortion and curvature of field at the wide-angle end. On the other hand, when the value goes below the lower limit value of the expression (6), the variable power allocation of the lens unit arranged on the image side of the lens unit LF becomes too small, and the variable power allocation to other lens units becomes large. For this reason, the refractive power of the other lens groups becomes too large, and it becomes difficult to correct spherical aberration and curvature of field.

In the zoom lens of each embodiment, the lateral magnification of the lens unit LF at the telephoto end is βLFt, the combined lateral magnification of the lens unit arranged on the image side of the lens unit LF at the telephoto end is βrt, and the F at the telephoto end is Frt. When the number is Fnot, it is preferable to satisfy the following conditional expression (7).
0.8 <| (1−βLFt ² ) × βrt ² /Fnot|<2.0 (7)

  Equation (7) sets the ratio of the focus sensitivity of the focus lens group LF to the F-number at the telephoto end appropriately. In a large-aperture zoom lens, it is necessary to drive and control the focus lens group with high precision. However, by satisfying the expression (7), the focus sensitivity can be reduced, and the drive control of the lens group LF as the focus lens group is achieved. Can be performed more easily.

  When the value exceeds the upper limit of the expression (7), the focus sensitivity becomes too large, and it becomes difficult to control the driving of the lens unit LF at the time of focusing with high accuracy. On the other hand, when the value goes below the lower limit value of the expression (7), the focus sensitivity becomes too small, and the amount of movement of the lens unit LF required for focusing on a desired focusing distance becomes large. It is difficult to shorten the overall length.

Further, the zoom lens of each embodiment satisfies the following expression (8) when the radius of curvature of the lens surface closest to the object side of the lens unit LF is r1, and the radius of curvature of the lens surface closest to the image is r2. Is preferred.
1.0 <(r1 + r2) / (r1-r2) <3.0 (8)

  Expression (8) is for appropriately setting the shape of the lens unit LF. By satisfying the expression (8), it is possible to make the shape of the lens unit LF, which is the focus lens unit, close to a concentric circle with respect to the image plane IP. Accordingly, the on-axis light beam passes through the lens unit LF without being refracted greatly, so that the amount of spherical aberration generated in the lens unit LF can be reduced. For this reason, it is possible to suppress fluctuation of spherical aberration due to focusing on the telephoto side.

Further, it is preferable that the zoom lens according to each of the embodiments satisfies the following expression (9) when the focal length of the lens unit LN is fLN.
0.5 <fLF / fLN <1.5 (9)

  Equation (9) defines an appropriate range as a value of the ratio of the focal length of the focus lens unit LF to the focal length of the lens unit LN. By satisfying the expression (9), it is possible to obtain good optical performance while making the lens unit LF compact.

  If the refractive power of the lens unit LF decreases as the upper limit of the expression (9) is exceeded, the amount of movement of the lens unit LF required for focusing on a desired focusing distance increases, and aberration variation due to focusing is reduced. It gets bigger. In addition, the drive mechanism of the focus lens group becomes large. Alternatively, the refractive power of the lens unit LN becomes too large, and it becomes difficult to sufficiently increase the distance from the exit pupil to the image plane IP at the wide-angle end.

  On the other hand, if the refractive power of the lens unit LF increases so as to fall below the lower limit of Expression (9), it becomes difficult to correct axial chromatic aberration and spherical aberration.

Further, in the zoom lens of each embodiment, it is preferable that when the focal length of the first lens unit L1 is f1, the following expression (10) is satisfied.
0.3 <f1 / ft <2.0 (10)

  Equation (10) defines an appropriate range as the focal length of the first lens unit L1. If the value exceeds the upper limit of Expression (10), the amount of movement of the first lens unit L1 due to zooming from the wide-angle end to the telephoto end increases, and it is difficult to reduce the total length of the zoom lens at the telephoto end. Become. On the other hand, when the value is below the lower limit of the expression (10), it is advantageous for increasing the zoom ratio, but the refractive power of the first lens unit L1 becomes too large, and it becomes difficult to correct spherical aberration at the telephoto end.

Further, in the zoom lens of each embodiment, it is preferable that when the focal length of the second lens unit L2 is f2, the following expression (11) is satisfied.
0.5 <| f2 / fw | <1.5 (11)

  Equation (11) defines an appropriate range as the focal length of the second lens unit L2.

  If the refractive power of the second lens unit L2 decreases as the value exceeds the upper limit of Expression (11), it becomes difficult to provide a retrofocus type refractive power arrangement at the wide-angle end, and the angle of view of the zoom lens at the wide-angle end becomes narrow. turn into.

  On the other hand, if the refracting power of the second lens group is increased so as to fall below the lower limit of Expression (11), the fluctuation of spherical aberration and chromatic aberration of magnification due to zooming increases. In this case, the diverging effect of the axial light flux by the second lens group becomes too large, so that it is difficult to make the rear group LB compact.

It is more preferable that the numerical range of Expressions (1) to (11) be in the range of Expressions (1a) to (11a) below.
0.40 <| fLF / fLP | <1.15 (1a)
0.2 <| fLF / ft | <0.8 (2a)
1.5 <fLP / fw <6.5 (3a)
0.1 <mLP / ft <0.4 (4a)
0.05 <(dt−dw) / ft <0.40 (5a)
1.1 <| βrt / βrw | <1.7 (6a)
1.0 <| (1−βLFt ² ) × βrt ² /Fnot|<1.9 (7a)
1.3 <(r1 + r2) / (r1-r2) <2.5 (8a)
0.6 <fLF / fLN <1.2 (9a)
0.35 <f1 / ft <1.70 (10a)
0.6 <| f2 / fw | <1.2 (11a)

Further, more preferably, the numerical range of the above-described equations (1) to (11) is preferably the range of the following equations (1b) to (11b).
0.50 <| fLF / fLP | <1.0 (1b)
0.2 <| fLF / ft | <0.7 (2b)
2.0 <fLP / fw <5.0 (3b)
0.10 <mLP / ft <0.30 (4b)
0.06 <(dt−dw) / ft <0.30 (5b)
1.12 <| βrt / βrw | <1.50 (6b)
1.1 <| (1−βLFt ² ) × βrt ² /Fnot|<1.8 (7b)
1.4 <(r1 + r2) / (r1-r2) <2.3 (8b)
0.7 <fLF / fLN <1.1 (9b)
0.5 <f1 / ft <1.6 (10b)
0.7 <| f2 / fw | <1.1 (11b)

  Further, it is preferable that the lens unit LN is disposed adjacent to the image side of the lens unit LF. By arranging the lens unit LN and the lens unit LF adjacent to each other, the overall length of the zoom lens can be reduced.

  Further, it is preferable that the lens unit LF includes one negative lens. Thus, the lens group LF can be made small, and the overall length of the zoom lens can be made small. Further, since the lens unit LF can be made light, focusing can be performed quickly.

  Further, it is preferable that the lens unit LN includes one negative lens. Thus, the lens unit LN can be made small, and the overall length of the zoom lens can be made small. Further, it is preferable that the lens group LP includes one positive lens. As a result, the lens group LP can be made smaller, and the overall length of the zoom lens can be made smaller.

  Next, the zoom lens of each embodiment will be described in detail.

[Example 1]
The zoom lens according to the first embodiment is a zoom lens having a six-unit configuration, and includes a first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, and a rear unit LB having a positive refractive power. The rear unit LB includes a third lens unit L3 having a positive refractive power, a fourth lens unit L4 having a negative refractive power, a fifth lens unit L5 having a negative refractive power, and a sixth lens unit L6 having a positive refractive power. . The lens sectional view is as shown in FIG.

  In the zoom lens according to the first embodiment, the fourth lens unit L4 is a lens unit corresponding to the above-described lens unit LF, and moves to the image side during focusing from infinity to a short distance. The fifth lens group L5 is arranged on the image side of the fourth lens group L4 (lens group LF), and is a lens group corresponding to the above-described lens group LN. The sixth lens group L6 is the lens group having the strongest refractive power among the lens groups having positive refractive power arranged on the image side of the fifth lens group L5 (lens group LN), and the above-described lens group LP Is equivalent to

  In the zoom lens according to the first embodiment, the first lens unit L1 moves toward the object side during zooming from the wide-angle end to the telephoto end. The second lens unit L2 moves to the object side so that the distance between the first lens unit L1 and the second lens unit L2 increases. The third lens unit L3 moves toward the object side such that the distance between the second lens unit L2 and the third lens unit L3 is reduced. The fourth lens unit L4 moves to the object side such that the distance between the third lens unit L3 and the fourth lens unit L4 is reduced. The fifth lens unit L5 moves to the object side so that the distance between the fourth lens unit L4 and the fifth lens unit increases. The sixth lens unit L6 moves to the object side such that the distance between the fifth lens unit L5 and the sixth lens unit L6 increases.

  FIGS. 2A and 2B are aberration diagrams of the zoom lens according to the first embodiment when focused on infinity at the wide-angle end and the telephoto end. FIGS. 3A and 3B are aberration diagrams of the zoom lens according to the first embodiment when an object at an object distance of 0.45 m is focused at the wide-angle end and the telephoto end.

  In each aberration diagram, Fno is an F number, and ω is a half angle of view (degree). In the spherical aberration diagram, d (solid line) is the d line (wavelength 587.6 nm), and g (two-dot chain line) is the g line (wavelength 435.8 nm). In the astigmatism diagram, S (solid line) is a sagittal image plane at d-line, and M (dashed line) is a meridional image plane at d-line. The distortion is shown for the d-line. The magnification chromatic aberration diagram is shown for the g-line.

[Example 2]
The zoom lens according to the second embodiment is a six-unit zoom lens, and includes a first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, and a rear unit LB having a positive refractive power. The rear unit LB includes a third lens unit L3 having a positive refractive power, a fourth lens unit L4 having a negative refractive power, a fifth lens unit L5 having a negative refractive power, and a sixth lens unit L6 having a positive refractive power. . The lens cross-sectional view is as shown in FIG.

  In the zoom lens of Example 2, the fourth lens unit L4 is a lens unit corresponding to the above-mentioned lens unit LF, and moves to the image side when focusing from infinity to short distance. The fifth lens group L5 is arranged on the image side of the fourth lens group L4 (lens group LF), and is a lens group corresponding to the above-described lens group LN. The sixth lens group L6 is the lens group having the strongest refractive power among the lens groups having positive refractive power arranged on the image side of the fifth lens group L5 (lens group LN), and the above-described lens group LP Is equivalent to

  In the zoom lens according to the second embodiment, the first lens unit L1 moves toward the object side during zooming from the wide-angle end to the telephoto end. The second lens unit L2 moves to the object side so that the distance between the first lens unit L1 and the second lens unit L2 increases. The third lens unit L3 moves toward the object side such that the distance between the second lens unit L2 and the third lens unit L3 is reduced. The fourth lens unit L4 moves to the object side such that the distance between the third lens unit L3 and the fourth lens unit L4 is reduced. The fifth lens unit L5 moves to the object side so that the distance between the fourth lens unit L4 and the fifth lens unit increases. The sixth lens unit L6 moves to the object side such that the distance between the fifth lens unit L5 and the sixth lens unit L6 increases.

  FIGS. 5A and 5B are aberration diagrams of the zoom lens according to the second embodiment when focused on infinity at the wide-angle end and the telephoto end. FIGS. 6A and 6B are aberration diagrams of the zoom lens according to the second embodiment when focusing on an object at an object distance of 0.38 m at the wide-angle end and the telephoto end.

[Example 3]
The zoom lens according to the third embodiment is a zoom lens having a seven-unit configuration, and includes a first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, and a rear unit LB having a positive refractive power. The rear unit LB includes a third lens unit L3 having a positive refractive power, a fourth lens unit L4 having a positive refractive power, a fifth lens unit L5 having a negative refractive power, a sixth lens unit L6 having a negative refractive power, and a positive lens unit. The seventh lens unit has a refractive power of? The lens cross-sectional view is as shown in FIG.

  In the zoom lens according to the third embodiment, the fifth lens unit L5 corresponds to the above-described lens unit LF, and moves to the image side when focusing from infinity to a short distance. The sixth lens unit L6 is arranged on the image side of the fifth lens unit L5 (lens unit LF), and is a lens unit corresponding to the above-described lens unit LN. The seventh lens group L7 is the lens group having the strongest refractive power among the lens groups having positive refractive power arranged on the image side of the sixth lens group L6 (lens group LN), and has the above-described lens group LP. Is equivalent to

  In the zoom lens according to the third embodiment, the first lens unit L1 moves toward the object side during zooming from the wide-angle end to the telephoto end. The second lens unit L2 moves to the object side so that the distance between the first lens unit L1 and the second lens unit L2 increases. The third lens unit L3 moves toward the object side such that the distance between the second lens unit L2 and the third lens unit L3 is reduced. The fourth lens unit L4 moves to the object side such that the distance between the third lens unit L3 and the fourth lens unit L4 is reduced. The fifth lens unit L5 moves to the object side so that the distance between the fourth lens unit L4 and the fifth lens unit increases. The sixth lens unit L6 moves to the object side such that the distance between the fifth lens unit L5 and the sixth lens unit L6 increases. The seventh lens unit L7 moves toward the object side such that the distance between the sixth lens unit L6 and the seventh lens unit L7 increases.

  FIGS. 8A and 8B are aberration diagrams of the zoom lens according to the third embodiment when focused on infinity at the wide-angle end and the telephoto end. 9A and 9B are aberration diagrams of the zoom lens according to the third embodiment when focusing on an object with an object distance of 0.70 m at the wide-angle end and the telephoto end.

[Example 4]
The zoom lens according to the fourth embodiment is a zoom lens having a seven-unit configuration, and includes a first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, and a rear unit LB having a positive refractive power. The rear unit LB includes a third lens unit L3 having a positive refractive power, a fourth lens unit L4 having a negative refractive power, a fifth lens unit L5 having a negative refractive power, a sixth lens unit L6 having a positive refractive power, and a positive lens unit. The seventh lens unit L7 has a refractive power of. The sectional view of the lens is as shown in FIG.

  In the zoom lens according to the fourth embodiment, the fourth lens unit L4 is a lens unit corresponding to the above-described lens unit LF, and moves to the image side when focusing from infinity to a short distance. The fifth lens group L5 is arranged on the image side of the fourth lens group L4 (lens group LF), and is a lens group corresponding to the above-described lens group LN. The sixth lens group L6 is the lens group having the strongest refractive power among the lens groups having positive refractive power arranged on the image side of the fifth lens group L5 (lens group LN), and the above-described lens group LP Is equivalent to

  In the zoom lens according to the fourth embodiment, the first lens unit L1 moves toward the object side during zooming from the wide-angle end to the telephoto end. The second lens unit L2 moves to the object side so that the distance between the first lens unit L1 and the second lens unit L2 increases. The third lens unit L3 moves toward the object side such that the distance between the second lens unit L2 and the third lens unit L3 is reduced. The fourth lens unit L4 moves to the object side such that the distance between the third lens unit L3 and the fourth lens unit L4 is reduced. The fifth lens unit L5 moves to the object side so that the distance between the fourth lens unit L4 and the fifth lens unit increases. The sixth lens unit L6 moves to the object side such that the distance between the fifth lens unit L5 and the sixth lens unit L6 increases. The seventh lens unit L7 does not move during zooming.

  FIGS. 11A and 11B are aberration diagrams of the zoom lens according to the fourth embodiment when focused on infinity at the wide-angle end and the telephoto end. FIGS. 12A and 12B are aberration diagrams of the zoom lens according to the fourth embodiment when focused on an object with an object distance of 0.45 m at the wide-angle end and the telephoto end.

  Next, Numerical Embodiments 1 to 4 corresponding to the zoom lenses of Embodiments 1 to 4 described above will be described.

In the surface data of each numerical example, r represents the radius of curvature of each lens surface, and d (mm) represents the axial distance (the distance on the optical axis) between the m-th surface and the (m + 1) -th surface. . Here, m is the number of the surface counted from the light incident side. Also, nd represents the refractive index of each optical member with respect to the d-line, and νd represents the Abbe number of the optical member. The Abbe number νd is a value defined by the following equation (12) when the refractive indices of the Fraunhofer line with respect to the g-line, F-line, d-line, and C-line are ng, nF, nd, and nC, respectively. .
νd = (nd−1) / (nF−nC) (12)

In the surface data of each numerical example, an asterisk (*) is added after the surface number for an aspheric lens surface. The aspherical surface data shows the aspherical surface coefficient of each aspherical surface. “E ± Z” in the aspheric coefficient means “× 10 ^{± Z} ”. The aspherical shape of the lens surface is such that the displacement amount from the surface vertex in the optical axis direction is X, the height from the optical axis in a direction perpendicular to the optical axis direction is H, the paraxial radius of curvature is R, the conic constant is K, When the aspheric coefficients are A4, A6, A8, A10, and A12, they are expressed by the following equation (13).

  In each numerical example, the focal length (mm), the F-number, and the half angle of view (°) are all values when the zoom lens of each example focuses on infinity. The back focus BF is the distance from the last lens surface to the image surface. The total lens length is a value obtained by adding the back focus to the distance from the first lens surface to the final lens surface.

[Numerical Example 1]
Unit: mm

Surface data surface number rd nd νd Effective diameter
1 360.812 1.80 1.84666 23.8 62.80
2 102.577 6.64 1.72916 54.7 60.93
3 -772.618 0.15 60.54
4 54.305 6.51 1.72916 54.7 55.83
5 145.050 (variable) 54.70
6 * 195.122 1.80 1.76802 49.2 36.16
7 15.928 10.58 25.29
8 -25.140 0.90 1.49700 81.5 23.93
9 -208.718 0.15 23.27
10 47.367 2.32 1.89286 20.4 22.65
11 190.240 (variable) 22.14
12 (aperture) ∞ 0.50 18.72
13 18.368 0.80 1.88 300 40.8 20.01
14 13.125 7.95 1.58313 59.4 19.19
15 * -57.788 0.99 18.82
16 -87.965 0.80 1.76200 40.1 18.45
17 16.252 3.22 2.00069 25.5 18.08
18 34.593 1.40 17.70
19 15.903 0.80 2.00 100 29.1 17.88
20 11.311 6.81 1.53775 74.7 16.78
21 6552.763 0.15 16.11
22 39.790 0.80 1.85478 24.8 15.80
23 19.824 4.52 1.58313 59.4 15.92
24 * -36.018 (variable) 16.42
25 64.857 0.80 1.57 250 57.7 17.03
26 16.869 (variable) 17.11
27 * -20.265 1.50 1.58313 59.4 22.44
28 * -77.916 (variable) 27.23
29 -98.804 5.29 1.88 300 40.8 35.44
30 -34.131 (variable) 36.52
Image plane ∞

Aspheric surface 6th surface
K = 0.00000e + 000 A 4 = 7.28875e-006 A 6 = -2.03079e-008 A 8 = 6.78458e-011 A10 = -1.61143e-013 A12 = 1.59482e-016

15th page
K = 0.00000e + 000 A 4 = 2.25823e-005 A 6 = -4.01819e-008 A 8 = -1.92298e-010 A10 = 3.85842e-013

Side 24
K = 0.00000e + 000 A 4 = 4.03627e-005 A 6 = 2.28646e-008 A 8 = 1.73530e-010 A10 = -8.03393e-012

Surface 27
K = 0.00000e + 000 A 4 = -9.10759e-006 A 6 = -3.96094e-007 A 8 = 1.03168e-009 A10 = 4.30404e-012 A12 = -1.28909e-013

Surface 28
K = 0.00000e + 000 A 4 = -1.23220e-005 A 6 = -2.88150e-007 A 8 = 2.01026e-009 A10 = -1.01180e-011 A12 = 1.58725e-014

Various data Zoom ratio 4.12
Wide-angle medium telephoto focal length 24.72 57.08 101.89
F-number 4.12 4.12 4.12
Angle of view 41.19 20.76 11.99
Image height 21.64 21.64 21.64
Total lens length 120.52 140.11 159.71
BF 13.52 18.44 26.90

d 5 0.70 18.51 35.81
d11 24.20 9.43 2.38
d24 1.58 2.26 0.96
d26 12.56 11.89 13.18
d28 0.78 12.42 13.30
d30 13.52 18.44 26.90

Zoom lens group data group Start surface Focal length
1 1 92.83
2 6 -20.76
3 12 22.08
4 25 -40.07
5 27 -47.42
6 29 56.87

[Numerical Example 2]
Unit: mm

Surface data surface number rd nd νd Effective diameter
1 457.815 2.10 1.84666 23.8 68.31
2 102.115 6.44 1.77250 49.6 65.81
3 1437.112 0.15 65.28
4 58.311 7.34 1.77250 49.6 59.87
5 182.081 (variable) 58.58
6 * 156.913 1.80 1.85400 40.4 39.98
7 * 19.258 9.93 29.40
8 -40.599 1.00 1.53775 74.7 28.42
9 25.229 6.70 1.85478 24.8 25.83
10 -75.996 3.99 24.78
11 -27.960 1.55 1.51742 52.4 20.98
12 -22.614 0.90 2.00100 29.1 21.30
13 -44.959 (variable) 22.40
14 (aperture) ∞ 0.50 24.33
15 26.600 3.79 1.43875 94.9 26.37
16 76.837 0.15 26.33
17 26.884 1.00 1.88300 40.8 26.61
18 15.319 10.32 1.61881 63.9 24.85
19 * -79.194 0.96 24.35
20 -101.307 0.90 1.72047 34.7 24.19
21 20.340 3.68 2.00100 29.1 24.01
22 41.892 3.51 23.68
23 28.473 0.90 2.00100 29.1 24.29
24 17.666 9.43 1.72916 54.7 23.28
25 * -26.848 (variable) 22.69
26 61.322 0.80 1.83481 42.7 21.51
27 23.239 (variable) 20.99
28 * -25.127 1.50 1.85400 40.4 22.71
29 * -69.764 (variable) 26.23
30 -44.620 3.96 2.00100 29.1 35.54
31 -28.914 (variable) 36.53
Image plane ∞

Aspheric surface 6th surface
K = 0.00000e + 000 A 4 = -1.41095e-006 A 6 = 3.45657e-008 A 8 = -1.07605e-010 A10 = 1.58603e-013 A12 = -8.57988e-017

Surface 7
K = 0.00000e + 000 A 4 = -7.83038e-006 A 6 = 1.45488e-008 A 8 = 9.28901e-011 A10 = -5.25682e-013

19th page
K = 0.00000e + 000 A 4 = 2.38855e-005 A 6 = -1.01986e-008 A 8 = -1.01928e-011 A10 = 4.97492e-014

Side 25
K = 0.00000e + 000 A 4 = 2.75519e-005 A 6 = -3.81740e-008 A 8 = 2.22228e-011 A10 = 7.70144e-015

Surface 28
K = 0.00000e + 000 A 4 = 8.71027e-006 A 6 = -7.11280e-007 A 8 = 2.97814e-009 A10 = -9.93103e-012 A12 = -3.41237e-014

Surface 29
K = 0.00000e + 000 A 4 = 7.65026e-006 A 6 = -5.84476e-007 A 8 = 3.80156e-009 A10 = -1.61546e-011 A12 = 2.91996e-014

Various data Zoom ratio 2.75
Wide-angle medium telephoto focal length
F-number 2.91 2.91 2.91
Angle of view 41.19 24.66 17.68
Image height 21.64 21.64 21.64
Total lens length 131.52 148.87 166.23
BF 18.27 22.71 26.93

d 5 0.70 14.03 27.17
d13 16.79 5.47 2.37
d25 1.63 1.82 0.96
d27 9.90 9.72 10.57
d29 0.91 11.81 14.90
d31 18.27 22.71 26.93

Zoom lens group data group Start surface Focal length
1 1 102.24
2 6 -20.14
3 14 23.07
4 26 -45.26
5 28 -46.71
6 30 72.87

[Numerical example 3]
Unit: mm

Surface data surface number rd nd νd Effective diameter
1 238.414 2.10 1.95375 32.3 66.00
2 106.904 6.14 1.49700 81.5 61.97
3 -2696.186 0.15 61.86
4 100.111 5.67 1.49700 81.5 61.16
5 1039.311 0.15 60.75
6 78.303 5.25 1.49700 81.5 58.47
7 247.955 (variable) 57.77
8 * 382.720 1.00 1.85135 40.1 32.74
9 * 15.693 9.93 24.38
10 -20.916 0.80 1.49700 81.5 22.95
11 76.879 0.15 22.38
12 58.907 4.49 1.92119 24.0 22.59
13 -39.904 3.50 23.23
14 -21.252 0.85 1.95375 32.3 23.53
15 -33.913 (variable) 24.96
16 (aperture) ∞ 0.39 26.83
17 * 25.080 7.85 1.63980 34.5 29.98
18 * -83.068 0.15 29.62
19 52.557 5.62 1.51633 64.1 28.30
20 -151.305 0.15 26.87
21 -349.132 0.90 2.00100 29.1 26.44
22 18.277 6.54 1.51742 52.4 24.36
23 190.216 (variable) 24.51
24 31.222 0.80 2.00069 25.5 25.30
25 16.268 9.12 1.76200 40.1 24.08
26 702.918 0.73 23.57
27 1024.579 2.77 1.58313 59.4 23.43
28 * -45.978 (variable) 23.26
29 184.776 3.56 2.00069 25.5 18.22
30 -26.133 0.75 1.95375 32.3 18.24
31 41.415 (variable) 18.23
32 86.680 1.10 2.00100 29.1 23.11
33 18.513 7.29 1.61293 37.0 23.47
34 1330.468 0.15 25.29
35 121.215 11.40 1.71736 29.5 26.10
36 -17.028 1.30 1.91082 35.3 27.67
37 * 17502.678 (variable) 32.50
38 63.160 3.42 1.85478 24.8 36.60
39 349.390 1.30 2.00100 29.1 36.57
40 131.704 (variable) 36.51
Image plane ∞

Aspheric surface 8th surface
K = 0.00000e + 000 A 4 = 3.01361e-007 A 6 = 2.50588e-008 A 8 = -3.48140e-011 A10 = 4.64746e-014

9th page
K = 0.00000e + 000 A 4 = -1.97615e-005 A 6 = -3.80863e-008

17th
K = 0.00000e + 000 A 4 = -5.89468e-006 A 6 = -3.70002e-009 A 8 = -2.36358e-012 A10 = -2.05744e-014

18th page
K = 0.00000e + 000 A 4 = 6.90751e-006 A 6 = -3.91500e-009

Surface 28
K = 0.00000e + 000 A 4 = 5.47126e-006 A 6 = -8.28986e-009 A 8 = -1.65522e-011 A10 = -1.78623e-013

Surface 37
K = 0.00000e + 000 A 4 = -7.62243e-006 A 6 = -7.72939e-009 A 8 = 2.74005e-012 A10 = -3.54345e-014

Various data Zoom ratio 11.77
Wide-angle medium telephoto focal length 24.72 90.83 290.86
F-number 4.12 5.00 5.88
Angle of view 41.19 13.40 4.25
Image height 21.64 21.64 21.64
Total lens length 165.57 210.57 255.57
BF 14.37 32.56 30.89

d 7 0.69 36.77 67.77
d15 29.33 9.51 0.59
d23 2.42 1.00 2.40
d28 1.00 8.71 7.67
d31 11.28 11.05 20.62
d37 1.00 5.48 20.13
d40 14.37 32.56 30.89


Zoom lens group data group Start surface Focal length
1 1 114.54
2 8 -15.91
3 16 47.18
4 24 35.80
5 29 -64.31
6 32 -63.57
7 38 151.52

[Numerical example 4]
Unit: mm

Surface data surface number rd nd νd Effective diameter
1 429.229 1.80 1.84666 23.8 63.30
2 129.679 5.26 1.72916 54.7 62.03
3 -2279.753 0.15 61.68
4 63.144 6.14 1.72916 54.7 57.94
5 181.719 (variable) 56.96
6 * 444.999 1.80 1.76802 49.2 41.04
7 18.334 12.32 29.25
8 -28.007 0.90 1.49700 81.5 28.19
9 -87.991 0.15 27.90
10 54.487 2.54 1.89286 20.4 27.05
11 197.466 (variable) 26.54
12 (aperture) ∞ 0.50 21.36
13 21.758 0.80 1.88300 40.8 22.63
14 15.435 8.36 1.58313 59.4 21.81
15 * -56.674 0.99 21.48
16 -101.283 0.80 1.76200 40.1 21.03
17 18.419 3.45 2.00069 25.5 20.57
18 39.245 1.67 20.17
19 18.103 0.80 2.00 100 29.1 20.30
20 12.952 9.83 1.53775 74.7 19.12
21 -82.340 0.15 17.92
22 76.800 0.80 1.85478 24.8 17.36
23 28.145 4.03 1.58313 59.4 16.77
24 * -50.736 (variable) 17.21
25 58.045 0.80 1.57 250 57.7 17.90
26 17.128 (variable) 17.92
27 * -23.790 1.50 1.58313 59.4 22.82
28 * -93.823 (variable) 27.09
29 -63.749 4.68 1.88 300 40.8 35.43
30 -32.022 (variable) 36.51
31 155.829 1.91 1.83481 42.7 42.15
32 351.247 (variable) 42.14
Image plane ∞

Aspheric surface 6th surface
K = 0.00000e + 000 A 4 = 6.53773e-006 A 6 = -1.12142e-008 A 8 = 2.35316e-011 A10 = -3.77465e-014 A12 = 2.66659e-017

15th page
K = 0.00000e + 000 A 4 = 1.55231e-005 A 6 = -2.87309e-008 A 8 = 2.20515e-011 A10 = -1.77413e-013

Side 24
K = 0.00000e + 000 A 4 = 2.54826e-005 A 6 = 5.96854e-008 A 8 = -7.03456e-010 A10 = 1.54199e-012

Surface 27
K = 0.00000e + 000 A 4 = -4.25162e-006 A 6 = -3.98601e-007 A 8 = 1.32578e-009 A10 = 1.61897e-012 A12 = -9.58394e-014

Surface 28
K = 0.00000e + 000 A 4 = -3.665848e-006 A 6 = -3.41509e-007 A 8 = 2.38399e-009 A10 = -1.18165e-011 A12 = 1.84765e-014

Various data Zoom ratio 4.12
Wide-angle medium telephoto focal length 24.72 60.36 101.89
F-number 4.12 4.12 4.12
Angle of view 41.19 19.72 11.99
Image height 21.64 21.64 21.64
Total lens length 134.63 158.14 181.65
BF 14.13 14.13 14.13

d 5 0.70 22.69 40.35
d11 32.05 12.53 4.85
d24 2.24 2.49 1.00
d26 11.82 11.57 13.06
d28 0.79 15.17 16.86
d30 0.79 7.45 19.28
d32 14.13 14.13 14.13

Zoom lens group data group Start surface Focal length
1 1 110.32
2 6 -25.11
3 12 25.20
4 25 -42.74
5 27 -55.09
6 29 68.15
7 31 334.02

  Table 1 summarizes various numerical values in each numerical example.

[Imaging device]
FIG. 13 is a schematic diagram of an imaging device (digital still camera) 100 as one embodiment of the present invention. An imaging device 100 according to the present embodiment includes a camera body 70, a zoom lens 71 similar to any one of the above-described first to fourth embodiments, and an imaging device that photoelectrically converts an image formed by the zoom lens 71. 72. As the light receiving element 72, an imaging element such as a CCD sensor or a CMOS sensor can be used.

  Since the imaging device 100 of the present embodiment has the same zoom lens 71 as any of the zoom lenses of Examples 1 to 4, drive control of the focus lens group is easy. Further, since the distance from the exit pupil to the image plane at the wide-angle end is long, a high-quality image can be obtained from the center to the periphery of the screen.

  The zoom lens of each embodiment described above can be applied not only to the digital still camera shown in FIG. 13, but also to various optical devices such as a silver halide film camera, a video camera, and a telescope.

  Although the preferred embodiments and examples of the present invention have been described above, the present invention is not limited to these embodiments and examples, and various combinations, modifications, and changes are possible within the scope of the gist.

L1 First lens group L2 Second lens group LB Rear group

Claims (17)

A first lens group having a positive refractive power, a second lens group having a negative refractive power, a rear group having a positive refractive power including a plurality of lens groups, arranged in order from the object side to the image side, A zoom lens in which the distance between adjacent lens groups changes during zooming,
The rear group moves to the image side during focusing from infinity to a short distance and has a negative refractive power. The lens group LF has a negative refractive power. The lens group LN has a negative refractive power and is disposed on the image side of the lens group LF. At least one lens group having a positive refractive power and disposed on the image side of the lens group LN.
The lens group LP having the largest refractive power and the lens group LN among the at least one lens group having a positive refractive power disposed on the image side of the lens group LN are used for zooming from a wide-angle end to a telephoto end. Move to the object side so that the distance between the lens group LP and the lens group LN increases,
When the focal length of the lens group LP is fLP, the focal length of the lens group LF is fLF, and the focal length of the zoom lens at the wide-angle end is fw,
0.36 <| fLF / fLP | <1.30
2.0 <fLP / fw <7.0
A zoom lens characterized by satisfying the following conditional expression. When the focal length of the lens unit LN is fLN,
0.5 <fLF / fLN <1.5
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. A first lens group having a positive refractive power, a second lens group having a negative refractive power, a rear group having a positive refractive power including a plurality of lens groups, arranged in order from the object side to the image side, A zoom lens in which the distance between adjacent lens groups changes during zooming,
The rear group moves to the image side during focusing from infinity to a short distance and has a negative refractive power. The lens group LF has a negative refractive power. The lens group LN has a negative refractive power and is disposed on the image side of the lens group LF. At least one lens group having a positive refractive power and disposed on the image side of the lens group LN.
The lens group LP having the largest refractive power and the lens group LN among the at least one lens group having a positive refractive power disposed on the image side of the lens group LN are used for zooming from a wide-angle end to a telephoto end. Move to the object side so that the distance between the lens group LP and the lens group LN increases,
When the focal length of the lens group LP is fLP, the focal length of the lens group LF is fLF, and the focal length of the lens group LN is fLN,
0.36 <| fLF / fLP | <1.30
0.5 <fLF / fLN <1.5
A zoom lens characterized by satisfying the following conditional expression.   4. The zoom lens according to claim 1, wherein the lens group LN is disposed adjacent to the lens group LF. 5. When the focal length of the zoom lens at the telephoto end is ft,
0.2 <| fLF / ft | <1.0
The zoom lens according to any one of claims 1 to 4, wherein the following conditional expression is satisfied. When the moving amount of the lens group LP accompanying zooming from the wide-angle end to the telephoto end is mLP, and the focal length of the zoom lens at the telephoto end is ft,
0.05 <mLP / ft <0.50
The zoom lens according to any one of claims 1 to 5, wherein the following conditional expression is satisfied. The distance between the lens group LN and the lens group LP at the wide angle end is dw, the distance between the lens group LN and the lens group LP at the telephoto end is dt, and the focal length of the zoom lens at the telephoto end is ft. When
0.05 <(dt−dw) / ft <0.50
The zoom lens according to any one of claims 1 to 6, wherein the following conditional expression is satisfied. When the combined lateral magnification of the lens unit arranged on the image side of the lens unit LF at the wide-angle end is βrw, and the combined lateral magnification of the lens unit arranged on the image side of the lens unit LF at the telephoto end is βrt. ,
1.0 <| βrt / βrw | <2.0
The zoom lens according to any one of claims 1 to 7, wherein the following conditional expression is satisfied. The lateral magnification of the lens unit LF at the telephoto end is βLFt, the composite lateral magnification at the telephoto end of the lens unit arranged on the image side of the lens unit LF is βrt, and the F-number of the zoom lens at the telephoto end is Fnot. And when
The zoom lens according to any one of claims 1 to 8, wherein the following conditional expression is satisfied: 0.8 <| (1-βLFt ² ) × βrt ² /Fnot|<2.0. When the radius of curvature of the lens surface closest to the object in the lens group LF is r1, and the radius of curvature of the lens surface closest to the image in the lens group LF is r2,
1.0 <(r1 + r2) / (r1-r2) <3.0
The zoom lens according to any one of claims 1 to 9, wherein the following conditional expression is satisfied. When the focal length of the first lens group is f1 and the focal length of the zoom lens at the telephoto end is ft,
0.3 <f1 / ft <2.0
The zoom lens according to any one of claims 1 to 10, wherein the following conditional expression is satisfied. When the focal length of the second lens group is f2 and the focal length of the zoom lens at the wide-angle end is fw,
0.5 <| f2 / fw | <1.5
The zoom lens according to any one of claims 1 to 11, wherein the following conditional expression is satisfied.   13. The zoom lens according to claim 1, wherein the lens group LF includes one negative lens.   14. The zoom lens according to claim 1, wherein the lens group LN includes one negative lens.   15. The zoom lens according to claim 1, wherein the lens group LP includes one positive lens.   The zoom lens according to any one of claims 1 to 15, wherein the lens group (LP) moves monotonously to an object side during zooming from a wide-angle end to a telephoto end.   An imaging apparatus comprising: the zoom lens according to claim 1; and an imaging element that receives an image formed by the zoom lens.

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